WO2018131513A1 - Information processing device, method, and program - Google Patents

Information processing device, method, and program Download PDF

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Publication number
WO2018131513A1
WO2018131513A1 PCT/JP2017/047286 JP2017047286W WO2018131513A1 WO 2018131513 A1 WO2018131513 A1 WO 2018131513A1 JP 2017047286 W JP2017047286 W JP 2017047286W WO 2018131513 A1 WO2018131513 A1 WO 2018131513A1
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Prior art keywords
expander
crest factor
audio signal
value
unit
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PCT/JP2017/047286
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French (fr)
Japanese (ja)
Inventor
米田　道昭
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ソニー株式会社
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Priority to JP2018561327A priority Critical patent/JPWO2018131513A1/en
Publication of WO2018131513A1 publication Critical patent/WO2018131513A1/en

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G7/00—Volume compression or expansion in amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones

Definitions

  • the present technology relates to an information processing apparatus, method, and program, and more particularly, to an information processing apparatus, method, and program that can suppress an increase in a user's load while suppressing a decrease in subjective sound quality.
  • the range of the audio signal remains narrow, and there is a possibility that it becomes difficult to hear or gives a sense of incongruity because all the sounds become small. That is, the subjective sound quality of the audio signal may be reduced.
  • the present technology has been proposed in view of such a situation, and an object thereof is to suppress an increase in a user's load while suppressing a decrease in subjective sound quality.
  • An information processing apparatus includes a crest factor calculation unit that calculates a crest factor of an input audio signal, and the audio crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold value.
  • the information processing apparatus includes an expander control unit that performs an expander process for reducing a signal value smaller than a predetermined threshold value for a signal.
  • a parameter setting unit that sets parameters used for the expander processing based on the crest factor calculated by the crest factor calculation unit may be further provided.
  • the parameter may include the threshold value to be compared with the signal value of the audio signal and a ratio to a signal value smaller than the threshold value of the audio signal.
  • the parameter setting unit can set the ratio value to a larger value when the crest factor is small than when the crest factor is large.
  • the apparatus further includes a storage unit that stores a candidate for a time constant of the expander process, and the parameter setting unit is configured to select a time constant to be applied from the candidates stored in the storage unit. Can be.
  • the expander control unit can perform the expander process on the audio signal when the peak value of the audio signal is larger than a predetermined threshold and the crest factor is smaller than the predetermined threshold.
  • the crest factor calculation unit can calculate the crest factor based on a peak value and an effective value of the audio signal.
  • a peak value detection unit that detects a peak value of the audio signal is further provided, and the crest factor calculation unit is configured to calculate the crest factor based on the peak value detected by the peak value detection unit. Can be.
  • An effective value detection unit that detects an effective value of the audio signal is further provided, and the crest factor calculation unit is configured to calculate the crest factor based on the effective value detected by the effective value detection unit. Can be.
  • the crest factor calculation unit calculates the crest factor every predetermined time interval, and the expander control unit calculates the crest factor based on the crest factor calculated by the crest factor calculation unit for each time interval. Execution of the panda process can be controlled.
  • the parameter setting unit can initialize the parameter when a silence period is detected in the audio signal.
  • the expander control unit can permit the execution of the expander process when the sound volume when outputting the audio signal is larger than a predetermined threshold.
  • a parameter setting unit configured to set a ratio of the threshold value to be compared with the signal value of the audio signal based on the crest factor calculated by the crest factor calculation unit and a signal value smaller than the threshold value of the audio signal;
  • the parameter setting unit may be configured to make the threshold value smaller when the noise cancellation process is performed on the audio signal than when the noise cancellation process is not performed.
  • An output device detection unit that detects a type of an output device that outputs the audio signal; and the expander control unit performs the expander process when a predetermined type of output device is detected by the output device detection unit.
  • a ratio correction unit that corrects the ratio set by the parameter setting unit can be further provided.
  • the ratio correction unit can correct the ratio of the audio signal to outside the audible band.
  • An information processing method calculates a crest factor of an input audio signal, and when the calculated crest factor is smaller than a predetermined threshold, a signal smaller than the predetermined threshold is obtained with respect to the audio signal. This is an information processing method for performing an expander process for reducing the value.
  • the program includes a crest factor calculation unit that calculates a crest factor of an input audio signal, and the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold,
  • a crest factor calculation unit that calculates a crest factor of an input audio signal, and the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold
  • the crest factor of an input audio signal is calculated, and when the calculated crest factor is smaller than a predetermined threshold, a signal value smaller than the predetermined threshold is made smaller for the audio signal. Expander processing is performed.
  • This technology can process information. Moreover, according to this technique, the increase in a user's load can be suppressed, suppressing the reduction of subjective sound quality.
  • FIG. 10 It is a figure explaining the example of the mode of a compressor process. It is a block diagram which shows the main structural examples of a reproducing
  • FIG. 9 for explaining an example of the flow of the expander control process.
  • 10 is a flowchart following FIG. 9 for explaining an example of the flow of the expander control process. It is a flowchart explaining the example of the flow of an expander control process. It is a flowchart following FIG. 12 explaining the example of the flow of an expander control process. It is a flowchart following FIG. 12 explaining the example of the flow of an expander control process. It is a block diagram which shows the main structural examples of a reproducing
  • FIG. 20 is a block diagram illustrating a main configuration example of a computer.
  • Compressor> Conventionally, in music production, there has been a method of increasing the effective value average level by narrowing the range by applying a lot of compressors for mastering or the like. For example, by applying compression processing to an audio signal having a waveform as shown in FIG. 1A, the range is compressed to increase the gain, and a waveform as shown in FIG. 1B is obtained.
  • the input / output level of this compressor processing has a relationship as shown in FIG.
  • a specified threshold value (threshold) is exceeded, an output corresponding to the ratio (ratio) is performed for an input exceeding the threshold value (threshold).
  • the ratio is set so that the output is reduced with respect to the input, and when the input to output becomes 1: 1 / ⁇ , the output becomes the same value as the threshold and functions as a limiter.
  • the overall gain is increased while the maximum value (0 dB) is not exceeded.
  • the range can be compressed while increasing the gain.
  • the input to output is 1: 1, the input level is output as it is.
  • the effective value average level of the audio signal can be increased by applying the compressor in this way.
  • audio signals audio signals
  • sound pressure competition there is a tendency to increase the sound pressure of music (audio signals), as is called so-called sound pressure competition, and there are many music produced using such a technique. It has become.
  • an audio signal having a large effective value average level may increase the load on the user's ear, and may be easily fatigued.
  • the range of the audio signal remains narrow, and there is a possibility that it becomes difficult to hear or gives a sense of incongruity because all the sounds become small. That is, the subjective sound quality of the audio signal may be reduced.
  • ⁇ Expander control based on crest factor> Therefore, the crest factor of the input audio signal is calculated, and when the calculated crest factor is smaller than a predetermined threshold value, an expander process is performed on the audio signal to make the signal value smaller than the predetermined threshold value smaller. I will let you.
  • the crest factor calculation unit that calculates the crest factor of the input audio signal and the crest factor calculated by the crest factor calculation unit are smaller than a predetermined threshold
  • an expander control unit that performs an expander process for making a signal value smaller than the threshold value smaller.
  • the effective value average level can be reduced while maintaining the peak value by increasing the crest factor by performing the expander processing in this way, the subjective sound quality can be reduced more than the method described in Patent Document 1.
  • An increase in the user's load can be suppressed while suppressing.
  • by performing the expander process according to the crest factor before the process it is possible to suppress the unnecessary expander process, thereby suppressing the expansion of the unnecessary range and preventing the user from feeling more uncomfortable. be able to. That is, the reduction of subjective sound quality can be further suppressed.
  • FIG. 2 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied.
  • a playback device 100 shown in FIG. 2 is a device that plays back an input audio signal. Further, the playback apparatus 100 performs signal processing for reducing the effective value average level for the audio signal to be played back, as necessary.
  • the playback apparatus 100 includes a delay processing unit 111, an expander 112, an amplification unit 113, an output unit 114, an output device 115, a detection unit 116, a parameter calculation unit 117, and a control unit 118.
  • the delay processing unit 111 temporarily holds the input audio signal in order to correspond the control timing of signal processing for the input audio signal and the reproduction timing of the audio signal. As a result, the reproduction timing of the audio signal is delayed and matched with the control timing of the signal processing.
  • the expander 112 performs an expander process on the audio signal supplied from the delay processing unit 111.
  • the expander process is a process that extends the range of the audio signal and lowers the gain.
  • the ratio is set to the difference between the input and the threshold.
  • FIG. 3C An example of the relationship between the input / output levels of this expander processing is shown in FIG. As shown in FIG. 3C, the ratio is set so that the output is smaller than the input.
  • the input-to-output ratio is 1: 1 / ⁇
  • the output becomes zero as much as possible, and it functions as a noise gate.
  • the expander 112 performs such an expander process in accordance with the control of the expander control unit 141 described later.
  • the amplification unit 113 amplifies the audio signal output from the expander 112 at an arbitrary amplification factor.
  • This amplification factor is arbitrary and may be variable.
  • the amplifying unit 113 amplifies the audio signal at an amplification factor specified by, for example, the user or the control unit. That is, the amplification unit 113 has a volume adjustment function when outputting an audio signal. For example, when the user or the like updates the amplification factor, the volume when outputting the audio signal can be increased or decreased.
  • the output unit 114 performs processing related to the output of the audio signal appropriately amplified by the amplification unit 113. For example, the output unit 114 performs D / A conversion on the audio signal or performs arbitrary filter processing.
  • the output device 115 outputs the audio signal (analog signal) output from the output unit 114 as sound.
  • the output device 115 is configured by a device having a sound output function, such as a speaker, headphones, and earphones.
  • the audio signal input to the playback device 100 is supplied to the delay processing unit 111 and also to the detection unit 116.
  • the detection unit 116 detects desired information from the audio signal. As illustrated in FIG. 2, the detection unit 116 includes a peak level detection unit 121 and an effective value detection unit 122.
  • the peak level detector 121 detects the peak value of the input audio signal. Note that this peak value detection method is arbitrary. The peak level detector 121 supplies the detected peak value to the crest factor calculator 131. At that time, the audio signal may be supplied to the crest factor calculator 131 together with the peak value.
  • the effective value detection unit 122 detects the effective value of the input audio signal.
  • the effective value Ve is calculated by the square root of ((total sum of squares of signal values) / (number of signal samples)), for example, as in the following equation (1).
  • N represents the number of samples and V (n) represents the signal value.
  • detection is performed using a plurality of sample values of an audio signal.
  • the above-mentioned effective value average level is the average value of the effective value, but if the effective value detection interval is the same as the effective value average level interval (that is, the effective value and the effective value average level are 1: 1), RMS value and RMS average level are synonymous. Therefore, in the following description, the effective value and the effective value average level are synonymous unless otherwise described.
  • the effective value detection unit 122 supplies the detected effective value to the crest factor calculation unit 131. At that time, the audio signal may be supplied to the crest factor calculator 131 together with the effective value.
  • the information detected by the detection unit 116 is arbitrary, and the detection unit 116 may detect information other than the peak value and the effective value.
  • the parameter calculation unit 117 calculates a desired parameter based on the information detected by the detection unit 116. As shown in FIG. 2, the parameter calculation unit 117 includes a crest factor calculation unit 131, an expander parameter calculation unit 132, and a memory 133.
  • the crest factor calculation unit 131 calculates the crest factor (crest factor) of the audio signal based on the peak value detected by the peak level detection unit 121 and the effective value detected by the effective value detection unit 122.
  • the crest factor is calculated, for example, as in the following formula (2).
  • the crest factor is calculated by the difference between the peak value and the effective value.
  • the peak value is ⁇ 1.0 (0 dB)
  • the effective value average level is 1.0 / ⁇ 2 ⁇ 0.707 (-3 dB)
  • the crest factor calculator 131 supplies the calculated crest factor and the peak value to the expander parameter calculator 132. At this time, an audio signal and an effective value may be supplied to the expander parameter calculation unit 132 together with those values.
  • the expander parameter calculation unit 132 calculates parameters used for the expander processing performed by the expander 112. For example, the expander parameter calculation unit 132 sets parameters based on the crest factor calculated by the crest factor calculation unit 131. For example, the expander parameter calculation unit 132 calculates a threshold value (threshold) and a ratio (ratio) of the expander process. As described above, this ratio is a ratio to a signal value that is smaller than the threshold value of the expander process.
  • the expander parameter calculation unit 132 calculates a threshold value based on the peak value, and calculates a ratio based on the crest factor. For example, the expander parameter calculation unit 132 sets the peak value as a threshold value. In that case, the expander processing is performed for the peak value or less (that is, all of the audio signals).
  • the expander parameter calculation unit 132 sets the ratio value to a larger value than when the crest factor is large. For example, the expander parameter calculation unit 132 calculates the ratio so that the input / output ratio is 2: 1 when the crest factor is less than 6 dB.
  • the expander parameter calculation unit 132 calculates the time constant of the expander process. For example, a plurality of time constant candidates may be stored in the memory 133, and the expander parameter calculation unit 132 may select a desired value from the candidates. For example, the expander parameter calculation unit 132 may analyze the audio signal and select an optimum candidate from the candidates stored in the memory 133 based on the analysis result. Further, the expander parameter calculation unit 132 may analyze the audio signal and calculate an optimal time constant based on the analysis result.
  • the parameters calculated by the expander parameter calculation unit 132 are arbitrary, and the expander parameter calculation unit 132 may calculate parameters other than those described above.
  • the expander parameter calculation unit 132 supplies the calculated parameters such as a threshold value, a ratio, and a time constant to the expander control unit 141. At that time, other information such as a crest factor, a peak value, an effective value, and an audio signal may be supplied to the expander control unit 141 together with these parameters.
  • the memory 133 has an arbitrary storage medium such as a semiconductor memory, stores a candidate for the time constant of the expander process, and supplies it to the expander parameter calculation unit 132 as necessary. Note that the information stored in the memory 133 is arbitrary, and information other than the time constant may be stored.
  • the parameter calculated by the parameter calculation unit 117 is arbitrary, and the parameter calculation unit 117 may calculate a parameter other than the example described above.
  • the control unit 118 performs processing related to control. As illustrated in FIG. 2, the control unit 118 includes an expander control unit 141.
  • the expander control unit 141 controls execution of the expander process by the expander 112. At that time, the expander control unit 141 may control the execution of the expander process based on the information supplied from the expander parameter calculation unit 132. For example, the expander control unit 141 controls the execution of the expander process based on the peak value and the crest factor. For example, the expander process may be executed when the crest factor is smaller than a predetermined threshold. In addition, for example, when the peak value is larger than a predetermined threshold and the crest factor is smaller than the predetermined threshold, the expander process may be executed.
  • the conditions for executing the expander process are arbitrary and are not limited to this example. Further, information other than the peak value and the crest factor may be used for controlling the execution of the expander process.
  • the expander control unit 141 executes the expander process, the expander control unit 141 sets a parameter used for the expander process in the expander 112. For example, the expander control unit 141 sets a threshold value, a ratio, and a time constant in the expander 112.
  • the parameters to be set are arbitrary, and other parameters may be set.
  • the expander 112 performs an expander process using the parameters set by the expander control unit 141 according to the execution control by the expander control unit 141.
  • the playback apparatus 100 analyzes (pre-analyzes) the audio signal before outputting the input audio signal, and controls the expander processing for the audio signal based on the analysis result. It is arbitrary in what data unit (for example, reproduction time unit) this preliminary analysis is performed.
  • an audio signal having a predetermined playback time is filed and played back for each file, such as a song.
  • a plurality of songs may be played back continuously.
  • the audio signal of the file is continuously reproduced by, for example, fade-in and fade-out, and it is difficult to divide the audio signal for each file.
  • the audio signal continues and the end is not determined, such as live audio.
  • the audio signal pre-analysis may be performed for each file (output after performing pre-analysis for one file) or at predetermined playback times (repeating pre-analysis and output for each section). You may do it.
  • a plurality of files may be analyzed in advance. That is, the pre-analysis can be performed in arbitrary data units such as a file and a reproduction time.
  • the pre-analysis and output of the audio signal are closed for each processing unit. That is, the pre-analysis result is used only for controlling the expander process in the section where the pre-analysis is performed (not used for controlling the expander process in other sections).
  • the playback device 100 performs a pre-analysis by executing a pre-analysis process.
  • An example of the flow of this pre-analysis process will be described with reference to the flowchart of FIG.
  • the peak level detector 121 detects the peak value of the input audio signal in step S101. For example, when the audio signal is music data, the peak value in the music is detected.
  • step S102 the effective value detection unit 122 detects the effective value of the input audio signal. For example, when the audio signal is music data, an effective value in the music is detected.
  • step S103 the crest factor calculation unit 131 calculates the crest factor of the audio signal based on the peak value detected in step S101 and the effective value detected in step S102.
  • the calculation method of the crest factor is arbitrary, it is calculated as, for example, the above-described equation (2).
  • step S104 the expander control unit 141 determines whether or not the peak value exceeds the expander process ON threshold. If it is determined that the peak value is greater than the expander process ON threshold, the process proceeds to step S105.
  • step S105 the expander control unit 141 determines whether or not the crest factor calculated in step S103 is smaller than a predetermined crest factor threshold. When it is determined that the crest factor is smaller than the crest factor threshold, the process proceeds to step S106. In this case, since the peak value of the audio signal is large and the crest factor is small, the effective value average level is large. Therefore, the expander control unit 141 performs control so that the expander process is performed on the audio signal.
  • step S106 the expander parameter calculation unit 132 calculates the expander processing threshold and ratio based on the peak value detected in step S101 and the crest factor calculated in step S103. Is calculated.
  • the expander control unit 141 controls the expander 112 to determine that the expander process is ON, and sets the calculated threshold value and ratio for the expander process in the expander 112.
  • the pre-analysis process ends.
  • step S104 If it is determined in step S104 that the peak value does not exceed the expander process ON threshold, the process proceeds to step S107. If it is determined in step S105 that the crest factor is equal to or higher than the crest factor threshold, the process proceeds to step S107. In this case, since the peak value of the audio signal is small or the peak value is small even if the peak value is large, the effective value average level is not large. Therefore, the expander control unit 141 performs control so that the expander process is not performed on the audio signal.
  • step S107 the expander control unit 141 controls the expander 112 to determine the expander processing OFF.
  • the pre-analysis process ends.
  • ⁇ Expander control process flow> The playback device 100 controls the expander process by performing the expander control process. An example of the flow of the expander control process will be described with reference to the flowchart of FIG.
  • the expander control unit 141 determines whether or not the expander process is ON. If it is determined that the expander process is ON, the process proceeds to step S122.
  • step S122 the expander control unit 141 controls the expander 112 to execute the expander process.
  • the expander 112 performs an expander process on the audio signal according to the control.
  • the expander control process ends. If it is determined in step S121 that the expander process is not ON, the process in step S122 is omitted and the expander control process ends.
  • FIG. 6A shows an example of the peak value of the audio signal before the expander process
  • FIG. 6B shows an example of the peak value of the audio signal after the expander process
  • FIG. 7A shows an example of the effective value of the audio signal before the expander process
  • FIG. 7B shows an example of the effective value of the audio signal after the expander process.
  • the peak value is not substantially changed by the expander process, but the effective value is lowered, so that the crest factor is increased.
  • the playback device 100 can reduce the effective value average level without reducing all the volumes, so that it is difficult to listen to the user and does not give the user a sense of discomfort due to the volume change.
  • An increase in load can be suppressed. That is, the playback device 100 can suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
  • the playback device 100 controls the execution of the expander process according to the crest factor before the process, so that the unnecessary expander process can be suppressed and the expansion of the unnecessary range can be suppressed. It is possible to prevent the user from feeling more uncomfortable. That is, the playback device 100 can further suppress the reduction in subjective sound quality.
  • Second Embodiment> Detection of the peak value and effective value, and calculation of the crest factor may be performed at predetermined time intervals. Then, for each time interval, execution control of the expander process and parameter calculation may be performed based on the calculated crest factor.
  • the audio signal to be processed is an audio signal corresponding to a moving image
  • the time interval may be set to a length corresponding to the frame rate of the moving image.
  • execution control of the expander processing and parameter calculation may be performed for each frame of the moving image. For example, if the video is 24 fps (frame per second) and the audio sampling frequency is 48 kHz, the number of samples per image frame is 2000 samples. That is, in this case, if the execution control of the expander process and the parameter calculation are performed for each frame of the moving image, the execution control of the expander process and the parameter calculation are performed for every 2000 samples of the audio signal. Become.
  • this time interval that is, a time interval (also referred to as a section) for performing detection of a peak value, an effective value, etc., calculation of a crest factor, execution control of an expander process, calculation of a parameter, and the like is arbitrary. It does not have to match the frame rate.
  • each section may be set so as not to overlap each other as in section 201 to section 204 shown in FIG. 8A, or like section 211 to section 214 shown in FIG. 8B.
  • the sections may be overlapped with each other (for example, overlap each other by half).
  • information detected from the audio signal is a past section unless information (peak value, etc.) detected in the current processing target section (current section) satisfies a predetermined condition. You may make it inherit a value.
  • This condition is arbitrary.
  • the peak value may be updated when the peak value in the current section is larger than the past peak value with a time constant.
  • an effective value an average value of effective values of all the sections may be held, and an expander processing parameter may be calculated using the average value.
  • the threshold value to be compared with the peak value is different from the threshold value to be compared with the peak value when the execution of the expander process is switched from ON to OFF. May be. For example, if the peak value exceeds the threshold value for turning off the execution of the expander process, the peak value is smaller than the threshold value, and smaller than the threshold value for turning off the execution of the expander process. Until this happens, the expander process may be executed.
  • the threshold for turning the execution of the expander process from OFF to ON may be set to -2 dB
  • the threshold for turning the execution of the expander process from ON to OFF may be set to -8 dB.
  • the reproducing device 100 controls the expander process by executing the expander control process.
  • An example of the flow of the expander control process will be described with reference to the flowcharts of FIGS.
  • the peak level detection unit 121 detects the peak value of the audio signal in step S201, and the peak value detected in the past section holding the peak value. If it is larger than (also referred to as a peak value with a previous time constant), the peak value with a previous time constant is updated to the peak value detected this time.
  • step S202 the effective value detection unit 122 detects the effective value, and updates the frame average of the previous effective value using the effective value (that is, obtains the average of all the intervals).
  • step S203 the crest factor calculation unit 131 calculates the crest factor using the peak value with time constant and the frame average of the effective values.
  • step S204 the expander control unit 141 determines whether or not the peak value exceeds the threshold value from the expander process OFF to the ON. If it is determined that the peak value has exceeded the expander process OFF to ON threshold, the process proceeds to step S211 in FIG.
  • step S211 of FIG. 10 the expander control unit 141 determines whether the frame average of the effective values exceeds the threshold value. If it is determined that the number has exceeded, the process proceeds to step S212.
  • step S212 the expander control unit 141 determines whether or not the current expander process setting is ON (that is, the expander process is executed). If it is determined that the current expander process setting is OFF (that is, the expander process is not executed), the process proceeds to step S213.
  • step S213 the expander parameter calculator 132 calculates the expander processing threshold and ratio.
  • the expander control unit 141 sets the calculated threshold value and ratio in the expander 112.
  • step S214 the expander control unit 141 changes the setting of the expander process from OFF to ON, and causes the expander 112 to execute the expander process.
  • step S216 the process proceeds to step S216.
  • step S211 If it is determined in step S211 that the average frame value of the effective value does not exceed the threshold value, the process proceeds to step S215. If it is determined in step S212 that the expander process setting is ON, the process proceeds to step S215.
  • step S215 the expander parameter calculation unit 132 determines that the peak value of the current frame is greater than the peak value with the previous time constant (that is, the past peak value), or the crest factor of the current frame is the preceding crest factor (that is, Only when it is smaller than the past crest factor, the threshold value and ratio of the expander processing are calculated.
  • the expander control unit 141 supplies the calculated threshold value and ratio to the expander 112 and sets them.
  • step S216 the expander control unit 141 controls the expander 112 to perform the expander process.
  • the expander 112 executes expander processing on the audio signal according to the control of the expander control unit 141.
  • step S216 ends, the expander control process ends.
  • step S204 in FIG. 9 If it is determined in step S204 in FIG. 9 that the peak value does not exceed the threshold value from the expander process OFF to ON, the process proceeds to step S221 in FIG.
  • step S221 in FIG. 11 the expander control unit 141 determines whether the current expander process setting is ON (that is, the expander process is executed). If it is determined that the current expander process setting is ON, the process proceeds to step S222.
  • step S222 the expander control unit 141 determines whether or not the peak value is below the threshold value from the expander process ON to the OFF. If it is determined that the peak value has fallen below the threshold value from the expander process ON to OFF, the process returns to step S215 in FIG. 10 and the subsequent processes are repeated. On the other hand, if it is determined in step S222 that the peak value is not below the expander process ON to OFF threshold, the process proceeds to step S223.
  • step S223 the expander control unit 141 sets the expander processing setting from ON to OFF.
  • step S224 the expander control unit 141 initializes the peak value, effective value, expander processing threshold value, and ratio. When the process of step S224 ends, the expander control process ends.
  • step S221 If it is determined in step S221 that the current expander process setting is OFF, the expander control process ends.
  • the playback apparatus 100 increases the load on the user while suppressing the reduction of subjective sound quality more than the method described in Patent Document 1, as in the case of the first embodiment. Can be suppressed.
  • the silent section is a joint between a plurality of contents.
  • the silent section is a section in which the continuity of the audio signal is interrupted, and therefore the correlation between the expander processes before and after that may be low. Therefore, when a silence period is detected in the audio signal, parameters relating to the expander process may be initialized. For example, when a silent section is detected, the playback apparatus 100 may initialize parameters such as a peak value, an effective value, a threshold value for an expander process, and a ratio.
  • a period in which silence continues for a predetermined time or more may be set as the silence period.
  • the duration of the silent period is arbitrary. For example, it may be 0.5 seconds or longer.
  • step S254 If it is determined in step S254 that the peak value has exceeded the threshold value from the expander process OFF to ON, the process proceeds to step S261 in FIG.
  • step S265 is executed in the same manner as the processes in steps S211 to S215 in FIG.
  • step S265 ends, the process proceeds to step S266.
  • step S266 the expander control unit 141 determines whether or not silence has continued in the audio signal for a predetermined time or more. If it is determined that silence has not continued for a predetermined time or more, that is, no silence period has been detected, the process proceeds to step S267.
  • step S267 the expander control unit 141 controls the expander 112 to perform an expander process.
  • the expander 112 executes expander processing on the audio signal according to the control of the expander control unit 141.
  • the expander control process ends.
  • step S254 in FIG. 12 If it is determined in step S254 in FIG. 12 that the peak value does not exceed the threshold value from the expander process OFF to ON, the process proceeds to step S271 in FIG.
  • or step S274 of FIG. 14 is performed similarly to each process of step S221 thru
  • step S266 in FIG. 13 If it is determined in step S266 in FIG. 13 that silence has continued in the audio signal for a predetermined time or more, that is, a silence period has been detected, the process proceeds to step S274 in FIG.
  • step S274 the expander control unit 141 initializes the peak value, effective value, expander processing threshold and ratio. When the process of step S274 ends, the expander control process ends.
  • the playback device 100 increases the load on the user while suppressing the reduction in subjective sound quality as compared with the method described in Patent Document 1, as in the case of the second embodiment. Can be suppressed. Further, by detecting the silent section and initializing the parameters, unnecessary correlation of the expander processing can be reduced, and more appropriate expander processing can be performed.
  • FIG. 15 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied.
  • a playback device 300 shown in FIG. 15 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100.
  • the playback apparatus 300 includes a control unit 318 instead of the control unit 118. Similar to the control unit 118, the control unit 318 performs processing related to control.
  • the control unit 318 includes a volume control unit 341 in addition to the expander control unit 141.
  • the volume control unit 341 controls the amplification unit 113 to perform processing related to the control of the volume of the audio signal. For example, the volume control unit 341 sets a volume setting designated from the outside such as a user in the amplification unit 113.
  • the amplifying unit 113 amplifies the audio signal so as to be output at the set volume.
  • the volume control unit 341 also controls the expander control unit 141 and controls the execution of the expander process according to the volume setting. For example, the volume control unit 341 allows the expander control unit 141 to execute the expander process when the volume is larger than a predetermined threshold. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. For example, the volume control unit 341 prohibits the expander control unit 141 from executing the expander process when the volume is equal to or lower than a predetermined threshold. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • the volume control unit 341 determines whether or not the volume is larger than a predetermined threshold in step S301. If it is determined that the volume is greater than the threshold, the process proceeds to step S302.
  • step S302 the volume control unit 341 allows the expander control unit 141 to execute the expander process.
  • the expander control unit 141 can execute the expander process by controlling the expander 112.
  • the expander control process ends.
  • step S301 If it is determined in step S301 that the volume is equal to or lower than the threshold value, the process proceeds to step S303.
  • step S303 the volume control unit 341 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • step S303 ends, the expander control process ends.
  • the playback device 300 can control the execution of the expander processing according to the volume when the audio signal is output. Therefore, it is possible to suppress unnecessary execution of the expander process and to prevent the user from feeling more uncomfortable. That is, the playback device 100 can suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
  • the method for controlling the expander process according to the sound volume is not limited to this.
  • the sound volume control unit 341 may control the expander parameter calculation unit 132 and the like so that the parameter is set to a value according to the sound volume. .
  • it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
  • Noise canceling picks up the sound around the output device 115 and superimposes the opposite phase of the sound signal on the audio signal, so that the sound corresponding to the audio signal output from the output device 115 reduces the surrounding noise. This is a technique that makes it easier to listen to the sound of the original audio signal by suppressing the sound.
  • the voice of the audio signal can reach the user's ear more clearly, so the subjective sound quality can be easily reduced.
  • the effect of suppressing the subjective sound quality reduction according to the present technology can be more strongly experienced by the user. That is, by using the present technology and noise canceling together, it is possible to suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
  • the execution of the expander process may be controlled according to the noise canceling setting. For example, the execution of the expander process may be permitted only when noise canceling is performed (in other words, the expander process is prohibited when noise canceling is not performed).
  • FIG. 17 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied.
  • a playback device 400 shown in FIG. 17 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100.
  • the playback apparatus 400 includes a control unit 418 instead of the control unit 118.
  • the playback apparatus 400 includes a microphone 451, a microphone amplifier 452, an NC filter 453, a switch 454, and a calculation unit 455.
  • the control unit 418 performs processing related to control in the same manner as the control unit 118.
  • the control unit 418 includes an NC control unit 441 in addition to the expander control unit 141.
  • NC control unit 441 controls switch 454 to control whether or not to perform noise canceling. For example, when performing noise canceling, the NC control unit 441 connects the NC filter 453 and the calculation unit 455 by turning on the switch 454. When noise canceling is not performed, the NC control unit 441 disconnects the NC filter 453 and the calculation unit 455 by turning off the switch 454.
  • the NC control unit 441 also controls the expander control unit 141 to control the execution of the expander process according to the setting related to the noise canceling. For example, the NC control unit 441 permits the expander control unit 141 to execute an expander process when performing noise canceling. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. Further, for example, the NC control unit 441 prohibits the expander control unit 141 from executing the expander process when noise canceling is not performed. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • the microphone 451 collects sound around the output device 115 and supplies the sound signal to the microphone amplifier 452.
  • the microphone amplifier 452 amplifies the audio signal and supplies it to the NC filter 453.
  • the NC filter 453 performs predetermined filter processing on the audio signal, for example, performs phase inversion.
  • the switch 454 is controlled and driven by the NC control unit 441 and controls connection between the NC filter 453 and the calculation unit 455.
  • the switch 454 when the switch 454 is turned on, the NC filter 453 and the calculation unit 455 are connected, and the sound signal processed by the NC filter 453 is supplied to the calculation unit 455. That is, noise canceling is performed.
  • the switch 454 when the switch 454 is turned off, the NC filter 453 and the calculation unit 455 are disconnected, and the audio signal processed by the NC filter 453 is not supplied to the calculation unit 455. That is, noise canceling is not performed.
  • the computing unit 455 synthesizes (superimposes) the audio signal supplied via the switch 454 with the audio signal amplified by the amplifying unit 113 and supplies the synthesized signal to the output unit 114. Since the phase of the audio signal supplied from the NC filter 453 is inverted, when the synthesized signal is output as audio, the audio signal component in which the phase included in the synthesized signal is inverted is output around the output device 115. Compete with the voice. This makes the original audio signal more clearly reach the user's ear.
  • the NC control unit 441 determines whether or not to perform noise canceling in step S401. If it is determined that noise canceling is to be performed, the process proceeds to step S402.
  • step S402 the NC control unit 441 permits the expander control unit 141 to execute the expander process.
  • the expander control unit 141 can execute the expander process by controlling the expander 112.
  • the expander control process ends.
  • step S401 If it is determined in step S401 that noise canceling is not performed, the process proceeds to step S403.
  • step S403 the NC control unit 441 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • step S403 ends, the expander control process ends.
  • the playback apparatus 400 can control the execution of the expander processing according to the noise canceling setting. Therefore, the expander process and noise canceling can be used in combination, and an increase in the load on the user can be suppressed while further reducing the decrease in subjective sound quality. Further, the execution of the expander process can be suppressed when the effect of suppressing the reduction of the subjective sound quality is small, for example, when the surrounding noise is large. Thereby, the increase in the load of the reproducing apparatus 400 can be suppressed.
  • the NC control unit 441 may control the expander parameter calculation unit 132 and the like to set the parameter to a value according to the noise canceling setting. For example, when noise canceling is performed on an audio signal, the expander processing threshold may be made smaller than when noise canceling is not performed. By doing in this way, it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
  • the output device 115 is an earphone or a headphone
  • the sound is output from the side of the user's ear and reaches the eardrum via the external auditory canal, which may cause a load on the user's ear.
  • execution of the expander process may be controlled according to the type of the output device 115. For example, when the output device 115 is an earphone or a headphone, execution of the expander process may be permitted (in other words, when the output device 115 is a speaker or the like, the expander process is prohibited).
  • FIG. 19 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied.
  • a playback device 500 shown in FIG. 19 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100.
  • the playback apparatus 500 further includes an output device detection unit 511.
  • the output device detection unit 511 detects the type of the output device 115.
  • the output device detection unit 511 controls the expander control unit 141 and controls the execution of the expander process according to the detection result (that is, the type of the output device 115). For example, when the output device 115 is an earphone or a headphone, the output device detection unit 511 permits the expander control unit 141 to execute the expander process. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. For example, when the output device 115 is a speaker, the output device detection unit 511 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • the output device detection unit 511 detects the output device 115 in step S501. In step S502, the output device detection unit 511 determines whether the output device 115 is an earphone or a headphone. If it is determined that the output device 115 is an earphone or a headphone, the process proceeds to step S503.
  • step S503 the output device detection unit 511 permits the expander control unit 141 to execute the expander process.
  • the expander control unit 141 can execute the expander process by controlling the expander 112.
  • the expander control process ends.
  • step S502 If it is determined in step S502 that the output device 115 is a speaker or the like (not an earphone or a headphone), the process proceeds to step S504.
  • step S504 the output device detection unit 511 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
  • step S504 ends, the expander control process ends.
  • the playback device 500 can control the execution of the expander processing according to the type of the output device 115. Therefore, for example, when the output device 115 is a speaker or the like and there are few effects obtained by suppressing the effective value average level, execution of the expander process can be suppressed. As a result, an increase in the load on the playback device 500 can be suppressed. In addition, it is possible to suppress a reduction in subjective sound quality due to unnecessary expander processing.
  • the output device 115 is an earphone, a headphone, etc., and the effect obtained by suppressing the effective value average level is large, the expander process can be executed, and the user's An increase in load can be suppressed.
  • the expander processing control method according to the type of the output device 115 is not limited to this.
  • the output device detection unit 511 controls the expander parameter calculation unit 132 and the like, and the parameter is set according to the type of the output device 115. It may be set to a different value. By doing in this way, it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
  • the peak value and the effective value may be detected not only within the audible band but also outside the audible band.
  • the effective value average level may be reduced without increasing the peak rate and reducing the peak value not only within the audible band but also outside the audible band. For example, when the difference between the RMS average level of the entire band and the RMS average level outside the audible band is small, it is determined that many signals are included outside the audible band, and the RMS average level is further reduced. You may make it correct
  • the specific range of the audible band is arbitrary.
  • the frequency may be about 20 Hz to about 20000 Hz.
  • FIG. 21 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied.
  • a playback device 600 shown in FIG. 21 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100.
  • the playback apparatus 600 includes a detection unit 616 instead of the detection unit 116, and includes a parameter calculation unit 617 instead of the parameter calculation unit 117.
  • the detection unit 616 performs processing related to detection in the same manner as the detection unit 116.
  • the detection unit 616 includes a filter 621 and an effective value detection unit 622 in addition to the configuration of the detection unit 116 (the peak level detection unit 121 and the effective value detection unit 122).
  • the peak level detector 121 detects peak values for all bands inside and outside the audible band.
  • the peak level detector 121 supplies the detected peak value to the crest factor calculator 131.
  • the effective value detection unit 122 detects effective values of all bands inside and outside the audible band.
  • the effective value detector 122 supplies the detected effective values of all the bands to the crest factor calculator 131 and the ratio corrector 631.
  • the filter 621 has a high-pass filter, and extracts a signal outside the audible band from the input audio signal.
  • the filter 621 supplies the extracted signal outside the audible band to the effective value detection unit 622.
  • the effective value detection unit 622 detects an effective value from a signal outside the audible band extracted by the filter 621.
  • the effective value detection unit 622 supplies the detected effective value outside the audible band to the ratio correction unit 631.
  • the parameter calculation unit 617 performs processing related to parameter calculation in the same manner as the parameter calculation unit 117.
  • the parameter calculation unit 617 further includes a ratio correction unit 631 in addition to the configuration of the parameter calculation unit 117.
  • the crest factor calculation unit 131 calculates the crest factor for all bands based on the peak value of all the bands detected by the peak level detection unit 121 and the effective value of all the bands detected by the effective value detection unit 122.
  • the expander parameter calculation unit 132 generates parameters related to the expander process, such as a threshold value, a ratio, and a time constant of the expander process, based on the crest factor of the entire band calculated by the crest factor calculation unit 131.
  • the ratio correction unit 631 is calculated by the expander parameter calculation unit 132 based on the effective value of the entire band detected by the effective value detection unit 122 and the effective value outside the audible band detected by the effective value detection unit 622. Correct the expanded expander ratio. For example, when the difference between the effective value of the entire band and the effective value outside the audible band is small, the ratio correction unit 631 determines that many components outside the audible band are included, and corrects the ratio so as to lower the effective value. To do.
  • the ratio correction unit 631 may uniformly correct the ratio with respect to the entire band, for example. By doing so, it is possible to reduce the effective value of the entire band including the outside of the audible band. Therefore, the playback device 600 can further suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
  • the ratio may be corrected so that the effective value outside the audible band is lower than the effective value within the audible band.
  • FIG. 22A shows an example of the frequency distribution of the audio signal before the expander process
  • FIG. 22B shows an example of the frequency distribution of the audio signal after the expander process.
  • a portion surrounded by a square frame 661 is a component outside the audible band.
  • the portion surrounded by the square frame 662 is a component outside the audible band.
  • the playback device 600 can suppress an increase in the user's load while further suppressing the reduction in subjective sound quality.
  • the peak level detection unit 121 detects peak values for all bands inside and outside the audible band in step S601.
  • the effective value detection unit 122 detects effective values for all bands inside and outside the audible band.
  • the crest factor calculation unit 131 calculates the crest factor of all bands based on the peak value of all the bands detected in step S601 and the effective value of all the bands detected in step S602.
  • step S604 the expander control unit 141 determines whether or not the peak value detected in step S601 exceeds the expander process ON threshold. If it is determined that the peak value is larger than the expander process ON threshold, the process proceeds to step S605. In step S605, the expander control unit 141 determines whether the crest factor calculated in step S603 is smaller than a predetermined crest factor threshold. If it is determined that the crest factor is smaller than the crest factor threshold, the process proceeds to step S606. In this case, since the peak value of the audio signal is large and the crest factor is small, the effective value average level is large. Therefore, the expander control unit 141 performs control so that the expander process is performed on the audio signal.
  • step S606 the expander parameter calculation unit 132 uses the peak value of the entire band detected in step S601 and the crest factor of the entire band calculated in step S603 to set a threshold (threshold) for the expander process. And the ratio.
  • the expander control unit 141 controls the expander 112 to determine the expander process ON.
  • step S607 the filter 621 extracts a component outside the audible band from the audio signal.
  • the effective value detection unit 622 detects an effective value outside the audible band from components outside the audible band.
  • step S608 the ratio correction unit 631 calculates the difference between the effective value of the entire band detected in step S602 and the effective value outside the audible band detected in step S607.
  • step S609 the ratio correction unit 631 determines whether the difference value is smaller than a predetermined threshold value. If it is determined that the difference value is smaller than the threshold value, the process proceeds to step S610.
  • step S610 the ratio correction unit 631 controls the expander parameter calculation unit 132 to correct the ratio calculated in step S606 so as to reduce at least the effective value outside the audible band.
  • the expander control unit 141 sets the corrected ratio in the expander 112 together with the threshold value calculated in step S606.
  • the pre-analysis process ends. If it is determined in step S609 that the difference value is equal to or greater than the threshold value, the ratio correction is omitted because there are few components outside the audible band. That is, the expander control unit 141 sets the threshold value and the ratio calculated in step S606 in the expander 112. Then, the pre-analysis process ends.
  • step S604 If it is determined in step S604 that the peak value does not exceed the expander process ON threshold, the process proceeds to step S611. If it is determined in step S605 that the crest factor is equal to or greater than the crest factor threshold, the process proceeds to step S611. In this case, since the peak value of the audio signal is small or the peak value is small even if the peak value is large, the effective value average level is not large. Therefore, the expander control unit 141 performs control so that the expander process is not performed on the audio signal. That is, in step S611, the expander control unit 141 controls the expander 112 to determine the expander process OFF. When the process of step S611 ends, the pre-analysis process ends.
  • the playback device 600 can suppress an increase in the load on the user while suppressing a decrease in subjective sound quality even for high resolution audio including components outside the audible band.
  • the series of processes described above can be executed by hardware or can be executed by software.
  • a program constituting the software is installed in the computer.
  • the computer includes, for example, a general-purpose personal computer that can execute various functions by installing a computer incorporated in dedicated hardware and various programs.
  • FIG. 24 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processing by a program.
  • a CPU Central Processing Unit
  • ROM Read Only Memory
  • RAM Random Access Memory
  • An input / output interface 910 is also connected to the bus 904.
  • An input unit 911, an output unit 912, a storage unit 913, a communication unit 914, and a drive 915 are connected to the input / output interface 910.
  • the input unit 911 includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, and the like.
  • the output unit 912 includes, for example, a display, a speaker, an output terminal, and the like.
  • the storage unit 913 includes, for example, a hard disk, a RAM disk, a nonvolatile memory, and the like.
  • the communication unit 914 includes a network interface, for example.
  • the drive 915 drives a removable medium 921 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.
  • the CPU 901 loads the program stored in the storage unit 913 to the RAM 903 via the input / output interface 910 and the bus 904 and executes the program. A series of processing is performed.
  • the RAM 903 also appropriately stores data necessary for the CPU 901 to execute various processes.
  • the program executed by the computer 900 can be recorded and applied to, for example, a removable medium 921 as a package medium or the like.
  • the program can be installed in the storage unit 913 via the input / output interface 910 by attaching the removable medium 921 to the drive 915.
  • This program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In that case, the program can be received by the communication unit 914 and installed in the storage unit 913.
  • a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.
  • the program can be received by the communication unit 914 and installed in the storage unit 913.
  • this program can be installed in advance in the ROM 902, the storage unit 913, or the like.
  • the present technology may be applied to any configuration that constitutes an apparatus or system, for example, a processor as a system LSI (Large Scale Integration), a module that uses a plurality of processors, a unit that uses a plurality of modules, etc. It can also be implemented as a set or the like to which functions are added (that is, a partial configuration of the apparatus).
  • a processor as a system LSI (Large Scale Integration)
  • a module that uses a plurality of processors
  • a unit that uses a plurality of modules etc.
  • It can also be implemented as a set or the like to which functions are added (that is, a partial configuration of the apparatus).
  • the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units).
  • the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit).
  • a configuration other than that described above may be added to the configuration of each device (or each processing unit).
  • a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit). .
  • the present technology can take a configuration of cloud computing in which one function is shared and processed by a plurality of devices via a network.
  • the above-described program can be executed in an arbitrary device.
  • the device may have necessary functions (functional blocks and the like) so that necessary information can be obtained.
  • each step described in the above flowchart can be executed by one device or can be executed by a plurality of devices. Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.
  • the program executed by the computer may be executed in a time series in the order described in this specification for the processing of the steps describing the program, or in parallel or called. It may be executed individually at a necessary timing. That is, as long as no contradiction occurs, the processing of each step may be executed in an order different from the order described above. Furthermore, the processing of the steps describing this program may be executed in parallel with the processing of other programs, or may be executed in combination with the processing of other programs.
  • the system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .
  • this technique can also take the following structures.
  • a crest factor calculator for calculating a crest factor of the input audio signal;
  • An expander control unit that, when the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold value, performs an expander process for reducing a signal value smaller than the predetermined threshold value for the audio signal;
  • Information processing apparatus provided.
  • the information processing apparatus according to (1) further including a parameter setting unit that sets a parameter used for the expander processing based on the crest factor calculated by the crest factor calculation unit.
  • the parameter includes the threshold value to be compared with a signal value of the audio signal and a ratio to a signal value smaller than the threshold value of the audio signal.
  • the information processing apparatus according to (3), wherein when the crest factor is small, the parameter setting unit sets the ratio value to a larger value than when the crest factor is large.
  • a storage unit for storing time constant candidates for the expander processing is further provided.
  • the information processing apparatus according to any one of (2) to (4), wherein the parameter setting unit is configured to select a time constant to be applied from the candidates stored in the storage unit.
  • the expander control unit causes the audio signal to perform the expander process.
  • the information processing apparatus according to any one of 1) to (5).
  • the crest factor calculation unit calculates the crest factor based on a peak value and an effective value of the audio signal.
  • (8) further comprising a peak value detector for detecting a peak value of the audio signal;
  • (9) further comprising an effective value detection unit for detecting an effective value of the audio signal;
  • the information processing apparatus according to any one of (1) to (9), further including: an expander processing unit that performs the expander process on the audio signal according to the control of the expander control unit.
  • the crest factor calculation unit calculates the crest factor every predetermined time interval, The expander control unit controls execution of the expander processing based on the crest factor calculated by the crest factor calculation unit at each time interval.
  • Information processing device (12)
  • the system further includes a parameter setting unit that sets a parameter used for the expander processing based on the crest factor calculated by the crest factor calculation unit at each time interval.
  • the information processing apparatus according to any one of the above.
  • (13) The information processing apparatus according to (12), wherein the parameter setting unit initializes the parameter when a silence period is detected in the audio signal.
  • An output device detection unit that detects a type of an output device that outputs the audio signal
  • the expander control unit is configured to permit execution of the expander process when a predetermined type of output device is detected by the output device detection unit.
  • a ratio correction unit that corrects the ratio set by the parameter setting unit when the difference between the effective value of the entire band of the audio signal and the effective value outside the audible band is small
  • 100 playback device 111 delay processing unit, 112 expander, 113 amplification unit, 114 output unit, 115 output device, 116 detection unit, 117 parameter calculation unit, 118 control unit, 121 peak level detection unit, 122 effective value detection unit, 131 Crest factor calculation unit, 132 Expander parameter calculation unit, 133 memory, 141 expander control unit, 300 playback device, 341 volume control unit, 400 playback device, 441 NC control unit, 451 microphone, 452 microphone amplifier, 453 NC filter , 454 switch, 455 arithmetic unit, 500 playback device, 511 output device detection unit, 600 playback device, 616 detection unit, 617 parameter calculation unit, 62 1 filter, 622 RMS detection unit, 631 ratio correction unit, 900 computer

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  • Engineering & Computer Science (AREA)
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Abstract

The present feature relates to an information processing device, method, and program with which it is possible to suppress an increase in a user's burden while suppressing a reduction in subjective tone quality. The peak-to-rms ratio of an inputted audio signal is calculated and, when the calculated peak-to-rms ratio is smaller than a prescribed threshold, an expander process for further reducing a signal value smaller than the prescribed threshold is performed on the audio signal. The present disclosure can be applied to, for example, an information processing device, an electronic apparatus, a computer, a server, a program, a recording medium, and a system, etc.

Description

情報処理装置および方法、並びにプログラムInformation processing apparatus and method, and program
　本技術は、情報処理装置および方法、並びにプログラムに関し、特に、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができるようにした情報処理装置および方法、並びにプログラムに関する。 The present technology relates to an information processing apparatus, method, and program, and more particularly, to an information processing apparatus, method, and program that can suppress an increase in a user's load while suppressing a decrease in subjective sound quality.
　従来、楽曲制作において、マスタリング等でコンプレッサを多くかけることによりレンジを狭くして実効値平均レベルを上げる方法があった。近年、楽曲制作においては、所謂音圧競争とも称されるように、楽曲（オーディオ信号）の音圧を増大させることが好まれる傾向があり、このような手法を用いて制作される楽曲が多くなっている。しかしながら、実効値平均レベルが大きいオーディオ信号はユーザの耳への負荷が増大するおそれがあり、疲れやすくなるおそれがあった。 Conventionally, in music production, there was a method of increasing the effective value average level by narrowing the range by applying a lot of compressors for mastering or the like. In recent years, in music production, there is a tendency to increase the sound pressure of music (audio signals), as is called so-called sound pressure competition, and there are many music produced using such a technique. It has become. However, an audio signal having a large effective value average level may increase the load on the user's ear, and may be easily fatigued.
　そこで、実効値平均レベルが大きいオーディオ信号を、音量を低減させて再生する方法が考えられた（例えば、特許文献１参照）。 Therefore, there has been considered a method of reproducing an audio signal having a large effective average level with a reduced volume (see, for example, Patent Document 1).
特開２０１２－１６９８２８号公報JP 2012-169828 A
　しかしながら、この方法の場合、オーディオ信号のレンジは狭いままであり、全ての音が小さくなることで聴きづらくなったり、違和感を与えたりするおそれがあった。つまり、オーディオ信号の主観音質が低減するおそれがあった。 However, in this method, the range of the audio signal remains narrow, and there is a possibility that it becomes difficult to hear or gives a sense of incongruity because all the sounds become small. That is, the subjective sound quality of the audio signal may be reduced.
　本技術は、このような状況に鑑みて提案されたものであり、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することを目的とする。 The present technology has been proposed in view of such a situation, and an object thereof is to suppress an increase in a user's load while suppressing a decrease in subjective sound quality.
　本技術の一側面の情報処理装置は、入力されたオーディオ信号の波高率を算出する波高率算出部と、前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部とを備える情報処理装置である。 An information processing apparatus according to an aspect of the present technology includes a crest factor calculation unit that calculates a crest factor of an input audio signal, and the audio crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold value. The information processing apparatus includes an expander control unit that performs an expander process for reducing a signal value smaller than a predetermined threshold value for a signal.
　前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備えることができる。 A parameter setting unit that sets parameters used for the expander processing based on the crest factor calculated by the crest factor calculation unit may be further provided.
　前記パラメータは、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオとを含むようにすることができる。 The parameter may include the threshold value to be compared with the signal value of the audio signal and a ratio to a signal value smaller than the threshold value of the audio signal.
　前記パラメータ設定部は、前記波高率が小さい場合、前記レシオの値を、前記波高率が大きい場合よりも大きな値に設定することができる。 The parameter setting unit can set the ratio value to a larger value when the crest factor is small than when the crest factor is large.
　前記エキスパンダ処理の時定数の候補を記憶する記憶部をさらに備え、前記パラメータ設定部は、前記記憶部に記憶されている前記候補の中から適用する時定数を選択するように構成されるようにすることができる。 The apparatus further includes a storage unit that stores a candidate for a time constant of the expander process, and the parameter setting unit is configured to select a time constant to be applied from the candidates stored in the storage unit. Can be.
　前記エキスパンダ制御部は、前記オーディオ信号のピーク値が所定の閾値より大きく、かつ、前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して前記エキスパンダ処理を行わせることができる。 The expander control unit can perform the expander process on the audio signal when the peak value of the audio signal is larger than a predetermined threshold and the crest factor is smaller than the predetermined threshold.
　前記波高率算出部は、前記オーディオ信号のピーク値と実効値とに基づいて前記波高率を算出することができる。 The crest factor calculation unit can calculate the crest factor based on a peak value and an effective value of the audio signal.
　前記オーディオ信号のピーク値を検出するピーク値検出部をさらに備え、前記波高率算出部は、前記ピーク値検出部により検出された前記ピーク値に基づいて前記波高率を算出するように構成されるようにすることができる。 A peak value detection unit that detects a peak value of the audio signal is further provided, and the crest factor calculation unit is configured to calculate the crest factor based on the peak value detected by the peak value detection unit. Can be.
　前記オーディオ信号の実効値を検出する実効値検出部をさらに備え、前記波高率算出部は、前記実効値検出部により検出された前記実効値に基づいて前記波高率を算出するように構成されるようにすることができる。 An effective value detection unit that detects an effective value of the audio signal is further provided, and the crest factor calculation unit is configured to calculate the crest factor based on the effective value detected by the effective value detection unit. Can be.
　前記エキスパンダ制御部の制御に従って、前記オーディオ信号に対して前記エキスパンダ処理を行うエキスパンダ処理部をさらに備えるようにすることができる。 It is possible to further include an expander processing unit that performs the expander process on the audio signal according to the control of the expander control unit.
　前記波高率算出部は、所定の時間間隔毎に前記波高率を算出し、前記エキスパンダ制御部は、前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて前記エキスパンダ処理の実行を制御することができる。 The crest factor calculation unit calculates the crest factor every predetermined time interval, and the expander control unit calculates the crest factor based on the crest factor calculated by the crest factor calculation unit for each time interval. Execution of the panda process can be controlled.
　前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備えるようにすることができる。 It is possible to further include a parameter setting unit that sets parameters used for the expander processing based on the crest factor calculated by the crest factor calculation unit at each time interval.
　前記パラメータ設定部は、前記オーディオ信号に無音期間が検出された場合、前記パラメータを初期化することができる。 The parameter setting unit can initialize the parameter when a silence period is detected in the audio signal.
　前記エキスパンダ制御部は、前記オーディオ信号を出力する際の音量が所定の閾値より大きい場合、前記エキスパンダ処理の実行を許可することができる。 The expander control unit can permit the execution of the expander process when the sound volume when outputting the audio signal is larger than a predetermined threshold.
　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部をさらに備え、前記パラメータ設定部は、前記オーディオ信号に対してノイズキャンセル処理が行われる場合、前記閾値を、前記ノイズキャンセル処理が行われない場合よりも小さくするように構成されるようにすることができる。 A parameter setting unit configured to set a ratio of the threshold value to be compared with the signal value of the audio signal based on the crest factor calculated by the crest factor calculation unit and a signal value smaller than the threshold value of the audio signal; The parameter setting unit may be configured to make the threshold value smaller when the noise cancellation process is performed on the audio signal than when the noise cancellation process is not performed. .
　前記オーディオ信号を出力する出力デバイスの種類を検出する出力デバイス検出部をさらに備え、前記エキスパンダ制御部は、前記出力デバイス検出部により所定の種類の出力デバイスが検出された場合、前記エキスパンダ処理の実行を許可するように構成されるようにすることができる。 An output device detection unit that detects a type of an output device that outputs the audio signal; and the expander control unit performs the expander process when a predetermined type of output device is detected by the output device detection unit. Can be configured to allow execution of
　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部と、前記オーディオ信号の全帯域の実効値と可聴帯域外の実効値との差分が小さい場合、前記パラメータ設定部により設定された前記レシオを補正するレシオ補正部とをさらに備えるようにすることができる。 Based on the crest factor calculated by the crest factor calculation unit, the threshold value to be compared with the signal value of the audio signal, and a parameter setting unit for setting a ratio for a signal value smaller than the threshold value of the audio signal; When the difference between the effective value of the entire band of the audio signal and the effective value outside the audible band is small, a ratio correction unit that corrects the ratio set by the parameter setting unit can be further provided.
　前記レシオ補正部は、前記オーディオ信号の可聴帯域外に対するレシオを補正することができる。 The ratio correction unit can correct the ratio of the audio signal to outside the audible band.
　本技術の一側面の情報処理方法は、入力されたオーディオ信号の波高率を算出し、算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせる情報処理方法である。 An information processing method according to an aspect of the present technology calculates a crest factor of an input audio signal, and when the calculated crest factor is smaller than a predetermined threshold, a signal smaller than the predetermined threshold is obtained with respect to the audio signal. This is an information processing method for performing an expander process for reducing the value.
　本技術の一側面のプログラムは、コンピュータを、入力されたオーディオ信号の波高率を算出する波高率算出部と、前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部として機能させるプログラムである。 According to one aspect of the present technology, the program includes a crest factor calculation unit that calculates a crest factor of an input audio signal, and the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold, This is a program that functions as an expander control unit that performs an expander process for reducing a signal value smaller than a predetermined threshold value for an audio signal.
　本技術の一側面においては、入力されたオーディオ信号の波高率が算出され、算出された波高率が所定の閾値より小さい場合、オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理が行われる。 In one aspect of the present technology, the crest factor of an input audio signal is calculated, and when the calculated crest factor is smaller than a predetermined threshold, a signal value smaller than the predetermined threshold is made smaller for the audio signal. Expander processing is performed.
　本技術によれば、情報を処理することが出来る。また本技術によれば、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 This technology can process information. Moreover, according to this technique, the increase in a user's load can be suppressed, suppressing the reduction of subjective sound quality.
コンプレッサ処理の様子の例を説明する図である。It is a figure explaining the example of the mode of a compressor process. 再生装置の主な構成例を示すブロック図である。It is a block diagram which shows the main structural examples of a reproducing | regenerating apparatus. エキスパンダ処理の様子の例を説明する図である。It is a figure explaining the example of the mode of an expander process. 事前解析処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of a prior analysis process. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. ピークレベルの変化の様子の例を説明する図である。It is a figure explaining the example of the mode of a change of a peak level. 実効値の変化の様子の例を説明する図である。It is a figure explaining the example of the mode of a change of an effective value. フレーム単位での処理の様子の例を説明する図である。It is a figure explaining the example of the mode of a process in a frame unit. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. エキスパンダ制御処理の流れの例を説明する図９に続くフローチャートである。10 is a flowchart following FIG. 9 for explaining an example of the flow of the expander control process. エキスパンダ制御処理の流れの例を説明する図９に続くフローチャートである。10 is a flowchart following FIG. 9 for explaining an example of the flow of the expander control process. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. エキスパンダ制御処理の流れの例を説明する図１２に続くフローチャートである。It is a flowchart following FIG. 12 explaining the example of the flow of an expander control process. エキスパンダ制御処理の流れの例を説明する図１２に続くフローチャートである。It is a flowchart following FIG. 12 explaining the example of the flow of an expander control process. 再生装置の主な構成例を示すブロック図である。It is a block diagram which shows the main structural examples of a reproducing | regenerating apparatus. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. 再生装置の主な構成例を示すブロック図である。It is a block diagram which shows the main structural examples of a reproducing | regenerating apparatus. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. 再生装置の主な構成例を示すブロック図である。It is a block diagram which shows the main structural examples of a reproducing | regenerating apparatus. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. 再生装置の主な構成例を示すブロック図である。It is a block diagram which shows the main structural examples of a reproducing | regenerating apparatus. 周波数特性の変化の様子の例を説明する図である。It is a figure explaining the example of the mode of a change of a frequency characteristic. エキスパンダ制御処理の流れの例を説明するフローチャートである。It is a flowchart explaining the example of the flow of an expander control process. コンピュータの主な構成例を示すブロック図である。And FIG. 20 is a block diagram illustrating a main configuration example of a computer.
　以下、本開示を実施するための形態（以下実施の形態とする）について説明する。なお、説明は以下の順序で行う。
１．コンプレッサ
２．第１の実施の形態（波高率を用いたエキスパンダ制御）
３．第２の実施の形態（単位時間毎のエキスパンダ制御）
４．第３の実施の形態（無音区間に応じたエキスパンダ制御）
５．第４の実施の形態（音量に応じたエキスパンダ制御）
６．第５の実施の形態（ノイズキャンセルに応じたエキスパンダ制御）
７．第６の実施の形態（出力デバイスに応じたエキスパンダ制御）
８．第７の実施の形態（ハイレゾリューションオーディオのエキスパンダ制御）
９．第８の実施の形態（コンピュータ）
１０．その他 Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. Compressor 2. First embodiment (expander control using crest factor)
3. Second embodiment (expander control per unit time)
4). Third embodiment (expander control according to a silent section)
5). Fourth embodiment (expander control according to volume)
6). Fifth embodiment (expander control according to noise cancellation)
7). Sixth embodiment (expander control according to output device)
8). Seventh Embodiment (Expander Control of High Resolution Audio)
9. Eighth Embodiment (Computer)
10. Other
　＜１．コンプレッサ＞
　従来、楽曲制作において、マスタリング等でコンプレッサを多くかけることによりレンジを狭くして実効値平均レベルを上げる方法があった。例えば、図１のＡに示されるような波形のオーディオ信号に対してコンプレッサ処理をかけることによりレンジを圧縮してゲインを上げ、図１のＢに示されるような波形が得られる。 <1. Compressor>
Conventionally, in music production, there has been a method of increasing the effective value average level by narrowing the range by applying a lot of compressors for mastering or the like. For example, by applying compression processing to an audio signal having a waveform as shown in FIG. 1A, the range is compressed to increase the gain, and a waveform as shown in FIG. 1B is obtained.
　このコンプレッサ処理の入出力のレベルは、例えば図１のＣのような関係になる。つまり、指定された閾値（threshold）を越えた場合、その閾値（threshold）を越えた入力に対してレシオ（ratio）に応じた出力を行う。コンプレッサの場合、入力に対して出力が小さくなるようにレシオ（ratio）が設定され、入力対出力が、1:1/∞となると出力は閾値（threshold）と同じ値になり、リミッターとして働く。また、コンプレッサの場合、閾値（threshold）とレシオ（ratio）により最大値が導き出せる入力に対する出力のゲインを上げることで、全体のゲインを上げつつ、最大値（0dB）を越えないようにすることで、ゲインを上げつつレンジを圧縮することができる。なお、入力対出力が1:1の場合、入力のレベルがそのまま出力される。 The input / output level of this compressor processing has a relationship as shown in FIG. In other words, when a specified threshold value (threshold) is exceeded, an output corresponding to the ratio (ratio) is performed for an input exceeding the threshold value (threshold). In the case of a compressor, the ratio is set so that the output is reduced with respect to the input, and when the input to output becomes 1: 1 / ∞, the output becomes the same value as the threshold and functions as a limiter. Also, in the case of a compressor, by raising the output gain for the input that can derive the maximum value by the threshold (threshold) and ratio (ratio), the overall gain is increased while the maximum value (0 dB) is not exceeded. The range can be compressed while increasing the gain. When the input to output is 1: 1, the input level is output as it is.
　このようにコンプレッサをかけることによりオーディオ信号の実効値平均レベルを増大させることができる。近年、楽曲制作においては、所謂音圧競争とも称されるように、楽曲（オーディオ信号）の音圧を増大させることが好まれる傾向があり、このような手法を用いて制作される楽曲が多くなっている。しかしながら、実効値平均レベルが大きいオーディオ信号はユーザの耳への負荷が増大するおそれがあり、疲れやすくなるおそれがあった。 * The effective value average level of the audio signal can be increased by applying the compressor in this way. In recent years, in music production, there is a tendency to increase the sound pressure of music (audio signals), as is called so-called sound pressure competition, and there are many music produced using such a technique. It has become. However, an audio signal having a large effective value average level may increase the load on the user's ear, and may be easily fatigued.
　そこで、特許文献１に記載の方法のように、実効値平均レベルが大きいオーディオ信号を、音量を低減させて再生する方法が考えられた。 Therefore, as in the method described in Patent Document 1, a method of reproducing an audio signal having a large effective value average level with a reduced volume is considered.
　しかしながら、この方法の場合、オーディオ信号のレンジは狭いままであり、全ての音が小さくなることで聴きづらくなったり、違和感を与えたりするおそれがあった。つまり、オーディオ信号の主観音質が低減するおそれがあった。 However, in this method, the range of the audio signal remains narrow, and there is a possibility that it becomes difficult to hear or gives a sense of incongruity because all the sounds become small. That is, the subjective sound quality of the audio signal may be reduced.
　　＜波高率に基づくエキスパンダ制御＞
　そこで、入力されたオーディオ信号の波高率を算出し、その算出された波高率が所定の閾値より小さい場合、オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるようにする。例えば、情報処理装置において、入力されたオーディオ信号の波高率を算出する波高率算出部と、その波高率算出部により算出された波高率が所定の閾値より小さい場合、オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部とを備えるようにする。 <Expander control based on crest factor>
Therefore, the crest factor of the input audio signal is calculated, and when the calculated crest factor is smaller than a predetermined threshold value, an expander process is performed on the audio signal to make the signal value smaller than the predetermined threshold value smaller. I will let you. For example, in the information processing apparatus, when the crest factor calculation unit that calculates the crest factor of the input audio signal and the crest factor calculated by the crest factor calculation unit are smaller than a predetermined threshold, And an expander control unit that performs an expander process for making a signal value smaller than the threshold value smaller.
　このようにエキスパンダ処理を行わせて波高率を増大させることにより、ピーク値を維持しながら実効値平均レベルを低減させることができるので、特許文献１に記載の方法よりも主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。また、処理前の波高率に応じてエキスパンダ処理を行うことにより、不要なエキスパンダ処理を抑制することができるので、不要なレンジの拡大を抑制し、ユーザに違和感をより感じさせないようにすることができる。すなわち、主観音質の低減をより抑制することができる。 Since the effective value average level can be reduced while maintaining the peak value by increasing the crest factor by performing the expander processing in this way, the subjective sound quality can be reduced more than the method described in Patent Document 1. An increase in the user's load can be suppressed while suppressing. Also, by performing the expander process according to the crest factor before the process, it is possible to suppress the unnecessary expander process, thereby suppressing the expansion of the unnecessary range and preventing the user from feeling more uncomfortable. be able to. That is, the reduction of subjective sound quality can be further suppressed.
　＜２．第１の実施の形態＞
　　＜再生装置＞
　図２は、本技術を適用した情報処理装置の一実施の形態である再生装置の主な構成例を示す図である。図２に示される再生装置１００は、入力されたオーディオ信号の再生を行う装置である。また、再生装置１００は、必要に応じて、その再生するオーディオ信号に対して実効値平均レベルを低減させる信号処理を行う。 <2. First Embodiment>
<Reproducing device>
FIG. 2 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied. A playback device 100 shown in FIG. 2 is a device that plays back an input audio signal. Further, the playback apparatus 100 performs signal processing for reducing the effective value average level for the audio signal to be played back, as necessary.
　図２に示されるように、再生装置１００は、遅延処理部１１１、エキスパンダ１１２、増幅部１１３、出力部１１４、出力デバイス１１５、検出部１１６、パラメータ算出部１１７、および制御部１１８を有する。 2, the playback apparatus 100 includes a delay processing unit 111, an expander 112, an amplification unit 113, an output unit 114, an output device 115, a detection unit 116, a parameter calculation unit 117, and a control unit 118.
　遅延処理部１１１は、入力されたオーディオ信号に対する信号処理の制御タイミングと、そのオーディオ信号の再生タイミングとを対応させるために、入力されたオーディオ信号を一時的に保持する。これによりオーディオ信号の再生タイミングが遅延され、信号処理の制御タイミングに合わせられる。 The delay processing unit 111 temporarily holds the input audio signal in order to correspond the control timing of signal processing for the input audio signal and the reproduction timing of the audio signal. As a result, the reproduction timing of the audio signal is delayed and matched with the control timing of the signal processing.
　エキスパンダ１１２は、遅延処理部１１１から供給されるオーディオ信号に対してエキスパンダ処理を行う。エキスパンダ処理は、オーディオ信号のレンジを伸張してゲインを下げる処理であり、入力が指定された閾値（threshold）を下回る場合、その入力と閾値（threshold）との差に対してレシオ（ratio）に応じた出力を行う。例えば、図３のＡに示されるような波形のオーディオ信号にエキスパンダ処理を行うことにより、図３のＢに示されるような波形が得られる。 The expander 112 performs an expander process on the audio signal supplied from the delay processing unit 111. The expander process is a process that extends the range of the audio signal and lowers the gain. When the input falls below a specified threshold, the ratio is set to the difference between the input and the threshold. Output according to. For example, by performing an expander process on an audio signal having a waveform as shown in FIG. 3A, a waveform as shown in B of FIG. 3 is obtained.
　このエキスパンダ処理の入出力のレベルの関係の例を図３のＣに示す。図３のＣに示されるように、レシオ（ratio）は入力に対して出力が小さくなるように設定される。一般的に、エキスパンダ処理においては、入力対出力が1:1/∞となると出力は限りなく０になり、ノイズゲートとして働く。 An example of the relationship between the input / output levels of this expander processing is shown in FIG. As shown in FIG. 3C, the ratio is set so that the output is smaller than the input. In general, in the expander process, when the input-to-output ratio is 1: 1 / ∞, the output becomes zero as much as possible, and it functions as a noise gate.
　図２に戻り、エキスパンダ１１２は、後述するエキスパンダ制御部１４１の制御に従ってこのようなエキスパンダ処理を行う。 Returning to FIG. 2, the expander 112 performs such an expander process in accordance with the control of the expander control unit 141 described later.
　増幅部１１３は、エキスパンダ１１２から出力されるオーディオ信号を任意の増幅率で増幅する。この増幅率は任意であり、可変であってもよい。その場合、増幅部１１３は、例えばユーザや制御部等により指定される増幅率でオーディオ信号を増幅する。すなわち、増幅部１１３は、オーディオ信号を出力する際の音量（ボリューム）調整機能を有する。例えばユーザ等がこの増幅率を更新することにより、オーディオ信号を出力する際の音量を大きくしたり、小さくしたりすることができる。 The amplification unit 113 amplifies the audio signal output from the expander 112 at an arbitrary amplification factor. This amplification factor is arbitrary and may be variable. In that case, the amplifying unit 113 amplifies the audio signal at an amplification factor specified by, for example, the user or the control unit. That is, the amplification unit 113 has a volume adjustment function when outputting an audio signal. For example, when the user or the like updates the amplification factor, the volume when outputting the audio signal can be increased or decreased.
　出力部１１４は、増幅部１１３により適宜増幅されたオーディオ信号の出力に関する処理を行う。例えば、出力部１１４は、オーディオ信号をD/A変換したり、任意のフィルタ処理を施したりする。 The output unit 114 performs processing related to the output of the audio signal appropriately amplified by the amplification unit 113. For example, the output unit 114 performs D / A conversion on the audio signal or performs arbitrary filter processing.
　出力デバイス１１５は、出力部１１４より出力されるオーディオ信号（アナログ信号）を音声として出力する。例えば、出力デバイス１１５は、スピーカ、ヘッドホン、イヤホン等の音声出力機能を有するデバイスにより構成される。 The output device 115 outputs the audio signal (analog signal) output from the output unit 114 as sound. For example, the output device 115 is configured by a device having a sound output function, such as a speaker, headphones, and earphones.
　再生装置１００に入力されたオーディオ信号は、遅延処理部１１１に供給されるとともに、検出部１１６にも供給される。検出部１１６は、そのオーディオ信号から所望の情報を検出する。図２に示されるように、検出部１１６は、ピークレベル検出部１２１および実効値検出部１２２を有する。 The audio signal input to the playback device 100 is supplied to the delay processing unit 111 and also to the detection unit 116. The detection unit 116 detects desired information from the audio signal. As illustrated in FIG. 2, the detection unit 116 includes a peak level detection unit 121 and an effective value detection unit 122.
　ピークレベル検出部１２１は、入力されたオーディオ信号のピーク値を検出する。なお、このピーク値の検出方法は任意である。ピークレベル検出部１２１は、検出したピーク値を波高率算出部１３１に供給する。その際、ピーク値とともにオーディオ信号も波高率算出部１３１に供給されるようにしてもよい。 The peak level detector 121 detects the peak value of the input audio signal. Note that this peak value detection method is arbitrary. The peak level detector 121 supplies the detected peak value to the crest factor calculator 131. At that time, the audio signal may be supplied to the crest factor calculator 131 together with the peak value.
　実効値検出部１２２は、入力されたオーディオ信号の実効値を検出する。実効値Veは、例えば以下の式（１）のように、（（信号値の２乗の合計）／（信号のサンプル数））の平方根により算出される。 The effective value detection unit 122 detects the effective value of the input audio signal. The effective value Ve is calculated by the square root of ((total sum of squares of signal values) / (number of signal samples)), for example, as in the following equation (1).
Figure JPOXMLDOC01-appb-M000001
 　・・・（１）
Figure JPOXMLDOC01-appb-M000001
 ... (1)
　なお、式（１）において、Ｎはサンプル数、V(n)は信号値をそれぞれ示す。式（１）に示されるように、一般的には、オーディオ信号の複数のサンプル値を用いて検出される。上述の実効値平均レベルは実効値の平均値であるが、実効値の検出区間を実効値平均レベルの区間と同一にすれば（つまり実効値と実効値平均レベルが１対１の場合）、実効値と実効値平均レベルは同義となる。したがって、以下においては、特にこれらの違いを説明しない限り、実効値と実効値平均レベルは同義であるとする。実効値検出部１２２は、検出した実効値を波高率算出部１３１に供給する。その際、実効値とともにオーディオ信号も波高率算出部１３１に供給されるようにしてもよい。 In Equation (1), N represents the number of samples and V (n) represents the signal value. As shown in Expression (1), generally, detection is performed using a plurality of sample values of an audio signal. The above-mentioned effective value average level is the average value of the effective value, but if the effective value detection interval is the same as the effective value average level interval (that is, the effective value and the effective value average level are 1: 1), RMS value and RMS average level are synonymous. Therefore, in the following description, the effective value and the effective value average level are synonymous unless otherwise described. The effective value detection unit 122 supplies the detected effective value to the crest factor calculation unit 131. At that time, the audio signal may be supplied to the crest factor calculator 131 together with the effective value.
　また、検出部１１６が検出する情報は任意であり、検出部１１６がピーク値と実効値以外の情報を検出するようにしてもよい。 Further, the information detected by the detection unit 116 is arbitrary, and the detection unit 116 may detect information other than the peak value and the effective value.
　パラメータ算出部１１７は、検出部１１６により検出された情報に基づいて所望のパラメータを算出する。図２に示されるように、パラメータ算出部１１７は、波高率算出部１３１、エキスパンダパラメータ算出部１３２、およびメモリ１３３を有する。 The parameter calculation unit 117 calculates a desired parameter based on the information detected by the detection unit 116. As shown in FIG. 2, the parameter calculation unit 117 includes a crest factor calculation unit 131, an expander parameter calculation unit 132, and a memory 133.
　波高率算出部１３１は、ピークレベル検出部１２１により検出されたピーク値と、実効値検出部１２２により検出された実効値とに基づいて、オーディオ信号の波高率（クレストファクタ）を算出する。波高率は例えば以下の式（２）のように算出される。 The crest factor calculation unit 131 calculates the crest factor (crest factor) of the audio signal based on the peak value detected by the peak level detection unit 121 and the effective value detected by the effective value detection unit 122. The crest factor is calculated, for example, as in the following formula (2).
　波高率＝ピーク値／実効値
　・・・（２） Crest factor = peak value / effective value (2)
　つまり、log換算[dB]では、波高率はピーク値と実効値の差分により算出される。例えば、フルスケールの単一周波数の正弦波波形では、ピーク値は±1.0（0dB）、実効値平均レベルは1.0/√2≒0.707(-3dB)となり、波高率は、1.0/（1.0/√2）=√2≒1.414(3dB)となる。波高率算出部１３１は、算出した波高率とピーク値をエキスパンダパラメータ算出部１３２に供給する。その際、それらの値とともに、オーディオ信号や実効値もエキスパンダパラメータ算出部１３２に供給されるようにしてもよい。 That is, in log conversion [dB], the crest factor is calculated by the difference between the peak value and the effective value. For example, in a full-scale single-frequency sine wave waveform, the peak value is ± 1.0 (0 dB), the effective value average level is 1.0 / √2 ≒ 0.707 (-3 dB), and the crest factor is 1.0 / (1.0 / √ 2) = √2 ≒ 1.414 (3dB) The crest factor calculator 131 supplies the calculated crest factor and the peak value to the expander parameter calculator 132. At this time, an audio signal and an effective value may be supplied to the expander parameter calculation unit 132 together with those values.
　エキスパンダパラメータ算出部１３２は、エキスパンダ１１２により行われるエキスパンダ処理に用いられるパラメータを算出する。例えば、エキスパンダパラメータ算出部１３２は、波高率算出部１３１により算出された波高率に基づいてパラメータを設定する。例えば、エキスパンダパラメータ算出部１３２は、エキスパンダ処理の閾値（threshold）とレシオ（ratio）とを算出する。上述したようにこのレシオは、エキスパンダ処理の閾値より小さい信号値に対するレシオである。 The expander parameter calculation unit 132 calculates parameters used for the expander processing performed by the expander 112. For example, the expander parameter calculation unit 132 sets parameters based on the crest factor calculated by the crest factor calculation unit 131. For example, the expander parameter calculation unit 132 calculates a threshold value (threshold) and a ratio (ratio) of the expander process. As described above, this ratio is a ratio to a signal value that is smaller than the threshold value of the expander process.
　例えば、エキスパンダパラメータ算出部１３２は、ピーク値に基づいて閾値を算出し、波高率に基づいてレシオを算出する。例えば、エキスパンダパラメータ算出部１３２は、ピーク値を閾値とする。その場合、ピーク値以下（つまりオーディオ信号の全て）に対してエキスパンダ処理が行われる。 For example, the expander parameter calculation unit 132 calculates a threshold value based on the peak value, and calculates a ratio based on the crest factor. For example, the expander parameter calculation unit 132 sets the peak value as a threshold value. In that case, the expander processing is performed for the peak value or less (that is, all of the audio signals).
　また、例えば、エキスパンダパラメータ算出部１３２は、波高率が小さい場合、レシオの値を、波高率が大きい場合よりも大きな値に設定する。例えば、エキスパンダパラメータ算出部１３２は、波高率が6dB未満の場合入出力比が2:1になるようにレシオを算出する。 Also, for example, when the crest factor is small, the expander parameter calculation unit 132 sets the ratio value to a larger value than when the crest factor is large. For example, the expander parameter calculation unit 132 calculates the ratio so that the input / output ratio is 2: 1 when the crest factor is less than 6 dB.
　また、エキスパンダパラメータ算出部１３２は、エキスパンダ処理の時定数を算出する。例えば、メモリ１３３に時定数の候補が複数記憶されており、エキスパンダパラメータ算出部１３２がその候補の中から所望の値を選択するようにしてもよい。例えば、エキスパンダパラメータ算出部１３２が、オーディオ信号を解析し、その解析結果に基づいてメモリ１３３に記憶されている候補の中から最適な候補を選択するようにしてもよい。また、エキスパンダパラメータ算出部１３２が、オーディオ信号を解析し、その解析結果に基づいて最適な時定数を算出するようにしてもよい。 Also, the expander parameter calculation unit 132 calculates the time constant of the expander process. For example, a plurality of time constant candidates may be stored in the memory 133, and the expander parameter calculation unit 132 may select a desired value from the candidates. For example, the expander parameter calculation unit 132 may analyze the audio signal and select an optimum candidate from the candidates stored in the memory 133 based on the analysis result. Further, the expander parameter calculation unit 132 may analyze the audio signal and calculate an optimal time constant based on the analysis result.
　もちろん、エキスパンダパラメータ算出部１３２が算出するパラメータは任意であり、エキスパンダパラメータ算出部１３２が上述した例以外のパラメータを算出するようにしてもよい。エキスパンダパラメータ算出部１３２は、閾値、レシオ、時定数等、算出したパラメータをエキスパンダ制御部１４１に供給する。その際、波高率、ピーク値、実効値、オーディオ信号等の、その他の情報もそれらのパラメータとともにエキスパンダ制御部１４１に供給されるようにしてもよい。 Of course, the parameters calculated by the expander parameter calculation unit 132 are arbitrary, and the expander parameter calculation unit 132 may calculate parameters other than those described above. The expander parameter calculation unit 132 supplies the calculated parameters such as a threshold value, a ratio, and a time constant to the expander control unit 141. At that time, other information such as a crest factor, a peak value, an effective value, and an audio signal may be supplied to the expander control unit 141 together with these parameters.
　メモリ１３３は、半導体メモリ等、任意の記憶媒体を有し、エキスパンダ処理の時定数の候補を記憶し、必要に応じてそれをエキスパンダパラメータ算出部１３２に供給する。なお、メモリ１３３が記憶する情報は任意であり、時定数以外の情報を記憶するようにしてもよい。 The memory 133 has an arbitrary storage medium such as a semiconductor memory, stores a candidate for the time constant of the expander process, and supplies it to the expander parameter calculation unit 132 as necessary. Note that the information stored in the memory 133 is arbitrary, and information other than the time constant may be stored.
　パラメータ算出部１１７が算出するパラメータは任意であり、パラメータ算出部１１７が上述した例以外のパラメータを算出するようにしてもよい。 The parameter calculated by the parameter calculation unit 117 is arbitrary, and the parameter calculation unit 117 may calculate a parameter other than the example described above.
　制御部１１８は、制御に関する処理を行う。図２に示されるように、制御部１１８は、エキスパンダ制御部１４１を有する。エキスパンダ制御部１４１は、エキスパンダ１１２によるエキスパンダ処理の実行を制御する。その際、エキスパンダ制御部１４１が、エキスパンダパラメータ算出部１３２から供給される情報に基づいてエキスパンダ処理の実行を制御するようにしてもよい。例えば、エキスパンダ制御部１４１が、ピーク値と波高率に基づいてエキスパンダ処理の実行を制御する。例えば、波高率が所定の閾値よりも小さい場合に、エキスパンダ処理が実行されるようにしてもよい。また、例えば、ピーク値が所定の閾値よりも大きく、かつ、波高率が所定の閾値よりも小さい場合に、エキスパンダ処理が実行されるようにしてもよい。 The control unit 118 performs processing related to control. As illustrated in FIG. 2, the control unit 118 includes an expander control unit 141. The expander control unit 141 controls execution of the expander process by the expander 112. At that time, the expander control unit 141 may control the execution of the expander process based on the information supplied from the expander parameter calculation unit 132. For example, the expander control unit 141 controls the execution of the expander process based on the peak value and the crest factor. For example, the expander process may be executed when the crest factor is smaller than a predetermined threshold. In addition, for example, when the peak value is larger than a predetermined threshold and the crest factor is smaller than the predetermined threshold, the expander process may be executed.
　もちろん、エキスパンダ処理実行の条件は任意であり、この例に限定されない。また、エキスパンダ処理の実行の制御に、ピーク値と波高率以外の情報が用いられるようにしてもよい。 Of course, the conditions for executing the expander process are arbitrary and are not limited to this example. Further, information other than the peak value and the crest factor may be used for controlling the execution of the expander process.
　また、エキスパンダ制御部１４１は、エキスパンダ処理を実行させる場合、そのエキスパンダ処理に用いられるパラメータをエキスパンダ１１２にセットする。例えば、エキスパンダ制御部１４１は、閾値、レシオ、時定数をエキスパンダ１１２にセットする。もちろん、セットされるパラメータは任意であり、これら以外のパラメータがセットされるようにしてもよい。 Further, when the expander control unit 141 executes the expander process, the expander control unit 141 sets a parameter used for the expander process in the expander 112. For example, the expander control unit 141 sets a threshold value, a ratio, and a time constant in the expander 112. Of course, the parameters to be set are arbitrary, and other parameters may be set.
　エキスパンダ１１２は、このエキスパンダ制御部１４１による実行制御に従って、エキスパンダ制御部１４１によりセットされたパラメータを用いてエキスパンダ処理を行う。 The expander 112 performs an expander process using the parameters set by the expander control unit 141 according to the execution control by the expander control unit 141.
　　＜事前解析処理の流れ＞
　再生装置１００は、上述のように、入力されたオーディオ信号を出力する前にそのオーディオ信号の解析（事前解析）を行い、その解析結果に基づいてオーディオ信号に対するエキスパンダ処理を制御する。この事前解析をどのようなデータ単位（例えば再生時間単位）で行うかは任意である。 <Flow of pre-analysis processing>
As described above, the playback apparatus 100 analyzes (pre-analyzes) the audio signal before outputting the input audio signal, and controls the expander processing for the audio signal based on the analysis result. It is arbitrary in what data unit (for example, reproduction time unit) this preliminary analysis is performed.
　例えば楽曲のように、所定の再生時間のオーディオ信号がファイル化され、そのファイル毎に再生が行われるような場合が考えらえるが、例えば複数の楽曲が連続して再生される等、複数のファイルのオーディオ信号が例えばフェードインフェードアウト等で連続して再生され、オーディオ信号をファイル毎に分けることが困難な場合も考えられる。さらに、例えばライブ音声等のように、オーディオ信号が継続して終端が未決定であるような場合も考えられる。 For example, there may be a case where an audio signal having a predetermined playback time is filed and played back for each file, such as a song. For example, a plurality of songs may be played back continuously. There may be a case where the audio signal of the file is continuously reproduced by, for example, fade-in and fade-out, and it is difficult to divide the audio signal for each file. Further, there may be a case where the audio signal continues and the end is not determined, such as live audio.
　したがって、オーディオ信号の事前解析は、ファイル毎に行う（１ファイル分の事前解析をした後に出力する）ようにしてもよいし、所定の再生時間毎に行う（各区間の事前解析と出力を繰り返す）ようにしてもよい。もちろん、複数ファイルをまとめて事前解析するようにしてもよい。つまり、事前解析は、ファイルや再生時間等、任意のデータ単位で行うことができる。 Accordingly, the audio signal pre-analysis may be performed for each file (output after performing pre-analysis for one file) or at predetermined playback times (repeating pre-analysis and output for each section). You may do it. Of course, a plurality of files may be analyzed in advance. That is, the pre-analysis can be performed in arbitrary data units such as a file and a reproduction time.
　ただし、本実施の形態においては、いずれの場合であっても、オーディオ信号の事前解析と出力は、その処理単位毎に閉じているものとする。つまり、事前解析結果は、その事前解析を行った区間内のエキスパンダ処理の制御にのみ用いられる（他の区間のエキスパンダ処理の制御には用いられない）ものとする。 However, in this embodiment, in any case, the pre-analysis and output of the audio signal are closed for each processing unit. That is, the pre-analysis result is used only for controlling the expander process in the section where the pre-analysis is performed (not used for controlling the expander process in other sections).
　再生装置１００は、事前解析処理を実行することにより、その事前解析を行う。この事前解析処理の流れの例を、図４のフローチャートを参照して説明する。 The playback device 100 performs a pre-analysis by executing a pre-analysis process. An example of the flow of this pre-analysis process will be described with reference to the flowchart of FIG.
　事前解析処理が開始されると、ピークレベル検出部１２１は、ステップＳ１０１において、入力されたオーディオ信号のピーク値を検出する。例えば、オーディオ信号が楽曲のデータである場合、その曲中のピーク値が検出される。 When the pre-analysis process is started, the peak level detector 121 detects the peak value of the input audio signal in step S101. For example, when the audio signal is music data, the peak value in the music is detected.
　ステップＳ１０２において、実効値検出部１２２は、入力されたオーディオ信号の実効値を検出する。例えば、オーディオ信号が楽曲のデータである場合、その曲中の実効値が検出される。 In step S102, the effective value detection unit 122 detects the effective value of the input audio signal. For example, when the audio signal is music data, an effective value in the music is detected.
　ステップＳ１０３において、波高率算出部１３１は、ステップＳ１０１において検出されたピーク値と、ステップＳ１０２において検出された実効値とに基づいて、オーディオ信号の波高率を算出する。波高率の算出方法は任意であるが、例えば上述の式（２）のように算出される。 In step S103, the crest factor calculation unit 131 calculates the crest factor of the audio signal based on the peak value detected in step S101 and the effective value detected in step S102. Although the calculation method of the crest factor is arbitrary, it is calculated as, for example, the above-described equation (2).
　ステップＳ１０４において、エキスパンダ制御部１４１は、ピーク値がエキスパンダ処理ON用の閾値を越えているか否かを判定する。ピーク値がそのエキスパンダ処理ON用の閾値よりも大きいと判定された場合、処理はステップＳ１０５に進む。 In step S104, the expander control unit 141 determines whether or not the peak value exceeds the expander process ON threshold. If it is determined that the peak value is greater than the expander process ON threshold, the process proceeds to step S105.
　ステップＳ１０５において、エキスパンダ制御部１４１は、ステップＳ１０３において算出された波高率が所定の波高率用の閾値より小さいか否かを判定する。波高率が波高率用の閾値より小さいと判定された場合、処理はステップＳ１０６に進む。この場合、オーディオ信号のピーク値が大きく、かつ、波高率が小さいので、その実効値平均レベルは大きい。したがって、エキスパンダ制御部１４１は、オーディオ信号に対してエキスパンダ処理を実行するように制御する。 In step S105, the expander control unit 141 determines whether or not the crest factor calculated in step S103 is smaller than a predetermined crest factor threshold. When it is determined that the crest factor is smaller than the crest factor threshold, the process proceeds to step S106. In this case, since the peak value of the audio signal is large and the crest factor is small, the effective value average level is large. Therefore, the expander control unit 141 performs control so that the expander process is performed on the audio signal.
　ステップＳ１０６において、エキスパンダパラメータ算出部１３２は、ステップＳ１０１において検出されたピーク値と、ステップＳ１０３において算出された波高率とに基づいて、エキスパンダ処理用の閾値（スレッショルド）とレシオ（Ratio）とを算出する。エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理ONを決定し、算出されたエキスパンダ処理用の閾値とレシオとをエキスパンダ１１２にセットする。ステップＳ１０６の処理が終了すると、事前解析処理が終了する。 In step S106, the expander parameter calculation unit 132 calculates the expander processing threshold and ratio based on the peak value detected in step S101 and the crest factor calculated in step S103. Is calculated. The expander control unit 141 controls the expander 112 to determine that the expander process is ON, and sets the calculated threshold value and ratio for the expander process in the expander 112. When the process of step S106 ends, the pre-analysis process ends.
　また、ステップＳ１０４において、ピーク値がエキスパンダ処理ON用の閾値を越えていないと判定された場合、処理はステップＳ１０７に進む。また、ステップＳ１０５において、波高率が波高率用の閾値以上であると判定された場合、処理はステップＳ１０７に進む。この場合、オーディオ信号のピーク値が小さいか、または、ピーク値が大きくても波高率が小さいので、その実効値平均レベルは大きくない。したがって、エキスパンダ制御部１４１は、オーディオ信号に対してエキスパンダ処理を実行しないように制御する。 If it is determined in step S104 that the peak value does not exceed the expander process ON threshold, the process proceeds to step S107. If it is determined in step S105 that the crest factor is equal to or higher than the crest factor threshold, the process proceeds to step S107. In this case, since the peak value of the audio signal is small or the peak value is small even if the peak value is large, the effective value average level is not large. Therefore, the expander control unit 141 performs control so that the expander process is not performed on the audio signal.
　ステップＳ１０７において、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理OFFを決定する。ステップＳ１０７の処理が終了すると、事前解析処理が終了する。 In step S107, the expander control unit 141 controls the expander 112 to determine the expander processing OFF. When the process of step S107 ends, the pre-analysis process ends.
　　＜エキスパンダ制御処理の流れ＞
　再生装置１００は、エキスパンダ制御処理を行うことにより、エキスパンダ処理を制御する。図５のフローチャートを参照して、エキスパンダ制御処理の流れの例を説明する。エキスパンダ処理が開始されると、ステップＳ１２１において、エキスパンダ制御部１４１は、エキスパンダ処理ONであるか否かを判定する。エキスパンダ処理ONであると判定された場合、処理はステップＳ１２２に進む。 <Expander control process flow>
The playback device 100 controls the expander process by performing the expander control process. An example of the flow of the expander control process will be described with reference to the flowchart of FIG. When the expander process is started, in step S121, the expander control unit 141 determines whether or not the expander process is ON. If it is determined that the expander process is ON, the process proceeds to step S122.
　ステップＳ１２２において、エキスパンダ制御部１４１は、エキスパンダ１１２を制御し、エキスパンダ処理を実行させる。エキスパンダ１１２は、その制御に従ってオーディオ信号に対してエキスパンダ処理を行う。ステップＳ１２２の処理が終了するとエキスパンダ制御処理が終了する。また、ステップＳ１２１において、エキスパンダ処理ONでないと判定された場合、ステップＳ１２２の処理が省略されてエキスパンダ制御処理が終了する。 In step S122, the expander control unit 141 controls the expander 112 to execute the expander process. The expander 112 performs an expander process on the audio signal according to the control. When the process of step S122 ends, the expander control process ends. If it is determined in step S121 that the expander process is not ON, the process in step S122 is omitted and the expander control process ends.
　　＜エキスパンダ処理結果＞
　エキスパンダ処理によるピーク値の変化の例を図６に示す。図６のＡは、エキスパンダ処理を行う前のオーディオ信号のピーク値の例を示し、図６のＢは、エキスパンダ処理を行った後のオーディオ信号のピーク値の例を示す。また、エキスパンダ処理による実効値の変化の例を図７に示す。図７のＡは、エキスパンダ処理を行う前のオーディオ信号の実効値の例を示し、図７のＢは、エキスパンダ処理を行った後のオーディオ信号の実効値の例を示す。図６および図７に示されるように、エキスパンダ処理によりピーク値はほぼ変化しないが、実効値が下がるので波高率は大きくなる。 <Expander processing result>
An example of a change in peak value due to the expander process is shown in FIG. 6A shows an example of the peak value of the audio signal before the expander process, and FIG. 6B shows an example of the peak value of the audio signal after the expander process. An example of the change in effective value due to the expander process is shown in FIG. 7A shows an example of the effective value of the audio signal before the expander process, and FIG. 7B shows an example of the effective value of the audio signal after the expander process. As shown in FIGS. 6 and 7, the peak value is not substantially changed by the expander process, but the effective value is lowered, so that the crest factor is increased.
　このように、再生装置１００は、全ての音量を小さくすることなく、実効値平均レベルを低減させることができるので、聴きづらくなったり、音量変化による違和感をユーザに与えたりすることなく、ユーザの負荷の増大を抑制することができる。つまり、再生装置１００は、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。また、再生装置１００は、上述のように、処理前の波高率に応じてエキスパンダ処理の実行を制御するので、不要なエキスパンダ処理を抑制することができ、不要なレンジの拡大を抑制し、ユーザに違和感をより感じさせないようにすることができる。すなわち、再生装置１００は、主観音質の低減をより抑制することができる。 In this way, the playback device 100 can reduce the effective value average level without reducing all the volumes, so that it is difficult to listen to the user and does not give the user a sense of discomfort due to the volume change. An increase in load can be suppressed. That is, the playback device 100 can suppress an increase in the user's load while suppressing a decrease in subjective sound quality. Further, as described above, the playback device 100 controls the execution of the expander process according to the crest factor before the process, so that the unnecessary expander process can be suppressed and the expansion of the unnecessary range can be suppressed. It is possible to prevent the user from feeling more uncomfortable. That is, the playback device 100 can further suppress the reduction in subjective sound quality.
　＜３．第２の実施の形態＞
　　＜時間間隔毎の制御＞
　ピーク値や実効値の検出、波高率の算出を所定の時間間隔毎に行うようにしてもよい。そして、その時間間隔毎に、算出された波高率に基づいてエキスパンダ処理の実行制御やパラメータの算出が行われるようにしてもよい。例えば、処理対象のオーディオ信号が動画像に対応する音声信号である場合、その時間間隔を、その動画像のフレームレートに応じた長さとしてもよい。例えば、動画像のフレーム毎に、エキスパンダ処理の実行制御やパラメータの算出が行われるようにしてもよい。例えば、映像が２４fps（frame per second）であり、音声のサンプリング周波数が４８kHzであるとすると、画像１フレーム当たりのサンプル数は２０００サンプルである。つまり、この場合、動画像のフレーム毎にエキスパンダ処理の実行制御やパラメータの算出が行われるようにすると、オーディオ信号の２０００サンプル毎にエキスパンダ処理の実行制御やパラメータの算出が行われることになる。 <3. Second Embodiment>
<Control every time interval>
Detection of the peak value and effective value, and calculation of the crest factor may be performed at predetermined time intervals. Then, for each time interval, execution control of the expander process and parameter calculation may be performed based on the calculated crest factor. For example, when the audio signal to be processed is an audio signal corresponding to a moving image, the time interval may be set to a length corresponding to the frame rate of the moving image. For example, execution control of the expander processing and parameter calculation may be performed for each frame of the moving image. For example, if the video is 24 fps (frame per second) and the audio sampling frequency is 48 kHz, the number of samples per image frame is 2000 samples. That is, in this case, if the execution control of the expander process and the parameter calculation are performed for each frame of the moving image, the execution control of the expander process and the parameter calculation are performed for every 2000 samples of the audio signal. Become.
　なお、この時間間隔、すなわち、ピーク値や実効値等の検出、波高率の算出、エキスパンダ処理の実行制御やパラメータの算出等を行う時間間隔（区間とも称する）は、任意であり、動画像のフレームレートに一致していなくてもよい。例えば、図８のＡに示される区間２０１乃至区間２０４のように、互いに重ならないように各区間を設定するようにしてもよいし、図８のＢに示される区間２１１乃至区間２１４のように、区間の一部が互いに重なるように（例えば半分ずつオーバーラップするように）してもよい。 Note that this time interval, that is, a time interval (also referred to as a section) for performing detection of a peak value, an effective value, etc., calculation of a crest factor, execution control of an expander process, calculation of a parameter, and the like is arbitrary. It does not have to match the frame rate. For example, each section may be set so as not to overlap each other as in section 201 to section 204 shown in FIG. 8A, or like section 211 to section 214 shown in FIG. 8B. The sections may be overlapped with each other (for example, overlap each other by half).
　例えば、図８のＡのように隣接する区間同士が互いに重ならない場合、ピーク値や実効値等の検出を区間毎に独立に設定すると、ピーク値や実効値の区間同士の相関性が低く、値が急激に変化する可能性があった。これらの値が急激に変化すると、波高率が急激に変化することになり、エキスパンダ処理のパラメータが急激に変化することになる可能性がある。つまり、オーディオ信号が不自然に（急激に）変化して、ユーザに違和感を与えてしまう可能性がある。 For example, when adjacent sections do not overlap each other as shown in FIG. 8A, if the detection of the peak value or the effective value is set independently for each section, the correlation between the peak value or effective value sections is low, The value could change abruptly. If these values change abruptly, the crest factor changes abruptly, and the expander processing parameters may change abruptly. That is, there is a possibility that the audio signal changes unnaturally (abruptly) and gives the user a sense of discomfort.
　これに対して図８のＢの場合、隣接する区間の一部が互いに重なっているので、各区間において検出されるピーク値や実効値の相関性が増大し、急激な変化が抑制される。したがって、波高率やエキスパンダ処理のパラメータの急激な変化も抑制され、ユーザに与える違和感を抑制することができる。 On the other hand, in the case of B in FIG. 8, since the adjacent sections partially overlap each other, the correlation between the peak value and the effective value detected in each section increases, and a rapid change is suppressed. Therefore, a sudden change in the crest factor and the expander processing parameter is also suppressed, and the uncomfortable feeling given to the user can be suppressed.
　また、オーディオ信号から検出される情報（例えば、ピーク値等）は、現在処理対象の区間（カレント区間）において検出された情報（ピーク値等）が所定の条件を満たさない限り、過去の区間の値を継承するようにしてもよい。この条件は任意である。例えば、カレント区間のピーク値が過去の時定数付きのピーク値よりも大きい場合にピーク値が更新されるようにしてもよい。また、例えば、実効値として、全区間の実効値の平均値を保持し、その平均値を用いてエキスパンダ処理のパラメータが算出されるようにしてもよい。このようにすることにより、エキスパンダ処理のパラメータの急激な変化が抑制され、ユーザに与える違和感を抑制することができる。 Further, information detected from the audio signal (for example, a peak value) is a past section unless information (peak value, etc.) detected in the current processing target section (current section) satisfies a predetermined condition. You may make it inherit a value. This condition is arbitrary. For example, the peak value may be updated when the peak value in the current section is larger than the past peak value with a time constant. Further, for example, as an effective value, an average value of effective values of all the sections may be held, and an expander processing parameter may be calculated using the average value. By doing in this way, the rapid change of the parameter of an expander process is suppressed, and the discomfort given to a user can be suppressed.
　また、例えば、エキスパンダ処理の実行をOFFからONにする際にピーク値と比較する閾値と、エキスパンダ処理の実行をONからOFFにする際にピーク値と比較する閾値とが互いに異なるようにしてもよい。例えば、エキスパンダ処理の実行をOFFからONにする用の閾値をピーク値が越えた場合、ピーク値が、その閾値よりも小さな、エキスパンダ処理の実行をONからOFFにする用の閾値より小さくなるまで、エキスパンダ処理が実行されるようにしてもよい。例えば、エキスパンダ処理の実行をOFFからONにする用の閾値を-2dBとし、エキスパンダ処理の実行をONからOFFにする用の閾値を-8dBとしてもよい。このようにすることにより、ピーク値が閾値近辺で変動することにより、パラメータの更新頻度が増大することを抑制することができ、パラメータの算出をより安定化させることができる。 Also, for example, when the execution of the expander process is switched from OFF to ON, the threshold value to be compared with the peak value is different from the threshold value to be compared with the peak value when the execution of the expander process is switched from ON to OFF. May be. For example, if the peak value exceeds the threshold value for turning off the execution of the expander process, the peak value is smaller than the threshold value, and smaller than the threshold value for turning off the execution of the expander process. Until this happens, the expander process may be executed. For example, the threshold for turning the execution of the expander process from OFF to ON may be set to -2 dB, and the threshold for turning the execution of the expander process from ON to OFF may be set to -8 dB. By doing in this way, it can suppress that the update frequency of a parameter increases because a peak value fluctuates in the vicinity of a threshold value, and can further stabilize calculation of a parameter.
　　＜エキスパンダ制御処理の流れ＞
　この場合、再生装置１００は、エキスパンダ制御処理を実行することにより、エキスパンダ処理を制御する。このエキスパンダ制御処理の流れの例を、図９乃至図１１のフローチャートを参照して説明する。 <Expander control process flow>
In this case, the reproducing device 100 controls the expander process by executing the expander control process. An example of the flow of the expander control process will be described with reference to the flowcharts of FIGS.
　図９において、エキスパンダ制御処理が開始されると、ピークレベル検出部１２１は、ステップＳ２０１において、オーディオ信号のピーク値を検出し、そのピーク値を保持している過去の区間において検出したピーク値（前時定数付きピーク値とも称する）と比較して、大きければ、前時定数付きピーク値を、今回検出されたピーク値に更新する。 In FIG. 9, when the expander control process is started, the peak level detection unit 121 detects the peak value of the audio signal in step S201, and the peak value detected in the past section holding the peak value. If it is larger than (also referred to as a peak value with a previous time constant), the peak value with a previous time constant is updated to the peak value detected this time.
　ステップＳ２０２において、実効値検出部１２２は、実効値を検出し、その実効値を用いて前実効値のフレーム平均を更新する（つまり全区間の平均を求める）。 In step S202, the effective value detection unit 122 detects the effective value, and updates the frame average of the previous effective value using the effective value (that is, obtains the average of all the intervals).
　ステップＳ２０３において、波高率算出部１３１は、時定数付きピーク値と実効値のフレーム平均とを用いて波高率を算出する。 In step S203, the crest factor calculation unit 131 calculates the crest factor using the peak value with time constant and the frame average of the effective values.
　ステップＳ２０４において、エキスパンダ制御部１４１は、ピーク値がエキスパンダ処理OFFからONへの閾値を越えたか否かを判定する。ピーク値がエキスパンダ処理OFFからONへの閾値を越えたと判定された場合、処理は図１０のステップＳ２１１に進む。 In step S204, the expander control unit 141 determines whether or not the peak value exceeds the threshold value from the expander process OFF to the ON. If it is determined that the peak value has exceeded the expander process OFF to ON threshold, the process proceeds to step S211 in FIG.
　図１０のステップＳ２１１において、エキスパンダ制御部１４１は、実効値のフレーム平均が閾値を越えているか否かを判定する。越えていると判定された場合、処理はステップＳ２１２に進む。 In step S211 of FIG. 10, the expander control unit 141 determines whether the frame average of the effective values exceeds the threshold value. If it is determined that the number has exceeded, the process proceeds to step S212.
　ステップＳ２１２において、エキスパンダ制御部１４１は、現在のエキスパンダ処理の設定がONである（つまり、エキスパンダ処理を実行させる設定である）か否かを判定する。現在のエキスパンダ処理の設定がOFFである（つまり、エキスパンダ処理を実行させない設定である）と判定された場合、処理はステップＳ２１３に進む。 In step S212, the expander control unit 141 determines whether or not the current expander process setting is ON (that is, the expander process is executed). If it is determined that the current expander process setting is OFF (that is, the expander process is not executed), the process proceeds to step S213.
　ステップＳ２１３において、エキスパンダパラメータ算出部１３２は、エキスパンダ処理の閾値とレシオを算出する。エキスパンダ制御部１４１は、その算出された閾値とレシオをエキスパンダ１１２にセットする。 In step S213, the expander parameter calculator 132 calculates the expander processing threshold and ratio. The expander control unit 141 sets the calculated threshold value and ratio in the expander 112.
　ステップＳ２１４において、エキスパンダ制御部１４１は、エキスパンダ処理の設定をOFFからONにし、エキスパンダ１１２にエキスパンダ処理を実行させるようにする。ステップＳ２１４の処理が終了すると処理はステップＳ２１６に進む。 In step S214, the expander control unit 141 changes the setting of the expander process from OFF to ON, and causes the expander 112 to execute the expander process. When the process of step S214 ends, the process proceeds to step S216.
　また、ステップＳ２１１において、実効値のフレーム平均が閾値を越えていないと判定された場合、処理はステップＳ２１５に進む。また、ステップＳ２１２において、エキスパンダ処理の設定がONであると判定された場合、処理はステップＳ２１５に進む。 If it is determined in step S211 that the average frame value of the effective value does not exceed the threshold value, the process proceeds to step S215. If it is determined in step S212 that the expander process setting is ON, the process proceeds to step S215.
　ステップＳ２１５において、エキスパンダパラメータ算出部１３２は、カレントフレームのピーク値が前時定数付きピーク値（すなわち、過去のピーク値）より大きいか、または、カレントフレームの波高率が前波高率（すなわち、過去の波高率）よりも小さい場合のみ、エキスパンダ処理の閾値とレシオを算出する。エキスパンダ制御部１４１は、その算出された閾値とレシオをエキスパンダ１１２に供給し、セットする。 In step S215, the expander parameter calculation unit 132 determines that the peak value of the current frame is greater than the peak value with the previous time constant (that is, the past peak value), or the crest factor of the current frame is the preceding crest factor (that is, Only when it is smaller than the past crest factor, the threshold value and ratio of the expander processing are calculated. The expander control unit 141 supplies the calculated threshold value and ratio to the expander 112 and sets them.
　ステップＳ２１６において、エキスパンダ制御部１４１は、エキスパンダ１１２を制御し、エキスパンダ処理を行わせる。エキスパンダ１１２は、そのエキスパンダ制御部１４１の制御に従って、オーディオ信号に対するエキスパンダ処理を実行する。 In step S216, the expander control unit 141 controls the expander 112 to perform the expander process. The expander 112 executes expander processing on the audio signal according to the control of the expander control unit 141.
　ステップＳ２１６の処理が終了すると、エキスパンダ制御処理が終了する。 When the process of step S216 ends, the expander control process ends.
　また、図９のステップＳ２０４において、ピーク値がエキスパンダ処理OFFからONへの閾値を越えていないと判定された場合、処理は図１１のステップＳ２２１に進む。 If it is determined in step S204 in FIG. 9 that the peak value does not exceed the threshold value from the expander process OFF to ON, the process proceeds to step S221 in FIG.
　図１１のステップＳ２２１において、エキスパンダ制御部１４１は、現在のエキスパンダ処理の設定がONである（つまり、エキスパンダ処理を実行させる設定である）か否かを判定する。現在のエキスパンダ処理の設定がONであると判定された場合、処理はステップＳ２２２に進む。 In step S221 in FIG. 11, the expander control unit 141 determines whether the current expander process setting is ON (that is, the expander process is executed). If it is determined that the current expander process setting is ON, the process proceeds to step S222.
　ステップＳ２２２において、エキスパンダ制御部１４１は、ピーク値がエキスパンダ処理ONからOFFへの閾値を下回ったか否かを判定する。ピーク値がエキスパンダ処理ONからOFFへの閾値を下回ったと判定された場合、処理は図１０のステップＳ２１５に戻り、それ以降の処理を繰り返す。また、ステップＳ２２２において、ピーク値がエキスパンダ処理ONからOFFへの閾値を下回っていないと判定された場合、処理はステップＳ２２３に進む。 In step S222, the expander control unit 141 determines whether or not the peak value is below the threshold value from the expander process ON to the OFF. If it is determined that the peak value has fallen below the threshold value from the expander process ON to OFF, the process returns to step S215 in FIG. 10 and the subsequent processes are repeated. On the other hand, if it is determined in step S222 that the peak value is not below the expander process ON to OFF threshold, the process proceeds to step S223.
　ステップＳ２２３において、エキスパンダ制御部１４１は、エキスパンダ処理の設定をONからOFFに設定する。そして、ステップＳ２２４において、エキスパンダ制御部１４１は、ピーク値、実効値、エキスパンダ処理用の閾値とレシオを初期化する。ステップＳ２２４の処理が終了すると、エキスパンダ制御処理が終了する。 In step S223, the expander control unit 141 sets the expander processing setting from ON to OFF. In step S224, the expander control unit 141 initializes the peak value, effective value, expander processing threshold value, and ratio. When the process of step S224 ends, the expander control process ends.
　また、ステップＳ２２１において、現在のエキスパンダ処理の設定がOFFであると判定された場合、エキスパンダ制御処理が終了する。 If it is determined in step S221 that the current expander process setting is OFF, the expander control process ends.
　以上のように処理を行うことにより、再生装置１００は、第１の実施の形態の場合と同様に、特許文献１に記載の方法よりも主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 By performing the processing as described above, the playback apparatus 100 increases the load on the user while suppressing the reduction of subjective sound quality more than the method described in Patent Document 1, as in the case of the first embodiment. Can be suppressed.
　＜４．第３の実施の形態＞
　　＜無音区間の検出と制御＞
　オーディオ信号に無音区間が含まれる場合、その無音区間が複数のコンテンツのつなぎ目であると考えることができる。例えば、楽曲と楽曲のつなぎ目であったり、コマーシャルのつなぎ目であったり、コマーシャルと本編コンテンツとのつなぎ目であったりすると考えることができる。つまり、無音区間は、オーディオ信号の連続性が途切れる区間であるので、その前後のエキスパンダ処理の相関性は低くても差し支えない。そこで、オーディオ信号に無音期間が検出された場合、エキスパンダ処理に関するパラメータを初期化するようにしてもよい。例えば、再生装置１００が、無音区間が検出された場合、ピーク値、実効値、エキスパンダ処理の閾値やレシオ等のパラメータを初期化するようにしてもよい。 <4. Third Embodiment>
<Detection and control of silent section>
When the audio signal includes a silent section, it can be considered that the silent section is a joint between a plurality of contents. For example, it can be considered as a joint between music pieces, a joint between commercials, or a joint between commercials and main contents. In other words, the silent section is a section in which the continuity of the audio signal is interrupted, and therefore the correlation between the expander processes before and after that may be low. Therefore, when a silence period is detected in the audio signal, parameters relating to the expander process may be initialized. For example, when a silent section is detected, the playback apparatus 100 may initialize parameters such as a peak value, an effective value, a threshold value for an expander process, and a ratio.
　ただし、例えば楽曲内等、オーディオ信号が連続している（１コンテンツ内である）場合にも、一瞬の無音区間が発生することが考えられる。そのような場合はエキスパンダ処理結果が急激に変化しないように、相関性を維持することが望ましい。そこで、無音期間の検出においては、所定の時間以上無音が継続する期間を無音期間としてもよい。この無音期間する時間の長さは任意である。例えば、0.5秒以上としてもよい。 However, even when audio signals are continuous (within one content), for example, in a music piece, it is conceivable that an instantaneous silent section occurs. In such a case, it is desirable to maintain the correlation so that the expander processing result does not change abruptly. Therefore, in detecting the silence period, a period in which silence continues for a predetermined time or more may be set as the silence period. The duration of the silent period is arbitrary. For example, it may be 0.5 seconds or longer.
　　＜エキスパンダ制御処理の流れ＞
　この場合のエキスパンダ制御処理の流れの例を、図１２乃至図１４のフローチャートを参照して説明する。 <Expander control process flow>
An example of the flow of the expander control process in this case will be described with reference to the flowcharts of FIGS.
　図１２のステップＳ２５１乃至ステップＳ２５４の各処理は、図９のステップＳ２０１乃至ステップＳ２０４の各処理と同様に実行される。ステップＳ２５４において、ピーク値がエキスパンダ処理OFFからONへの閾値を越えたと判定された場合、処理は図１３のステップＳ２６１に進む。 12 is executed in the same manner as the processes in steps S201 to S204 in FIG. If it is determined in step S254 that the peak value has exceeded the threshold value from the expander process OFF to ON, the process proceeds to step S261 in FIG.
　図１３のステップＳ２６１乃至ステップＳ２６５の各処理は、図１０のステップＳ２１１乃至ステップＳ２１５の各処理と同様に実行される。ステップＳ２６５の処理が終了すると、処理はステップＳ２６６に進む。 13 is executed in the same manner as the processes in steps S211 to S215 in FIG. When the process of step S265 ends, the process proceeds to step S266.
　ステップＳ２６６において、エキスパンダ制御部１４１は、オーディオ信号において無音が所定の時間以上連続しているか否かを判定する。無音が所定の時間以上連続していない、すなわち、無音期間が検出されないと判定された場合、処理はステップＳ２６７に進む。 In step S266, the expander control unit 141 determines whether or not silence has continued in the audio signal for a predetermined time or more. If it is determined that silence has not continued for a predetermined time or more, that is, no silence period has been detected, the process proceeds to step S267.
　ステップＳ２６７において、エキスパンダ制御部１４１は、エキスパンダ１１２を制御し、エキスパンダ処理を行わせる。エキスパンダ１１２は、そのエキスパンダ制御部１４１の制御に従って、オーディオ信号に対するエキスパンダ処理を実行する。ステップＳ２１６の処理が終了すると、エキスパンダ制御処理が終了する。 In step S267, the expander control unit 141 controls the expander 112 to perform an expander process. The expander 112 executes expander processing on the audio signal according to the control of the expander control unit 141. When the process of step S216 ends, the expander control process ends.
　また、図１２のステップＳ２５４において、ピーク値がエキスパンダ処理OFFからONへの閾値を越えていないと判定された場合、処理は図１４のステップＳ２７１に進む。図１４のステップＳ２７１乃至ステップＳ２７４の各処理は、図１１のステップＳ２２１乃至ステップＳ２２４の各処理と同様に行われる。 If it is determined in step S254 in FIG. 12 that the peak value does not exceed the threshold value from the expander process OFF to ON, the process proceeds to step S271 in FIG. Each process of step S271 thru | or step S274 of FIG. 14 is performed similarly to each process of step S221 thru | or step S224 of FIG.
　なお、図１３のステップＳ２６６において、オーディオ信号において、無音が所定の時間以上連続している、すなわち、無音期間が検出されたと判定された場合、処理は図１４のステップＳ２７４に進む。ステップＳ２７４において、エキスパンダ制御部１４１は、ピーク値、実効値、エキスパンダ処理用の閾値とレシオを初期化する。ステップＳ２７４の処理が終了すると、エキスパンダ制御処理が終了する。 If it is determined in step S266 in FIG. 13 that silence has continued in the audio signal for a predetermined time or more, that is, a silence period has been detected, the process proceeds to step S274 in FIG. In step S274, the expander control unit 141 initializes the peak value, effective value, expander processing threshold and ratio. When the process of step S274 ends, the expander control process ends.
　以上のように処理を行うことにより、再生装置１００は、第２の実施の形態の場合と同様に、特許文献１に記載の方法よりも主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。また、無音区間を検出し、パラメータを初期化することにより、エキスパンダ処理の不要な相関性を低減させることができ、より適切なエキスパンダ処理を行うことができる。 By performing the processing as described above, the playback device 100 increases the load on the user while suppressing the reduction in subjective sound quality as compared with the method described in Patent Document 1, as in the case of the second embodiment. Can be suppressed. Further, by detecting the silent section and initializing the parameters, unnecessary correlation of the expander processing can be reduced, and more appropriate expander processing can be performed.
　＜５．第４の実施の形態＞
　　＜音量に応じた制御＞
　オーディオ信号の出力時の音量が小さい場合は、ユーザの耳への負荷も小さい。そこで、音量設定に応じてエキスパンダ処理の実行を制御するようにしてもよい。例えば、オーディオ信号を出力する際の音量が所定の閾値より大きい場合にエキスパンダ処理の実行を許可する（換言するに、音量が所定の閾値以下の場合、エキスパンダ処理を禁止する）ようにしてもよい。 <5. Fourth Embodiment>
<Control according to volume>
When the volume of the audio signal is small, the load on the user's ear is small. Therefore, execution of the expander process may be controlled according to the volume setting. For example, the execution of the expander process is permitted when the volume at the time of outputting the audio signal is larger than a predetermined threshold (in other words, the expander process is prohibited when the volume is equal to or lower than the predetermined threshold). Also good.
　　＜再生装置＞
　図１５は、本技術を適用した情報処理装置の一実施の形態である再生装置の主な構成例を示す図である。図１５に示される再生装置３００は、図２の再生装置１００と同様の装置であり、再生装置１００と基本的に同様の構成を有し、再生装置１００と基本的に同様の処理を行う。ただし、再生装置３００は、制御部１１８の代わりに制御部３１８を有する。制御部３１８は、制御部１１８と同様、制御に関する処理を行う。ただし、制御部３１８は、エキスパンダ制御部１４１に加え、音量制御部３４１を有する。 <Reproducing device>
FIG. 15 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied. A playback device 300 shown in FIG. 15 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100. However, the playback apparatus 300 includes a control unit 318 instead of the control unit 118. Similar to the control unit 118, the control unit 318 performs processing related to control. However, the control unit 318 includes a volume control unit 341 in addition to the expander control unit 141.
　音量制御部３４１は、増幅部１１３を制御し、オーディオ信号の音量の制御に関する処理を行う。例えば、音量制御部３４１は、ユーザ等の外部から指定された音量設定を増幅部１１３にセットする。増幅部１１３は、そのセットされた音量で出力されるようにオーディオ信号を増幅する。 The volume control unit 341 controls the amplification unit 113 to perform processing related to the control of the volume of the audio signal. For example, the volume control unit 341 sets a volume setting designated from the outside such as a user in the amplification unit 113. The amplifying unit 113 amplifies the audio signal so as to be output at the set volume.
　音量制御部３４１は、また、エキスパンダ制御部１４１を制御し、その音量設定に応じてエキスパンダ処理の実行を制御する。例えば、音量制御部３４１は、音量が所定の閾値より大きい場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。また、例えば、音量制御部３４１は、音量が所定の閾値以下の場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２にエキスパンダ処理を実行するように制御することができない。 The volume control unit 341 also controls the expander control unit 141 and controls the execution of the expander process according to the volume setting. For example, the volume control unit 341 allows the expander control unit 141 to execute the expander process when the volume is larger than a predetermined threshold. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. For example, the volume control unit 341 prohibits the expander control unit 141 from executing the expander process when the volume is equal to or lower than a predetermined threshold. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
　　＜エキスパンダ制御処理の流れ＞
　図１６のフローチャートを参照して、このような音量設定に基づくエキスパンダ処理の制御を行うエキスパンダ制御処理の流れの例を説明する。 <Expander control process flow>
An example of the flow of an expander control process for controlling the expander process based on such volume setting will be described with reference to the flowchart of FIG.
　エキスパンダ制御処理が開始されると、音量制御部３４１は、ステップＳ３０１において、音量が所定の閾値より大きいか否かを判定する。音量がその閾値より大きいと判定された場合、処理はステップＳ３０２に進む。 When the expander control process is started, the volume control unit 341 determines whether or not the volume is larger than a predetermined threshold in step S301. If it is determined that the volume is greater than the threshold, the process proceeds to step S302.
　ステップＳ３０２において、音量制御部３４１は、エキスパンダ制御部１４１に対してエキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。ステップＳ３０２の処理が終了すると、エキスパンダ制御処理が終了する。 In step S302, the volume control unit 341 allows the expander control unit 141 to execute the expander process. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. When the process of step S302 ends, the expander control process ends.
　また、ステップＳ３０１において、音量が閾値以下であると判定された場合、処理はステップＳ３０３に進む。ステップＳ３０３において、音量制御部３４１は、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができない。ステップＳ３０３の処理が終了すると、エキスパンダ制御処理が終了する。 If it is determined in step S301 that the volume is equal to or lower than the threshold value, the process proceeds to step S303. In step S303, the volume control unit 341 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process. When the process of step S303 ends, the expander control process ends.
　以上のように処理を実行することにより、再生装置３００は、オーディオ信号の出力時の音量に応じてエキスパンダ処理の実行を制御することができる。したがって、不要なエキスパンダ処理の実行を抑制することができ、ユーザに違和感をより感じさせないようにすることができる。すなわち、再生装置１００は、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 By executing the processing as described above, the playback device 300 can control the execution of the expander processing according to the volume when the audio signal is output. Therefore, it is possible to suppress unnecessary execution of the expander process and to prevent the user from feeling more uncomfortable. That is, the playback device 100 can suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
　なお、音量に応じたエキスパンダ処理の制御方法はこれに限らず、例えば、音量制御部３４１がエキスパンダパラメータ算出部１３２等を制御し、パラメータを音量に応じた値にするようにしてもよい。このようにすることにより、エキスパンダ処理のかけすぎやかけなさすぎ等が生じるのを抑制することができ、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 Note that the method for controlling the expander process according to the sound volume is not limited to this. For example, the sound volume control unit 341 may control the expander parameter calculation unit 132 and the like so that the parameter is set to a value according to the sound volume. . By doing in this way, it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
　＜６．第５の実施の形態＞
　　＜ノイズキャンセリング＞
　本技術はノイズキャンセリングと併用するようにしてもよい。ノイズキャンセリングは、出力デバイス１１５の周辺の音声を収音し、その音声信号の逆位相をオーディオ信号に重畳することにより、出力デバイス１１５から出力されたオーディオ信号に対応する音声が周辺の騒音を抑制するようにして、本来のオーディオ信号の音声をより聴きやすくする技術である。 <6. Fifth embodiment>
<Noise canceling>
The present technology may be used in combination with noise canceling. Noise canceling picks up the sound around the output device 115 and superimposes the opposite phase of the sound signal on the audio signal, so that the sound corresponding to the audio signal output from the output device 115 reduces the surrounding noise. This is a technique that makes it easier to listen to the sound of the original audio signal by suppressing the sound.
　ノイズキャンセリングを適用するとオーディオ信号の音声がより明確にユーザの耳に届くようになるので、主観音質の低減が目立ちやすくなる。換言するに、本技術による主観音質低減の抑制効果をユーザにより強く体感させることができる。つまり、本技術とノイズキャンセリングを併用することにより、主観音質の低減をより抑制しながらユーザの負荷の増大を抑制することができる。 When noise canceling is applied, the voice of the audio signal can reach the user's ear more clearly, so the subjective sound quality can be easily reduced. In other words, the effect of suppressing the subjective sound quality reduction according to the present technology can be more strongly experienced by the user. That is, by using the present technology and noise canceling together, it is possible to suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
　　＜ノイズキャンセリングに基づくエキスパンダ処理の制御＞
　さらに、ノイズキャンセリングの設定に応じてエキスパンダ処理の実行を制御するようにしてもよい。例えば、ノイズキャンセリングを行う場合のみ、エキスパンダ処理の実行を許可する（換言するに、ノイズキャンセリングを行わない場合、エキスパンダ処理を禁止する）ようにしてもよい。 <Control of expander processing based on noise canceling>
Furthermore, the execution of the expander process may be controlled according to the noise canceling setting. For example, the execution of the expander process may be permitted only when noise canceling is performed (in other words, the expander process is prohibited when noise canceling is not performed).
　　＜再生装置＞
　図１７は、本技術を適用した情報処理装置の一実施の形態である再生装置の主な構成例を示す図である。図１７に示される再生装置４００は、図２の再生装置１００と同様の装置であり、再生装置１００と基本的に同様の構成を有し、再生装置１００と基本的に同様の処理を行う。ただし、再生装置４００は、制御部１１８の代わりに制御部４１８を有する。また、再生装置４００は、マイクロホン４５１、マイクアンプ４５２、NCフィルタ４５３、スイッチ４５４、および演算部４５５を備える。 <Reproducing device>
FIG. 17 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied. A playback device 400 shown in FIG. 17 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100. However, the playback apparatus 400 includes a control unit 418 instead of the control unit 118. In addition, the playback apparatus 400 includes a microphone 451, a microphone amplifier 452, an NC filter 453, a switch 454, and a calculation unit 455.
　制御部４１８は、制御部１１８と同様、制御に関する処理を行う。ただし、制御部４１８は、エキスパンダ制御部１４１に加え、NC制御部４４１を有する。 The control unit 418 performs processing related to control in the same manner as the control unit 118. However, the control unit 418 includes an NC control unit 441 in addition to the expander control unit 141.
　NC制御部４４１は、スイッチ４５４を制御し、ノイズキャンセリングを行うか否かを制御する。例えば、ノイズキャンセリングを行う場合、NC制御部４４１は、スイッチ４５４をオン状態にすることにより、NCフィルタ４５３と演算部４５５とを接続する。また、ノイズキャンセリングを行わない場合、NC制御部４４１は、スイッチ４５４をオフ状態とすることにより、NCフィルタ４５３と演算部４５５とを切断する。 NC control unit 441 controls switch 454 to control whether or not to perform noise canceling. For example, when performing noise canceling, the NC control unit 441 connects the NC filter 453 and the calculation unit 455 by turning on the switch 454. When noise canceling is not performed, the NC control unit 441 disconnects the NC filter 453 and the calculation unit 455 by turning off the switch 454.
　NC制御部４４１は、また、エキスパンダ制御部１４１を制御し、そのノイズキャンセリングに関する設定に応じてエキスパンダ処理の実行を制御する。例えば、NC制御部４４１は、ノイズキャンセリングを行う場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。また、例えば、NC制御部４４１は、ノイズキャンセリングを行わない場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２にエキスパンダ処理を実行するように制御することができない。 The NC control unit 441 also controls the expander control unit 141 to control the execution of the expander process according to the setting related to the noise canceling. For example, the NC control unit 441 permits the expander control unit 141 to execute an expander process when performing noise canceling. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. Further, for example, the NC control unit 441 prohibits the expander control unit 141 from executing the expander process when noise canceling is not performed. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
　マイクロホン４５１は、出力デバイス１１５周辺の音声を収音し、その音声信号をマイクアンプ４５２に供給する。マイクアンプ４５２は、その音声信号を増幅し、NCフィルタ４５３に供給する。NCフィルタ４５３は、その音声信号に対して所定のフィルタ処理を行い、例えば、位相の反転等を行う。スイッチ４５４は、NC制御部４４１に制御されて駆動し、NCフィルタ４５３と演算部４５５との接続を制御する。 The microphone 451 collects sound around the output device 115 and supplies the sound signal to the microphone amplifier 452. The microphone amplifier 452 amplifies the audio signal and supplies it to the NC filter 453. The NC filter 453 performs predetermined filter processing on the audio signal, for example, performs phase inversion. The switch 454 is controlled and driven by the NC control unit 441 and controls connection between the NC filter 453 and the calculation unit 455.
　例えば、スイッチ４５４がオン状態になるとNCフィルタ４５３と演算部４５５とが接続され、NCフィルタ４５３で処理された音声信号が演算部４５５に供給される。つまりノイズキャンセリングが行われる。これに対して、例えば、スイッチ４５４がオフ状態になるとNCフィルタ４５３と演算部４５５とが切断され、NCフィルタ４５３で処理された音声信号が演算部４５５に供給されなくなる。つまりノイズキャンセリングが行われなくなる。 For example, when the switch 454 is turned on, the NC filter 453 and the calculation unit 455 are connected, and the sound signal processed by the NC filter 453 is supplied to the calculation unit 455. That is, noise canceling is performed. On the other hand, for example, when the switch 454 is turned off, the NC filter 453 and the calculation unit 455 are disconnected, and the audio signal processed by the NC filter 453 is not supplied to the calculation unit 455. That is, noise canceling is not performed.
　演算部４５５は、増幅部１１３において増幅されたオーディオ信号にスイッチ４５４を介して供給される音声信号を合成（重畳）し、その合成信号を出力部１１４に供給する。NCフィルタ４５３から供給される音声信号は、位相が反転されているので、合成信号が音声として出力されると、その合成信号に含まれる位相が反転された音声信号成分が、出力デバイス１１５周辺の音声と打ち消し合う。これにより、本来のオーディオ信号がユーザの耳によりはっきりと届くようになる。 The computing unit 455 synthesizes (superimposes) the audio signal supplied via the switch 454 with the audio signal amplified by the amplifying unit 113 and supplies the synthesized signal to the output unit 114. Since the phase of the audio signal supplied from the NC filter 453 is inverted, when the synthesized signal is output as audio, the audio signal component in which the phase included in the synthesized signal is inverted is output around the output device 115. Compete with the voice. This makes the original audio signal more clearly reach the user's ear.
　　＜エキスパンダ制御処理の流れ＞
　図１８のフローチャートを参照して、このようなノイズキャンセリングに基づくエキスパンダ処理の制御を行うエキスパンダ制御処理の流れの例を説明する。 <Expander control process flow>
An example of the flow of expander control processing for controlling expander processing based on such noise canceling will be described with reference to the flowchart of FIG.
　エキスパンダ制御処理が開始されると、NC制御部４４１は、ステップＳ４０１において、ノイズキャンセリングを行うか否かを判定する。ノイズキャンセリングを行うと判定された場合、処理はステップＳ４０２に進む。 When the expander control process is started, the NC control unit 441 determines whether or not to perform noise canceling in step S401. If it is determined that noise canceling is to be performed, the process proceeds to step S402.
　ステップＳ４０２において、NC制御部４４１は、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。ステップＳ４０２の処理が終了すると、エキスパンダ制御処理が終了する。 In step S402, the NC control unit 441 permits the expander control unit 141 to execute the expander process. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. When the process of step S402 ends, the expander control process ends.
　また、ステップＳ４０１において、ノイズキャンセリングを行わないと判定された場合、処理はステップＳ４０３に進む。ステップＳ４０３において、NC制御部４４１は、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができない。ステップＳ４０３の処理が終了すると、エキスパンダ制御処理が終了する。 If it is determined in step S401 that noise canceling is not performed, the process proceeds to step S403. In step S403, the NC control unit 441 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process. When the process of step S403 ends, the expander control process ends.
　以上のように処理を実行することにより、再生装置４００は、ノイズキャンセリングの設定に応じてエキスパンダ処理の実行を制御することができる。したがって、エキスパンダ処理とノイズキャンセリングとを併用することができ、主観音質の低減をより抑制しながらユーザの負荷の増大を抑制することができる。また、例えば周囲の雑音が大きい場合等、主観音質の低減抑制効果が少ない場合にエキスパンダ処理の実行を抑制するようにすることができる。これにより、再生装置４００の負荷の増大を抑制することができる。 By executing the processing as described above, the playback apparatus 400 can control the execution of the expander processing according to the noise canceling setting. Therefore, the expander process and noise canceling can be used in combination, and an increase in the load on the user can be suppressed while further reducing the decrease in subjective sound quality. Further, the execution of the expander process can be suppressed when the effect of suppressing the reduction of the subjective sound quality is small, for example, when the surrounding noise is large. Thereby, the increase in the load of the reproducing apparatus 400 can be suppressed.
　なお、これに限らず、例えば、NC制御部４４１がエキスパンダパラメータ算出部１３２等を制御し、パラメータをノイズキャンセリングの設定に応じた値にするようにしてもよい。例えば、オーディオ信号に対してノイズキャンセリングが行われる場合、エキスパンダ処理の閾値をノイズキャンセリングが行われない場合よりも小さくするようにしてもよい。このようにすることにより、エキスパンダ処理のかけすぎやかけなさすぎ等が生じるのを抑制することができ、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 For example, the NC control unit 441 may control the expander parameter calculation unit 132 and the like to set the parameter to a value according to the noise canceling setting. For example, when noise canceling is performed on an audio signal, the expander processing threshold may be made smaller than when noise canceling is not performed. By doing in this way, it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
　＜７．第６の実施の形態＞
　　＜出力デバイスの検出＞
　出力デバイス１１５がスピーカの場合、音声は空気を伝搬してユーザの耳に到達するので、その伝搬の間に実効値平均レベルが緩和され、ユーザの耳への負荷が低減する可能性がある。また、スピーカの指向性等や音響環境等によってさらに実効値平均レベルが緩和されやすくなる可能性もある。 <7. Sixth Embodiment>
<Detection of output device>
When the output device 115 is a speaker, the sound propagates through the air and reaches the user's ear, so that the effective average level is relaxed during the propagation, and the load on the user's ear may be reduced. In addition, there is a possibility that the effective average level is more easily relaxed depending on the directivity of the speaker and the acoustic environment.
　これに対して出力デバイス１１５がイヤホンやヘッドホンの場合、音声はユーザの耳傍から出力され、外耳道を介して鼓膜に到達するため、ユーザの耳により負荷がかかりやすい可能性がある。 On the other hand, when the output device 115 is an earphone or a headphone, the sound is output from the side of the user's ear and reaches the eardrum via the external auditory canal, which may cause a load on the user's ear.
　そこで、出力デバイス１１５の種類に応じてエキスパンダ処理の実行を制御するようにしてもよい。例えば、出力デバイス１１５がイヤホンやヘッドホン等の場合、エキスパンダ処理の実行を許可する（換言するに、出力デバイス１１５がスピーカ等の場合、エキスパンダ処理を禁止する）ようにしてもよい。 Therefore, execution of the expander process may be controlled according to the type of the output device 115. For example, when the output device 115 is an earphone or a headphone, execution of the expander process may be permitted (in other words, when the output device 115 is a speaker or the like, the expander process is prohibited).
　　＜再生装置＞
　図１９は、本技術を適用した情報処理装置の一実施の形態である再生装置の主な構成例を示す図である。図１９に示される再生装置５００は、図２の再生装置１００と同様の装置であり、再生装置１００と基本的に同様の構成を有し、再生装置１００と基本的に同様の処理を行う。ただし、再生装置５００は、出力デバイス検出部５１１をさらに備える。 <Reproducing device>
FIG. 19 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied. A playback device 500 shown in FIG. 19 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100. However, the playback apparatus 500 further includes an output device detection unit 511.
　出力デバイス検出部５１１は、出力デバイス１１５の種類を検出する。また、出力デバイス検出部５１１は、エキスパンダ制御部１４１を制御し、その検出結果（すなわち出力デバイス１１５の種類）に応じて、エキスパンダ処理の実行を制御する。例えば、出力デバイス検出部５１１は、出力デバイス１１５がイヤホンやヘッドホンの場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。また、例えば、出力デバイス検出部５１１は、出力デバイス１１５がスピーカの場合、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２にエキスパンダ処理を実行するように制御することができない。 The output device detection unit 511 detects the type of the output device 115. The output device detection unit 511 controls the expander control unit 141 and controls the execution of the expander process according to the detection result (that is, the type of the output device 115). For example, when the output device 115 is an earphone or a headphone, the output device detection unit 511 permits the expander control unit 141 to execute the expander process. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. For example, when the output device 115 is a speaker, the output device detection unit 511 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process.
　　＜エキスパンダ制御処理の流れ＞
　図２０のフローチャートを参照して、このような出力デバイス１１５の種類に基づくエキスパンダ処理の制御を行うエキスパンダ制御処理の流れの例を説明する。 <Expander control process flow>
An example of the flow of an expander control process for controlling the expander process based on the type of the output device 115 will be described with reference to the flowchart of FIG.
　エキスパンダ制御処理が開始されると、出力デバイス検出部５１１は、ステップＳ５０１において、出力デバイス１１５を検出する。ステップＳ５０２において出力デバイス検出部５１１は、出力デバイス１１５がイヤホンまたはヘッドホンであるか否かを判定する。出力デバイス１１５がイヤホンまたはヘッドホンであると判定された場合、処理はステップＳ５０３に進む。 When the expander control process is started, the output device detection unit 511 detects the output device 115 in step S501. In step S502, the output device detection unit 511 determines whether the output device 115 is an earphone or a headphone. If it is determined that the output device 115 is an earphone or a headphone, the process proceeds to step S503.
　ステップＳ５０３において、出力デバイス検出部５１１は、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を許可する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができる。ステップＳ５０３の処理が終了すると、エキスパンダ制御処理が終了する。 In step S503, the output device detection unit 511 permits the expander control unit 141 to execute the expander process. In this case, the expander control unit 141 can execute the expander process by controlling the expander 112. When the process of step S503 ends, the expander control process ends.
　また、ステップＳ５０２において、出力デバイス１１５がスピーカ等である（イヤホンやヘッドホンでない）と判定された場合、処理はステップＳ５０４に進む。ステップＳ５０４において、出力デバイス検出部５１１は、エキスパンダ制御部１４１に対して、エキスパンダ処理の実行を禁止する。この場合、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理を実行させることができない。ステップＳ５０４の処理が終了すると、エキスパンダ制御処理が終了する。 If it is determined in step S502 that the output device 115 is a speaker or the like (not an earphone or a headphone), the process proceeds to step S504. In step S504, the output device detection unit 511 prohibits the expander control unit 141 from executing the expander process. In this case, the expander control unit 141 cannot control the expander 112 to execute the expander process. When the process of step S504 ends, the expander control process ends.
　以上のように処理を実行することにより、再生装置５００は、出力デバイス１１５の種類に応じてエキスパンダ処理の実行を制御することができる。したがって、例えば出力デバイス１１５がスピーカ等であり、実効値平均レベルを抑制することにより得られる効果が少ない場合、エキスパンダ処理の実行を抑制することができる。これにより再生装置５００の負荷の増大を抑制することができる。また、不要なエキスパンダ処理による主観音質の低減を抑制することができる。 By executing the processing as described above, the playback device 500 can control the execution of the expander processing according to the type of the output device 115. Therefore, for example, when the output device 115 is a speaker or the like and there are few effects obtained by suppressing the effective value average level, execution of the expander process can be suppressed. As a result, an increase in the load on the playback device 500 can be suppressed. In addition, it is possible to suppress a reduction in subjective sound quality due to unnecessary expander processing.
　また、例えば出力デバイス１１５がイヤホンやヘッドホン等であり、実効値平均レベルを抑制することにより得られる効果が大きい場合にエキスパンダ処理を実行することができ、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 Further, for example, when the output device 115 is an earphone, a headphone, etc., and the effect obtained by suppressing the effective value average level is large, the expander process can be executed, and the user's An increase in load can be suppressed.
　なお、出力デバイス１１５の種類に応じたエキスパンダ処理の制御方法はこれに限らず、例えば、出力デバイス検出部５１１がエキスパンダパラメータ算出部１３２等を制御し、パラメータを出力デバイス１１５の種類に応じた値にするようにしてもよい。このようにすることにより、エキスパンダ処理のかけすぎやかけなさすぎ等が生じるのを抑制することができ、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 Note that the expander processing control method according to the type of the output device 115 is not limited to this. For example, the output device detection unit 511 controls the expander parameter calculation unit 132 and the like, and the parameter is set according to the type of the output device 115. It may be set to a different value. By doing in this way, it can suppress that an expander process is excessively applied or not applied, and an increase in a user's load can be suppressed while suppressing a decrease in subjective sound quality.
　＜８．第７の実施の形態＞
　　＜ハイレゾリューションオーディオ＞
　従来より、可聴帯域外の信号も含むオーディオ信号（ハイレゾリューションオーディオ）が存在する。このようなハイレゾリューションオーディオにおいて、レンジが狭く実効値平均レベルが高い場合、可聴帯域だけでなく可聴帯域外においても同様に、レンジが狭く実効値平均レベルが高い可能性が高い。このような場合、可聴帯域のみ実効値平均レベルを低減させても、可聴帯域外の成分が残り、ユーザの耳への負荷をかけてしまうおそれがあった。 <8. Seventh Embodiment>
<High resolution audio>
Conventionally, there is an audio signal (high resolution audio) including a signal outside the audible band. In such a high-resolution audio, when the range is narrow and the effective value average level is high, it is highly likely that the range is narrow and the effective value average level is high not only in the audible band but also outside the audible band. In such a case, even if the effective value average level is reduced only in the audible band, the component outside the audible band remains, and there is a possibility that a load is applied to the user's ear.
　そこで、可聴帯域内に限らず、可聴帯域外においてもピーク値や実効値を検出するようにしてもよい。また、可聴帯域内に限らず、可聴帯域外においても波高率を増大させてピーク値を下げずに実効値平均レベルを低減させるようにしてもよい。例えば、全帯域の実効値平均レベルと可聴帯域外の実効値平均レベルとの差が少ない場合、可聴帯域外に多くの信号が含まれると判定し、実効値平均レベルをより低減させるように、エキスパンダ処理のレシオを補正するようにしてもよい。その際、全帯域に対するレシオを補正するようにしてもよいし、可聴帯域外に対するレシオを可聴帯域内に対するレシオとは独立して設定する（補正する）ようにしてもよい。 Therefore, the peak value and the effective value may be detected not only within the audible band but also outside the audible band. Further, the effective value average level may be reduced without increasing the peak rate and reducing the peak value not only within the audible band but also outside the audible band. For example, when the difference between the RMS average level of the entire band and the RMS average level outside the audible band is small, it is determined that many signals are included outside the audible band, and the RMS average level is further reduced. You may make it correct | amend the ratio of an expander process. At this time, the ratio for the entire band may be corrected, or the ratio for the outside of the audible band may be set (corrected) independently of the ratio for the inside of the audible band.
　なお、可聴帯域の具体的な範囲は任意である。例えば、約２０Hz程度から約２００００Hz程度であるようにしてもよい。 Note that the specific range of the audible band is arbitrary. For example, the frequency may be about 20 Hz to about 20000 Hz.
　　＜再生装置＞
　図２１は、本技術を適用した情報処理装置の一実施の形態である再生装置の主な構成例を示す図である。図２１に示される再生装置６００は、図２の再生装置１００と同様の装置であり、再生装置１００と基本的に同様の構成を有し、再生装置１００と基本的に同様の処理を行う。ただし、再生装置６００は、検出部１１６の代わりに検出部６１６を備え、パラメータ算出部１１７の代わりにパラメータ算出部６１７を備えている。 <Reproducing device>
FIG. 21 is a diagram illustrating a main configuration example of a playback device that is an embodiment of an information processing device to which the present technology is applied. A playback device 600 shown in FIG. 21 is the same device as the playback device 100 of FIG. 2, has basically the same configuration as the playback device 100, and performs basically the same processing as the playback device 100. However, the playback apparatus 600 includes a detection unit 616 instead of the detection unit 116, and includes a parameter calculation unit 617 instead of the parameter calculation unit 117.
　検出部６１６は、検出部１１６と同様、検出に関する処理を行う。検出部６１６は、検出部１１６の構成（ピークレベル検出部１２１および実効値検出部１２２）に加えさらに、フィルタ６２１および実効値検出部６２２を備える。ピークレベル検出部１２１は、可聴帯域内外の全ての帯域についてピーク値を検出する。ピークレベル検出部１２１は、検出したピーク値を波高率算出部１３１に供給する。実効値検出部１２２は、可聴帯域内外の全ての帯域の実効値を検出する。実効値検出部１２２は、検出した全帯域の実効値を波高率算出部１３１およびレシオ補正部６３１に供給する。フィルタ６２１は、ハイパスフィルタを有し、それによって入力されたオーディオ信号から可聴帯域外の信号を抽出する。フィルタ６２１は、抽出した可聴帯域外の信号を実効値検出部６２２に供給する。実効値検出部６２２は、フィルタ６２１により抽出された可聴帯域外の信号から実効値を検出する。実効値検出部６２２は、検出した可聴帯域外の実効値をレシオ補正部６３１に供給する。 The detection unit 616 performs processing related to detection in the same manner as the detection unit 116. The detection unit 616 includes a filter 621 and an effective value detection unit 622 in addition to the configuration of the detection unit 116 (the peak level detection unit 121 and the effective value detection unit 122). The peak level detector 121 detects peak values for all bands inside and outside the audible band. The peak level detector 121 supplies the detected peak value to the crest factor calculator 131. The effective value detection unit 122 detects effective values of all bands inside and outside the audible band. The effective value detector 122 supplies the detected effective values of all the bands to the crest factor calculator 131 and the ratio corrector 631. The filter 621 has a high-pass filter, and extracts a signal outside the audible band from the input audio signal. The filter 621 supplies the extracted signal outside the audible band to the effective value detection unit 622. The effective value detection unit 622 detects an effective value from a signal outside the audible band extracted by the filter 621. The effective value detection unit 622 supplies the detected effective value outside the audible band to the ratio correction unit 631.
　パラメータ算出部６１７は、パラメータ算出部１１７と同様、パラメータの算出に関する処理を行う。パラメータ算出部６１７は、パラメータ算出部１１７の構成に加え、さらにレシオ補正部６３１を有する。波高率算出部１３１は、ピークレベル検出部１２１により検出された全帯域のピーク値と、実効値検出部１２２により検出された全帯域の実効値とに基づいて全帯域についての波高率を算出する。エキスパンダパラメータ算出部１３２は、波高率算出部１３１により算出された全帯域の波高率等に基づいて、エキスパンダ処理の閾値、レシオ、時定数等の、エキスパンダ処理に関するパラメータを生成する。 The parameter calculation unit 617 performs processing related to parameter calculation in the same manner as the parameter calculation unit 117. The parameter calculation unit 617 further includes a ratio correction unit 631 in addition to the configuration of the parameter calculation unit 117. The crest factor calculation unit 131 calculates the crest factor for all bands based on the peak value of all the bands detected by the peak level detection unit 121 and the effective value of all the bands detected by the effective value detection unit 122. . The expander parameter calculation unit 132 generates parameters related to the expander process, such as a threshold value, a ratio, and a time constant of the expander process, based on the crest factor of the entire band calculated by the crest factor calculation unit 131.
　レシオ補正部６３１は、実効値検出部１２２により検出された全帯域の実効値と、実効値検出部６２２により検出された可聴帯域外の実効値とに基づいて、エキスパンダパラメータ算出部１３２により算出されたエキスパンダ処理のレシオを補正する。例えば、全帯域の実効値と可聴帯域外の実効値との差分が小さい場合、レシオ補正部６３１は、可聴帯域外の成分が多く含まれると判断し、実効値をより下げるようにレシオを補正する。 The ratio correction unit 631 is calculated by the expander parameter calculation unit 132 based on the effective value of the entire band detected by the effective value detection unit 122 and the effective value outside the audible band detected by the effective value detection unit 622. Correct the expanded expander ratio. For example, when the difference between the effective value of the entire band and the effective value outside the audible band is small, the ratio correction unit 631 determines that many components outside the audible band are included, and corrects the ratio so as to lower the effective value. To do.
　その際、レシオ補正部６３１は、例えば、全帯域に対するレシオを一律に補正するようにしてもよい。このようにすることにより、可聴帯域外も含む全帯域の実効値を低減させることができる。したがって、再生装置６００は、主観音質の低減を抑制しながらユーザの負荷の増大をより抑制することができる。 At that time, the ratio correction unit 631 may uniformly correct the ratio with respect to the entire band, for example. By doing so, it is possible to reduce the effective value of the entire band including the outside of the audible band. Therefore, the playback device 600 can further suppress an increase in the user's load while suppressing a decrease in subjective sound quality.
　また、可聴帯域外に対する実効値を可聴帯域内に対する実効値に比べてより下げるようにレシオを補正するようにしてもよい。例えば、図２２のＡは、エキスパンダ処理される前のオーディオ信号の周波数分布の例を示し、図２２のＢは、エキスパンダ処理された後のオーディオ信号の周波数分布の例を示している。図２２のＡにおいて四角枠６６１により囲まれる部分が可聴帯域外の成分である。また、図２２のＢにおいて四角枠６６２により囲まれる部分が可聴帯域外の成分である。可聴帯域外に対する実効値をより下げるようにレシオを補正することにより、四角枠６６１から四角枠６６２のように、可聴帯域外の成分を他の帯域の成分に比べてより小さくすることができる。可聴帯域外の成分はユーザに感知されにくいので、このように大きく低減させてもユーザに違和感を与えにくい。つまり、再生装置６００は、主観音質の低減をより抑制しながら、ユーザの負荷の増大を抑制することができる。 Also, the ratio may be corrected so that the effective value outside the audible band is lower than the effective value within the audible band. For example, FIG. 22A shows an example of the frequency distribution of the audio signal before the expander process, and FIG. 22B shows an example of the frequency distribution of the audio signal after the expander process. In FIG. 22A, a portion surrounded by a square frame 661 is a component outside the audible band. In FIG. 22B, the portion surrounded by the square frame 662 is a component outside the audible band. By correcting the ratio so as to lower the effective value outside the audible band, components outside the audible band can be made smaller than components in other bands, such as the square frame 661 to the square frame 662. Since components outside the audible band are not easily perceived by the user, it is difficult for the user to feel uncomfortable even if they are greatly reduced in this way. That is, the playback device 600 can suppress an increase in the user's load while further suppressing the reduction in subjective sound quality.
　　＜エキスパンダ制御処理の流れ＞
　図２３のフローチャートを参照して、このような再生装置６００により実行されるエキスパンダ制御処理の流れの例を説明する。 <Expander control process flow>
With reference to the flowchart of FIG. 23, an example of the flow of expander control processing executed by such a playback apparatus 600 will be described.
　エキスパンダ制御処理が開始されると、ピークレベル検出部１２１は、ステップＳ６０１において、可聴帯域内外の全帯域についてピーク値を検出する。ステップＳ６０２において、実効値検出部１２２は、可聴帯域内外の全帯域について実効値を検出する。ステップＳ６０３において、波高率算出部１３１は、ステップＳ６０１において検出された全帯域のピーク値と、ステップＳ６０２において検出された全帯域の実効値とに基づいて、全帯域の波高率を算出する。 When the expander control process is started, the peak level detection unit 121 detects peak values for all bands inside and outside the audible band in step S601. In step S602, the effective value detection unit 122 detects effective values for all bands inside and outside the audible band. In step S603, the crest factor calculation unit 131 calculates the crest factor of all bands based on the peak value of all the bands detected in step S601 and the effective value of all the bands detected in step S602.
　ステップＳ６０４において、エキスパンダ制御部１４１は、ステップＳ６０１において検出されたピーク値がエキスパンダ処理ON用の閾値を越えているか否かを判定する。ピーク値がそのエキスパンダ処理ON用の閾値よりも大きいと判定された場合、処理はステップＳ６０５に進む。ステップＳ６０５において、エキスパンダ制御部１４１は、ステップＳ６０３において算出された波高率が所定の波高率用の閾値より小さいか否かを判定する。波高率がその波高率用の閾値より小さいと判定された場合、処理はステップＳ６０６に進む。この場合、オーディオ信号のピーク値が大きく、かつ、波高率が小さいので、その実効値平均レベルは大きい。したがって、エキスパンダ制御部１４１は、オーディオ信号に対してエキスパンダ処理を実行するように制御する。 In step S604, the expander control unit 141 determines whether or not the peak value detected in step S601 exceeds the expander process ON threshold. If it is determined that the peak value is larger than the expander process ON threshold, the process proceeds to step S605. In step S605, the expander control unit 141 determines whether the crest factor calculated in step S603 is smaller than a predetermined crest factor threshold. If it is determined that the crest factor is smaller than the crest factor threshold, the process proceeds to step S606. In this case, since the peak value of the audio signal is large and the crest factor is small, the effective value average level is large. Therefore, the expander control unit 141 performs control so that the expander process is performed on the audio signal.
　ステップＳ６０６において、エキスパンダパラメータ算出部１３２は、ステップＳ６０１において検出された全帯域のピーク値と、ステップＳ６０３において算出された全帯域の波高率とに基づいて、エキスパンダ処理用の閾値（スレッショルド）とレシオ（Ratio）とを算出する。エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理ONを決定する。 In step S606, the expander parameter calculation unit 132 uses the peak value of the entire band detected in step S601 and the crest factor of the entire band calculated in step S603 to set a threshold (threshold) for the expander process. And the ratio. The expander control unit 141 controls the expander 112 to determine the expander process ON.
　ステップＳ６０７において、フィルタ６２１は、オーディオ信号から可聴帯域外の成分を抽出する。実効値検出部６２２は、その可聴帯域外の成分から可聴帯域外の実効値を検出する。ステップＳ６０８において、レシオ補正部６３１は、ステップＳ６０２において検出された全帯域の実効値と、ステップＳ６０７において検出された可聴帯域外の実効値との差分を算出する。ステップＳ６０９において、レシオ補正部６３１は、その差分値が所定の閾値より小さいか否かを判定する。差分値が閾値より小さいと判定された場合、処理はステップＳ６１０に進む。ステップＳ６１０において、レシオ補正部６３１は、エキスパンダパラメータ算出部１３２を制御して、少なくとも可聴帯域外の実効値をより低減させるように、ステップＳ６０６において算出されたレシオを補正する。エキスパンダ制御部１４１は、その補正されたレシオをステップＳ６０６において算出された閾値とともにエキスパンダ１１２にセットする。ステップＳ６１０の処理が終了すると、事前解析処理が終了する。また、ステップＳ６０９において、差分値が閾値以上であると判定された場合、可聴帯域外の成分が少ないのでレシオの補正が省略される。つまり、エキスパンダ制御部１４１は、ステップＳ６０６において算出された閾値およびレシオをエキスパンダ１１２にセットする。そして、事前解析処理が終了する。 In step S607, the filter 621 extracts a component outside the audible band from the audio signal. The effective value detection unit 622 detects an effective value outside the audible band from components outside the audible band. In step S608, the ratio correction unit 631 calculates the difference between the effective value of the entire band detected in step S602 and the effective value outside the audible band detected in step S607. In step S609, the ratio correction unit 631 determines whether the difference value is smaller than a predetermined threshold value. If it is determined that the difference value is smaller than the threshold value, the process proceeds to step S610. In step S610, the ratio correction unit 631 controls the expander parameter calculation unit 132 to correct the ratio calculated in step S606 so as to reduce at least the effective value outside the audible band. The expander control unit 141 sets the corrected ratio in the expander 112 together with the threshold value calculated in step S606. When the process of step S610 ends, the pre-analysis process ends. If it is determined in step S609 that the difference value is equal to or greater than the threshold value, the ratio correction is omitted because there are few components outside the audible band. That is, the expander control unit 141 sets the threshold value and the ratio calculated in step S606 in the expander 112. Then, the pre-analysis process ends.
　また、ステップＳ６０４において、ピーク値がエキスパンダ処理ON用の閾値を越えていないと判定された場合、処理はステップＳ６１１に進む。また、ステップＳ６０５において、波高率が波高率用の閾値以上であると判定された場合、処理はステップＳ６１１に進む。この場合、オーディオ信号のピーク値が小さいか、または、ピーク値が大きくても波高率が小さいので、その実効値平均レベルは大きくない。したがって、エキスパンダ制御部１４１は、オーディオ信号に対してエキスパンダ処理を実行しないように制御する。つまり、ステップＳ６１１において、エキスパンダ制御部１４１は、エキスパンダ１１２を制御してエキスパンダ処理OFFを決定する。ステップＳ６１１の処理が終了すると、事前解析処理が終了する。 If it is determined in step S604 that the peak value does not exceed the expander process ON threshold, the process proceeds to step S611. If it is determined in step S605 that the crest factor is equal to or greater than the crest factor threshold, the process proceeds to step S611. In this case, since the peak value of the audio signal is small or the peak value is small even if the peak value is large, the effective value average level is not large. Therefore, the expander control unit 141 performs control so that the expander process is not performed on the audio signal. That is, in step S611, the expander control unit 141 controls the expander 112 to determine the expander process OFF. When the process of step S611 ends, the pre-analysis process ends.
　このようにすることにより、再生装置６００は、可聴帯域外の成分も含むハイレゾリューションオーディオに対しても、主観音質の低減を抑制しながらユーザの負荷の増大を抑制することができる。 By doing so, the playback device 600 can suppress an increase in the load on the user while suppressing a decrease in subjective sound quality even for high resolution audio including components outside the audible band.
　＜９．第８の実施の形態＞
　　＜コンピュータ＞
　上述した一連の処理は、ハードウエアにより実行させることもできるし、ソフトウエアにより実行させることもできる。一連の処理をソフトウエアにより実行する場合には、そのソフトウエアを構成するプログラムが、コンピュータにインストールされる。ここでコンピュータには、専用のハードウエアに組み込まれているコンピュータや、各種のプログラムをインストールすることで、各種の機能を実行することが可能な、例えば汎用のパーソナルコンピュータ等が含まれる。 <9. Eighth Embodiment>
<Computer>
The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer that can execute various functions by installing a computer incorporated in dedicated hardware and various programs.
　図２４は、上述した一連の処理をプログラムにより実行するコンピュータのハードウエアの構成例を示すブロック図である。 FIG. 24 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processing by a program.
　図２４に示されるコンピュータ９００において、CPU（Central Processing Unit）９０１、ROM（Read Only Memory）９０２、RAM（Random Access Memory）９０３は、バス９０４を介して相互に接続されている。 In the computer 900 shown in FIG. 24, a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, and a RAM (Random Access Memory) 903 are connected to each other via a bus 904.
　バス９０４にはまた、入出力インタフェース９１０も接続されている。入出力インタフェース９１０には、入力部９１１、出力部９１２、記憶部９１３、通信部９１４、およびドライブ９１５が接続されている。 An input / output interface 910 is also connected to the bus 904. An input unit 911, an output unit 912, a storage unit 913, a communication unit 914, and a drive 915 are connected to the input / output interface 910.
　入力部９１１は、例えば、キーボード、マウス、マイクロホン、タッチパネル、入力端子などよりなる。出力部９１２は、例えば、ディスプレイ、スピーカ、出力端子などよりなる。記憶部９１３は、例えば、ハードディスク、RAMディスク、不揮発性のメモリなどよりなる。通信部９１４は、例えば、ネットワークインタフェースよりなる。ドライブ９１５は、磁気ディスク、光ディスク、光磁気ディスク、または半導体メモリなどのリムーバブルメディア９２１を駆動する。 The input unit 911 includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, and the like. The output unit 912 includes, for example, a display, a speaker, an output terminal, and the like. The storage unit 913 includes, for example, a hard disk, a RAM disk, a nonvolatile memory, and the like. The communication unit 914 includes a network interface, for example. The drive 915 drives a removable medium 921 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.
　以上のように構成されるコンピュータ９００では、CPU９０１が、例えば、記憶部９１３に記憶されているプログラムを、入出力インタフェース９１０およびバス９０４を介して、RAM９０３にロードして実行することにより、上述した一連の処理が行われる。RAM９０３にはまた、CPU９０１が各種の処理を実行する上において必要なデータなども適宜記憶される。 In the computer 900 configured as described above, for example, the CPU 901 loads the program stored in the storage unit 913 to the RAM 903 via the input / output interface 910 and the bus 904 and executes the program. A series of processing is performed. The RAM 903 also appropriately stores data necessary for the CPU 901 to execute various processes.
　コンピュータ９００が実行するプログラムは、例えば、パッケージメディア等としてのリムーバブルメディア９２１に記録して適用することができる。その場合、プログラムは、リムーバブルメディア９２１をドライブ９１５に装着することにより、入出力インタフェース９１０を介して、記憶部９１３にインストールすることができる。 The program executed by the computer 900 can be recorded and applied to, for example, a removable medium 921 as a package medium or the like. In that case, the program can be installed in the storage unit 913 via the input / output interface 910 by attaching the removable medium 921 to the drive 915.
　また、このプログラムは、ローカルエリアネットワーク、インターネット、デジタル衛星放送といった、有線または無線の伝送媒体を介して提供することもできる。その場合、プログラムは、通信部９１４で受信し、記憶部９１３にインストールすることができる。 This program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In that case, the program can be received by the communication unit 914 and installed in the storage unit 913.
　その他、このプログラムは、ROM９０２や記憶部９１３等に、あらかじめインストールしておくこともできる。 In addition, this program can be installed in advance in the ROM 902, the storage unit 913, or the like.
　＜１０．その他＞
　また、本技術の実施の形態は、上述した実施の形態に限定されるものではなく、本技術の要旨を逸脱しない範囲において種々の変更が可能である。 <10. Other>
The embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.
　例えば、本技術は、装置またはシステムを構成するあらゆる構成、例えば、システムLSI（Large Scale Integration）等としてのプロセッサ、複数のプロセッサ等を用いるモジュール、複数のモジュール等を用いるユニット、ユニットにさらにその他の機能を付加したセット等（すなわち、装置の一部の構成）として実施することもできる。 For example, the present technology may be applied to any configuration that constitutes an apparatus or system, for example, a processor as a system LSI (Large Scale Integration), a module that uses a plurality of processors, a unit that uses a plurality of modules, etc. It can also be implemented as a set or the like to which functions are added (that is, a partial configuration of the apparatus).
　また、例えば、１つの装置（または処理部）として説明した構成を分割し、複数の装置（または処理部）として構成するようにしてもよい。逆に、以上において複数の装置（または処理部）として説明した構成をまとめて１つの装置（または処理部）として構成されるようにしてもよい。また、各装置（または各処理部）の構成に上述した以外の構成を付加するようにしてももちろんよい。さらに、システム全体としての構成や動作が実質的に同じであれば、ある装置（または処理部）の構成の一部を他の装置（または他の処理部）の構成に含めるようにしてもよい。 Further, for example, the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units). Conversely, the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit). Of course, a configuration other than that described above may be added to the configuration of each device (or each processing unit). Furthermore, if the configuration and operation of the entire system are substantially the same, a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit). .
　また、例えば、本技術は、１つの機能を、ネットワークを介して複数の装置で分担、共同して処理するクラウドコンピューティングの構成をとることができる。 Also, for example, the present technology can take a configuration of cloud computing in which one function is shared and processed by a plurality of devices via a network.
　また、例えば、上述したプログラムは、任意の装置において実行することができる。その場合、その装置が、必要な機能（機能ブロック等）を有し、必要な情報を得ることができるようにすればよい。 Also, for example, the above-described program can be executed in an arbitrary device. In that case, the device may have necessary functions (functional blocks and the like) so that necessary information can be obtained.
　また、例えば、上述のフローチャートで説明した各ステップは、１つの装置で実行する他、複数の装置で分担して実行することができる。さらに、１つのステップに複数の処理が含まれる場合には、その１つのステップに含まれる複数の処理は、１つの装置で実行する他、複数の装置で分担して実行することができる。 Also, for example, each step described in the above flowchart can be executed by one device or can be executed by a plurality of devices. Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.
　なお、コンピュータが実行するプログラムは、プログラムを記述するステップの処理が、本明細書で説明する順序に沿って時系列に実行されるようにしても良いし、並列に、あるいは呼び出しが行われたとき等の必要なタイミングで個別に実行されるようにしても良い。つまり、矛盾が生じない限り、各ステップの処理が上述した順序と異なる順序で実行されるようにしてもよい。さらに、このプログラムを記述するステップの処理が、他のプログラムの処理と並列に実行されるようにしても良いし、他のプログラムの処理と組み合わせて実行されるようにしても良い。 Note that the program executed by the computer may be executed in a time series in the order described in this specification for the processing of the steps describing the program, or in parallel or called. It may be executed individually at a necessary timing. That is, as long as no contradiction occurs, the processing of each step may be executed in an order different from the order described above. Furthermore, the processing of the steps describing this program may be executed in parallel with the processing of other programs, or may be executed in combination with the processing of other programs.
　また、本明細書において、システムとは、複数の構成要素（装置、モジュール（部品）等）の集合を意味し、全ての構成要素が同一筐体中にあるか否かは問わない。したがって、別個の筐体に収納され、ネットワークを介して接続されている複数の装置、及び、１つの筐体の中に複数のモジュールが収納されている１つの装置は、いずれも、システムである。 In this specification, the system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .
　なお、本明細書において複数説明した本技術は、矛盾が生じない限り、それぞれ独立に単体で実施することができる。もちろん、任意の複数の本技術を併用して実施することもできる。例えば、いずれかの実施の形態において説明した本技術を、他の実施の形態において説明した本技術と組み合わせて実施することもできる。また、上述した任意の本技術を、上述していない他の技術と併用して実施することもできる。 In addition, as long as there is no contradiction, the technologies described in this specification can be implemented independently. Of course, any of a plurality of present technologies can be used in combination. For example, the present technology described in any of the embodiments can be implemented in combination with the present technology described in other embodiments. Further, any of the above-described techniques can be implemented in combination with other techniques not described above.
　なお、本技術は以下のような構成も取ることができる。
　（１）　入力されたオーディオ信号の波高率を算出する波高率算出部と、
　前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部と
　を備える情報処理装置。
　（２）　前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備える
　（１）に記載の情報処理装置。
　（３）　前記パラメータは、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオとを含む
　（２）に記載の情報処理装置。
　（４）　前記パラメータ設定部は、前記波高率が小さい場合、前記レシオの値を、前記波高率が大きい場合よりも大きな値に設定する
　（３）に記載の情報処理装置。
　（５）　前記エキスパンダ処理の時定数の候補を記憶する記憶部をさらに備え、
　前記パラメータ設定部は、前記記憶部に記憶されている前記候補の中から適用する時定数を選択するように構成される
　（２）乃至（４）のいずれかに記載の情報処理装置。
　（６）　前記エキスパンダ制御部は、前記オーディオ信号のピーク値が所定の閾値より大きく、かつ、前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して前記エキスパンダ処理を行わせる
　（１）乃至（５）のいずれかに記載の情報処理装置。
　（７）　前記波高率算出部は、前記オーディオ信号のピーク値と実効値とに基づいて前記波高率を算出する
　（１）乃至（６）のいずれかに記載の情報処理装置。
　（８）　前記オーディオ信号のピーク値を検出するピーク値検出部をさらに備え、
　前記波高率算出部は、前記ピーク値検出部により検出された前記ピーク値に基づいて前記波高率を算出するように構成される
　（７）に記載の情報処理装置。
　（９）　前記オーディオ信号の実効値を検出する実効値検出部をさらに備え、
　前記波高率算出部は、前記実効値検出部により検出された前記実効値に基づいて前記波高率を算出するように構成される
　（７）または（８）に記載の情報処理装置。
　（１０）　前記エキスパンダ制御部の制御に従って、前記オーディオ信号に対して前記エキスパンダ処理を行うエキスパンダ処理部をさらに備える
　（１）乃至（９）のいずれかに記載の情報処理装置。
　（１１）　前記波高率算出部は、所定の時間間隔毎に前記波高率を算出し、
　前記エキスパンダ制御部は、前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて前記エキスパンダ処理の実行を制御する
　（１）乃至（１０）のいずれかに記載の情報処理装置。
　（１２）　前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備える
　（１）乃至（１１）のいずれかに記載の情報処理装置。
　（１３）　前記パラメータ設定部は、前記オーディオ信号に無音期間が検出された場合、前記パラメータを初期化する
　（１２）に記載の情報処理装置。
　（１４）　前記エキスパンダ制御部は、前記オーディオ信号を出力する際の音量が所定の閾値より大きい場合、前記エキスパンダ処理の実行を許可する
　（１）乃至（１３）のいずれかに記載の情報処理装置。
　（１５）　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部をさらに備え、
　前記パラメータ設定部は、前記オーディオ信号に対してノイズキャンセル処理が行われる場合、前記閾値を、前記ノイズキャンセル処理が行われない場合よりも小さくするように構成される
　（１）乃至（１４）のいずれかに記載の情報処理装置。
　（１６）　前記オーディオ信号を出力する出力デバイスの種類を検出する出力デバイス検出部をさらに備え、
　前記エキスパンダ制御部は、前記出力デバイス検出部により所定の種類の出力デバイスが検出された場合、前記エキスパンダ処理の実行を許可するように構成される
　（１）乃至（１５）のいずれかに記載の情報処理装置。
　（１７）　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部と、
　前記オーディオ信号の全帯域の実効値と可聴帯域外の実効値との差分が小さい場合、前記パラメータ設定部により設定された前記レシオを補正するレシオ補正部と
　をさらに備える
　（１）乃至（１６）のいずれかに記載の情報処理装置。
　（１８）　前記レシオ補正部は、前記オーディオ信号の可聴帯域外に対するレシオを補正する
　（１７）に記載の情報処理装置。
　（１９）　入力されたオーディオ信号の波高率を算出し、
　算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせる
　情報処理方法。
　（２０）　コンピュータを、
　入力されたオーディオ信号の波高率を算出する波高率算出部と、
　前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部と
　して機能させるプログラム。 In addition, this technique can also take the following structures.
(1) a crest factor calculator for calculating a crest factor of the input audio signal;
An expander control unit that, when the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold value, performs an expander process for reducing a signal value smaller than the predetermined threshold value for the audio signal; Information processing apparatus provided.
(2) The information processing apparatus according to (1), further including a parameter setting unit that sets a parameter used for the expander processing based on the crest factor calculated by the crest factor calculation unit.
(3) The information processing apparatus according to (2), wherein the parameter includes the threshold value to be compared with a signal value of the audio signal and a ratio to a signal value smaller than the threshold value of the audio signal.
(4) The information processing apparatus according to (3), wherein when the crest factor is small, the parameter setting unit sets the ratio value to a larger value than when the crest factor is large.
(5) A storage unit for storing time constant candidates for the expander processing is further provided.
The information processing apparatus according to any one of (2) to (4), wherein the parameter setting unit is configured to select a time constant to be applied from the candidates stored in the storage unit.
(6) When the peak value of the audio signal is larger than a predetermined threshold value and the crest factor is smaller than the predetermined threshold value, the expander control unit causes the audio signal to perform the expander process. The information processing apparatus according to any one of 1) to (5).
(7) The information processing apparatus according to any one of (1) to (6), wherein the crest factor calculation unit calculates the crest factor based on a peak value and an effective value of the audio signal.
(8) further comprising a peak value detector for detecting a peak value of the audio signal;
The information processing apparatus according to (7), wherein the crest factor calculation unit is configured to calculate the crest factor based on the peak value detected by the peak value detection unit.
(9) further comprising an effective value detection unit for detecting an effective value of the audio signal;
The information processing apparatus according to (7) or (8), wherein the crest factor calculation unit is configured to calculate the crest factor based on the effective value detected by the effective value detection unit.
(10) The information processing apparatus according to any one of (1) to (9), further including: an expander processing unit that performs the expander process on the audio signal according to the control of the expander control unit.
(11) The crest factor calculation unit calculates the crest factor every predetermined time interval,
The expander control unit controls execution of the expander processing based on the crest factor calculated by the crest factor calculation unit at each time interval. (1) to (10) Information processing device.
(12) The system further includes a parameter setting unit that sets a parameter used for the expander processing based on the crest factor calculated by the crest factor calculation unit at each time interval. The information processing apparatus according to any one of the above.
(13) The information processing apparatus according to (12), wherein the parameter setting unit initializes the parameter when a silence period is detected in the audio signal.
(14) The information according to any one of (1) to (13), wherein the expander control unit permits execution of the expander process when a volume at the time of outputting the audio signal is larger than a predetermined threshold. Processing equipment.
(15) Parameter setting for setting the threshold value to be compared with the signal value of the audio signal based on the crest factor calculated by the crest factor calculating unit and the ratio of the audio signal to a signal value smaller than the threshold value Further comprising
The parameter setting unit is configured to make the threshold smaller when noise cancellation processing is performed on the audio signal than when the noise cancellation processing is not performed (1) to (14) The information processing apparatus according to any one of the above.
(16) An output device detection unit that detects a type of an output device that outputs the audio signal,
The expander control unit is configured to permit execution of the expander process when a predetermined type of output device is detected by the output device detection unit. (1) to (15) The information processing apparatus described.
(17) Parameter setting for setting the threshold value to be compared with the signal value of the audio signal and the ratio of the audio signal to a signal value smaller than the threshold value based on the crest factor calculated by the crest factor calculating unit And
A ratio correction unit that corrects the ratio set by the parameter setting unit when the difference between the effective value of the entire band of the audio signal and the effective value outside the audible band is small (1) to (16) The information processing apparatus according to any one of the above.
(18) The information processing apparatus according to (17), wherein the ratio correction unit corrects a ratio of the audio signal to outside the audible band.
(19) Calculate the crest factor of the input audio signal,
When the calculated crest factor is smaller than a predetermined threshold value, an expander process is performed on the audio signal to make the signal value smaller than the predetermined threshold value smaller.
(20)
A crest factor calculator for calculating the crest factor of the input audio signal;
When the crest factor calculated by the crest factor calculating unit is smaller than a predetermined threshold value, an expander control unit that performs an expander process for reducing a signal value smaller than the predetermined threshold value for the audio signal. Program to function.
　１００　再生装置，　１１１　遅延処理部，　１１２　エキスパンダ，　１１３　増幅部，　１１４　出力部，　１１５　出力デバイス，　１１６　検出部，　１１７　パラメータ算出部，　１１８　制御部，　１２１　ピークレベル検出部，　１２２　実効値検出部，　１３１　波高率算出部，　１３２　エキスパンダパラメータ算出部，　１３３　メモリ，　１４１　エキスパンダ制御部，　３００　再生装置，　３４１　音量制御部，　４００　再生装置，　４４１　NC制御部，　４５１　マイクロホン，　４５２　マイクアンプ，　４５３　NCフィルタ，　４５４　スイッチ，　４５５　演算部，　５００　再生装置，　５１１　出力デバイス検出部，　６００　再生装置，　６１６　検出部，　６１７　パラメータ算出部，　６２１　フィルタ，　６２２　実効値検出部，　６３１　レシオ補正部，　９００　コンピュータ 100 playback device, 111 delay processing unit, 112 expander, 113 amplification unit, 114 output unit, 115 output device, 116 detection unit, 117 parameter calculation unit, 118 control unit, 121 peak level detection unit, 122 effective value detection unit, 131 Crest factor calculation unit, 132 Expander parameter calculation unit, 133 memory, 141 expander control unit, 300 playback device, 341 volume control unit, 400 playback device, 441 NC control unit, 451 microphone, 452 microphone amplifier, 453 NC filter , 454 switch, 455 arithmetic unit, 500 playback device, 511 output device detection unit, 600 playback device, 616 detection unit, 617 parameter calculation unit, 62 1 filter, 622 RMS detection unit, 631 ratio correction unit, 900 computer

Claims (20)

  1. 　入力されたオーディオ信号の波高率を算出する波高率算出部と、
    　前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部と
    　を備える情報処理装置。     A crest factor calculator for calculating the crest factor of the input audio signal;
    An expander control unit that, when the crest factor calculated by the crest factor calculation unit is smaller than a predetermined threshold value, performs an expander process for reducing a signal value smaller than the predetermined threshold value for the audio signal; Information processing apparatus provided.
  2. 　前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備える
    　請求項１に記載の情報処理装置。     The information processing apparatus according to claim 1, further comprising: a parameter setting unit that sets a parameter used for the expander process based on the crest factor calculated by the crest factor calculation unit.
  3. 　前記パラメータは、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオとを含む
    　請求項２に記載の情報処理装置。     The information processing apparatus according to claim 2, wherein the parameter includes the threshold value to be compared with a signal value of the audio signal and a ratio with respect to a signal value smaller than the threshold value of the audio signal.
  4. 　前記パラメータ設定部は、前記波高率が小さい場合、前記レシオの値を、前記波高率が大きい場合よりも大きな値に設定する
    　請求項３に記載の情報処理装置。     The information processing apparatus according to claim 3, wherein when the crest factor is small, the parameter setting unit sets the ratio value to a larger value than when the crest factor is large.
  5. 　前記エキスパンダ処理の時定数の候補を記憶する記憶部をさらに備え、
    　前記パラメータ設定部は、前記記憶部に記憶されている前記候補の中から適用する時定数を選択するように構成される
    　請求項２に記載の情報処理装置。     A storage unit for storing candidate time constants for the expander processing;
    The information processing apparatus according to claim 2, wherein the parameter setting unit is configured to select a time constant to be applied from the candidates stored in the storage unit.
  6. 　前記エキスパンダ制御部は、前記オーディオ信号のピーク値が所定の閾値より大きく、かつ、前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して前記エキスパンダ処理を行わせる
    　請求項１に記載の情報処理装置。     The expander control unit causes the expander processing to be performed on the audio signal when a peak value of the audio signal is larger than a predetermined threshold and the crest factor is smaller than a predetermined threshold. The information processing apparatus described.
  7. 　前記波高率算出部は、前記オーディオ信号のピーク値と実効値とに基づいて前記波高率を算出する
    　請求項１に記載の情報処理装置。     The information processing apparatus according to claim 1, wherein the crest factor calculation unit calculates the crest factor based on a peak value and an effective value of the audio signal.
  8. 　前記オーディオ信号のピーク値を検出するピーク値検出部をさらに備え、
    　前記波高率算出部は、前記ピーク値検出部により検出された前記ピーク値に基づいて前記波高率を算出するように構成される
    　請求項７に記載の情報処理装置。     A peak value detector for detecting a peak value of the audio signal;
    The information processing apparatus according to claim 7, wherein the crest factor calculation unit is configured to calculate the crest factor based on the peak value detected by the peak value detection unit.
  9. 　前記オーディオ信号の実効値を検出する実効値検出部をさらに備え、
    　前記波高率算出部は、前記実効値検出部により検出された前記実効値に基づいて前記波高率を算出するように構成される
    　請求項７に記載の情報処理装置。     Further comprising an effective value detection unit for detecting an effective value of the audio signal,
    The information processing apparatus according to claim 7, wherein the crest factor calculation unit is configured to calculate the crest factor based on the effective value detected by the effective value detection unit.
  10. 　前記エキスパンダ制御部の制御に従って、前記オーディオ信号に対して前記エキスパンダ処理を行うエキスパンダ処理部をさらに備える
    　請求項１に記載の情報処理装置。     The information processing apparatus according to claim 1, further comprising: an expander processing unit that performs the expander process on the audio signal according to control of the expander control unit.
  11. 　前記波高率算出部は、所定の時間間隔毎に前記波高率を算出し、
    　前記エキスパンダ制御部は、前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて前記エキスパンダ処理の実行を制御する
    　請求項１に記載の情報処理装置。     The crest factor calculation unit calculates the crest factor at predetermined time intervals,
    The information processing apparatus according to claim 1, wherein the expander control unit controls execution of the expander process based on the crest factor calculated by the crest factor calculation unit at each time interval.
  12. 　前記時間間隔毎に、前記波高率算出部により算出された前記波高率に基づいて、前記エキスパンダ処理に用いられるパラメータを設定するパラメータ設定部をさらに備える
    　請求項１に記載の情報処理装置。     The information processing apparatus according to claim 1, further comprising: a parameter setting unit that sets a parameter used for the expander processing based on the crest factor calculated by the crest factor calculation unit for each time interval.
  13. 　前記パラメータ設定部は、前記オーディオ信号に無音期間が検出された場合、前記パラメータを初期化する
    　請求項１２に記載の情報処理装置。     The information processing apparatus according to claim 12, wherein the parameter setting unit initializes the parameter when a silence period is detected in the audio signal.
  14. 　前記エキスパンダ制御部は、前記オーディオ信号を出力する際の音量が所定の閾値より大きい場合、前記エキスパンダ処理の実行を許可する
    　請求項１に記載の情報処理装置。     The information processing apparatus according to claim 1, wherein the expander control unit permits execution of the expander process when a volume at the time of outputting the audio signal is larger than a predetermined threshold.
  15. 　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部をさらに備え、
    　前記パラメータ設定部は、前記オーディオ信号に対してノイズキャンセル処理が行われる場合、前記閾値を、前記ノイズキャンセル処理が行われない場合よりも小さくするように構成される
    　請求項１に記載の情報処理装置。     A parameter setting unit configured to set a ratio of the threshold value to be compared with the signal value of the audio signal based on the crest factor calculated by the crest factor calculation unit and a signal value smaller than the threshold value of the audio signal; Prepared,
    The information processing according to claim 1, wherein the parameter setting unit is configured to make the threshold smaller when noise cancellation processing is performed on the audio signal than when the noise cancellation processing is not performed. apparatus.
  16. 　前記オーディオ信号を出力する出力デバイスの種類を検出する出力デバイス検出部をさらに備え、
    　前記エキスパンダ制御部は、前記出力デバイス検出部により所定の種類の出力デバイスが検出された場合、前記エキスパンダ処理の実行を許可するように構成される
    　請求項１に記載の情報処理装置。     An output device detector for detecting the type of output device that outputs the audio signal;
    The information processing apparatus according to claim 1, wherein the expander control unit is configured to permit execution of the expander process when a predetermined type of output device is detected by the output device detection unit.
  17. 　前記波高率算出部により算出された前記波高率に基づいて、前記オーディオ信号の信号値と比較される前記閾値と、前記オーディオ信号の前記閾値より小さい信号値に対するレシオを設定するパラメータ設定部と、
    　前記オーディオ信号の全帯域の実効値と可聴帯域外の実効値との差分が小さい場合、前記パラメータ設定部により設定された前記レシオを補正するレシオ補正部と
    　をさらに備える
    　請求項１に記載の情報処理装置。     Based on the crest factor calculated by the crest factor calculation unit, the threshold value to be compared with the signal value of the audio signal, and a parameter setting unit for setting a ratio for a signal value smaller than the threshold value of the audio signal;
    The information according to claim 1, further comprising: a ratio correction unit that corrects the ratio set by the parameter setting unit when a difference between an effective value of the entire band of the audio signal and an effective value outside the audible band is small. Processing equipment.
  18. 　前記レシオ補正部は、前記オーディオ信号の可聴帯域外に対するレシオを補正する
    　請求項１７に記載の情報処理装置。     The information processing apparatus according to claim 17, wherein the ratio correction unit corrects a ratio of the audio signal to an outside audible band.
  19. 　入力されたオーディオ信号の波高率を算出し、
    　算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせる
    　情報処理方法。     Calculate the crest factor of the input audio signal,
    When the calculated crest factor is smaller than a predetermined threshold value, an expander process is performed on the audio signal to make the signal value smaller than the predetermined threshold value smaller.
  20. 　コンピュータを、
    　入力されたオーディオ信号の波高率を算出する波高率算出部と、
    　前記波高率算出部により算出された前記波高率が所定の閾値より小さい場合、前記オーディオ信号に対して、所定の閾値より小さい信号値をより小さくするエキスパンダ処理を行わせるエキスパンダ制御部と
    　して機能させるプログラム。     Computer
    A crest factor calculator for calculating the crest factor of the input audio signal;
    When the crest factor calculated by the crest factor calculating unit is smaller than a predetermined threshold value, an expander control unit that performs an expander process for reducing a signal value smaller than the predetermined threshold value for the audio signal. Program to function.
PCT/JP2017/047286 2017-01-13 2017-12-28 Information processing device, method, and program WO2018131513A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100241256A1 (en) * 2006-05-20 2010-09-23 Personics Holdings Inc. Method of modifying audio content
JP2013507842A (en) * 2009-10-09 2013-03-04 ディーティーエス・インコーポレイテッド Adaptive dynamic range enhancement for recording
JP2014506076A (en) * 2011-01-12 2014-03-06 クゥアルコム・インコーポレイテッド Maximizing loudness using constrained loudspeaker excursions

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100241256A1 (en) * 2006-05-20 2010-09-23 Personics Holdings Inc. Method of modifying audio content
JP2013507842A (en) * 2009-10-09 2013-03-04 ディーティーエス・インコーポレイテッド Adaptive dynamic range enhancement for recording
JP2014506076A (en) * 2011-01-12 2014-03-06 クゥアルコム・インコーポレイテッド Maximizing loudness using constrained loudspeaker excursions

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