JP3387088B2 - Optical recording medium, audio signal transmission method and audio decoding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, a voice signal transmission method and a voice decoding method for predictively encoding and compressing a voice signal.

[0002]

2. Description of the Related Art A Huffman code is known as a method for encoding a voice signal with high efficiency, as disclosed in, for example, Japanese Patent Laid-Open No. 58-75341. In addition, as a method of predictively encoding a voice signal, the present inventor has proposed that in the previous application (Japanese Patent Application No. 9-289159), a single domain original digital voice signal is processed in a time domain by a plurality of predictors having different characteristics. , A plurality of linear prediction values of the current signal are calculated from past signals, and a prediction residual of each predictor is calculated from the original digital audio signal and the plurality of linear prediction values, and the minimum value of the plurality of prediction residuals is calculated. Suggests a way to choose.

[0003]

However, in the above method, the original digital audio signal has a sampling frequency = 96.
In the case of kHz and the number of quantization bits = about 20 bits, some compression effect can be obtained.
Since the audio disk uses twice the sampling frequency (= 192 kHz) and the quantization bit number also tends to be 24 bits, it is necessary to improve the compression rate.

By the way, in order to enable reproduction by both a simple model such as a CD reproducing device and a higher model such as a DVD reproducing device, for example, Japanese Patent Laid-Open No. 9-31206.
As shown in Japanese Patent Publication No. 6, only high-end models can play 2
A method has been proposed in which 0-bit (or 24-bit) sample data is separated into upper 16 bits and lower 4 bits (or 8 bits) that can be reproduced by a simplified model and transmitted.

Therefore, in the present invention, in view of the fact that the upper bit data of each channel of the audio signals of a plurality of channels (channels) have a strong correlation and the lower bit data have no correlation, the audio signals of a plurality of channels are processed. An object of the present invention is to provide an optical recording medium, an audio signal transmission method, and an audio decoding method capable of improving the compression rate when performing predictive coding.

[0006]

In order to achieve the above object, the present invention comprises the following means 1) to 3). That is,

1) converting the digital audio signals of the first plurality of channels having the same sampling frequency and consisting of two systems into the audio signals of the second plurality of channels which are correlated with each other by a predetermined matrix calculation; , The converted second multi-channel audio signal,
The head sample value is obtained in frame units for a predetermined time in response to the audio signal input for each channel, and the linear prediction values of the past to present signal in the time domain are predicted by multiple linear prediction methods with different characteristics. , a linear prediction method, such as prediction residues obtained from the audio signal and the linear prediction value being the predicted is minimized, further said frame
A step of selecting and performing predictive coding in units of divided subframes; a predictive code including a leading sample value of each of the selected channels, a prediction residual, a linear prediction method, and a bit number flag of the prediction residual When packing the encoded data,
Pack the measurement residual with the number of bits based on the bit information
At the same time, the predictive coded data is
Compressed PCM Private Header and Audio Compressed PCM
The data in the user data packetized with the data part
Step of packing in audio compression PCM data section
When, predicted an audio decoding method for decoding the original audio signal from the encoded data by the speech coding method, comprising the top sampled value and the prediction residual and linear prediction method for each channel said it selected consisting of Calculating a prediction value from encoded data, and calculating the first prediction value from the calculated prediction value.
A voice decoding method comprising a step of restoring digital audio signals of a plurality of channels . 2) converting the digital audio signals of the first plurality of channels, which have the same sampling frequency and consist of two systems, into the audio signals of the second plurality of channels which are correlated with each other by a predetermined matrix operation; In response to the audio signal input for each channel, the sampled second multi-channel audio signal is set to the first sample value for a predetermined time.
Of each frame, the linear prediction values of the current signal are predicted from the past in the time domain by a plurality of linear prediction methods having different characteristics, and the prediction residual obtained from the predicted linear prediction value and the speech signal. A linear prediction method that minimizes the difference is used as a subframe obtained by further dividing the frame.
A step of performing predictive coding by selecting in units of rams, and a case of packing predictive coded data including a leading sample value of each selected channel, a prediction residual, a linear prediction method, and a bit number flag of the prediction residual , Bit the prediction residual
With packing the number of bits based on the information, the
Predictive coded data is sent to the packet header and compressed PCM
The header and audio compression PCM data section
The audio compression P in the packetized user data
A voice signal transmission method for transmitting a voice signal encoded by a voice encoding method, which comprises a step of packing in a CM data part, the method comprising: a head sample value of each selected channel, a prediction residual, and a linear prediction. A method for transmitting a voice signal, characterized by packetizing predictive-coded data including the method and transmitting the packet via a communication line. 3) converting the digital audio signals of the first plurality of channels, which have the same sampling frequency and consist of two systems, into the audio signals of the second plurality of channels which are correlated with each other by a predetermined matrix operation; In response to the audio signal input for each channel, the sampled second multi-channel audio signal is set to the first sample value for a predetermined time.
Of each frame, the linear prediction values of the current signal are predicted from the past in the time domain by a plurality of linear prediction methods having different characteristics, and the prediction residual obtained from the predicted linear prediction value and the speech signal. A linear prediction method that minimizes the difference is used as a subframe obtained by further dividing the frame.
A step of performing predictive coding by selecting in units of rams, and a case of packing predictive coded data including a leading sample value of each selected channel, a prediction residual, a linear prediction method, and a bit number flag of the prediction residual , Bit the prediction residual
With packing the number of bits based on the information, the
The predictive coded data contains packet header and compressed PCM
The header and audio compression PCM data section
The audio compression P in the packetized user data
An optical recording medium, which is packed and recorded in a CM data part, and the predictive coded data is recorded as data for calculating a predictive value used for restoring an original audio signal.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a first embodiment of a voice encoding device and a voice decoding device corresponding to the present invention, FIG. 2 is a block diagram showing the encoder of FIG. 1 in detail, and FIG. 3 is a DVD pack. FIG. 4 is an explanatory diagram showing a format, FIG. 4 is an explanatory diagram showing a format of a DVD audio pack, and FIG. 5 is a block diagram showing the decoder of FIG. 1 in detail.

The channel correlation circuit A shown in FIG. 1 has an adding circuit 1a and a subtracting circuit 1b. Each channel (hereinafter, ch) of the adder circuit 1a has, for example, a sampling frequency = 192k.
The sum signal (L + R) of the stereo 2ch signals L and R of Hz and the number of quantization bits = 24 bits is calculated and output to the 1ch lossless encoder 2D1 for sum ch, and the subtraction circuit 1b outputs the difference signal (LR). It is calculated and output to the 1ch lossless encoder for difference channel 2D2. As shown in detail in FIG. 2, the encoders 2D1 and 2D2 each have an upper 16 bits out of 24 bits.
Difference Δ between bit sum signal (L + R) and difference signal (L−R)
(L + R), Δ (L-R) are predictively coded, and
The lower 8 bits are transmitted as they are through a recording medium or a communication medium.

When the original data is 20 bits, the number of upper bits is fixed and the number of lower bits is variable to separate the upper 16 bits and the lower 4 bits. If the original data has 16 bits, the 16-bit data is predictively encoded without separation.

On the decoding side, as shown in detail in FIG. 6, the decoders 3D1 and 3D2 are the upper 16 bits of each channel.
The predictive coded data for bits is decoded into a sum signal (L + R) and a difference signal (LR), and lower 16 bits are added to this 16-bit data to restore the original 24-bit data. Then, the channel correlation circuit B restores the 24-bit sum signal (L + R) and difference signal (LR) to the stereo 2ch signals L and R.

Referring to FIG. 2, encoders 2D1 and 2D2
Will be described in detail. The sum signal (L + R) and the difference signal (LR) are stored in the one frame buffer 10 for each frame. Then, the upper 16-bit sample values (L + R) and (LR) of one frame are applied to the difference calculation circuits 11D1 and 11D2, respectively, and the difference Δ (L + R), Δ (LR) between the current time and the previous time, That is, the difference PCM (D
PCM) data is calculated. In addition, 24-bit data (L + R) and (LR) of the first sample of each frame
And the lower 8-bit data (L + R), (L
-R) is applied to the multiplexer 19.

The difference Δ (L + R) calculated by the difference calculation circuit 11D1 is calculated by a plurality of predictors 12 having different prediction coefficients.
a-1 to 12a-n and subtractors 13a-1 to 13a-n. Then, the predictors 12a-1 to 12a-n calculate the respective predicted values of the difference Δ (L + R) based on the respective prediction coefficients, and the subtractors 13a-1 to 13b-n respectively calculate the respective predicted values and the difference Δ. Each prediction residual of (L + R) is calculated. The buffer / selector 16D1 temporarily stores the plurality of prediction residuals, selects the minimum prediction residual for each subframe designated by the selection signal generator 17, and outputs the selected prediction residual to the packing circuit 18. Note that this subframe has a sample length of about one tenth of the frame, and one frame is 80 subframes as an example. here,
Predictors 12a-1 to 12a-n and subtractors 13a-1 to 1
3a-n form a prediction circuit 15D1 for the sum signal ch, and the prediction circuit 15D1 and the buffer / selector 16D1.
Constitutes a predictive coding circuit for the sum signal ch.

Similarly, the difference Δ (L−R) calculated by the difference calculation circuit 11D2 includes a plurality of predictors 12b-1 to 12b-n having different prediction coefficients and subtractors 13b-1 to 13b.
applied to b-n. Then, the predictors 12b-1 to 12b-12
In b-n, the difference Δ (L-
R) each predicted value is calculated, and the subtracters 13b-1 to 13b
In −n, the respective prediction residuals of the respective prediction values and the difference Δ (L−R) are calculated. The buffer / selector 16D2 temporarily stores the plurality of prediction residuals, and the selection signal generator 17
The minimum prediction residual is selected for each subframe designated by and is output to the packing circuit 18. Predictor 12b-
1 to 12b-n and subtractors 13b-1 to 13b-n form a prediction circuit 15D2 for the difference signal ch, and the prediction circuit 15D2 and the buffer / selector 16D2 form a prediction coding circuit for the difference signal ch. is doing.

The selection signal generator 17 applies the bit number flag of the prediction residual to the packing circuit 18 and the multiplexer 19, and the predictor selection flag indicating the predictor with the minimum prediction residual to the multiplexer 19. To apply.
The packing circuit 18 includes buffers / selectors 16D1 and 16D.
The prediction residuals for 2 channels selected by D2 are packed with the specified number of bits based on the bit number flag specified by the selection signal generator 17.

Next, the multiplexer 19 responds to the upper 16-bit data for one frame: a frame header, a separation flag 120 indicating whether or not the original 24-bit data is separated into upper 16 bits and lower 8 bits, -The start sample value of one frame of the sum signal ch (L + R) -The start sample value of one frame of the difference signal ch (L-R) -The predictor selection flag for each subframe of the sum signal ch (L + R) A predictor selection flag for each sub-frame of the difference signal ch (LR), a bit number flag for each sub-frame of the sum signal ch (L + R), and a sub-signal of the difference signal ch (L-R) A number-of-bits flag for each frame, a prediction residual data string (variable number of bits) of the sum signal ch (L + R), and a prediction residual data string (variable number of bits) of the difference signal ch (L-R) , Many However, output as a variable rate bit stream.

Further, the lower 8 bits which are not predictively coded are output as another bit stream.
According to such predictive coding, when the original signal has, for example, a sampling frequency of 192 kHz and a quantization bit number of 24 bits and two channels, a compression rate of 57% can be realized on average.

When recording the variable rate bit stream data on a DVD audio disc,
It is packed in the audio (A) pack of the compressed PCM shown in FIG. This pack has pack start information of 4 bytes for user data (A packet, V packet) of 2034 bytes and SCR (System Clock) of 6 bytes.
Reference: System time reference value) information, Mux rate information of 3 bytes, and stuffing of 1 byte, a pack header of 14 bytes in total is added (1 pack = 2048 bytes in total). In this case, the SCR information, which is a time stamp, is set to "1" in the first pack in the ACB unit and is consecutive in the same title, so that the time of the A pack in the same title can be managed.

As shown in detail in FIG. 4, the A packet is 1
Packet header of 7, 9 or 14 bytes and compressed PCM
And the compressed audio PCM data of 1 to 2011 bytes in the above format, and the upper 16-bit data and the lower 8-bit data are contained in another A packet. The private header of the compressed PCM includes: 1-byte substream ID, 2-byte UPC / EAN-ISRC (Universal Pr
oduct Code / European Article Number-International S
tandard Recording Code) number and UPC / EAN-
ISRC data, 1-byte private header length, 2-byte first access unit pointer, 8-byte audio data information (ADI), and 0-7 bytes of stuffing bytes. There is.

Next, the decoders D1 and D2 will be described with reference to FIG. The variable rate bit stream data in the above-mentioned format is separated by the demultiplexer 21 based on the frame header. Then, the leading sample values of one frame of the sum signal ch (L + R) and the difference signal ch (L-R) are respectively accumulated operation circuits 25a and 25a.
applied to the sum signal ch (L + R) and the difference signal ch
The (LR) predictor selection flags are predictor (24
a-1 to 24a-n) and (24b-1 to 24b-n) are applied as selection signals, and the number-of-bits flag and the prediction residual data of the sum signal ch (L + R) and the difference signal ch (LR) are applied. The column is applied to the unpacking circuit 22. Further, when the variable rate bit stream data includes lower bit data, the lower bit data is separated and applied to the adders 28a and 28b, and the separation flag is applied as a control signal to the adders 28a and 28b. .

Here, the predictors (24a-1 to 24a-
n) and (24b-1 to 24b-n) are predictors (12a-1 to 12a-n) and (12b-1) on the coding side, respectively.
.About.12b-n) and the same characteristic is selected by the predictor selection flag.

The unpacking circuit 22 adds the sum signal ch (L
+ R) and the prediction residual data sequence of the difference signal ch (LR) are separated based on each bit number flag and output to the adder circuits 23a and 23b, respectively. In the adder circuits 23a and 23b, respectively, the sum signal ch from the unpacking circuit 22 is added.
(L + R) and the current prediction residual data of the difference signal ch (LR) and the predictors (24a-1 to 24a-n) and (24
b-1 to 24b-n), the previous predicted value predicted by each one selected by the predictor selection flag is added to calculate the current predicted value. This forecast value is
Differences Δ (L + R) and Δ (LR) calculated by the difference calculation circuits 11D1 and 11D2 shown in FIG. 2, that is, DPCM data, and predictors (24a-1 to 24a).
-N), (24b-1 to 24b-n) and the cumulative operation circuit 2
5a, 25b.

The cumulative operation circuits 25a and 25b are respectively
Difference Δ (L +
R) and Δ (L-R) are cumulatively added for each sample, and the PCM data (upper 16-bit data) of the sum signal ch (L + R) and the difference signal ch (L-R) are respectively added by an adder 28a,
28b. If the separation flag is "separation present", the adders 28a and 28b output the sum signal ch (L + R),
Each upper 16-bit PCM data of the difference signal ch (LR) and the lower bit PCM data separated by the demultiplexer 21 are added and output, while if the separation flag is "no separation", upper 16 bits The bit PCM data is output as it is.

The sum signal (L + R) and the difference signal (L-R)
As shown in FIG. 1, the adder circuit 4a calculates the 2L signal and the subtractor circuit 4b calculates the 2R signal. Then, the 2L signal and the 2R signal are divided into ½ by the dividers 5a and 5b, respectively, and the original stereo 2
The channel signals L and R are restored.

Next, a second embodiment will be described with reference to FIGS. In the above embodiment, the sum signal (L +
R), each difference Δ (L + R) of the difference signal (LR), Δ (L
-R), that is, it is configured to predictively encode only DPCM data, but in the second embodiment, a sum signal (L + R), a difference signal (LR), that is, PCM data, or each difference Δ thereof. (L + R), Δ (L−R), that is, DPCM data is selectively predictively coded.

Therefore, in the encoding device shown in FIG.
With respect to the configuration shown in (1), a sum signal (L + R) and a difference signal (L-
Prediction circuits 15A for predictively encoding R),
15S and buffer / selectors 16A and 16S are added. Further, the selection signal generator 17 is the buffer / selector 1.
Sum signal (L + selected by 6A and 16S, respectively)
R), difference signal (LR) and buffer / selector 16D
Differences Δ (L +
R), Δ (LR) based on the minimum value of each prediction residual,
It is determined which of the PCM data and the DPCM data has a higher compression rate, and the higher data is selected. At this time, the selection flag (prediction circuit selection flag) of the PCM / DPCM is added and multiplexed.

Here, the prediction circuit 15A for the sum signal (L + R) and the prediction circuit 15D1 for the difference Δ (L + R) shown in FIG. 6 have the same configuration, and the prediction circuit 15S for the difference signal (LR) is the same. When the prediction circuit 15D2 for the difference Δ (L−R) has the same configuration, the decoding device uses PCM as shown in FIG.
It is not necessary to provide prediction circuits for both data and DPCM data, and a prediction circuit for one data is sufficient. Then, based on the prediction circuit selection flag transmitted from the encoder, the selectors 26a and 26b select the outputs of the cumulative operation circuits 25a and 25b in the case of DPCM data, and the PC
In the case of M data, the output of the adder circuits 23a and 23b is selected. Then, the upper 16-bit data and the lower bit data of each channel selected by the selectors 26a and 26b are added by the adders 28a and 28b.

In the third embodiment, as shown in FIG. 8, original signals L and R (PCM data), sum signal (L + R), difference signal (LR) (PCM data), and their respective differences Δ. (L
+ R), Δ (LR) (DPCM data), one of three groups is selectively predictively coded.

Therefore, in the encoding device shown in FIG.
Prediction circuits 15L and 15R and buffer / selectors 16L and 16R for predictively encoding the original signals L and R, respectively, are added to the configuration shown in FIG. The selection signal generator 17 includes the original signals L and R selected by the buffer / selectors 16L and 16R and the buffer / selectors 16A and 16S.
Sum signal (L + R), difference signal (LR) selected by
And the data of the group having a high compression rate based on the minimum value of the prediction residuals of the differences Δ (L + R) and Δ (L−R) selected by the buffer / selectors 16D1 and 16D2. At this time, the selection flag (prediction circuit selection flag) is added and multiplexed.

When the three groups of prediction circuits shown in FIG. 8 have the same configuration, the decoding device does not need to have three groups of prediction circuits as shown in FIG. Good. Then, based on the prediction circuit selection flag transmitted from the encoding device, the output of the cumulative operation circuits 25a and 25b is selected in the case of DPCM data, and the output of the addition circuits 23a and 23b is selected in the case of PCM data. Then, the channel correlation circuit B outputs the original signals L and R.
(Upper 16-bit data) is restored. Then, the selectors 27a and 27b further select the outputs of the adder circuits 23a and 23b in the case of the group of the original signals L and R, and select the output of the channel correlation circuit B in other cases. Next, the upper 16-bit data and the lower bit data of each channel selected by the selectors 27a and 27b are added by the adders 28a and 28b.

In the first to third embodiments described above,
Although the case where the original signal has two channels has been described, the present invention can also be applied to the case of a multi-channel signal. Here, the following four methods are known as multi-channel methods. (1) Dolby Surround system front L, C, R 3 channels + rear S 1 channel 4 channels in total (2) Dolby AC-3 system front L, C, R, SW 4 channels + rear SL, SR 2 channels in total 6 channels (3) DTS (Digital Theater System) system 6 channels (L, C,
(R, SW, SL, SR) (4) SDDS (Sony Dynamic Digital Sound) system 6 channels of front L, LC, C, RC, R, SW + 2 channels of rear SL, SR, total 8 channels

Therefore, the correlation circuit A shown in FIG. 1 uses, as an example of a multi-channel signal, left (L), center (C), right (R), surround left (SL) and surround right (SR) 5ch PCM. Data to L
The channel is converted into the next 5 channels (L) and (D1) to (D4) with reference to the channel. L = L (reference channel) D1 = C− (L + R) / 2 D2 = R−L D3 = SL−a × L D4 = SR−b × R However, 0 ≦ a, b ≦ 1

Then, each channel data of 5 channels is separated into upper 16 bits and lower bits, the upper 16 bits data is predictively encoded and transmitted, and the lower bit data is transmitted as it is. Further, when obtaining the correlation, conversion to the next 5 channels may be performed. L = L (reference channel) D1 = C-L D2 = R-L D3 = SL-L D4 = SR-R

When the variable rate bit stream data predictively coded by the coding side is transmitted through the network, the coding side packetizes it for transmission as shown in FIG. 10 (step S41) and then packetizes it. A header is added (step S42), and then this packet is sent out on the network (step S43). On the decoding side, the header is removed as shown in FIG. 11 (step S
51), then restore the data (step S52), then store this data in memory and wait for decoding (step S53).

[0035]

As described above, according to the present invention, the audio signals of a plurality of channels are separated into upper bit data and lower bit data for each channel, and the upper bit data is predictively coded. It is possible to improve the compression ratio when predictively encoding a multi-channel audio signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a speech coding apparatus and speech decoding apparatus to which the present invention has been applied.

FIG. 2 is a detailed block diagram of the encoder of FIG.

FIG. 3 is an explanatory diagram showing a format of a DVD pack.

FIG. 4 is an explanatory diagram showing a format of a DVD audio pack.

5 is a detailed block diagram of the decoder of FIG. 1. FIG.

FIG. 6 is a block diagram showing an encoder of a second embodiment.

FIG. 7 is a block diagram showing a decoder of the second embodiment.

FIG. 8 is a block diagram showing an encoder of a third embodiment.

FIG. 9 is a block diagram showing a decoder of the third embodiment.

FIG. 10 is a flowchart showing a voice transmission method.

FIG. 11 is a flowchart showing a voice transmission method.

[Explanation of symbols]

1a addition circuit (addition means) 1b subtraction circuit (subtraction means) 10 1 frame buffer (separation means) 11D1 difference calculation circuit (first difference calculation means) 11D2 difference calculation circuit (second difference calculation means) 12a-1 to 12a-1 12a-n predictor (subtractors 13a-1 to 13a-1
13a-n and the buffer / selector 16D1 constitute a first predictive coding means. ) 12b-1 to 12b-n Predictor (subtractor 13b-1 to
13b-n and the buffer / selector 16D2 constitute second predictive coding means. ) 13a-1 to 13a-n, 13b-1 to 13b-n Subtractors 16D1, 16D2, 16A, 16S, 16L, 16R
Buffer / selector 15A Prediction circuit (with buffer / selector 16A
The predictive coding means of is constructed. ) 15S Prediction circuit (fourth with buffer / selector 16S)
The predictive coding means of is constructed. ) 15L prediction circuit (fifth with buffer / selector 16L)
The predictive coding means of is constructed. ) 15R prediction circuit (sixth with buffer / selector 16R)
The predictive coding means of is constructed. ) 19 multiplexer (multiplexing means) A correlation circuit (correlation means)

Continuation of the front page (56) References JP-A 64-44499 (JP, A) JP-A 3-108824 (JP, A) JP-A 6-133252 (JP, A) JP-A 10-233058 (JP , A) JP-A-10-320928 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G10L 19/00

Claims (3)

(57) [Claims] 1. The same sampling frequency and 2
The digital audio signals of the first multiple channels consisting of two channels are correlated with each other by a predetermined matrix operation.
Converting the second multi-channel audio signal into two multi-channel audio signals, and obtaining a leading sample value in frame units of a predetermined time in response to the audio signal input for each channel. At the same time, the linear prediction values of the current signal are predicted from the past in the time domain by a plurality of linear prediction methods having different characteristics, and the prediction residual obtained from the predicted linear prediction value and the speech signal is minimized. the linear prediction methods as further dividing the frame
And a step of performing predictive coding in the selected subframe unit, and packing the predictive coded data including the leading sample value of each selected channel, the prediction residual, the linear prediction method, and the bit number flag of the prediction residual. If the prediction residual is
The predicted coded data with a packet header and a compressed PCM.
Private header and audio compression PCM data section
Audio pressure in user data packetized by
A voice decoding method for decoding an original voice signal from data encoded by a voice encoding method, which comprises a step of packing in a reduced PCM data part , wherein a leading sample value and a prediction residual of each selected channel are included. Calculating a predictive value from predictive coded data including a difference and a linear predictive method, and calculating the predictive value from the calculated predictive value of the first plurality of channels.
A voice decoding method comprising the steps of recovering a digital voice signal. 2. The same sampling frequency and 2
The digital audio signals of the first multiple channels consisting of two channels are correlated with each other by a predetermined matrix operation.
Converting the second multi-channel audio signal into two multi-channel audio signals, and obtaining a leading sample value in frame units of a predetermined time in response to the audio signal input for each channel. At the same time, the linear prediction values of the current signal are predicted from the past in the time domain by a plurality of linear prediction methods having different characteristics, and the prediction residual obtained from the predicted linear prediction value and the speech signal is minimized. the linear prediction methods as further dividing the frame
And a step of performing predictive coding in the selected subframe unit, and packing the predictive coded data including the leading sample value of each selected channel, the prediction residual, the linear prediction method, and the bit number flag of the prediction residual. If the prediction residual is
The predicted coded data with a packet header and a compressed PCM.
Private header and audio compression PCM data section
Audio pressure in user data packetized by
A voice signal transmission method for transmitting a voice signal encoded by a voice encoding method, which comprises the step of packing in a reduced PCM data part , wherein the head sample value and the prediction residual of each selected channel are linear. A method of transmitting a voice signal, characterized in that predictive coded data including a predicting method is packetized and transmitted via a communication line. 3. Same sampling frequency and 2
The digital audio signals of the first multiple channels consisting of two channels are correlated with each other by a predetermined matrix operation.
Converting the second multi-channel audio signal into two multi-channel audio signals, and obtaining a leading sample value in frame units of a predetermined time in response to the audio signal input for each channel. At the same time, the linear prediction values of the current signal are predicted from the past in the time domain by a plurality of linear prediction methods having different characteristics, and the prediction residual obtained from the predicted linear prediction value and the speech signal is minimized. the linear prediction methods as further dividing the frame
And a step of performing predictive coding in the selected subframe unit, and packing the predictive coded data including the leading sample value of each selected channel, the prediction residual, the linear prediction method, and the bit number flag of the prediction residual. If the prediction residual is
The prediction coded data is packed in a packet header and a compressed PCM while being packed by the number of bits based on the packet information.
Private header and audio compression PCM data section
Audio pressure in user data packetized by
An optical recording medium, which is packed and recorded in a reduced PCM data part, and the predictive encoded data is recorded as data for calculating a predictive value used for restoring an original audio signal.