JP3386070B2 - Audio signal encoding and decoding methods - 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 encoding method and an audio signal decoding method, and more particularly to a data structure of a disc represented by a DVD audio disc.

[0002]

2. Description of the Related Art A CD (Compact Disc) is known as a conventional optical disc for audio reproduction. Also, a DVD (digital video disc) is known as an optical disc having a higher density than that of a CD. However, D
In VD (hereinafter referred to as DVD-video), a video signal is recorded as a main signal and an audio signal is recorded as a sub signal, which causes the following problems. (1) The audio signal is integrated with the video signal, and the recording capacity of the audio signal is small. (2) The time of the audio signal cannot be managed. (3) Simple character information such as song title cannot be retrieved.

Since audio users have a wider range of usage than video, a simple reproduction method is required by providing a TOC (table of contents) area like a CD. However, with DVD-Video, a navigation control pack (CONT
Pack) and a plurality of video (V) packs and audio (A) packs to configure a video content block unit and control playback of V and A packs by the CONT pack. There is a problem that it cannot be easily played back and is inconvenient to use.

Further, in the DVD-video, since the time management is performed only in video frame units, even if an audio signal is mainly recorded, the continuity of the audio signal is more important than that of the video, so that it is difficult to manage the real time. There is a problem that is.

Therefore, when an audio signal is mainly recorded, it can be easily reproduced for a user and is convenient, and in order to simplify real-time management, an audio data is stored in a pack including audio data. A DVD audio disc provided with a control pack including information for managing the disc can be considered.

[0006]

By the way, when an audio signal is recorded on such a DVD audio disc, since it is an optical disc having a higher density than that of a CD, a long-term audio signal can be transmitted in addition to a stereo signal of two left and right channels. It is possible to record with multi-channel signals of 5, 6, and 8. Therefore, the recorder side changes the number of channels, the sampling frequency and the number of quantization bits for recording depending on the disc, album, and song, changes the sampling frequency according to the channel, and changes the band depending on the channel. If it is possible to record with a narrower recording area, it is possible to realize a DVD audio disk having a desired recording time and various DVD audio disks having different recording times and sound qualities. Here, it is essential that such various DVD audio discs have compatibility with each other so that one type of player can reproduce them.

Therefore, according to the present invention, the recording side can record the audio signal so that the recording time and the sound quality of the audio signal are different from each other and the recording time is substantially constant. It is an object of the present invention to provide an encoding method and a decoding method of an audio signal that can be reproduced by one type of player even if they are different.

[0008]

In order to achieve the above object, the present invention comprises means described in 1) and 2) below. That is, 1) the number of quantized bits is different for each of the channels of the first group and the channels of the second group, in which the analog audio signals are allocated to the channels of the first group and the channels of the second group of the multi-channel, respectively. And a step of A / D-converting at a sampling frequency to generate a digital audio signal, and a recording area of the auxiliary signal and a recording area of the main signal are continuously arranged so that the first signal is recorded in the recording area of the main signal. Each digital audio signal A / D-converted with a different number of quantization bits and sampling frequency for each channel of the group and the channel of the second group is recorded.
An audio pack consisting of a Dio pack and the audio pack.
An audio consisting of the index and the index
And tail title, o consists of the audio title
Audio title set (ATS) and audio
The number of quantization bits and the sampling frequency for each channel of the first group and the channel of the second group of the digital audio signals recorded in the pack , and the assigned channels of the first group and the second group are described. The channel allocation information for specifying each is the audio type.
Quantization control information area recorded for each ittle set ,
And a title search information area in which search information for searching the audio title is recorded, and a step of formatting and recording the title search information area according to a predetermined format. 2) A decoding method for decoding an audio signal recorded by the encoding method according to claim 1, wherein a channel and a second group of the first group of digital audio signals recorded in the quantization control information area. The number of quantization bits and sampling frequency for each channel of
Digital audio of the channels of the first group and the channels of the second group recorded in the audio pack based on the channel allocation information specifying the channels of the first group and the channels of the second group, respectively. A method of decoding an audio signal, comprising the steps of decoding a signal and decoding the search information.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing an embodiment of a DVD-video format and a DVD-audio format applied to the present invention, and FIG. 2 is an explanatory diagram showing the audio manager (AMG) format of FIG. 1 in detail. 3 is the audio title set (A
FIG. 4 is an explanatory view showing the format of TS) in detail, and FIG.
Audio Manager Information (AMG
1) is an explanatory view showing the format in detail, FIG. 5 is an explanatory view showing the format of the audio title set attribute table (ATS-ATRT) in FIG. 4 in detail, and FIG. 6 is an audio title set attribute data (ATS-ATRT) in FIG. FIG. 7 is an explanatory view showing the format of the audio title set information (ATSI) in FIG. 3 in detail, and FIG. 8 is an audio title set information management table (ATS) shown in FIG.
FIG. 9 is an explanatory diagram showing in detail the format of (I-MAT).
Is the audio title set menu audio stream attribute data (ATSM-AS
T-ATR) in detail, FIG. 10 is an explanatory diagram showing in detail the format of the audio title set / audio stream attribute table (ATS-AST-ATRT) in FIG. 8, and FIG. 11 is a diagram showing each audio stream in FIG. Attribute data (ATS-A
It is an explanatory view showing ST-ATR) in detail.

FIG. 12 is an explanatory view showing the audio content block unit (ACBU) of FIG. 1, and FIG.
12 is an explanatory diagram showing in detail the formats of the audio pack and video pack of FIG. 12, FIG. 14 is an explanatory diagram showing the format of the audio control (A-CONT) pack of FIG. 12 in detail, and FIG. 15 is an audio character display (ACD) of FIG. ) An explanatory view showing the format of the area in detail, FIG. 16 is an explanatory view showing an example displayed by the namespace information of FIG. 15, and FIG. 17 is an explanatory view showing the format of the audio search data (ASD) area of FIG. 14 in detail. FIG. 18 is an explanatory diagram showing a modified example of the audio content block unit of FIG.

Here, in the DVD-audio disc described above, two stereo channels and 5/6/8 channels are used as audio signals in order to cope with a transitional period when the CD generation is changed to the DVD-audio generation. Both multi-channel signals are recorded. Further, it is considered that when this transition period elapses, only the 5/6/8 channel multi-channel signal is recorded.

1A and 1B show DVD-video and DVD-audio formats, respectively.
The VD-audio format is compatible with DVD-video although the area names are different. First, a DVD-video format is roughly divided into a video manager (VMG) at the beginning and each area of a plurality of video title sets (VTS) following the video manager (VMG).
Correspondingly, the audio format is composed of an audio manager (AMG) shown in detail in FIG. 2 and areas of a plurality of audio title sets (ATS) following the AMG as shown in detail in FIG.

Each of the VTSs is composed of the leading 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 leading ATS. Information (ATSI) followed by one or more audio content block sets (A
CBS) and the last ATSI. AT
In SI, the playing time of each song in ACBS is set in real time. In the present invention, menu information for displaying a menu screen is recorded in the first ACBS. This is similar to the DVD video and will not be described.

Each of the VCBSs is composed of a plurality of VCBs, while each of the ACBSs is composed of a plurality of ACBs. Each VCB has one title of video (Ti
Each of the ACBs corresponds to one title of audio. Each VCB (1 title) is composed of a plurality of chapters, while each ACB (1 title) is composed of a plurality of tracks (Track). Chapters include Part of Title (PTT),
The track contains a Part of Title (PTT).

Each chapter has a plurality of cells (CELL).
On the other hand, each of the tracks is composed of a plurality of indexes corresponding to this. Each cell has multiple VCB units (VCBU)
On the other hand, each of the indexes is correspondingly composed of a plurality of ACB units (ACBU). Each of the VCB unit and ACB unit,
It is composed of a plurality of packs, and one pack is composed of 2048 bytes.

Each of the VCB units is composed of a head control pack (hereinafter, CONT pack), followed by a plurality of video (V) packs, audio (A) packs and sub-picture (SP) packs, while A
Corresponding to this, each of the CB units has a head audio control pack (hereinafter, A-CONT pack).
And a plurality of A packs and V packs following it.

Information for controlling the succeeding V pack is arranged in the CONT pack, and the T of the CD is arranged in the A-CONT pack.
Information for managing the subsequent A-pack audio signal, such as OC information, is arranged. Audio data is placed in the A pack, and video data in the V pack,
For example, closed caption (CC) data other than audio data is arranged.

As shown in FIG. 2, the AMG (audio manager) includes: -audio manager information (AMGI) shown in detail in FIG. 4, -audio content block set (AMGM-ACBS) for AMG menu, and-for backup Have AMGI. AMGM-AC
The BS has presentation control information (PCI) and data search information (DSI) as control information.

As shown in FIG. 3, the ATS (audio title set) includes: -audio title set information (ATSI) shown in detail in FIG. 7, -audio content block set (ATSM-ACBS) for ATS menu, -ATS It has an audio content block set (ATSA-ACBS) for titles and an ATSI for backup. ATSM-AC
Both BS and ATSA-ACBS have the same P
It has CI and DSI.

AMGI (Audio Manager Information) is shown in detail in FIG. 4. AMGI management table (AMGI-MA)
T) and-Title search pointer table (T-SRPT)
Audio manager menu PGCI unit table (AMGM-PGCI-UT), parental management information table (PTL-MAIT), audio title set attribute table (ATS-ATRT) in detail in FIG. Text data manager (TXTDT-MG) ・ Audio manager menu cell (index)
Address table (AMGM-C-ADT),-Audio manager menu-Audio content block unit-Addressless map (AMGM-
ACBU-ADMAP).

ATS-ATRT (audio title set / attribute table) is shown in detail in FIG. 5, audio title set attribute table information (ATS-ATRTI), and audio titles of a plurality (n) of ATSs. Set attribute search pointer (ATS-ATR-
SRP # 1 to #n) and audio title set attribute data (ATS-ATR- # 1 to #n) of each of a plurality (n) of ATSs as shown in detail in FIG.

Each of the audio title set attribute data (ATS-ATR- # 1 to #n) is, as shown in detail in FIG. 6, ATS-ATR-EA (end address) and ATS-CAT (category). And-Has ATS-ATRI (information).

The ATSI (ATS information) shown in FIG. 3 is shown in detail in FIG. 7. The audio title set information management table (ATSI-MA) shown in detail in FIG.
T) and-Audio title set-Part of title-Search pointer table (ATS-PTT-SRPT)
-Audio title set-Program chain information table (ATS-PGCIT) -Audio title set menu-PGCI-Unit table (ATSM-PGCI-UT) -Audio title set-Time map table (ATS-TMAPT) , Audio title set menu cell address table (ATSM-C-ADT), audio title set menu audio content block unit address map (ATSM-ACBU-ADMAP)
Audio title set cell address table (ATS-C-ADT) Audio title set audio content block unit address map (ATS-ACBU-
ADMAP).

The ATSI-MAT (audio title set information management table) shown in FIG. 7 is, as shown in detail in FIG. 8, ATS-ID (identifier), ATS-EA (end address), and ATSI- EA ・ VERN (DVD audio spec version number) ・ ATS-CAT (category) ・ ATSI-MAT-EA ・ ATSM-ACBS-SA (start address) ・ ATSA-ACBS-SA ATS-PTA-SRPT-SA, ATS-PGCIT-SA, ATSM-PGCI-UT-SA, ATS-TMAP-SA, ATSM-C-ADT-SA, ATSM -ACBU-ADMAP-SA, -ATSM-as detailed in FIG. ST-ATR
(ATSM audio stream attributes)
ATS-AST-Ns (the number of ATS audio streams), and ATS-AST-ATRT as shown in detail in FIG.
(ATS audio stream attribute table).

The ATSM-AST-ATR is composed of 8 bytes (bits b63 to b0) as shown in detail in FIG. 9, and the following data (1) is provided as an attribute of the encoded audio signal recorded on this disc. ~ (4) are arranged (other bits are reserved). (1) Audio coding mode (3 bits b63 to b6
1) 000b: Dolby AC-3 010b: MPEG-1 or MPEG-2 (without extension bitstream) 011b: MPEG-2 (with extension bitstream) 100b: Linear PCM audio 101b: Linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch and 2ch + 8ch. )

(2) Quantization / DRC (Dynamic Range Control) information (2 bits b55, b54)-"11b" when the audio coding mode is "000b" -The audio coding mode is "010b" or " 011
In the case of "b", 00b: dynamic range control data does not exist in the MPEG audio stream 01b: dynamic range control data exists in the MPEG audio stream 10b, 11b: hold / audio encoding mode is "100b", "101"
In case of "b", 00b: 16 bits 01b: 20 bits 10b: 24 bits 11b: reserved for stereo 2ch

(3) Sampling frequency fs (2 bits b53, b52) 00b: 48 kHz 01b: 96 kHz 10b: 192 kHz for stereo 2 ch (4) Number of audio channels (3 bits b50 to b4)
8) 000b: 1ch (monaural) 001b: 2ch (stereo) 010b: 3ch 011b: 4ch 100b: (stereo 2ch + 5ch) 101b: (stereo 2ch + 6ch) 110b: 7ch 111b: (stereo 2ch + 8ch)

ATS-AST-ATRT shown in FIG.
As shown in detail in FIG. 11, the (ATS audio stream attribute table) has an ATS-AST-ATR for each of the audio streams # 0 to # 7.
Each of TS-AST-ATR is composed of 8 bytes (total of 64 bytes).

ATS-A for one audio stream
The ST-ATR is, as shown in FIG. 11, an audio title set menu, an audio stream, an audio stream set menu shown in FIG.
It is composed of 8 bytes (bits b63 to b0) similar to the attribute data (ATSM-AST-ATR), and in addition to the above attribute data (1) to (4), (5) multi-channel extension (ME) ( 1
Bit b60) and (6) audio type (2 bits b59, b58)
(7) Audio application mode (2-bit b
57, b56), (8) thinning information (2 bits b47, b46) for the stream (AST), and (9) LFE (Low Frequency Effect) thinning information for only one channel (2 bits b45, b44). Have. Then, in (7) audio application mode of this DVD audio disc, 11b: 2ch + surround mode is recorded, and (8) thinning information of the stream and (9) thinning information of only LFE1ch are both banded. As information, 00b: full (1/1) 01b: half (1/2) 10b: quarter (1/4) are recorded.

However, the number of (4) audio channels in this ATSM-AST-ATR is always 2ch in the audio stream # 0, and the audio stream # 1 includes the front 3ch. That is, for example, when an audio signal of one title is recorded in 2 + 6ch, a stereo signal of 2ch is output as audio stream # 0.
The front signal of 3ch out of 6ch to audio stream # 1 and the rear signal of 2ch and LFE.
The 1ch signal is assigned to audio stream # 2. The audio manager information management table (AMGI-MAT) shown in FIG. 4 and the audio title set information management table (ATSI-MAT) shown in FIG. 8 are both "3" as the usage data of streams # 0 to # 2. "
Is recorded.

When the analog audio signal of 2 + 6 ch is sampled at the following sampling frequency fs and quantized with the following quantization bit number and recorded, stereo 2 ch: 48 kHz, 20 bit front 3 ch: 96 kHz, 16-bit rear 2ch, LFE 1ch: 48 kHz, 16-bit (no thinning), audio title set menu audio stream attribute data (ATSM-AST-ATR) shown in FIG.
As an attribute of stereo 2ch, (1) audio encoding mode 101b: linear PCM audio (2ch + 5ch, 2ch
Includes + 6ch and 2ch + 8ch. (2) Quantization / DRC 01b: 20 bits (3) Sampling frequency fs 00b: 48 kHz (4) Number of audio channels 101b: (stereo 2ch + 6ch) is recorded.

Also, the ATS of audio stream # 0
-For AST-ATR, (1) Audio coding mode 101b: Linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch and 2ch + 8ch. ) (2) Quantization / DRC 01b: 20 bits (3) Sampling frequency fs 00b: 48 kHz (4) Number of audio channels 001b: 2ch (stereo) (7) Audio application mode 11b: 2ch + surround mode (8) Thinned-out information 00b: Full (1/1) (9) Only thinned-out information 00b: Full (1/1) is recorded on LFE1ch.

Also, the ATS of audio stream # 1
-For AST-ATR, (1) Audio coding mode 101b: Linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch and 2ch + 8ch. ) (2) Quantization / DRC 00b: 16 bits (3) Sampling frequency fs 01b: 96 kHz (4) Number of audio channels 010b: 3ch (7) Audio application mode 11b: 2ch + surround mode (8) Stream thinning information 00b : Full (1/1) (9) Thinning information 00b only for LFE 1ch: Full (1/1) is recorded.

Also, the ATS of the audio stream # 2
-For AST-ATR, (1) Audio coding mode 101b: Linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch and 2ch + 8ch. ) (2) Quantization / DRC 00b: 16 bits (3) Sampling frequency fs 00b: 48 kHz (4) Number of audio channels 010b: 3ch (7) Audio application mode 11b: 2ch + surround mode (8) Stream thinning information 00b : Full (1/1) (9) Thinning information 00b only for LFE 1ch: Full (1/1) is recorded.

Next, the A pack in which the audio stream is recorded and its control pack will be described. As shown in FIG. 12, the VCB unit is composed of an arbitrary number of packs for 0.4 to 1.0 seconds, and the ACB unit is 0.5.
It is composed of an arbitrary number of packs for 1.0 second. The A-CONT pack in the DVD-Audio ACB unit is arranged in the third pack in the DVD-Video VCB unit.

The A-CONT pack is basically arranged in units of 0.5 seconds of audio time, and is arranged so that it is completed in the range of 0.5 to 1.0 seconds at the index break. In addition, audio time (GOF: Group of Audio
A frame unit) is indicated by an A-CONT pack, and its data position is determined by the audio frame number, the first access unit pointer, and the number of frame headers. Also, the A pack immediately before the A-CONT pack is
Do not force padding in units of 0.5 seconds of audio time.

Adjacent A packs are arranged so that audio signals are related to each other. For example, in the case of stereo, the L channel pack and the R channel pack are arranged adjacent to each other, and the 5/6/8 channel In the case of multi-channel, they are also arranged adjacent to each other. The V pack is arranged adjacent to the A pack when displaying an image during reproduction of an audio signal. Figure 13 shows the A and V packs.
As shown in, the 4-byte pack start information, the 6-byte SCR (System Clock Reference) value, and the 3-byte Mux rate for the 2034-byte user data (A data, V data). It is configured by adding a pack header of 14 bytes in total including information and stuffing of 1 byte (1 pack = 2 in total).
048 bytes). In this case, the time stamp SC
It is possible to manage the time of the A pack in the same title by setting the R information as "1" in the first pack in the ACB unit and making it continuous in the same title.

On the other hand, the A-CONT pack is shown in FIG.
, A 14-byte pack header, a 24-byte system header, a 1003-byte ACD (Audio Character Display) packet, and a 1007
It is composed of a byte ASD (audio search data) packet. Also, the ACD packet has a 6-byte packet header and a 1-byte substream ID.
And a 636-byte ACD as shown in detail in FIG.
(Audio character display) information and 360
It consists of a byte reserve area. The ASD packet also has a 6-byte packet header, a 1-byte substream ID, and 10 bytes as shown in detail in FIG.
It is composed of ASD (audio search data) of 00 bytes.

The 636-byte ACD information area is shown in FIG.
As shown in detail in 5, the 48-byte general information area, the first language character "1" and the second language character "2"
Each has an area of 294 bytes, and each area is 93
It consists of a byte name space area, two free space areas of 93 bytes each, and a data pointer area of 15 bytes. In one name space area of the first language character "1" and the second language character "2", for example, as shown in FIG. 16, data for displaying the music title in Japanese is arranged, while the other name is displayed. Data for displaying in English is arranged in the space area. In addition,
The display language may be determined by the disc publisher.

The 48-byte general information is, for example, 1
6 bytes of service level information, 12 bytes of language code information, 6 bytes of character set code information, 6 bytes of display item information, 2 bytes of "difference from previous ACD information" information, and 6 bytes It is composed of reservation information of. The 16-byte service level information indicates the display size, the display type, the audio / video / SP distinction, the stream, etc., the characters are mandatory (required), and the bitmaps are optional (optional). 12
As with the video file, the language code information of the byte indicates the language of the characters “1” and “2” in 2 bytes, and indicates a maximum of 8 languages in one file. English is Mandatory.

The 6-byte character set code information can have up to 15 character codes corresponding to the language code, and the presence or absence of the language of the characters "1" and "2" and the type are indicated by 1 byte. A code example is shown below. 1. ISO646 2. ISO8859-1 3. The MS-JIS 6-byte display item information indicates the free space “1” and “2” shown in FIG. 15, the presence or absence of a data pointer, and the ID. The name space is the mandatory, and the title name, music name, and artist name must be described.

As shown in detail in FIG. 17, 1000-byte ASD (audio search data) includes 16-byte general information, 8-byte current number (No.) information, 16-byte current time information, and 8-byte current time information. Byte title set search information, 8-byte title search information, 404-byte track search information, 408-byte index search information, 80-byte highlight search information, and 52-byte reserved area. There is.

The 8-byte current number information includes the current title number of the title set (2 bytes: BCD) and the current track number of the title set (2 bytes: BC).
D), the current index number of the track (2 bytes: BCD), and the reserved area (2 bytes). The 16-byte current time information is the playback time of the track (4 bytes: BCD), the remaining playback time of the track (4 bytes: BCD), the absolute time of the title (4 bytes: BCD), and the remaining of the title. Of the absolute time (4 bytes: BCD).

The 8-byte title set search information is
It is composed of the first sector number (4 bytes) of the title set and the last sector number (4 bytes) of the title set. The 8-byte title search information is composed of the first sector number (4 bytes) of the title and the last sector number (4 bytes) of the title. Four
The 04-byte track search information is composed of the title track and sector number (4 bytes × 99), the first track number of the title (4 bytes), and the last track number of the title (4 bytes).

The 408-byte index search information consists of the track index and sector number (4 bytes × 100), and the track's first index number (4
Byte) and the last index number (4 bytes) of the track. The 80-byte highlight search information is the track in-sector number (4 bytes x 1
0) and track out-sector number (4 bytes x 10)
It is composed by.

According to such a format, at the beginning of a plurality of A packs, the subsequent A packs such as the TOC information of the CD are recorded.
A-CONT for managing pack audio signals
Since the packs are arranged, the audio data is not integrated with the video data, and the recording capacity can be increased. In addition, the A-CONT pack can manage the audio time, and the A-CONT pack can extract simple character information such as the song title of the audio data.

In addition, the title in the A-CONT pack,
Since the TOC information such as the start address and the playing time is arranged, the information corresponding to the user's operation can be taken out from the A-CONT pack and the reproduction can be started even during the audio reproduction. Further, by arranging the TOC information in the audio manager information (AMGI) and the audio title set information (ATSI), the necessary TOC information is stored in the memory in the reproducing device, and the information according to the user's operation is stored in the memory. Can be immediately read from to start playback. Further, since it is not necessary to store a large amount of information such as program chain information (PGCI) in DVD-video, the disc can be efficiently managed.

Further, 1. When there is no image (V) data in the content, (1) search, random access to three layers of title, song, and index becomes possible. (2) Cue, time search, and random access in GOF (audio frame) units are possible. (3) The time for titles, songs, and indexes can be managed in real time.

Further, 2. When there is image (V) data in the content, regarding audio data, in addition to (1) to (3) above, (4) title, current time in song, and remaining time are displayed and managed in real time. be able to.

Regarding video data, (1) search, random access to the three layers of title, PTT, and cell become possible. (2) It is possible to perform cueing for each video frame, time search, and random access. (3) The title, PTT, and cell time can be managed in real time. (4) The current time and remaining time in the PTT or title can be displayed and managed in video frame unit time.

The ACBU shown in FIG. 12 is A-CONT.
Although the pack and the CONT pack are included, the V pack and the CONT pack may not be included as shown in FIG. In this case, the video signal is not recorded, but there is a feature that the recording capacity of the audio signal is increased, so that the disc size can be reduced, and
Since the reproducing function can be simplified, it is possible to provide a portable reproducing apparatus suitable for the reproducing apparatus.

In FIG. 19, an analog audio signal is sampled at various sampling frequencies fs, quantized with various quantization bit numbers, and only 2ch is 2ch + multichannel (6ch, 8ch), D is multichannel (6ch, 8ch).
The VD-recording time (TIME) when recording on an audio disc is shown. In this way, if the recording side selects and records the sampling frequency fs and the number of quantization bits of each channel and records, the recording time is from several tens of minutes to 30 on one disc.
You can record up to 0 minutes.

FIG. 20 shows 2ch + 6ch, where 6ch is front (FRONT) 3ch and rear (REAR) 2ch +.
The respective recording times (TIME) are shown for the case of LFE 1ch, the case of 2ch + 5ch where 5ch is the front 3ch and the rear 2ch, and the case where there is only 6ch and the front 3ch and the rear 2ch + LFE 1ch. In this way, if the sampling frequency fs and the number of quantization bits of each channel are selected and the sampling frequency fs of each channel is common, the band of only the rear 2ch + LFE1ch or LFE1ch is narrowed and recorded. You can record about 1 hour on one disc. In the case where the data is compressed and recorded, the player side rear 2ch + LFE shown in FIG.
Interpolation based on thinned-out data for only 1ch or LFE 1ch,
After the expansion, D / A conversion can be performed at the original sampling frequency fs.

Further, in the case of recording the multi-channel and stereo 2-channel stream signals on the disc in this way, for example, as shown in FIG. 21, the disc D is placed inside and outside the multi-channel area 1 and the stereo 2-channel area 2. You may make it record separately. In this case, various restrictions can be reduced even if the sampling frequencies and the number of quantization bits of the multi-channel and the stereo 2-channel are different.

Although the above description has been made assuming that the multi-channel digital audio signal is linear PCM, the audio encoding modes are Dolby AC-3 and MPEG-1.
Alternatively, it may be MPEG-2. In this case, for example, the sampling frequency and the number of quantization bits are set to the front ch.
Others are standard, and ATSM-A is used for front ch.
By adopting the quantization / DRC information of ST-ATR (FIG. 9) and the sampling frequency fs, different sampling frequencies and the number of quantization bits can be selected. As a result, it is possible to provide a digital disc compatible with a wide range of users.

The ACD area in the ACD packet may be configured to have data of the character "1" of the first language and the character "2" of the second language as shown in FIG. As shown in FIG. 22, by omitting the data regarding the character “2”, a 48-byte general information area and one language for displaying a so-called “audio navigation” such as a music title as shown in FIG. 16 are displayed. It may be composed of a 294-byte area relating to the character "1" and an audio reproduction control information area of 294 bytes.
Similarly, the area of the character "1" is composed of a 93-byte name space area, two 93-byte free space areas, and a 15-byte data pointer area.

The content of the audio reproduction control information area is arbitrary, and is composed of, for example, 25 kinds of audio reproduction control information areas (250 bytes) for 10 types and a reserved area of 44 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, and this information is selected by the user to control the sound quality of the audio signal. To be done. These pieces of audio reproduction control information are, for example, according to the genre (classical, jazz, rock, BGM) of the music when the user reproduces the music arranged in the A pack, and even if the music is the same genre. This data is recommended by a so-called professional mixer so that the sound quality at the time of reproduction becomes the best according to the playing condition, recording condition, mood, etc. of the music. When the number of channels of the audio signal is 6, the holding area stores mixing coefficients such that the number of channels is mixed down to 2 and stereo reproduction is possible.

Next, FIG. 23 shows a DVD applied to the present invention.
The format of the second embodiment of the audio disc is shown. This format does not include the VTS as shown in FIGS. 25 to 27, but is composed of only the ATS. The ATS is an audio manager (AMG) shown in FIG. 1B, an audio manager menu for video and audio (AMGM), and ATS <1> and ATS <2 managed by AMGI in AMG.
>, And ATS <1> and ATS <2
24, as shown in FIG. 24, does not include an A-CONT pack, and is composed of an A pack and a still image pack. Further, this still image pack is not arranged much with respect to the A pack, and about 1 pack is arranged per track.

For reference, FIG. 25 shows a DVD-V.
An (video + audio navigation) disc format is shown, and this format is generally D
VD-Video title set (VT
S) and ANV title set (ANV-TS) as audio navigation (navigation) data. Further, in detail, the VTS has the same structure as the DVD video disc shown in FIG. 1A and FIG. 26 described later, while the ANV-TS has the audio manager (AMG) shown in FIG. 1B and the VTS side. VTS <1> and VTS <2> of the
ATS <1> and ATS <2> managed by I. Further, the format of the DVD video disc does not include ATS or ANV-TS as shown in FIG. 26 and FIG. 1A, but is composed of only VTS.

Further, FIG. 27 shows a format of a DVD-Avd (audio + AV data) disc. This format schematically shows a video title set (VTS) as DVD-video data and an audio title set (VTS) as DVD-audio data. ATS). Also, in detail, VTS is shown in FIG.
(A) Video manager (VMG) and video and audio video manager menu (VMGM)
And VTS <1> managed by VMGI in VMG
It is composed by.

On the other hand, the ATS forms a pair with the audio manager (AMG) shown in FIG. 1B, the audio manager menu for video and audio (AMGM), and the audio data in the VTS <1> on the VTS side. And ATS <1> managed by AMGI in AMG,
It is composed of ATS <2> which is not managed by the VTS side but is also managed by AMGI in AMG. Further, this ATS <2> is, as shown in FIG.
It is composed of A pack and still image pack, not including NT pack.

FIG. 28 is an audio-only title audio object attribute (AOTT-) recorded on the disc as attribute data indicating the contents of the audio data of the disc of the second embodiment applied to the present invention. AOB-ATR) is shown. This attribute data is composed of 8 bytes (64 bits b63 to b0), which will be described in detail in order from the MSB side. ・ 3 bit (b63 to b61) audio encoding mode ・ 1 bit (b60) downmix (D60) -M) mode, 4-bit (b59 to b56) multi-channel type, 4-bit (b55 to b52) channel group 1 quantization bit number Q1, and 4-bit (b51 to b48) channel Number of quantized bits Q2 of group 2, sampling frequency fs1 of channel group 1 of 4 bits (b47 to b44), sampling frequency fs2 of channel group 2 of 4 bits (b43 to b40), and 3 bits ( reserved area of b39 to b37), channel allocation of 5 bits (b36 to b32), and remaining It is composed of holding area of 32 bits (b31~b0). The remaining 32 bits (b31 to b
0) is used for attribute data of each channel.

The above data will be described in more detail below. (1) Audio encoding mode (b63 to b61) 0000b: Linear PCM mode 0001b: Reserved for compressed audio (Dolby Digital) 0010b: Reserved for compressed audio (without MPEG2 extension) 0011b: For compressed audio (with MPEG2 extension) Reserved 0100b: Reserved for compressed audio (DTS) 0101b: Reserved for compressed audio (SDDS) Others: Reserved for other encoding modes (2) Downmix mode (b60) 0b: Downmix stereo output permission 1b: Downmix stereo output prohibited (3) Multi-channel type (b59 to b56) 000b: Type 1 Others: Hold

(4) Number of quantization bits of channel group 1 Q1 (b55 to b52) 0000b: 16 bits 0001b: 20 bits 0010b: 24 bits Others: Reserved (5) Number of quantization bits of channel group 2 Q2 (b5
1 to b48) -The number of quantization bits Q1 of the channel group 1 is "000.
In the case of "0b", the number of quantization bits Q1 of channel group 1 is "000b".
1b ”is“ 0000b ”or“ 0001b ”. The number of quantization bits Q1 of channel group 1 is“ 001.
In the case of "0b", "0000b", "0001b" or "0010b" However, 0000b: 16 bits 0001b: 20 bits 0010b: 24 bits Others: Reserved

(6) Sampling frequency fs1 of channel group 1 (b47 to b44) 0000b: 48kHz 0001b: 96kHz 0010b: 192kHz 1000b: 44.1kHz 1001b: 88.2kHz 1010b: 176.4kHz Others: Reserved

(7) Sampling frequency fs2 of channel group 2 (b43 to b40)-"0000b" when sampling frequency fs1 of channel group 1 is "0000b" -Sampling frequency fs1 of channel group 1 is "0001b" In the case, "0000b" or "000
1b "-" 0000b "," 0001 "when the sampling frequency fs1 of the channel group 1 is" 0010b "
b "or" 0010b "-" 1000b "when the sampling frequency fs1 of the channel group 1 is" 1000b "-" 1000b "or" 100 "when the sampling frequency fs1 of the channel group 1 is" 1001b "
1b "-" 1000b "," 1001 "when the sampling frequency fs1 of the channel group 1 is" 1010b "
b ”or“ 1010b ”

(8) Channel allocation (b36 to b3)
2) FIG. 29 shows 21 types of channel allocation information (pattern) of groups “1” and “2” from 1 channel (monaural) to 6 channels. By the way, the symbols shown in the figures will be described below. C (mono): Monaural L, R: 2-channel stereo Lf: Multi-channel left front Rf: Multi-channel right front C: Multi-channel center LFE: Multi-channel Low Frequency Effect S: Multi-channel Surround Ls: Multi-channel left surround Rs: Multi-channel right surround none: Not applicable

The linear PCM mode is used in the disc of the second embodiment applied to the present invention. The A pack of the linear PCM is composed of 2048 bytes or less, and its breakdown is composed of a 14-byte pack header and an A packet as shown in FIG. A packet is 1
It is composed of a packet header of 7, 9 or 14 bytes, a private header shown in detail in FIG. 31, and audio data (linear PCM) of 1 to 2013 bytes.

The private header is, as shown in FIG. 31, an 8-bit substream ID, a 4-bit reserved area, a 4-bit ISRC number, an 8-bit ISRC data, and an 8-bit ISRC data. Private header length, 16-bit first access unit pointer, 6-byte audio data information (A
DI) and 0 to 7 bytes of stuffing bytes.

The ADI includes: 1-bit audio emphasis flag, 1 + 2 bit reserved area, 4-bit downmix code, 4-bit group "1" quantization word length "1"
Quantization word length “2” of 4-bit group “2”
A 4-bit group "1" audio sampling frequency fs1; a 4-bit group "2" audio sampling frequency fs2; a 4-bit reserved area; a 4-bit multi-channel type , 3-bit reserved area, 5-bit channel allocation information (see FIG. 29), and 8-bit dynamic range control information.

FIG. 32 is a block diagram showing an embodiment of an audio signal encoding apparatus applied to the present invention, and FIG. 33 is a block diagram showing the signal processing circuit of FIG. 32 in detail. In FIG. 32, the analog audio signal A is A /
The D converter 31 samples at a sufficiently high sampling frequency (sampling period Δt), for example, 192 kHz, and for example, a 24-bit high-resolution PCM.
The data strings converted into signals and corresponding to the high resolution curve α xb1, x1, xa1, x2, xb2, x3, xa2, ..., x
converted into bi, x2i-1, xai, x2i, .... This data string (xbi, x2i-1, xai, x2i) is encoded by the signal processing circuit 32 and the memory 33 shown in detail in FIG. 33, and then applied to the DVD formatting section 34.

The configuration of the signal processing circuit 32 will be described in detail with reference to FIG. First, when compression is not performed as in the second embodiment, the PCM data converted by the A / D converter 31 is directly used in the allocation circuit 40.
Applied to the audio data shown in FIG. 30 (linear P
CM), and is then formatted by the DVD formatting unit 34 into the A pack shown in FIG.

On the other hand, when performing compression, first,
Low-pass filter (LPF) that passes 1/2 band
36, for example, by a FIR filter, a high resolution curve α
From the data sequence (xbi, x2i-1, xai, x2i) corresponding to, the data sequence xc1, *, *, *, xc2, *, *, *, xc3, corresponding to the band-limited low resolution curve β *,
*, *, ..., xci, *, *, *, * are obtained, and then the data "*" in this data string is thinned out by the thinning circuit 37, so that the data strings xc1, xc2, xc3,・ ・
., Xci, ... Is generated. Here, the data string xci is a data string in which the sampling frequency is reduced to 1/4 by band limiting the digital data A / D converted by the A / D converter 31.

Further, the data string (xbi, x2i-1, xai, x
2i), the data sequence xb1, xa1, xb2, xa2, ..., X is obtained by thinning out the data xi by the thinning circuit 38.
generate bi, xai, ....

Then, these data strings xci, xbi, x
Based on ai, a difference xbi-xci = [Delta] 1i xai-xci = [Delta] 2i is calculated by the adder 39 acting as a difference calculator. Here, the difference data Δ1i and Δ2i are, for example, 24 bits or less, and the number of bits may be fixed or variable. The allocation circuit 40 uses the data string xci and the difference data Δ1i and Δ2i as user data (see FIG. 13).
(See packet) (1 packet = 2034 bytes), and the user data is packed in the DVD formatting unit 34.
Output to.

Further, the video signal V is the A / D converter 31V.
Is converted into a digital signal by the V encoder 32V, and the digital video signal is encoded in the MPEG format by the V encoder 32V, then packed into user data shown in FIG. 13 and applied to the DVD formatting section 34. Then, the DVD formatting section 34 packs in the format as described above. This DVD
The data formatted by the formatting unit 34 is modulated by the modulation circuit 35 by a modulation method according to the disc, and the disc is manufactured based on the modulated data.

FIG. 34 shows an apparatus for reproducing the disc according to the first embodiment shown in FIG. 1B. The DVD audio disc 1 is EFM-modulated with the data having the above structure and recorded in the form of pits. There is. When song selection, reproduction, fast-forward, and stop operations are performed by the operation unit 18 or the remote control device 19, the control unit (CPU) 23 controls the drive device 2 and the reproduction device 17 in accordance with the operations, and during reproduction, the DVD.
The pit data recorded on the audio disc 1 is read by the drive device 2 and then EFM demodulated.

In the reproducing device 17, this signal is sent to the CONT pack detector 3 and the A-CONT pack detector 9. The CONT pack detector 3 detects the CO in the reproduced data.
The NT pack is detected and the control parameter is set to the parameter section 8
And the V pack controlled by the CONT pack is sequentially written in the V pack buffer 4. The user data (video signal, sub-picture information) in the V pack written in the V pack buffer 4 is ordered by the buffer extracting unit 5 in the pack order based on the SCR (see FIG. 13) in the V pack, and in the CONT pack. PTS (Pr
esentation Time Stamp), and is output in the order of output time, and then output as an analog video signal via the image conversion unit 6, the D / A conversion unit 7, and the video output terminals 15 and 15 ′.

Further, the A-CONT pack detection unit 9 detects the A-CONT pack in the reproduction data and sets the control parameter in the parameter unit 14, and at the same time the A-CONT pack is detected.
The A pack controlled by the T pack is sequentially written in the A pack buffer 10. The user data (audio signal) in the A pack written in the A pack buffer 10 is
The buffer extraction unit 11 extracts the data in the pack order based on the SCR and in the output time order based on the current time (see FIG. 17) of the audio search data ASD in the A-CONT pack, and then the PCM conversion unit 12, D / A.
It is output as an analog audio signal via the conversion unit 13 and the audio output terminal 16. In addition, A-CONT
The display data in the pack (audio character display information ACD shown in FIGS. 15 and 16) is sent to the display signal generation unit to generate a display signal.

FIG. 35 is a block diagram functionally showing the structure shown in FIG. The reproduction means 2 corresponds to the drive device 2 shown in FIG. 34, and reproduction signal processing separation means A (9, 10,
11 and 14) correspond to the A-CONT pack detection unit 9, the A pack buffer 10, the buffer extraction unit 11 and the parameter unit 14, and the audio signal output means (12, 1).
3) corresponds to the PCM conversion unit 12 and the D / A conversion unit 13, and the character information output means 20 corresponds to the display signal generation unit. The display signal from the character information output means 20 is output through the display signal output terminal 22 or the built-in character display unit 21. Also, the reproduction signal processing separation means V
(3, 4, 5, 8) corresponds to the CONT pack detection unit 3, the V pack buffer 4, the buffer extraction unit 5, and the parameter unit 8, and the video signal output unit and the sub-picture information output unit (6, 7) are images. It corresponds to the converter 6 and the D / A converter 7. The control unit 23 corresponds to the control unit 23.

In FIG. 35, the control means 23 is the operation unit 1
8 or a remote control device 19 sends a command signal for reproducing a target music piece, an address control information signal corresponding to the reproduction command is sent to the reproducing means 2 to reproduce the target music piece from the DVD audio disc 1. Reproduce. The reproduction signal processing separation means A separates the reproduction data and A
-CONT information is sent to the control means 23, an audio signal is sent to the audio signal output means (12, 13), and character information is sent to the character information output means 20. The reproduction signal processing separation means V separates the reproduction data and sends the CONT information to the control means 23, and the video signal and the sub-picture information are supplied to the video signal means and the sub-picture information output means (6, 7), respectively.
Send to. Here, audio search data (ASD) as shown in FIG. 17 may be recorded in the TOC information area of the disc so as to find the beginning of a song.

FIGS. 36 and 37 show the second embodiment applied to the present invention.
FIG. 24 shows a disc reproducing device exemplified as the embodiment (format shown in FIG. 24) of FIG. 24. Similarly, when the operation unit 18 and the remote control device 19 perform song selection, reproduction, fast forward, and stop operations, the control unit 23 operates the operations. The drive device 2 and the reproducing device 17 are controlled according to the above, and during reproduction, the pit data recorded on the DVD audio disc 1 is read by the drive device 2 and then EFM demodulated.

In the reproducing device 17, this signal is sent to the V pack detector 3 and the A and D pack detector 9. When the V pack is recorded on the disc 1, the V pack detection unit 3 detects the V pack in the reproduced data, sets the control parameter in the parameter unit 8, and sequentially stores the V pack in the V pack buffer 4. Write. The user data (video signal, sub-picture information) in the V pack written in the V pack buffer 4 is ordered by the buffer extracting unit 5 in the pack order based on the SCR (see FIG. 13) in the V pack, and in the CONT pack. PTS (Presentation
Based on the Time Stamp), they are taken out in the order of output time, and then the image conversion unit 6, the D / A conversion unit 7, the video output terminal 1
It is output as an analog video signal via 5, 15 '.

Further, the A and D pack detection unit 9 detects the A pack and D pack in the reproduced data and sets the control parameter in the parameter unit 14, and the A pack and D pack in the A and D pack buffer 10. Write sequentially. A
And the user data (audio signals) in the A pack written in the D pack buffer 10 are extracted by the buffer extraction unit 11 in the pack order and in the output time order, and then the PCM conversion unit 12, the D / A conversion unit 13, It is output as an analog audio signal via the audio output terminal 16. The display data in the D pack is sent to the display signal generation unit 20 to generate a display signal, and the display signal is output through the display signal output terminal 22 or the built-in character display unit 21. It

[0085]

As described above, according to the present invention, the number of quantization bits and the sampling frequency of the digital audio signal of each multi-channel can be arbitrarily selected by the recorder and the digital of each channel can be selected. The audio signal, its quantized bit number, and the sampling frequency are recorded on the digital disk, and the digital audio signal of each channel can be D / A converted on the DVD audio disk player side based on the quantized bit number and the sampling frequency. So, so that the recording side has different recording time and sound quality,
Also, you can record with a substantially constant recording time,
Even if the recorded audio signal has different recording time and sound quality, it can be reproduced by one type of player.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a DVD-video format and a DVD-audio format applied to the present invention.

FIG. 2 is an explanatory diagram showing in detail a format of an audio manager (AMG) shown in FIG.

FIG. 3 is an explanatory diagram showing in detail the format of the audio title set (ATS) of FIG.

FIG. 4 is an explanatory diagram showing in detail a format of audio manager information (AMGI) shown in FIG.

5 is an explanatory diagram showing the format of an audio title set attribute table (ATS-ATRT) in FIG. 4 in detail.

6 is an explanatory diagram showing in detail the format of audio title set attribute data (ATS-ATR) in FIG. 5;

FIG. 7 is an explanatory diagram showing in detail a format of audio title set information (ATSI) of FIG.

FIG. 8 is an audio title set information management table (ATSI-MAT) of FIG. 7.
3 is an explanatory diagram showing the format of FIG.

9 is a diagram showing the audio title set menu audio stream attribute data (ATSM) of FIG.
It is an explanatory view showing in detail (-AST-ATR).

10 is an audio title set / audio stream attribute table (ATS-AS) of FIG. 8;
It is an explanatory view showing the format of (T-ATRT) in detail.

11 is an explanatory diagram showing the attribute data (ATS-AST-ATR) of each audio stream in FIG. 10 in detail.

12 is an explanatory diagram showing an audio content block unit (ACBU) of FIG. 1. FIG.

FIG. 13 is an explanatory diagram showing in detail formats of the audio pack and the video pack of FIG. 12;

FIG. 14 is an audio control (A-CO
It is an explanatory view showing the format of a (NT) pack in detail.

FIG. 15 is an explanatory diagram showing in detail the format of the audio character display (ACD) area of FIG.

16 is an explanatory diagram showing an example displayed by the namespace information of FIG.

FIG. 17 is an audio search data (ASD) of FIG.
It is explanatory drawing which shows the format of an area in detail.

FIG. 18 is an explanatory diagram showing a modified example of the audio content block unit of FIG. 1.

FIG. 19 is an explanatory diagram showing a relationship between a channel, a quantization bit rate, a sampling frequency, and a recording time.

FIG. 20 is an explanatory diagram showing a recording example in which channels, quantization bit numbers, and sampling frequencies are different.

FIG. 21 is an explanatory diagram showing another example of a multi-channel and stereo 2-channel audio area.

22 is an explanatory diagram showing another example of the format of the audio character display (ACD) area of FIG.

FIG. 23 is a DVD of the second embodiment applied to the present invention.
FIG. 6 is an explanatory diagram showing a basic format of an audio disc.

FIG. 24 is an explanatory diagram showing an audio data structure of the DVD-audio disc shown in FIG. 23.

FIG. 25 is an explanatory diagram showing a basic format of a DVD-Van disc.

FIG. 26 is an explanatory diagram showing a basic format of a DVD video disc.

FIG. 27 is an explanatory diagram showing a basic format of a DVD-Avd disc.

FIG. 28 is a DVD of the second embodiment applied to the present invention.
-AOTT-AOB-AT in audio discs
It is explanatory drawing which shows R.

FIG. 29 is an explanatory diagram showing the channel allocation information of FIG. 28 in detail.

FIG. 30 is a DVD of the second embodiment applied to the present invention.
Audio of linear PCM of audio disc (A)
It is explanatory drawing which shows the format of a pack.

FIG. 31 is an explanatory diagram showing the private header of FIG. 30 in detail.

FIG. 32 is a block diagram showing an embodiment of an audio signal encoding apparatus applied to the present invention.

FIG. 33 is a block diagram showing the signal processing circuit of FIG. 32 in detail.

FIG. 34 is a block diagram showing a DVD-audio disc reproducing apparatus applied to the present invention.

35 is a block diagram functionally showing the reproducing device in FIG. 34. FIG.

FIG. 36 is a DVD of the second embodiment applied to the present invention.
FIG. 3 is a block diagram showing an audio disc reproducing apparatus.

37 is a block diagram functionally showing the reproducing device in FIG. 36. FIG.

[Explanation of symbols]

1 Multi-channel area 2 Stereo 2-channel area A Audio pack (audio area) A-CONT Audio control pack ACB Audio content block ACBS Audio content block set ACBU Audio content block unit AMG Audio manager ATS Audio title set ATS-AST-ATRT Audio title Set audio stream attribute table (quantization control information area) ATS-ATRT audio title set attribute table (quantization control information area) ATSI audio title set information CONT control pack D disk V video pack

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-11-66754 (JP, A) JP-A-7-161140 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 20/10 G11B 27/00

Claims (2)

(57) [Claims] 1. An analog audio signal is multi-channel first.
Channel of the first group and the channel of the second group, respectively, are A / D-converted with different quantization bit numbers and sampling frequencies for the channels of the first group and the channels of the second group, and are digital audio signals. And a recording area for the auxiliary signal and a recording area for the main signal are arranged in succession, and the recording area for the main signal is different for each channel of the first group and the channel of the second group. Each digital audio signal A / D converted at the quantization bit rate and sampling frequency is recorded.
And over audio pack, and an index made up of the audio pack, and composed of audio title in the index, audio tight consists of the audio title
Set (ATS), the number of quantization bits and the sampling frequency for each channel of the first group and the second group of the digital audio signals recorded in the audio pack , and the assigned first group When the channel assignment information and the previous identifying a channel of the second group, respectively
The step of recording a quantization control information area recorded for each audio title set, a title search information area in which search information for searching the audio title is recorded, and formatting and recording the information in a predetermined format. Audio signal encoding method. 2. A decoding method for decoding an audio signal recorded by the encoding method according to claim 1, comprising a first group of channels and a first group of channels of the digital audio signal recorded in the quantization control information area. It is recorded in the audio pack based on the number of quantization bits and the sampling frequency for each channel of the two groups, and the channel allocation information for specifying the channel of the first group and the channel of the second group. First
And a step of decoding the digital audio signals of the channels of the second group and the channels of the second group, and the step of decoding the search information.