JP2993471B2 - Audio signal processing method, encoding device, recording medium, and decoding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio signal processing method including an audio signal reproducing method, an encoding device, a recording medium, and a decoding device, and more particularly, to level control during reproduction of a digital audio signal and reproduction of a test tone signal. Time mute control.

[0002]

2. Description of the Related Art (1) Generally, when a digital audio signal is recorded and transmitted on a CD (compact disk) or a DVD (digital versatile disk), the S / S
In order to improve the N ratio, the level of the original signal is raised to transmit (write). If the level of the original signal (readout signal) is very high, the original signal is transmitted (output) at a lower level to prevent discomfort during playback or to prevent the speaker from being damaged. ing. In this case, the user can reproduce at a desired level by adjusting the level at the time of reproduction.

(2) In general, a test tone of each channel of, for example, stereo or multi-channel is recorded at a maximum level on a disc, and when reproducing the test tone of each channel, an operator mutes the audio output and sets a level meter. The balance of each channel is checked while watching.

[0004]

However, in the conventional method (1) described above, since the level of the original digital audio signal is merely shifted and transmitted, the user must reproduce the original digital audio signal at the original level. It has to be adjusted and therefore cannot be played back automatically at the original level. However, when performing the above check (2), recording the test tone in all areas of the disc wastes the recording area of the disc. Therefore, a method of recording the test tone together with the mute flag in a part of the disc and muting the audio signal for which the mute flag is set can be considered.In this case, if the frequency of occurrence of the mute flag is increased, the reproduction is performed. There is a problem in that the burden when the device monitors the mute flag increases, and on the other hand, when the frequency of occurrence of the mute flag is reduced, fine mute control cannot be performed.

[0005] The present invention has been made in view of the above problems, a plurality Ji
A first object of the present invention is to provide an audio signal processing method, an encoding device, a recording medium, and a decoding device capable of automatically reproducing an original digital audio signal of a channel when the level of the signal is shifted and transmitted. Aim. Also, in view of the above problems, the present invention increases the burden when the playback device monitors a mute flag when recording a test tone on a disc and muting the audio output during playback and checking while looking at the level meter. It is a second object of the present invention to provide an audio signal processing method, an encoding device, a recording medium, and a decoding device capable of performing fine muting control without performing.

[0006]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention shifts the levels of original digital audio signals of a plurality of channels by a common shift amount at predetermined time intervals and transmits the signals. In such a case, the level shift data is added, and the reproduction side returns to the original level based on the common level shift data. That is, according to the present invention, the analog audio signals of a plurality of channels its
Comprising the steps of A / D conversion respectively a plurality of digital audio signals, comprising the steps of shifting the level of said plurality of digital audio signals at every predetermined time by a common shift amount, the digital audio signal the level is shifted Adding the common level shift data to the digital audio signal and the common
And transmitting through the medium of a shift amount level shift data indicating the said digital audio signal
And returning to their original level based on the level shift data indicating a common shift amount, the processing method of the audio signal with is provided.

Further, according to the present invention, the A / D converting means for A / D conversion of analog audio signals of a plurality of channels into digital audio signals of a plurality of channels, the A /
When the levels of the digital audio signals of a plurality of channels converted by the D conversion means are determined at a predetermined time by a common shift amount
And level shifting means for shifting between every, the level shift data adding means for adding a level shift data indicating the common shift amount with respect to the digital audio signal is level-shifted by the level shift means, having an audio signal Is provided.

According to the present invention, a recording area of an auxiliary signal is recorded.
Audio where the area and the main signal recording area are
(E) a recording medium for a signal, wherein the recording area is
Multiple channels shifted at predetermined time intervals by the same shift amount.
Channel digital audio signal and the plurality of channels
Indicates the level shift amount of the digital audio signal
And a recording medium for an audio signal on which the level shift data is recorded .

Further, according to the present invention, the analog audio signals of a plurality of channels A / D conversion into digital audio signals of a plurality of channels, predetermined by a common shift amount level of the digital audio signal of the plurality of channels
It shifted every time a plurality tea which the level is shifted
Said common shift relative channel digital audio signal
A decoding apparatus for decoding the recording medium of the audio signals recorded by adding a level shift data indicating the bets amount, multiple digital audio signals of the plurality of channels
An audio signal decoding device having level control means for returning to an original level based on the level shift data indicating a shift amount common to several channels is provided.

According to the present invention, in order to achieve the second object, a control pack including control information for reproducing an audio signal is arranged for each of a plurality of audio packs, and an audio pack on which a test tone signal is arranged. The mute control information for muting the test tone is arranged in the control pack for controlling the audio signal, and the reproduction side mutes the analog reproduction output of the audio signal in the audio pack controlled by the control pack including the mute control information. Things. That is, according to the present invention, A / D conversion of an analog audio signal of one or more channels including a test tone signal into a digital audio signal, arranging the digital audio signal in an audio pack, Mute control information for muting the test tone in a control pack for controlling an audio pack in which the test tone signal is arranged, while arranging a control pack including control information for reproducing Arranging; transmitting the arranged audio packs and control packs through a medium; decoding the transmitted audio packs and control packs; and providing the decoded control packs with mute control information. If it contains A step of controlling pack to mute the analog playback output of the audio signal in the audio pack controlled, method of processing an audio signal having is provided.

According to the present invention, A / D conversion means for A / D converting an analog audio signal of one or more channels including a test tone signal into a digital audio signal, and disposing the digital audio signal in an audio pack Arranging means for arranging, and a control pack including control information for reproducing the digital audio signal are arranged for each of a plurality of audio packs, and the test pack is arranged in a control pack for controlling the audio pack in which the test tone signal is arranged. An audio signal encoding device having mute control information arranging means for arranging mute control information for muting a tone is provided.

According to the present invention, the recording area of the auxiliary signal is
Audio where the area and the main signal recording area are
(E) a recording medium for the signal, wherein the recording area for the main signal includes:
One or more channels of digital audio including test tone signals
Storing the audio signal in the audio pack, as well as sequence control pack containing the control information for reproducing the digital audio signal for each of a plurality of audio packs, control for controlling the audio pack the test tone signals are stored There is provided a recording medium for an audio signal in which mute control information for muting the test tone is stored and recorded in a pack.

According to the present invention, an analog audio signal of one or more channels including a test tone signal is A / D converted into a digital audio signal, and the digital audio signal is arranged in an audio pack. A control pack including control information for reproducing a plurality of audio packs is arranged for each of a plurality of audio packs, and mute control information for muting the test tone in a control pack for controlling an audio pack in which the test tone signal is arranged is provided. What is claimed is: 1. A decoding device for decoding a recording medium of an audio signal arranged and recorded, comprising: decoding means for decoding the transmitted audio pack and control pack; and wherein the decoded control pack includes mute control information. Audio controlled by control pack And muting means for muting the analog playback output of the audio signal in Tsu the click, the decoding apparatus of an audio signal with is provided.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an encoding apparatus in an embodiment of an audio signal processing method, an encoding apparatus, a recording medium, and a decoding apparatus according to the present invention, and FIG. 2 shows processing of a level shift circuit and a level detection circuit in FIG. FIG. 3 is a block diagram showing the signal processing circuit of FIG. 1 in detail, FIG. 4 is an explanatory diagram showing a sampling cycle and a data string of the A / D converter of FIG. 1, and FIG. 5 is packed by the allocation circuit of FIG. FIG. 6 is an explanatory diagram showing user data, FIG. 6 is an explanatory diagram showing a DVD-video format and a DVD-audio format packed by the DVD encoding circuit in FIG. 1, and FIG. 7 is a diagram showing the audio content block unit in FIG. FIG. 8 is an explanatory diagram showing the format of the audio pack and the video pack of FIG. 7 in detail; 9 is an explanatory diagram showing the format of the audio control pack of FIG. 7 in detail, FIG. 10 is an explanatory diagram showing the format of the audio character display (ACD) area of FIG. 9 in detail, and FIG. 11 is a format of the audio reproduction control information area of FIG. FIG. 12 is an explanatory diagram showing the format of the audio search data area of FIG. 9 in detail, FIG. 13 is an explanatory diagram showing a DVD-Audio recording area, FIG. 14 is a block diagram showing a decoding device,
FIG. 15 is a block diagram showing the signal processing circuit of FIG. 14 in detail, and FIG. 16 is an explanatory diagram showing a data string decoded by the decoder of FIG. 14 and a sampling period.

The input terminal IN shown in FIG.
A channel analog audio signal is input. This signal is converted by the A / D converter 31 to a high sampling frequency,
For example, the signal is sampled at 192 kHz, converted to a 24-bit high-resolution PCM signal, and the PCM audio signal of each channel is applied to the level shift circuit 101 and the level detection circuit 102.

FIG. 2A shows an example in which the level range is M
AX = 0 dB to MIN = -144 dB, and among the maximum levels Lmax1 to Lmax6 of the channels Ch1 to Ch6,
The case where the maximum level Lmax2 of the channel Ch2 is the highest is shown. Lmax2> Lmax1 = Lmax3>Lmax4>Lmax5> Lmax6 When the level detection circuit 102 detects the maximum level Lmax2 of the channel Ch2, the level shift control data corresponding to (0-Lmax2) dB is converted to the level shift circuits 101 and D.
Output to the VD encoding circuit 34. Level shift circuit 10
1 is based on the level shift control data,
As shown in (b), the levels of the channels Ch1 to Ch6 are increased by (0-Lmax2) dB, and 24 bits are compressed to 20 bits. Therefore, channel Ch2
Is increased to the maximum value of the 20-bit PCM data.

The channel C thus level-shifted
As shown in FIG. 4, the PCM data of h1 to Ch6 are data strings xb1, x1, xa1, x2, xb2, x3, xa2,..., x corresponding to the sampling period Δt (curve α).
bi, x2i-1, xai, x2i,...

This data sequence (xbi, x2i-1, xai, x2
i) shows the signal processing circuit 32 and the memory 3 shown in detail in FIG.
3 and then the DVD encoding circuit 34
Packed by. This packing data is output to the output terminal OUT1, or is modulated by the modulation circuit 35 in a modulation method according to the medium and output to the output terminal OUT2.

The configuration of the signal processing circuit 32 will be described in detail with reference to FIG. First, a low-pass filter 36 for passing a half band, for example, an FIR filter, is used as shown in FIG.
(Xbi, x2i-1, xa)
i, x2i), a data sequence xc1, *, *, *, xc2, *, *, *, xc3, *, *, corresponding to the band-limited curve β
*,..., Xci, *, *, *,..., And by thinning out the data "*" from the data string by the thinning circuit 37, the data string xc1, xc2, xc3,. , Xci, ... are generated. In addition, data strings (xbi, x2i-1, xai, x
2i), the data sequence xb1, xa1, xb2, xa2,..., Xbi, xai,.

Then, these data strings xci, xbi, x
Based on ai, a difference calculator 39 composed of an adder
To calculate the difference xbi−xci = Δ1i xai−xci = Δ2i. Here, the data sequence xci is a data sequence in which the sampling frequency is reduced to ４ by limiting the band of the digital data level-shifted by the level shift circuit 101. The difference data Δ1i and Δ2i are, for example, 20 bits or less, and the number of bits may be fixed or variable.

As shown in FIG. 5, the allocation circuit 40 packs the data string xci and the difference data Δ1i and Δ2i as user data. When the user data is 2034 bytes like a DVD, the data xci and the difference data Δ1i and Δ2i are both 225, and the subheader is 9 bytes. Next, the DVD encoding circuit 34 packs the above-mentioned level shift control data and control data and user data as described later,
5 modulates the output signal of the DVD encoding circuit 34 according to the medium, and this modulated signal is recorded on a recording medium such as a DVD (digital video disk, digital versatile disc).
Disc) or transmitted to a transmission path.

Next, a DVD-audio format according to the present invention will be described with reference to FIGS. FIGS. 6A and 6B show DVD-video and D-video, respectively.
Each format of VD-Audio is shown. In the format of DVD-Audio, although the name of the area is different,
Compatible with D-Video. First, DVD-
The video format is the first video manager (VM
G) followed by multiple video titles (Titl
e) The DVD-Audio format is correspondingly constituted by an audio manager (AMG) followed by the respective areas of a plurality of audio title sets (ATS). I have.

Each of the VTSs is composed of the first VTS information (VTSI), followed by one or more video content block sets (VCBS) and the last VTSI, while each of the ATSs corresponds to the first ATS. Information (ATSI) followed by one or more audio content block sets (A
CBS) and the last ATSI. VC
Each of the BSs is constituted by a plurality of VCBs, while
Each of the BSs is configured by a plurality of ACBs. VC
Each of B is constituted by a plurality of Chapters, whereas each of the ACBs is constituted by a plurality of Tracks correspondingly. Both chapters and tracks are part-of-title (PTT)
including.

Each of the chapters includes a plurality of cells (CELL).
On the other hand, each of the tracks is correspondingly constituted by a plurality of indexes (Index). Each cell has a plurality of VCB units (VCBU)
On the other hand, each index is correspondingly constituted by a plurality of ACB units (ACBU). Each of the VCB unit and ACB unit is
Each pack is composed of a plurality of packs, and one pack is composed of 2048 bytes.

Each of the VCB units has a head navigation control pack (hereinafter referred to as a CONT pack).
, Followed by a plurality of video (V) packs, audio (A) packs, and sub-picture (SP) packs. On the other hand, each ACB unit corresponds to the first audio control pack (hereinafter referred to as A). -C
ONT pack), followed by a plurality of A packs and V packs. Subsequent V in CONT pack
Information for controlling the pack is arranged, and information for controlling the subsequent A pack is arranged in the A-CONT pack.

As shown in FIG. 7, the VCB unit is composed of packs of 0.4 to 1.0 seconds.
The CB unit is composed of packs for 0.5 to 1.0 seconds. The A-CONT pack in the DVD-Audio ACB unit is arranged in the third pack in the DVD-Video VCB unit. A
-The CONT pack is basically arranged in units of 0.5 second of the audio time, and 0.5 to
It is arranged to be completed within a range of 1.0 second. Audio time (GOF: Group of Audio Frame unit)
Is indicated by an A-CONT pack, and its data position is determined by the number of the audio frame number, the first access unit pointer and the frame header. The A-pack immediately before the A-CONT pack does not force padding in units of 0.5 seconds of the audio time.

Adjacent A-packs A1 are arranged so that audio signals are related to each other. For example, in the case of stereo, an L-channel pack and an R-channel pack are arranged adjacent to each other. Also in the case of the above, they are similarly arranged adjacently. The V pack is arranged adjacent to the A pack A when displaying an image during reproduction of an audio signal. A pack and V pack are shown in FIG.
As shown in FIG. 7, pack start information of 4 bytes, SCR information of 6 bytes, and mux ra of 3 bytes for 2034 bytes of user data (A data and V data shown in FIG. 7).
A total of 14 bytes of te information and 1-byte stuffing are added (1 pack = 2048 bytes in total).

On the other hand, as shown in FIG. 9, the A-CONT pack has a pack header of 14 bytes, a system header of 24 bytes, an ACD (Audio Character Display) packet of 1003 bytes, and an ASD (Audio Character Display) of 1007 bytes. Audio search data) packet. The ACD packet has a 6-byte packet header, a 1-byte substream ID,
A 636-byte AC as shown in detail in FIGS.
D (Audio Character Display) information and 36
It consists of a 0-byte reserved area. The ASD packet also has a 6-byte packet header and a 1-byte substream ID, and a 1-byte as shown in detail in FIG.
It is composed of ASD (audio search data) of 000 bytes.

The ACD information area of 636 bytes is shown in FIG.
0, a 48-byte general information area, a 93-byte namespace area,
Two free space areas of bytes, a data pointer area of 15 bytes, and two free space areas as shown in detail in FIG.
It is composed of a 94-byte audio reproduction control information area. In this example, the 294-byte audio reproduction control information area is composed of 10 types of audio reproduction control information area (250 bytes) of 25 bytes each, level shift control data of 3 bytes, and a reserved area of 41 bytes. In one type of audio reproduction control information area, 20 bytes of graphic equalizer information, 3 bytes of level balance information, and 2 bytes of reverberation additional information are arranged.

These pieces of audio playback control information are used when the user plays the music arranged in the A-pack.
For example, according to the genre (classical, jazz, rock, BGM) of the music, and even in the same genre, according to the playing state, recording state, atmosphere, etc. of the music, the sound quality at the time of reproduction is optimized. This is the data recommended by so-called professional mixers.

As shown in detail in FIG. 12, the 1000-byte ASD (audio search data) has 16-byte general information, 8-byte current song number information,
16-byte current time information, 8-byte album set search information, 8-byte album search information,
It is composed of track search information of 04 bytes, index search information of 408 bytes, highlight search information of 80 bytes, and a reserved area of 52 bytes.

Data in such a format is shown in FIG.
13 is recorded on a master disk after being subjected to EFM modulation or the like by a modulation circuit 35, and data on this master disk is stored in a DVD-Audio disk 7 as shown in FIG.
Is transferred to The DVD-Audio disk 7 has a radius D of 12 cm, for example, and a small
The disk 7 has a first lead-in area 7a, a first data area 7b, a first lead-out area 7c, a second lead-in area 7d, and a second data area 7e from the inner circumference to the outer circumference. , A second lead-out area 7f is provided.

Next, the decoder will be described with reference to FIG. DVD-Audio disc 7 shown in FIG.
Is read by a DVD-audio drive (not shown), demodulated by a demodulation circuit 41 in accordance with the modulation method of a modulation circuit 35 on the encoder side, and then A-packed and A-decoded by a DVD decoding circuit 42.
-Decoded to CONT pack or the like.

The user data (data sequence xci and difference data Δ1) in the A-pack decoded by the DVD decoding circuit 42
i, Δ2i) are applied to the signal processing circuit 43 (and the memory 44) shown in detail in FIG. In the signal processing circuit 43, as shown in FIG. 15, first, Δ1i + xci = xbi Δ2i + xci = xai is calculated by the adder 46, and the data strings xbi and xai are restored. Here, the data strings xbi and xai are 20 bits.

Next, in the interpolation processing circuit 47, the data string xa
Using a plurality of data i and xbi, a data sequence xi therebetween is interpolated as shown in FIG. Note that the interpolation processing circuit 47 can obtain the interpolation data sequence xi by, for example, using an up-sampling method and filling the data with 0 data and passing the data through a low-pass filter.
The interpolation data sequence xi may be obtained by curve approximation or prediction approximation. In this case, the approximation degree can be increased by additionally transmitting the approximation auxiliary data.

The data subjected to the interpolation processing as described above is represented by xb1, x1, xa1, x2, xb2, x3, xa2,.
Original PCM data (xbi, x2i-1, xai, x2, xbi, x2i-1, xai, x2i,...)
i), and is applied to a level / sound quality control unit 48 composed of a level shift unit / equalizer unit / level balance control unit / reverberation control unit.

A screen for instructing whether to return the level to the original level is displayed on the display section 61 shown in FIG. The display unit 61 also displays a screen for selecting audio playback control information arranged in the A-CONT pack shown in FIG. 11, and allows the user to start playback of music on the A pack or during playback. For example, 10 displayed on the display unit 61
One of the pieces of audio reproduction control information can be selected via the operation unit 62. When the user performs a sound quality selection operation or a level instruction, the control unit 63 outputs a selection signal or a level control signal of the audio reproduction control information to the level / sound quality control unit 48.

The level / sound quality control section 48 is constituted by, for example, a DSP. When an instruction to restore the level is given, the level / sound quality control section 48 is controlled based on the level shift control data corresponding to the level shift on the encoder side. As shown in a), the levels of the channels Ch1 to Ch6 are lowered by (0-Lmax2) dB. Therefore, even if the level of the original digital audio signal is shifted on the encoder side, it can be automatically returned to the original level on the decoder side. Here, since the A-CONT pack including the level shift control data is basically arranged in units of 0.5 seconds of the audio time,
The level can be adjusted automatically in this time unit. The level / sound quality control unit 48 also performs a data sequence (xbi, xbi) based on the graphic equalizer information in the audio reproduction control information, the level balance information and the reverberation additional information.
2i-1, xai, x2i), the level of each frequency band is changed, the level of each of the six channels is changed, and reverberation is added.

The output signal of the level / sound quality control unit 48 is shown in FIG.
4 is applied to a D / A converter 45 and an LPF (low-pass filter) 56. In the D / A converter 45, the 20-bit data sequence (xbi, x2i-1, xai, x2i) whose sound quality and level are controlled is converted into an analog signal and output via an analog output terminal 55. Also,
In the LPF 56, the input data is limited to, for example, a band of ４, and is output as digital data via the output terminal 53. When the decryption unit 50 determines that the personal identification number input via the terminal 49 is authentic, it turns on the switch 51, whereby the high-quality PCM which is not band-limited.
The data (xbi, x2i-1, xai, x2i) is the switch 51,
It is output via the digital output terminal 52.

Next, a second embodiment relating to "mute control" will be described with reference to FIGS. FIG. 17 is a block diagram illustrating an encoding device according to the second embodiment, FIG. 18 is an explanatory diagram illustrating audio reproduction control information according to the second embodiment, FIG. 19 is a block diagram illustrating a decoding device according to the second embodiment, FIG. 20 shows FIG.
6 is a flowchart showing mute control of the control unit.
FIG. 21 is a block diagram showing a modification of the decoding device shown in FIG.

The encoding device shown in FIG. 17 corresponds to FIG. 1 in the first embodiment, and the level shift circuit 101 and the level detection circuit 102 shown in FIG. 1 are omitted.
That is, in the second embodiment, a PCM signal sampled at, for example, 192 kHz by the A / D converter 31 and converted at a high resolution of, for example, 24 bits is converted into a bit stream without level shift. Are arranged in the user data area in the A pack shown in FIG.

In the second embodiment, for example, when a disc can record an audio signal for about one hour,
It is a sine wave of 400 Hz for about a second and has a maximum level (0
The test tone of (dB) is input, converted into a PCM signal, converted into a bit stream, and arranged in the user data area in the A-pack. Further, as shown in FIG. 18, the audio reproduction control information area in the A-CONT pack includes 10 types of audio reproduction control information areas (2 bytes each) of 25 bytes.
50 bytes), a 1-byte mute flag (F) data area, and a 43-byte reserved area.
The VD encoding circuit 34 manages the A-pack in which the test tone is arranged based on an external instruction.
Set the mute flag in the pack. If the audio signal is multi-channel, the mute flag may be provided for each channel. Other configurations of the encoding device, other formats and the data structure of the disc are the first.
The description is omitted because it is the same as that of the first embodiment.

The decoding device shown in FIG. 19 corresponds to FIG. 14 in the first embodiment. The operation unit 62 has a mute button for the operator to give a mute instruction,
Further, an analog mute circuit 108 and a level meter 109 are added at the subsequent stage of the D / A converter 45. The other configuration of the decoding device is the same as that of the first embodiment except for the one relating to “level shift”, and thus the description is omitted.

In such a configuration, A shown in FIG.
The mute flag (F) in the audio reproduction control information area in the CONT pack is separated by the DVD decoding circuit 42, and the control unit 63 controls the mute as shown in FIG. Perform control. Here, when the mute button of the operation unit 62 is pressed, the control unit 63 sets “mute instruction present” when the mute button flag buffer is “no mute instruction”, and on the other hand, sets the mute button flag buffer to “mute instruction”. When "Yes", "No mute instruction"
Set to. The control unit 63 also has a buffer area for storing the mute F in the previous A-CONT pack.

In FIG. 20, first, it is determined whether or not the mute button is turned on (step S1). If YES, the process proceeds to step S2, and if NO, the process proceeds to step S4. In step S2, it is determined whether or not the previous time is "with mute instruction". If NO, the process proceeds to step S3, where "mute instruction is present" is set and the mute circuit 10
Turn on 8 and end. On the other hand, if YES in step S2, the process proceeds to step S5. In step S4, it is determined whether or not the previous time is "no mute instruction", and YES
In the case of, the process proceeds to step S5. On the other hand, in the case of NO, the process proceeds to step S8 to turn off the mute circuit 108,
finish.

In step S5, it is determined whether or not the current mute flag is "1" = mute on. If YES, the flow proceeds to step S6, and if NO, the flow proceeds to step S7. In step S6, it is determined whether or not the previous mute flag is "1". In the case of NO, the mute flag has changed from previous time "0" to this time "1", so that the process proceeds to step S4, and the mute circuit 108 is activated. On, on the other hand, Y
In the case of ES, the mute flag is set to “1” both last time and this time
Therefore, the process ends.

In step S7, it is determined whether or not the previous mute flag is "0". In the case of YES, the mute flag continues to be "0", so that the process ends.
In the case of NO, the mute flag has changed from "1" in the previous time to "0" in the present time, so that the flow proceeds to step S8 to turn off the mute circuit 108.

Therefore, according to the second embodiment, since the A-CONT pack in which the mute flag is arranged is basically arranged in units of 0.5 second of the audio time, the test tone is recorded on the disc. When the audio output is muted at the time of reproduction and checking is performed while looking at the level meter 109, fine muting control can be performed without increasing the burden when the reproducing apparatus monitors the mute flag.

The analog type mute circuit 108
The digital mute circuit 108 and the level meter 109 may be provided before the D / A converter 45 as shown in FIG. As shown by the broken line, only the analog level meter 109 is
It may be provided after the / A converter 45.

[0050]

According to the present invention as described above, according to the present invention, multiple
Common level of the original digital audio signal having the channel
When transmission is performed by shifting the data at predetermined time intervals according to the shift amount , the level shift data is added, and the level is returned to the original level based on the common level shift data on the reproducing side. In the case where the level of the audio signal is shifted and transmitted, it can be automatically reproduced at the original level. According to the present invention, a control pack including control information for reproducing an audio signal is arranged for each of a plurality of audio packs, and a test tone is included in a control pack for controlling an audio pack in which a test tone signal is arranged. Since the mute control information for muting the audio signal is arranged, and on the reproduction side, the control pack including the mute control information mutes the analog reproduction output of the audio signal in the audio pack for controlling the reproduction. Fine mute control can be performed without increasing the burden when monitoring the data .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an encoding device in an embodiment of an audio signal processing method, an encoding device, a recording medium, and a decoding device according to the present invention.

FIG. 2 is an explanatory diagram showing processing of a level shift circuit and a level detection circuit of FIG. 1;

FIG. 3 is a block diagram illustrating a signal processing circuit of FIG. 1 in detail;

FIG. 4 is an explanatory diagram showing a sampling cycle and a data string of the A / D converter of FIG. 1;

FIG. 5 is an explanatory diagram showing user data packed by the allocation circuit of FIG. 3;

FIG. 6 shows a DVD-video format and a DV format shown in FIG.
FIG. 3 is an explanatory diagram illustrating a DVD-audio format packed by a D encoding circuit.

FIG. 7 is an explanatory diagram showing the audio content block unit of FIG. 6;

8 is an explanatory diagram showing the format of the audio pack and the video pack of FIG. 7 in detail.

9 is an explanatory diagram showing the format of the audio control pack of FIG. 7 in detail.

FIG. 10 is an explanatory diagram showing a format of an audio character display (ACD) area in FIG. 9 in detail.

11 is an explanatory diagram showing a format of an audio reproduction control information area in FIG. 10 in detail.

12 is an explanatory diagram showing the format of the audio search data area of FIG. 9 in detail.

FIG. 13 is an explanatory diagram showing a DVD-Audio recording area.

FIG. 14 is a block diagram illustrating a decoding device.

FIG. 15 is a block diagram showing the signal processing circuit of FIG. 14 in detail.

16 is an explanatory diagram showing a data string decoded by the decoder of FIG. 14 and a sampling period.

FIG. 17 is a block diagram illustrating an encoding device according to a second embodiment.

FIG. 18 is an explanatory diagram showing audio reproduction control information according to the second embodiment.

FIG. 19 is a block diagram illustrating a decoding device according to a second embodiment.

FIG. 20 is a flowchart illustrating mute control of the control unit in FIG. 19;

FIG. 21 is a block diagram showing a modification of the decoding device in FIG. 19;

[Explanation of symbols]

7 DVD audio disk (recording medium) 31 A / D converter (A / D conversion means) 34 DVD encoding circuit (level shift data adding means, layout means, mute control information layout means) 42 DVD decoding circuit (decoding means) 45 D / A converter (D / A conversion means) 48 Level / sound quality control section (level control means) 61 display section 62 operation section (operation means) 63 control section 101 level shift circuit (level shift means) 102 level detection circuit 108 mute Circuit (Mute means) 109 Level meter

Claims (11)

(57) [Claims] A step of A / D converting each of a plurality of channels of analog audio signals into a plurality of digital audio signals; and setting a level of the plurality of digital audio signals to a common system.
A step of shifting the predetermined time intervals by the shift amount, and the step of adding the common level shift data to the digital audio signal the level is shifted, the digital audio signal and said common shift amount shown
Transmitting a to level shift data through a medium, the digital audio signal to said common shift amount shown
And returning to their original level based on to the level shift data, method of processing an audio signal having. 2. The audio signal according to claim 1, further comprising a step of D / A converting the digital audio signal of the original level into an analog audio signal and outputting the analog audio signal.
Processing method. 3. A / D converting means for A / D conversion of the analog audio signals of a plurality of channels into digital audio signals of a plurality of channels, de <br/> digital multi-channel converted by the A / D conversion means The level of the audio signal is adjusted by a common shift amount.
Shows Te and level shifting means for shifting every predetermined time, the common shift amount to the de <br/> digital audio signal is level-shifted by the level shift means
And a level shift data adding means for adding level shift data. 4. A recording area for an auxiliary signal and a recording area for a main signal.
Are recording media for audio signals that are arranged consecutively.
Therefore, according to the shift amount common to the recording area of the main signal,
Digital audio of multiple channels shifted at predetermined time intervals
Audio signal and the multi-channel digital audio
Common level shift data indicating the level shift amount of the signal
And a recording medium for an audio signal on which is recorded . 5. An A / D converter for converting a plurality of channels of analog audio signals into a plurality of channels of digital audio signals, and shifting the levels of the plurality of channels of digital audio signals by a common shift amount at predetermined time intervals. a decoding apparatus for decoding the recording medium of the shifted multiple channels of digital audio signal audio signal recorded by adding a level shift data indicating the common shift amount with respect to the digital audio signal of the plurality of channels Multiple tea
An audio signal decoding device, comprising: level control means for returning to an original level based on the level shift data indicating a shift amount common to a channel . 6. An operation unit for a user to instruct whether to return the digital audio signal to an original level based on the level shift data, and the level control unit transmits the digital audio signal via the operation unit. 6. The audio signal decoding apparatus according to claim 5, wherein the level of the digital audio signal is controlled based on the content specified by the instruction. 7. A / D conversion of an analog audio signal of one or more channels including a test tone signal into a digital audio signal, arranging the digital audio signal in an audio pack, and reproducing the digital audio signal A control pack including control information for performing the test tone signal is arranged for each of a plurality of audio packs, and mute control information for muting the test tone is arranged in a control pack that controls an audio pack in which the test tone signal is arranged. Transmitting the arranged audio packs and control packs through a medium; decoding the transmitted audio packs and control packs; and the decoded control packs include mute control information. If the control And a step of muting the analog playback output of the audio signal in the audio pack click controls, method of processing an audio signal having. 8. A / D conversion means for A / D converting an analog audio signal of one or more channels including a test tone signal into a digital audio signal, arranging means for arranging the digital audio signal in an audio pack, A control pack including control information for reproducing a digital audio signal is arranged for each of a plurality of audio packs, and the test tone is muted in a control pack for controlling an audio pack in which the test tone signal is arranged. An audio signal encoding device, comprising: mute control information arranging means for arranging mute control information. 9. A recording area for an auxiliary signal and a recording area for a main signal.
Are recording media for audio signals that are arranged consecutively.
Therefore, a test tone signal is included in the main signal recording area.
Audio of one or more digital audio signals
Stored in Opakku, as well as sequence control pack containing the control information for reproducing the digital audio signal for each of a plurality of audio packs, the inside control pack for controlling the audio pack the test tone signals are stored An audio signal recording medium storing and recording mute control information for muting a test tone. 10. A control for A / D converting an analog audio signal of one or more channels including a test tone signal into a digital audio signal, arranging the digital audio signal in an audio pack, and reproducing the digital audio signal. A control pack containing information is arranged for each of a plurality of audio packs, and mute control information for muting the test tone is arranged and recorded in a control pack for controlling an audio pack in which the test tone signal is arranged. What is claimed is: 1. A decoding device for decoding a recording medium of an audio signal, comprising: decoding means for decoding the transmitted audio pack and control pack; and controlling the control pack when the decoded control pack includes mute control information. Audio in audio pack And muting means for muting the analog reproduction output O signal decoding apparatus of an audio signal having. 11. An operation unit for setting and canceling mute of an analog reproduction output of an audio signal in an audio pack, wherein the mute unit is configured to mute based on a content instructed through the operation unit. The set,
11. The audio signal decoding device according to claim 10, wherein the audio signal is canceled.