KR20020015578A - Apparatus and method for averaging an audio output level in a digital audio device - Google Patents

Abstract

PURPOSE: An equalizing device of sound volume in an MP3(Moving Picture Expert Group Audio Layer-3) player is provided to change the playing audio output into the desired proper volume for a user by calculating the average sound volume of an MP3 music file. CONSTITUTION: A sound volume equalizer in an MP3 player consists of a buffer(11) delaying and outputting an MP3 music file by temporarily saving the music file read out of a flash memory; a CODEC(Coder-Decoder,12) decoding the MP3 music file into playing audio data; a DAC(Digital to Analog Converter,13) converting the decoded playing audio data into analog audio signals; a sound volume level detector(14) detecting the sound volume level of the temporarily-saved MP3 music file in the buffer; and a sound volume level control unit(15) equalizing the sound volume of the playing audio data by controlling the decoding of the CODEC. The sound volume equalizer checks scale factor data included in the MP3 music file read out of the flash memory and calculates the average sound volume of the playing audio data. Thereby, the playing data are equalized into the desired proper sound volume of a user.

Description

Apparatus and method for averaging an audio output level in a digital audio device}

The present invention relates to a volume leveling device and a method in a digital audio device, and more particularly, to calculating a volume average value of a digital audio music file such as MP3 (MP3), and selecting a desired amount of playback audio output. A volume leveling device and method in a digital audio device for varying the volume.

First, Fig. 1 shows a configuration of a volume automatic control device in a general analog audio device, comprising: an audio head 2 for reading out a signal stored in an audio tape 1; An audio signal processor (3) which processes the signal read out from the audio head into a reproduced audio signal; An audio amplifier 4 for amplifying and outputting the signal-processed reproduction audio signal; And a level detector (5) for detecting the level of the signal-processed reproduction audio signal and variably adjusting the gain of the audio amplifier (4), wherein the level detector (5) is selected by a user. According to the on / off of the input volume automatic adjustment key, the volume automatic adjustment operation for variably adjusting the gain of the audio amplifier 4 is selectively performed.

Accordingly, when a plurality of audio tunes recorded and stored on the audio tape 1 are recorded and stored at different volumes, respectively, the level detection section 5 processes the signal by the audio signal processing section 3. The level of the reproduced audio signal is detected, and a comparison is made to determine whether it is out of a range of a preset reference audio level.

As a result of the determination, when the detected level of the reproduced audio signal is out of the range of the reference audio level, the gain of the audio amplifier 4 is variably adjusted to automatically adjust the volume of the reproduced output audio signal to a proper volume. Will be adjusted.

However, the automatic volume control device in the above-described general analog audio device detects the level of the reproduced audio signal signaled by the audio signal processor 3 and compares it with a preset reference audio level. Since the gain of the audio amplifier is variably adjusted, in order to variably adjust the volume level of the finally reproduced and output audio signal to an arbitrary volume level desired by the user, there is a problem that a preset reference audio level must be reset. do.

On the other hand, in digital audio apparatuses that record or store digital audio music files such as MP3 (MP3), which have been widely spread in recent years, on a recording medium such as flash memory, or read and play back, high quality digital audio music files can be stored in a personal computer ( It is possible to easily download and record through a connected device such as a PC), wherein a plurality of music files recorded in the flash memory are different from each other in the process of producing the corresponding music file or storing the data in the memory. Since each can be recorded and stored as a music file having a volume of the size, there is an urgent need for a solution that can be reproduced and output to the user's desired volume level arbitrarily.

Accordingly, the present invention has been made in view of the above problems and circumstances, and has been found in a digital audio device that records, stores, or reads and reproduces digital audio music files such as MP3 (MP3) on a recording medium such as a flash memory. It is an object of the present invention to provide a volume leveling device and a method in a digital audio apparatus for calculating a volume average value of a digital audio music file and varying the playback audio output to any appropriate volume desired by the user.

1 illustrates a configuration of an automatic volume control device in a general analog audio device,

2 illustrates a configuration of a volume leveling device in a digital audio device according to the present invention.

3 shows a data format for an audio frame of an ampi three (MP3),

4A and 4B illustrate an operation flowchart of a volume leveling method in a digital audio device according to the present invention.

5 and 6 show recording areas in which the volume average value according to the present invention is recorded and stored as additional information, respectively.

※ Explanation of code for main part of drawing

1: audio tape 2: audio head

3: audio signal processor 4: audio amplifier

5 level detection unit 11 buffer

12: Codec 13: D / A Converter

14: volume level detector 15: volume level controller

According to an aspect of the present invention, there is provided a volume leveling apparatus of a digital audio device, comprising: storage means for temporarily storing and delaying digital audio music files read from a recording medium; Restoring means for decoding the digital audio music file delayed output from the storage means and restoring the original audio data; Calculating means for calculating a volume average value for the digital audio music file temporarily stored in the storage means; And control means for varying the volume level of the audio data output from the restoring means based on the calculated volume mean value.

In addition, the volume leveling method in the digital audio device according to the present invention comprises the steps of: detecting the volume level information recorded in the digital audio music file; Calculating a volume average value for the digital audio music file based on the detected volume level information; And three steps of varying the intensity of the audio reproduction output based on the calculated volume average value.

In addition, the volume leveling method in the digital audio device according to the present invention comprises the steps of: calculating a volume average value for the digital audio music file to be decoded and output; Detecting an output strength arbitrarily set by a user with respect to the output music; And three steps of varying the output time according to the average value of audio music to be subsequently output based on the ratio of the calculated volume average value and the output intensity set by the user. ,

In addition, the volume leveling method in the digital audio device according to the present invention comprises the steps of: receiving a digital audio music file through the input means; Calculating a volume average value of the received music data; And recording and storing the calculated volume average value as additional information.

Hereinafter, a preferred embodiment of a volume leveling device and method in a digital audio device according to the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 2 illustrates a configuration of a volume leveling device in a digital audio device according to the present invention. For example, recording and storing a digital audio music file such as an MP3 (MP3) in a recording medium such as a flash memory. A volume leveling device in a digital audio device for reading or reproducing includes: a buffer 11 for temporarily storing and delaying audio music files read from a recording medium such as a flash memory; A codec (Codec-Decoder) 12 for decoding the audio music file delayed output from the buffer 11 into reproduction audio data; A D / A converter 13 for converting and outputting the decoded reproduction audio data into an analog audio signal; A volume level detector (14) for detecting a volume level of the audio music file temporarily stored in the buffer (11); And a volume level control unit 15 for controlling the decoding operation of the codec 12 in accordance with the detected volume level and a volume control value designated by the user to equalize the volume level of the reproduced audio data.

On the other hand, in each audio frame constituting the digital audio music file, i.e., an audio song read and reproduced with temporal continuity, as shown in FIG. 3, a field in which header information is recorded. And a field in which error checking (CRC: Cyclic Redundancy Checking) information is selectively recorded, and a field in which real-time audio data (Audio Data) is recorded, wherein the real-time audio data recording field includes a bit allocation (Bit Allot). ) Information, scale factor information, and sample audio data are separately recorded, and the scale factor information is used to restore the volume of audio data to its original value when decoding encoded audio data into original audio data. Is recorded and stored as volume level information.

Accordingly, the volume leveling device in the digital audio device configured as described above detects and confirms the scale factor information recorded in the digital audio music file read out from a recording medium such as a flash memory, and determines the volume average value of the reproduced audio song. After the calculation, a volume leveling operation for leveling the audio reproduction output to an arbitrary appropriate volume desired by the user is performed. The volume leveling operation as described above will be described in detail.

First, FIGS. 4A and 4B illustrate an operation flowchart of a volume leveling method in a digital audio device according to the present invention. When a volume level leveling control mode for a digital audio music file is set at the user's request, FIG. In operation S10, the buffer 11 starts a buffering operation for temporarily storing the first audio file, that is, the first audio song, that is read from the flash memory (S11). The volume level detector 14 ) Reads out the first audio song data temporarily stored in the buffer 11, and detects and confirms scale factor information recorded in each audio frame. For the scale factor information, refer to FIG. As described above, the recorded volume for restoring the volume of the audio data recorded in each audio frame to the original volume As the level information, the volume level detector 14 accumulates and accumulates the volume average value of each channel for the audio song (S12).

On the other hand, the volume level control unit 15 calculates the volume average value for the entire audio song by summing the average values for each channel (S13), and then outputs the audio data as the buffering ends in the buffer 11. The decoding operation in the codec 12 which restores the original audio data is controlled.

That is, the volume level leveling operation is performed such that the volume level of the audio data decoded and output by the codec 12 is changed based on the volume average value of the entire audio song (S14).

Accordingly, the first audio song read out from the flash memory is delayed for a predetermined time and the reproduced audio output is leveled to a predetermined volume level. In this case, the buffer 11 reads from the flash memory. In order to delay the output of the second audio song to be reproduced, the buffering operation for temporarily storing is restarted (S15), and the volume level detector 14 receives the second audio song data temporarily stored in the buffer 11. After reading and detecting the scale factor information recorded in each audio frame, the cumulative sum is calculated to calculate a volume average value of each channel for the audio song (S16).

In addition, the volume level control unit 15 calculates a volume average value of the entire second audio song by summing the average values for each channel (S17). In this case, the user controls the volume of the first audio song that is being reproduced and output. It is confirmed whether the variable is arbitrarily adjusted (S18).

That is, the user may check whether the audio volume key is variably adjusted while the first audio song is reproduced and output. If the audio volume key is not variably adjusted, the volume level control unit 15 then determines that: The decoding operation in the codec 12 which restores the audio data of the second audio song output as the end of the buffering in the buffer 11 to the original audio data is based on the volume average value of the entire second audio song. The control is performed (S19).

On the other hand, when the audio volume key is variably adjusted by the user as a result of the checking, the volume level control unit 15 compares the volume control value variably adjusted by the user with the volume average value of the first audio song, and After calculating the ratio (S20), the calculated ratio is multiplied by the volume average value of the second audio song to calculate a relative volume average value corresponding to the volume level desired by the user (S21).

Subsequently, the decoding operation in the codec 12 which restores the second audio song output as the end of the buffering in the buffer 11 to the original audio data is controlled based on the relative volume average value (S22).

That is, for the second audio song, the volume level leveling is performed such that the volume of the audio data is changed based on the calculated relative volume average value reflecting the volume control value arbitrarily variable adjusted by the user while listening to the first audio song. The operation is repeatedly performed, and when the volume level leveling adjustment mode is released, the operation is terminated (S23).

Therefore, the audio songs read out and reproduced from a recording medium such as a flash memory are outputted by varying to an appropriate volume desired by the user.

For reference, in order to shorten the playback output time of the first audio song delayed by the buffering operation in the buffer 11, the volume average value of the first audio song may be calculated through a sampling process.

Meanwhile, the volume average value of the audio song calculated through the above-described process is calculated in advance at the time of performing the reproducing operation or the recording operation, and recorded and stored as additional information on the audio song, and the volume level is leveled according to a user's request. When the adjustment mode is set, by using the readout, it is possible to make a faster volume level leveling adjustment operation, for example, as follows.

First, as shown in FIG. 5, a plurality of audio access units (AAU: Audio Access Units) constituting audio songs recorded and stored in a flash memory are used to calculate average volume values of audio songs calculated when a playback operation is performed or a recording operation is performed. If the volume level leveling control mode is set according to the user's request, the recording is stored as additional information at the rear end of the first audio access unit, for example, where the actual recording amount of audio data is relatively low. By searching for the audio access unit and reading out and using the volume average value of the recorded and recorded audio tunes as additional information thereafter, it is possible to make the volume level leveling adjustment operation faster.

Also, as shown in FIG. 6, the volume average value of the audio song calculated at the time of performing the reproducing operation or performing the recording operation is provided as additional information at the rear end of each audio song recorded in the flash memory, that is, each audio music file. If the volume level leveling control mode is set according to the user's request, the volume level leveling control operation can be performed by reading out the volume average value of the recorded audio song at the rear end of the corresponding audio music file. In this case, the information on the volume average value additionally recorded is " TAG " in which additional information, such as a singer's name or a playing time, is additionally recorded at the rear end of the audio music file. It is recorded and stored at the end of the string "."

Therefore, as described above with reference to FIGS. 4A and 4B, the step of accumulating and summing up the scale factor information recorded in the digital audio music file read out from the flash memory to calculate a volume average value of the corresponding audio song is omitted. Instead, the volume average value of additionally recorded audio songs can be read out and used as additional information at the end of the first audio access unit of the corresponding audio song or at the end of the corresponding audio music file, so that the volume level leveling control can be performed more quickly. Will be.

On the other hand, by measuring the volume average value in advance at the time of recording the music file or at the time when the player is not operating, storing the measured value separately in the player's memory, and reading and referring to it when performing the playback operation, Volume level leveling adjustments can also be made more quickly.

In addition, the volume average value of the music file may not be obtained from the player, but may be measured in advance when the music file is created, for example, and provided to the player in the music format by the method shown in the above embodiment.

As mentioned above, preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art can improve and change various other embodiments within the technical spirit and technical scope of the present invention disclosed in the appended claims below. , Replacement or addition would be possible.

The volume leveling device and method in the digital audio device according to the present invention constituted and constructed as described above is a digital recording and storing or reading / playback of digital audio music files such as MP3 (MP3) on a recording medium such as a flash memory. In the audio device, the volume average value of the corresponding audio song is calculated from the scale factor information included in the digital audio music file, and the audio reproduction output is equalized to an appropriate volume, and the volume control value arbitrarily adjusted by the user is reflected. By calculating the relative volume average value, it is possible to vary the audio reproduction output to any desired volume desired by the user. Also, when performing the audio song reproducing operation or recording operation, the volume average value of the audio song is calculated to calculate the corresponding audio song. After the first audio access unit in, or It is a very useful invention that a further volume level leveling control operation is performed by additionally recording as additional information at the rear end of the corresponding audio music file and reading and using the volume level leveling control operation.

Claims (12)

Detecting the volume level information recorded in the digital audio music file; Calculating a volume average value for the digital audio music file based on the detected volume level information; And And varying the intensity of the audio reproduction output based on the calculated volume average value. The method of claim 1, And said step 1 detects scale factor information recorded in each audio frame constituting said digital audio music file. The method of claim 1, In step 3, the intensity of the audio reproduction output is varied by controlling a decoding operation of restoring audio data corresponding to the digital audio music file to original audio data based on the calculated volume average value. Volume leveling method in digital audio equipment. Calculating a volume average value of the decoded digital audio music file; Detecting an output strength arbitrarily set by a user with respect to the output music; And And a three step of varying the output intensity according to the average value of the audio music to be subsequently output based on the ratio of the calculated volume average value and the output intensity set by the user. Volume leveling method for audio equipment. Receiving a digital audio music file through the input means; Calculating a volume average value of the received music data; And And recording and storing the calculated volume average value as additional information. 3. The method of claim 5, And varying intensities of audio reproduction outputs for the digital audio music file based on the recorded stored additional information. The method of claim 5, In the step 3, the volume leveling method of the digital audio device, characterized in that for storing the calculated average value of the volume as additional information at the rear end of the digital audio music file. The method of claim 5, In the step 3, the volume leveling method of the digital audio device, characterized in that for recording the additional volume at the rear end of the first audio access unit of the digital audio music file as additional information. The method of claim 5, In the step 3, the volume leveling method of the digital audio device, characterized in that for recording and storing the calculated volume average value in the storage unit of the digital audio device. The method of claim 5, A volume leveling method in a digital audio device, characterized in that the steps 2 and 3 are executed and recorded in advance in the production of a digital audio music file or before reception by a player. Storage means for temporarily storing and delaying the digital audio music file read out from the recording medium; Restoring means for decoding the digital audio music file delayed output from the storage means and restoring the original audio data; Calculating means for calculating a volume average value for the digital audio music file temporarily stored in the storage means; And And a control means for varying the volume level of the audio data output from the restoring means based on the calculated volume average value. The method of claim 11, And said control means variably controls the decoding operation in said restoring means on the basis of said calculated volume average value and a volume adjustment value arbitrarily adjusted by a user.