JP2009020922A - Reproducing device, program, and reproduction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a reproducing device to reproduce audio data, which are recorded under non-compression, reversible compression or high bit rate to be reproduced in a high quality, in a high quality mode without the need for confirming file information thereof, each time, by the user. <P>SOLUTION: The reproducing device is provided with a reading means (step 21) for reading out data capable of specifying sound quality of audio data from a storage means when audio data stored in the prescribed storage means is reproduced; and a determination means (steps 22, 23) determining whether the audio data is to be reproduced in the prescribed high-quality mode based on the data capable of specifying-the sound quality read out by the reading means. The data capable of specifying sound quality is, for example, recorded in a header part of the audio data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a playback apparatus and a playback method capable of playing back audio data in a predetermined high sound quality mode, and a program for causing a computer to function as the playback apparatus.

  In recent years, the market for audio playback devices having large-capacity HDDs and memories has expanded. In these storage means, files such as MP3 format, WMA format, and WAV format, which are recorded from various sound sources or purchased through a network, can be recorded as audio sources. In that case, various file formats and multiple types of bit rates may be recorded together. On the other hand, as an audio playback device, there is a device in which a portable playback device having a large-capacity HDD or memory is connected and the data held therein is played back as an audio source in addition to the above-described large-capacity HDD and memory built-in.

  Furthermore, for the purpose of performing reproduction based on these audio sources with the highest possible sound quality, a technique as disclosed in Patent Document 1 has also been proposed. In this technology, in an audio reproduction device having a signal reception function for receiving a broadcast signal and an audio signal processing function for processing an audio signal from an audio reproduction device, when there is no need to process the broadcast signal, the signal reception function Is turned off to prevent deterioration of the sound quality of the sound signal from the sound reproducing device and to reduce generation of unnecessary radiation.

  In addition, in order to realize reproduction with high sound quality, a means for selecting a high sound quality mode by user operation is provided, and when the high sound quality mode is selected, functions unnecessary for reproduction of audio signals are stopped or unnecessary. There is also known one that enables high-quality audio reproduction by bypassing a circuit. As an unnecessary function stop, for example, power-off of a display unit, a surround channel amplification unit, or the like is applicable. As an unnecessary circuit bypass, for example, a path of an equalizer circuit or the like is applicable. These functions and circuits can be a source of unwanted radiation and other noise sources and resistance to the audio signal transmission path. By reducing the use of these functions and circuits, it is possible to reproduce high-quality audio. Can do.

  FIG. 5 is a block diagram showing a reproducing apparatus according to a conventional example provided with a selection means for a high sound quality mode. As shown in the figure, the playback device 50 includes a CPU 51 that controls each part of the device and performs necessary information processing in cooperation with a predetermined program, a storage unit 52 that stores audio data processed by the CPU 51, and a CPU 51. A display unit 53 for performing necessary display for the user, an operation unit 54 for the user to input an operation to the CPU 51, a DA converter 55 for converting a digital signal output from the CPU 51 into an analog signal, and a DA converter 55 The selector 57 for selecting either the signal from the external input source 56 or the analog signal from the external input source 56, the tone circuit 58 for adjusting the sound quality for the signal selected by the selector 57, the signal from the DA converter 55 or the tone circuit 58 An amplifying unit 59 for amplifying is provided. In addition, a manual switching unit 63 that performs switching between the high sound quality mode and the normal mode based on a user's manual operation is provided.

  The storage unit 52 is configured by a hard disk or memory built in the apparatus. The audio data to be processed by the CPU 51 may be stored in the external storage device 60 in addition to the data stored in the storage unit 52. The external storage device 60 is constituted by, for example, a hard disk or a semiconductor memory. It may exist on a server that can communicate via a network. The audio signal amplified by the amplifying unit 59 is output as audio by the external output means 61 such as a speaker.

  In this configuration, audio data in the storage unit 52 that is to be played back in accordance with a user instruction via the operation unit 54 is decoded by the CPU 51 and converted into an analog signal by the DA converter 55. When the manual switching unit 63 is switched to the normal mode side, the analog signal from the DA converter 55 passes through the manual switching unit 63, the selector 57, the tone circuit 58, and the amplifying unit 59, and then the external output means 61, the sound is output.

  On the other hand, when the manual switching unit 63 is switched to the high sound quality mode side, the analog signal from the DA converter 55 is directly input to the amplifying unit 59 without passing through the tone circuit 58. In this case, the high sound quality signal included in the audio data is reproduced in a state closer to the original sound.

JP 2002-352570 A

  By the way, when audio data of various file formats and bit rates is mixed in a large-capacity recording medium included in the playback device, the audio data by non-compression, lossless compression, or compression at a high bit rate can be determined by the user. In order to listen to the audio data with high sound quality, it is often recorded in such a format and bit rate.

  However, according to the prior art provided with the selection means for the high sound quality mode described above, in order to reproduce the audio data that the user wants to listen to with high sound quality, when the user tries to switch to the high sound quality mode, It is inconvenient because it is necessary to confirm information related to sound quality such as what type of file and what bit rate it is compressed at.

  In view of the problems of the prior art, the object of the present invention is to provide audio quality information related to audio data recorded in a high quality format such as non-compression, lossless compression, high bit rate, etc. Therefore, it is possible to reproduce in the high sound quality mode without the user having to check and judge each time.

  In order to achieve this object, the reproducing apparatus according to the first aspect of the present invention, when reproducing audio data stored in a predetermined storage means, reads out from the storage means data that can specify the sound quality of the audio data. And determining means for determining whether or not to reproduce the audio data in a predetermined high sound quality mode based on data that can specify the sound quality read by the reading means.

  Here, as the data that can specify the sound quality, for example, whether the audio data is a compressed file, whether it is a lossy compressed file, file format, bit rate, sampling frequency, or quantization Data relating to the number of bits, or a combination of two or more arbitrarily selected from these. As the predetermined high sound quality mode, for example, a mode in which the display unit of the playback device is turned off, a mode in which power supply to an unnecessary channel amplification unit is turned off, or a mode in which a playback signal bypasses the tone circuit, etc. Or a combination of any two or more of these modes.

  In this configuration, when reproducing the audio data stored in the predetermined storage means, data that can specify the sound quality of the audio data is read from the storage means, and the sound quality can be specified based on the data that can specify the sound quality. It is determined whether or not the audio data is reproduced in a predetermined high sound quality mode. That is, for example, when the data for which sound quality can be specified indicates that the audio data is recorded with high sound quality in an uncompressed format or a lossless compression format, it is determined that the data is to be played back in the high sound quality mode. . Therefore, the user can enjoy the determination result by the device without having to confirm what the sound quality of the audio data to be reproduced is. For example, playback in the high sound quality mode or the normal mode can be automatically performed according to the determination result.

  According to a second aspect of the present invention, in the first aspect, the data capable of specifying the sound quality is data recorded in a header portion of the audio data.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the determination means has data in which the sound quality read by the reading means can specify the audio data file format, When the audio data indicates an uncompressed format or a lossless compressed format, it is determined that the audio data is reproduced in a predetermined high sound quality mode.

  In the playback device according to a fourth aspect of the present invention, in any one of the first to third aspects of the invention, the determination means includes data that can specify the sound quality read by the reading means, and that represents the compression rate of the audio data. The audio data is in a predetermined compression format, and indicates that the audio data has a bit rate that can be reproduced at a frequency higher than a predetermined frequency. It is characterized in that it is determined that the data is to be reproduced.

  A program according to a fifth invention causes a computer to function as each unit in the playback device according to any one of the first to fourth inventions.

  According to a sixth aspect of the present invention, there is provided a reproduction method in which, when reproducing the audio data stored in the predetermined storage means, the reading means reads out from the storage means data that can specify the sound quality of the audio data; And means for determining whether or not the audio data is to be reproduced in a predetermined high sound quality mode based on data that can specify the sound quality read by the reading means.

  According to the present invention, when reproducing the audio data stored in the storage means, the predetermined sound quality related data related to the sound quality of the audio data is read from the storage means, and the audio data is determined based on the sound quality related data. Since the audio data to be played is recorded with high sound quality, the user does not need to be aware of the file format and bit rate, and the high sound quality mode is selected. Can be played.

  FIG. 1 is a block diagram showing a playback apparatus according to an embodiment of the present invention. As shown in the figure, this playback device 10 includes a CPU 1 that controls each part of the device and performs necessary information processing in cooperation with a predetermined program, a storage unit 2 that stores audio data processed by the CPU 1, and a CPU 1 A display unit 3 for displaying to the user, an operation unit 4 for the user to input an operation to the CPU 1, a DA converter 5 for converting a digital signal output by the CPU 1 into an analog signal, a signal from the DA converter 5, or A selector 7 that selects one of the analog signals from the external input source 6, and a signal from the tone circuit 8, the DA converter 5, or the tone circuit 8 for adjusting the sound quality of the signal selected by the selector 7 is amplified. An amplifying unit 9 is provided. Moreover, the automatic switching part 13 which switches an operation mode between high sound quality mode and normal mode is provided.

  The storage unit 2 is configured by a hard disk or memory built in the apparatus. Note that the audio data to be processed by the CPU 1 may be stored in the external storage device 12 in addition to the data stored in the storage unit 2. The external storage device 12 is configured by, for example, a hard disk or a semiconductor memory. It may exist on a server that can communicate via a network. The audio signal amplified by the amplifying unit 9 is output as audio by the external output means 11 such as a speaker. The audio data stored in the storage unit 2 corresponds to music content files such as MP3 format, WMA format, and WAV format. The tone circuit 8 may include an equalizing function.

  In this configuration, the audio data in the storage unit 2 that is a reproduction target in accordance with a user instruction via the operation unit 4 is decoded by the CPU 1 and converted into an analog signal by the DA converter 5. In the normal mode, the analog signal from the DA converter 5 is output as sound by the external output means 11 via the selector 7, the tone circuit 8, and the amplifier 9.

  On the other hand, when operating in a high sound quality mode for reproducing audio data with high sound quality, the analog signal from the DA converter 5 is directly input to the amplifying unit 9 without passing through the tone circuit 8. In this case, the high-quality sound signal of the audio data is reproduced as much as possible, and a sound closer to the original sound can be obtained.

  FIG. 2 is a flowchart showing a reproduction process performed in the reproduction apparatus of FIG. 1 when reproducing the audio data. When one or a plurality of audio data to be reproduced is selected via the operation unit 4 and the start of reproduction is instructed, the CPU 1 first sets the frame header of the first audio data to be reproduced in step 21. Read. Next, in step 22, it is determined whether the audio data is to be reproduced in the high sound quality mode based on the frame header.

  Further, in step 23, it is determined whether or not the reproduction target is set in the high sound quality mode. If it is determined that the target is the high sound quality mode, in step 24, reproduction is performed in the high sound quality mode based on the audio data. Specifically, the display on the display unit 3 is turned off, and reproduction is performed by directly outputting an audio signal from the DA converter 5 to the amplifier 9 without going through the tone circuit 8. Further, in the case of a playback apparatus capable of multi-channel playback, the amplifier circuit for unnecessary channels in the amplifier 9 may be turned off. As a result, reproduction with high sound quality that is less influenced by noise and the like and closer to the original sound is performed.

  If it is determined in step 23 that the target is not the target of the high sound quality mode, in step 25, reproduction is performed with sound quality close to high sound quality by performing high sound range interpolation based on the audio data. In this case, reproduction is performed via the tone circuit 8. The high-frequency range interpolation is a well-known technique for reproducing high-quality sound approaching the sound quality before compression by interpolating the high-frequency range portion lost during compression recording.

  When the reproduction of the audio data in step 24 or 25 is completed, it is determined in step 26 whether or not there is next audio data to be reproduced. If it is determined that it exists, the process returns to step 21 to repeat the process from step 21 onward for the next audio data. If it is determined that it does not exist, the reproduction process in FIG. 2 is terminated.

  FIG. 3 is a flowchart showing the determination processing of the high sound quality mode in step 22 described above. First, in steps 31 to 33, based on the header information read in step 21 described above, the audio data is data of a non-compressed file or a lossless compression file, or is a lossy compression file and has a predetermined bit rate. It is determined whether the data is the above. An example of the uncompressed file is a WAVE format. The lossless compression file corresponds to a lossless compression format, for example. The lossy compressed file corresponds to, for example, an MP3 or WMA format.

  In this determination, based on the read header information, it is possible to determine which file format the audio data is based on the characteristics of the bit configuration. Further, based on the data of the bit rate storage position in the found file format, it can be determined whether or not the bit rate is a predetermined value or more. For example, if the upper 11 bits of the read frame header are all “1”, it is found that the audio data is in the MP3 format and is a lossy compressed file. The MP3 data includes a frame header, a data area, and an ID3 tag, and a bit rate value is stored in the first half of the third byte of the frame header. Therefore, based on this bit rate value, it can be determined whether or not the bit rate is equal to or higher than a predetermined value.

  In the case of MP3, the upper limit of the reproduction frequency is about 15 [kHz] at a bit rate of 128 [kbps], about 18 [kHz] at 160 [kbps], and about 21 [kHz] at 192 [kbps]. Yes. Therefore, for example, 192 [kbps] is adopted as the predetermined value in the determination of the bit rate in step 33, and if it is more than this, it can be set as a reproduction target in the high sound quality mode.

  If it is determined in steps 31 to 33 that the data is a non-compressed file or a reversible compressed file, or is a lossy compressed file and the bit rate is equal to or higher than a predetermined value, in step 34 the audio data is It is determined that the target is to be reproduced in the high sound quality mode, and the processing in FIG. 3 is terminated. If it is determined that none of them is applicable, it is determined in step 35 that the audio data is not to be reproduced in the high sound quality mode, and the processing in FIG. 3 is terminated. After the processing in FIG. 3 is completed, the process proceeds to step 23 in FIG.

  According to the present embodiment, when it is determined that the bit rate of the non-compressed file, the lossless-compressed file, or the lossy-compressed file is greater than or equal to a predetermined value based on the header information of the audio data, the audio data is Playback is performed in mode, and in other cases, high-frequency interpolation is performed and playback is performed with a sound quality close to that of the high sound quality, so the user can record with high sound quality without having to be aware of the file format and bit rate of the audio data. The audio data being played can be reproduced in the high sound quality mode. At that time, based on the header information, whether or not the file is an uncompressed file or a lossless compressed file, and whether the bit rate is higher than a predetermined value is surely recognized, and it is determined whether or not to be a target of the high sound quality mode. can do.

  In addition, since the audio data in the uncompressed file format and the lossless compressed file format is set as the target of reproduction in the high sound quality mode, it is possible to perform reproduction in the high sound quality mode utilizing these high sound quality audio data.

  Also, audio data that is not subject to the high sound quality mode with a bit rate lower than the predetermined value is played back with high-frequency interpolation, so even if the audio data is not subject to the high sound quality mode, Playback can be performed with sound quality close to that of audio data.

  FIG. 4 shows an example of the operation of the playback apparatus in the above-described high sound quality mode. The “target” column in the figure indicates what is to be switched on / off or avoided / passed in the high sound quality mode and the non-high sound quality mode. The “high sound quality mode” and “non-high sound quality mode” columns indicate these switching contents. As shown in the figure, each target is controlled to turn on or pass when operating in the non-high sound quality mode, and is controlled to turn off or avoid when operating in the high sound quality mode. As a result, when operating in the high sound quality mode, unnecessary processing of the CPU 1 is stopped to reduce the load on the CPU 1, and the disturbance and loss of the reproduction waveform are reduced by preventing signals from passing through unnecessary circuits. In addition, unnecessary radiation from the power source can be reduced without using an unnecessary power source. Therefore, when operating in the high sound quality mode, playback can be performed with high sound quality compared to when operating in the non-high sound quality mode. The target and switching content are not limited to those illustrated in FIG. 4, and other target and switching content may be used.

  Specifically, the playback device generally has a display unit such as a liquid crystal display device, an organic EL display device, an FL tube, a light emitting diode, etc., and information such as the operating state of the playback device and the name of the audio data being played back Is displayed. In the high sound quality mode of FIG. 4, the display unit is turned off by reducing the load on the CPU 1 by not performing this display, and by not operating the display unit 4 or the power source that drives the display unit 4. Enables playback with higher sound quality than in the case of.

  The sound quality adjustment mechanism adjusts the volume for each frequency of reproduced audio data, such as a tone and an equalizer. As a sound quality adjustment mechanism, there are a mechanism for adjusting audio data by the CPU 1 in a digital state and a mechanism for adjusting an analog output by passing it through a tone circuit. The sound quality adjustment mechanism in the high sound quality mode in FIG. 4 is turned off by not performing these operations by the sound quality adjustment mechanism, or by not passing through the sound quality adjustment mechanism, than when the sound quality adjustment mechanism is on. Enables high-quality playback.

  The avoidance of the selector in the high sound quality mode in FIG. 4 is obtained by converting the audio data into an analog waveform by the DA converter 5 and then amplifying the audio data without passing through the selector 7 that switches between other analog input sources. High-quality sound reproduction is possible compared to the case of passing through 7.

  The surround processing / amplification unit is turned off. If the playback device is a multi-channel playback device that can play back surround channels, etc., and the audio data is a stereo 2-channel source, the CPU does not need to process channels other than the 2 channels. By not amplifying channels other than 2 channels, the CPU load is reduced, power supply to the amplification unit 59 is unnecessary, and higher sound quality reproduction is possible than when the surround processing / amplification unit is off. To.

  Video-related processing / output is turned off when the playback device is a so-called AV amplifier or video playback device that supports a source with video, and the operation of the CPU 1 that processes video and the operation of an integrated circuit for video processing. By not performing the above, it is possible to reproduce with higher sound quality than when the video-related processing / output is turned on.

  In the high sound quality mode, the audio data includes frequency information up to the high sound range. Accordingly, the high sound range interpolation process is turned off by not performing the interpolation process by the CPU, thereby enabling higher sound quality reproduction than when the high sound range interpolation process is off.

  Note that the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, in the above description, 192 [kbps] in the case of MP3 format audio data is given as an example of the predetermined value in step 33 in FIG. 3, but the predetermined value is not limited to this. In each case of audio data in which the file format is MP3 format or WMA format, each bit rate value capable of reproducing a frequency equal to or higher than a predetermined value may be adopted. According to this, even if the data is in a compressed format, the bit rate data having a relatively high sound quality can be reproduced utilizing the high sound quality.

  In the above description, whether or not audio data is to be reproduced in the high sound quality mode is determined based on the file format and the bit rate. Instead of or in addition to this, the sampling frequency is used. Or based on the number of quantization bits.

  Although not particularly mentioned in the above description, when the audio data has a variable bit rate, the processing of FIGS. 2 and 4 may not be performed.

  Further, in the above description, when it is determined that the target is to be reproduced in the high sound quality mode, the reproduction is performed in the high sound quality mode as it is (step 24). Instead, the reproduction in the high sound quality mode is performed. If it is determined that the target is to be played, the user's consent may be obtained for playback in the high sound quality mode. At this time, it may be displayed that the audio data has a qualification suitable for playback in the high sound quality mode.

  Further, in the above description, whether or not to be the target of the high sound quality mode is determined based on the frame header of the audio data to be reproduced, but the bit rate described above is included in the tag information of the audio data to be reproduced. If the file format is described, it may be determined whether or not to be the target of the high sound quality mode based on the tag information. Also, if the tag information does not contain information for determining whether or not to use the above-described high sound quality mode, the frame header information is once read and a determination is made as to whether or not to use the high sound quality mode. After that, the information may be written into the tag information, and the tag information may be read from the next time to determine whether or not the high sound quality mode is set.

  Further, the determination result as to whether or not the audio data to be reproduced is to be reproduced in the high sound quality mode is made into a database and stored in association with the audio data to be reproduced in the storage unit 2 or the external storage device 12. It may be determined whether or not to reproduce the audio data to be reproduced in the high sound quality mode by updating and reading the database.

  In the above-described embodiment, the example of determining whether or not to be reproduced in the high sound quality mode for each audio data has been described. However, the present invention is not limited to this, and the determination is performed in units of albums or folders. It may be. In this case, it is determined whether or not the first audio data or arbitrary audio data in the corresponding album or folder is to be reproduced in the high sound quality mode, and the audio data is included in the album or folder in which the audio data is included. What is necessary is just to continue reproduction | regeneration with the determined mode with respect to another audio data.

It is a block diagram which shows the reproducing | regenerating apparatus which concerns on one Embodiment of this invention. 3 is a flowchart showing a reproduction process performed in the reproduction apparatus of FIG. 1. It is a flowchart which shows the judgment process of the high sound quality mode in the process of FIG. It is an example of operation | movement of the high sound quality mode in the process of FIG. It is a block diagram which shows the reproducing | regenerating apparatus concerning a prior art example.

Explanation of symbols

  1, 51: CPU, 2, 52: Storage unit, 3, 53: Display unit, 4, 54: Operation unit, 5, 55: DAC, 6, 56: External input source, 7, 57: Selector, 8, 58 : Tone circuit, 9, 59: amplification unit, 10, 50: playback device, 11, 61: external output means, 12, 60 external storage device, 13: automatic switching unit, 63: manual switching unit.

Claims (6)

Reading means for reading out data capable of specifying the sound quality of the audio data from the storage means when reproducing the audio data stored in the predetermined storage means;
A playback apparatus comprising: determination means for determining whether or not to play back the audio data in a predetermined high sound quality mode based on data that can specify the sound quality read by the reading means.   2. The playback apparatus according to claim 1, wherein the data capable of specifying the sound quality is data recorded in a header portion of the audio data.   In the case where the determination unit has data that can specify the sound quality read by the reading unit includes data representing a file format of the audio data, and indicates that the audio data is in an uncompressed format or a lossless compressed format The playback apparatus according to claim 1 or 2, wherein the audio data is determined to be played back in a predetermined high sound quality mode.   The determination means includes data that can specify the sound quality read by the reading means, and includes data representing a compression rate of the audio data, the audio data is of a predetermined compression format, and has a frequency equal to or higher than a predetermined frequency. The determination according to claim 1, wherein the audio data is determined to be reproduced in a predetermined high sound quality mode when indicating that the bit rate is reproducible. The playback apparatus according to any one of the above.   A program for causing a computer to function as each means in the playback apparatus according to claim 1. When reproducing audio data stored in a predetermined storage unit, a reading unit reads out from the storage unit data that can specify the sound quality of the audio data; and
And a determination step of determining whether or not the audio data is to be reproduced in a predetermined high sound quality mode based on data that can specify the sound quality read by the reading means. .

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