JP2002251836A - Method for encoding audio signal, and method for recording audio signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a user recording sound to perform recording so as to change the recording time or the sound quality of an audio signal or to perform record ing in an almost fixed recording time. SOLUTION: On a region for recording the main signal of a disk, analog signals are recorded as digital audio signals are sampled at different sampling frequencies for every mltichannels of a first group and a second group, and quantized by the number of quantization bits different for every channels of the first group and the second group. Furthermore, the digital audio signals are sampled at sampling frequencies identical with or different from the frequencies in the above mltichannels, and are recorded as digital audios of stereo 2 channels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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 disk represented by a DVD audio disk.

[0002]

2. Description of the Related Art As a conventional optical disk for audio reproduction, a CD (compact disk) is known. A DVD (digital video disk) is known as an optical disk having a higher density than 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. (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 a song title cannot be extracted.

[0003] Also, since audio users have a wider range of usage layers than video, a simple reproduction method is required by providing a TOC (table of contents) area like a CD. However, for DVD-Video, the navigation control pack (CONT
) And a plurality of video (V) packs and audio (A) packs to form a video content block unit and control the playback of the V and A packs by the CONT pack. There is a problem that playback cannot be performed easily and the usability is poor.

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

[0005] Therefore, when an audio signal is mainly recorded, it can be easily reproduced for the user and is easy to use. In addition, in order to simplify real-time management, audio data is stored in a pack containing audio data. A DVD audio disk provided with a control pack including information for managing the DVD is conceivable.

[0006]

When an audio signal is recorded on such a DVD audio disk, since the optical disk has a higher density than a CD, a long-time audio signal can be recorded in addition to left and right two-channel stereo signals. Recording can be performed using multi-channel signals of 5, 6, and 8 channels. Therefore, the recorder changes the number of channels, the sampling frequency and the number of quantization bits according to the disc, album, and music, and records, changes the sampling frequency according to the channel, and changes the bandwidth according to the channel. If the recording time can be reduced, it is possible to realize a DVD audio disk having a desired recording time or various DVD audio disks having different recording times and sound qualities. Here, it is essential that such various DVD audio discs have compatibility such that one kind of player can reproduce them.

[0007] Therefore, the present invention provides a recording apparatus in which a recording time and a sound quality of an audio signal are different so that recording can be performed at a substantially constant recording time. It is an object of the present invention to provide an audio signal encoding method and decoding method that can be reproduced by one type of player even if the audio signals differ.

[0008]

Means for Solving the Problems In order to achieve the above object, the present invention comprises the following means 1) and 2). That is, 1) the recording area for the auxiliary signal and the recording area for the main signal are continuously arranged, and the analog audio signal is provided in the recording area for the main signal in the first group of channels of the multi-channel and the second group.
Digitally sampled at a different sampling frequency for each channel of the first group and quantized with a different number of quantization bits for each of the first group and the second group of channels and coded in a predetermined coding mode. An audio area recorded as an audio signal, a sampling frequency and a quantization bit number for each of a first group of channels and a second group of channels of the digital audio signal recorded in the audio area;
And a quantization control information area in which channel group assignments and second group channel assignments and the encoding mode are recorded are recorded in a predetermined format. Encoding method. 2) A decoding method for decoding an audio signal recorded by the encoding method according to claim 1, wherein a channel of a first group and a second group of digital audio signals recorded in the quantization control information area. Based on the sampling frequency and the number of quantization bits for each channel, the assignment of the first group of channels and the second group of channels, and the encoding mode. And a second group of channels.

[0009]

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 according to a reference example of the present invention. FIG. 2 is an explanatory diagram showing a format of an audio manager (AMG) in FIG. 1 in detail. FIG. 3 is an explanatory view showing the format of the audio title set (ATS) of FIG. 1 in detail, and FIG. 4 is an audio manager information (AM) of FIG.
FIG. 5 is an explanatory diagram showing the format of the GI) in detail, and FIG.
FIG. 6 is an explanatory diagram showing the format of the audio title set attribute table (ATS-ATRT) in detail, FIG. 6 is an explanatory diagram showing the format of the audio title set attribute data (ATS-ATR) in FIG. 5, and FIG. FIG. 8 is an explanatory diagram showing in detail the format of the audio title set information (ATSI). FIG. 8 is an audio title set information management table (ATS) shown in FIG.
FIG. 9 is an explanatory diagram showing the format of I-MAT in detail.
Is the audio title set menu, audio stream, and attribute data (ATSM-AS) shown in FIG.
FIG. 10 is an explanatory diagram showing the format of the audio title set / audio stream attribute table (ATS-AST-ATRT) of FIG. 8 in detail. FIG. 11 is a diagram showing the format of each audio stream of FIG. Attribute data (ATS-A
FIG. 3 is an explanatory diagram showing (ST-ATR) in detail.

FIG. 12 is an explanatory diagram showing the audio content block unit (ACBU) of FIG. 1, and FIG.
14 is an explanatory diagram showing the format of the audio pack and the video pack of FIG. 12 in detail, 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. 16 is an explanatory diagram showing the format of the area in detail, FIG. 16 is an explanatory diagram showing an example displayed by the namespace information in FIG. 15, FIG. 17 is an explanatory diagram showing the format of the audio search data (ASD) area in FIG. 14 in detail, FIG. 18 is an explanatory diagram showing a modification of the audio content block unit of FIG.

Here, the DVD-audio disc of this description has two stereo channels and a 5/6/8 channel as an audio signal so as to correspond to a transition period when shifting from the CD generation to the DVD-audio generation. Are recorded. Also, it is considered that when this transition period has elapsed, only the multi-channel signal of 5/6/8 channel will be recorded.

FIGS. 1A and 1B show DVD-Video and DVD-Audio formats, respectively.
The VD-audio format is compatible with DVD-Video, though the area name is different. First, the DVD-video format is roughly divided into a video manager (VMG) at the head and areas following a plurality of video title sets (VTS).
The audio format is correspondingly constituted by an audio manager (AMG) shown in detail in FIG. 2 and, as shown in detail in FIG. 3, each area of a plurality of audio title sets (ATS) following the AMG.

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. AT
The performance time of each music piece in the ACBS is set in SI in real time. In the present invention, menu information for displaying a menu screen is recorded in the first ACBS. This is the same as a DVD video, and the description is omitted.

Each of the VCBSs is constituted by a plurality of VCBs, while each of the ACBSs is constituted by a plurality of ACBs. Each VCB has one video title (Ti
tre), and each ACB is correspondingly one audio title. Each VCB (one title) is constituted by a plurality of chapters (Chapter), while each ACB (one title) is correspondingly constituted by a plurality of tracks (Track). Chapters include part of title (PTT),
The track contains a part of title (PTT).

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 VCB unit is composed of a head 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.
Each of the CB units has a corresponding audio control pack (hereinafter referred to as A-CONT pack)
, Followed by a plurality of A packs and V packs.

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

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

As shown in FIG. 3, ATS (audio title set) includes: audio title set information (ATSI) shown in detail in FIG. 7; audio content block set for ATS menu (ATSM-ACBS); It has an audio content block set (ATSA-ACBS) for title and ATSI for backup. Both ATSM-ACBS and ATSA-ACBS have the PCI and DSI described above (FIG. 2).

The AMGI (Audio Manager Information) is shown in detail in FIG. 4 as follows: An AMGI management table (AMGI-MA)
T) and a 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) shown in detail in FIG. A text data manager (TXTDT-MG); an audio manager menu cell (index)
An address table (AMGM-C-ADT); an audio manager menu; an audio content block unit; and an addressless map (AMGM-C-ADT).
ACBU-ADMAP).

The ATS-ATRT (audio title set attribute table) is shown in detail in FIG. 5 as follows: 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) for each of a plurality (n) of ATSs as shown in detail in FIG.

As shown in detail in FIG. 6, the audio title set attribute data (ATS-ATR- # 1 to #n) includes: ATS-ATR-EA (end address); and ATS-CAT (category). And ATS-ATRI (information).

The ATSI (ATS information) shown in FIG. 3 is shown in detail in FIG. 7, and the audio title set information management table (ATSI-MA) shown in FIG.
T), 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 includes: ATS-ID (identifier); ATS-EA (end address); EA, VERN (DVD audio specification 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 shown in detail in FIG. ST-ATR
(ATSM audio stream attributes)
ATS-AST-Ns (the number of ATS audio streams); ATS-AST-ATRT as detailed 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 used as an attribute of an encoded audio signal recorded on this disk. To (4) are allocated (other bits are reserved). (1) Audio encoding mode (3 bits b63 to b6
1) 000b: Dolby AC-3 010b: MPEG-1 or MPEG-2 (without extended bitstream) 011b: MPEG-2 (with extended bitstream) 100b: Linear PCM audio 101b: Linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch, 2ch + 8ch. )

(2) Quantization / DRC (Dynamic Range Control) information (2 bits b55, b54)-"11b" when the audio encoding mode is "000b"-"010b" or "10b" when the audio encoding mode is "000b" 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-The audio encoding mode is "100b", "101"
"b" for stereo 2ch 00b: 16 bits 01b: 20 bits 10b: 24 bits 11b: Reserved

(3) Sampling frequency fs (2 bits b53, b52) 00b: 48 kHz 01b: 96 kHz 10b: 192 kHz for two stereo channels (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.
The (ATS audio stream attribute table) has ATS-AST-ATR for each of audio streams # 0 to # 7, as shown in detail in FIG.
Each of the TS-AST-ATRs is composed of 8 bytes (64 bytes in total).

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

However, (4) the number of audio channels in the 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 + 6 ch, the stereo signal of 2 ch is converted to audio stream # 0
, And 3 of the 6 channels are assigned to the audio stream # 1, and the 2ch rear signal and LFE
One channel signal is assigned to audio stream # 2. Then, both 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. "
Is recorded.

When the 2 + 6 ch analog audio signal is sampled at, for example, 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 bits Rear 2 ch, LFE 1 ch: 48 kHz, 16 bits (no thinning), and the audio title set menu audio stream attribute data (AT
SM-AST-ATR) has attributes of stereo 2ch. (1) Audio encoding mode 101b: linear PCM audio (2ch + 5ch, 2ch)
Includes + 6ch, 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.

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

The ATS of audio stream # 1
For AST-ATR: (1) Audio encoding mode 101b: Linear PCM audio (2ch + 5ch, 2ch
Includes + 6ch, 2ch + 8ch. (2) Quantization / DRC 00b: 16 bits (3) Sampling frequency fs 01b: 96 kHz (4) Number of audio channels 010b: 3 ch (7) Audio application mode 11b: 2 ch + surround mode (8) Thinning information of the stream 00b : Full (1/1) (9) Thinning information of only LFE1ch 00b: Full (1/1) is recorded.

The ATS of audio stream # 2
For AST-ATR: (1) Audio encoding mode 101b: Linear PCM audio (2ch + 5ch, 2ch
Includes + 6ch, 2ch + 8ch. (2) Quantization / DRC 00b: 16 bits (3) Sampling frequency fs 00b: 48 kHz (4) Number of audio channels 010b: 3 ch (7) Audio application mode 11b: 2 ch + surround mode (8) Thinning information of the stream 00b : Full (1/1) (9) Thinning information of only LFE1ch 00b: Full (1/1) is recorded.

Next, the A pack in which an 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 up to 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 second of the audio time, and is arranged so as to be completed within the range of 0.5 to 1.0 second at the break of the index. Also, audio time (GOF: Group of Audio)
(Frame unit) is indicated by the A-CONT pack, and the 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 is
Do not force padding to 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, an L-channel pack and an R-channel pack are arranged adjacent to each other. Similarly, in the case of multi-channel, they are arranged adjacently. The V pack is arranged adjacent to the A pack when displaying an image during reproduction of an audio signal. A pack and V pack are shown in FIG.
As shown in the figure, for 2034 bytes of user data (A data, V data), 4 bytes of pack start information, 6 bytes of SCR (System Clock Reference) information, and 3 bytes of Mux rate A pack header of a total of 14 bytes of information and 1-byte stuffing is added (1 pack = 2 total).
048 bytes). In this case, the time stamp SC
By setting the R information as “1” in the first pack in the ACB unit and making it continuous within the same title, the time of the A pack in the same title can be managed.

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,
It is composed of byte ASD (Audio Search Data) packets. 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 reserved area of bytes. The ASD packet also has a 6-byte packet header and a 1-byte substream ID, and a
It is composed of 00 bytes of ASD (audio search data).

The 636-byte ACD information area is shown in FIG.
As shown in detail in FIG. 5, a general information area of 48 bytes, a character "1" in the first language and a character "2" in the second language
Each has an area of 294 bytes, and each area has 93 bytes.
It consists of a name space area of bytes, two free space areas of 93 bytes each, and a data pointer area of 15 bytes. For example, as shown in FIG. 16, data for displaying a song name in Japanese is arranged in one namespace area of the first language character "1" and the second language character "2", and the other name is displayed. Data to be displayed in English is arranged in the space area. In addition,
This 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 , And the hold information. The 16-byte service level information indicates display size, display type, audio / video / SP distinction, stream, and the like. Characters are mandatory (mandatory), and bitmaps are optional (optional). 12
The language code information of the byte indicates the language of the characters “1” and “2” in 2 bytes each as in the case of the video file, and indicates up to eight languages in one file. English is mandatory.

The 6-byte character set code information can have a maximum of 15 character codes corresponding to the language codes, and indicates the presence / absence and type of the characters "1" and "2" in 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 spaces “1” and “2”, the presence / absence of a data pointer, and the ID shown in FIG. The namespace is mandatory, and the title name, music name, and artist name must be described.

As shown in detail in FIG. 17, the 1000-byte ASD (audio search data) includes 16-byte general information, 8-byte current number (No.) information, 16-byte current time information, and 8 bytes. It is composed of title set search information of 8 bytes, title search information of 8 bytes, track search information of 404 bytes, index search information of 408 bytes, highlight search information of 80 bytes, and a reserved area of 52 bytes. I have.

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 (2 bytes: BCD) of the track, and the reserved area (2 bytes). The 16-byte current time information includes the track playback time (4 bytes: BCD), the remaining playback time of the track (4 bytes: BCD), the absolute time of the title (4 bytes: BCD), and the rest of the title. (4 bytes: BCD).

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

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

According to such a format, at the head of a plurality of A packs, subsequent A packs such as TOC information of a CD are provided.
A-CONT for managing audio signal of pack
Since the packs are arranged, the audio data is not integrated with the video data and the like, and the recording capacity can be increased. Also, audio time can be managed by the A-CONT pack, and simple character information such as a song title relating to audio data can be extracted by the A-CONT pack.

Also, the title in the A-CONT pack,
Since TOC information such as a start address and performance time is arranged, even during audio reproduction, information corresponding to a user operation can be taken out from the A-CONT pack and reproduction can be started. 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 playback device, and the information according to the user operation is stored in the memory. And immediately start playback. Also, since there is no need to store large-capacity information such as program chain information (PGCI) in DVD-Video, it is possible to efficiently manage disks.

Further, 1. When there is no image (V) data in the content, (1) Search and random access to three layers of title, music, and index become possible. (2) Cueing, time search, and random access in GOF (audio frame) units become possible. (3) Title, song, and index time can be managed in real time.

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

Regarding video data, (1) Search and random access to three layers of title, PTT, and cell become possible. (2) Cueing, time search, and random access in video frame units become possible. (3) Title, PTT, and cell time can be managed in real time. (4) The current time and the remaining time in the PTT or the title can be displayed and managed in video frame unit time.

The ACBU shown in FIG.
Although the pack and the CONT pack are included, the configuration may be such that the V pack and the CONT pack are not included as shown in FIG. In this case, the video signal is not recorded, but the recording capacity of the audio signal is increased, and the disc size can be reduced.
Since the playback function can be simplified, a device suitable for a portable playback device can be provided.

FIG. 19 shows that an analog audio signal is sampled at various sampling frequencies fs and quantized with various quantization bits, and only two channels are used, 2 channels + multi-channels (6 channels, 8 channels) and multi-channels (6 channels, 8 channels).
It shows the recording time (TIME) when recording on a VD-audio disc. In this way, if the recording side selects and records the sampling frequency fs and the number of quantization bits of each channel, it takes several tens of minutes to 30 on a single disk.
You can record up to 0 minutes or more.

FIG. 20 shows 2ch + 6ch, where 6ch are 3ch front (FRONT) and 2ch + rear (REAR).
Each recording time (TIME) is shown in the case of LFE 1ch, 2ch + 5ch, 5ch is 3ch front and 2ch rear, and only 6ch, and 6ch is 3ch front and 2ch rear + 1ch LFE. As described above, if the sampling frequency fs and the number of quantization bits of each channel are selected, and even if the sampling frequency fs of each channel is shared, the band of only the rear 2ch + LFE1ch or the LFE1ch only is narrowed and compressed and recorded. It is possible to record around one hour on one disc. Note that when compressed and recorded, the player uses the rear 2ch + LFE shown in FIG.
Interpolation based on thinning data of only 1ch and 1ch of LFE,
After decompression, D / A conversion can be performed at the original sampling frequency fs.

When the multi-channel and stereo 2-channel stream signals are recorded on the disk, the disk D is divided into the inner and outer multi-channel areas 1 and the stereo 2-channel area 2 as shown in FIG. You may make it record separately. In this case, various restrictions can be reduced even if the sampling frequency and the number of quantization bits of the multi-channel and the stereo two channels are different.

Although the multi-channel digital audio signal has been described as being a linear PCM, the audio encoding mode is Dolby AC-3 or MPEG-1.
Or MPEG-2. In this case, for example, the sampling frequency and the number of quantization bits are set to the front channel.
Other than the standard, ATSM-A for the front channel
By using the quantization / DRC information of ST-ATR (FIG. 9) and the sampling frequency fs, different sampling frequencies and different numbers of quantization bits can be selected. This makes it possible to provide a digital disk corresponding to a wide range of users.

The ACD area in the ACD packet may be configured to have data of the first language character "1" and the second language character "2" as shown in FIG. As shown in FIG. 22, the data relating to the character "2" is omitted, and a general information area of 48 bytes and a so-called "audio navigation" such as a song title as shown in FIG. It may be composed of a 294-byte area for the character "1" and a 294-byte audio reproduction control information area.
The area of the character "1" is similarly composed of a 93-byte name space area, two 93-byte free space areas, and a 15-byte data pointer area.

The contents of the audio reproduction control information area are arbitrary, and are constituted by, for example, 10 types of audio reproduction control information areas (250 bytes) of 25 bytes each and a reserve 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. Is done. When the user reproduces the music arranged in the A-pack, the audio reproduction control information is set according to, for example, the genre (classical, jazz, rock, BGM) of the music, or even if the genre is the same. This data is recommended by a so-called professional mixer so that the sound quality at the time of reproduction is optimized according to the performance state, recording state, atmosphere, and the like of the music. In the case where the number of channels of the audio signal is 6, the number of channels is reduced to 2 and the mixing coefficient for stereo reproduction is stored in the holding area.

Next, an embodiment of the present invention will be described. FIG. 23 shows a format of the embodiment of the DVD audio disc applied to the present invention, and this format does not include a VTS as shown in FIGS.
It is composed of ATS only. And this ATS
Is the audio manager (AMG) shown in FIG.
24, an audio manager menu (AMGM) for video and audio, and ATS <1> and ATS <2> managed by AMGI in the AMG. ATS <1> and ATS <2> are shown in FIG. As shown, the A-CONT pack is not included, and the A-CONT pack is composed of the A pack and the still image pack. Further, this still image pack is not arranged in a large amount with respect to the A pack,
A pack is arranged.

Here, for reference, FIG. 25 shows a DVD-V
an (video + audio navigation) disc, which format is roughly D
Video title set (VT) as VD-video data
S) and an ANV title set (ANV-TS) as audio navigation data. More specifically, the VTS has the same configuration as the DVD video disk shown in FIG. 1A and FIG. 26 described later, while the ANV-TS has an audio manager (AMG) shown in FIG. ATS in the AMG in pairs with VTS <1> and VTS <2> of
It is composed of ATS <1> and ATS <2> managed by I. The format of the DVD video disk does not include ATS or ANV-TS as shown in FIG. 26 and FIG. 1A, and is composed of only VTS.

FIG. 27 shows the format of a DVD-Avd (audio + AV data) disc. The format is roughly a video title set (VTS) as DVD-video data and an audio title set (VTS) as DVD-audio data. ATS). In more detail, VTS
A video manager (VMG) shown in (a) and a video and audio video manager menu (VMGM)
And VTS <1> managed by VMGI in VMG
It consists of.

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

FIG. 28 shows an audio-only title audio object attribute (AOT) recorded on a disc as attribute data indicating the contents of audio data on the disc of the embodiment applied to the present invention.
T-AOB-ATR). This attribute data is composed of 8 bytes (64 bits b63 to b0),
Detailed description in order from the MSB side: 3 bit (b63 to b61) audio encoding mode; 1 bit (b60) downmix (DM) mode; 4 bit (b59 to b56) multi-channel 4 bits (b55 to b52) of the quantization bit number Q1 of the channel group 1; 4 bits (b51 to b48) of the quantization bit number Q2 of the channel group 2; 4 bits (b47 to b44) ), A sampling frequency fs1 of channel group 1; a 4-bit (b43 to b40) sampling frequency fs2 of channel group 2; a 3-bit (b39 to b37) reserved area; and a 5-bit (b36 to b32). And the reserved area of the remaining 32 bits (b31 to b0). Note that 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) 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 permitted 1b: Downmix stereo output prohibited (3) Multi-channel type (b59-b56) 000b: Type 1 Other: Hold

(4) Number of quantization bits Q1 of channel group 1 (b55 to b52) 0000b: 16 bits 0001b: 20 bits 0010b: 24 bits Others: reserved (5) Number of quantization bits Q2 of channel group 2 (b5)
1 to b48) When the quantization bit number Q1 of the channel group 1 is “000”
"0000b" in the case of "0b" ・ Quantization bit number Q1 of channel group 1 is "000"
1b "is" 0000b "or" 0001b ". The quantization bit number Q1 of the channel group 1 is" 001 ".
In the case of “0b”, “0000b”, “0001b” or “0010b” where 0000b: 16 bits 0001b: 20 bits 0010b: 24 bits Other: reserved

(6) Sampling frequency fs1 of channel group 1 (b47 to b44) 0000b: 48 kHz 0001b: 96 kHz 0010b: 192 kHz 1000b: 44.1 kHz 1001b: 88.2 kHz 1010b: 176.4 kHz 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 of “0001b” In this 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 assignment (b36 to b3)
2) FIG. 29 shows 21 types of channel assignment information (patterns) of groups “1” and “2” from 1 channel (monaural) to 6 channels. Incidentally, the symbols shown in the figure 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 Ls: multi-channel left surround Rs: multi-channel right surround none: not applicable

The disk applied to this embodiment uses the linear PCM mode. The A pack of the linear PCM is composed of 2048 bytes or less, and is composed of a 14 byte pack header and an A packet as shown in FIG. The A packet includes a packet header of 17, 9, or 14 bytes, a private header shown in detail in FIG. 31, and audio data (linear PCM) of 1 to 2013 bytes.

As shown in FIG. 31, the private header includes: an 8-bit substream ID; a 4-bit reserved area; a 4-bit ISRC number; an 8-bit ISRC data; A 16-bit first access unit pointer; a 6-byte audio data information (A
DI) and • stuffing bytes of 0 to 7 bytes.

The ADI includes: a 1-bit audio emphasis flag, a 1 + 2 bit reserved area, a 4-bit downmix code, and a 4-bit group “1” quantization word length “1”.
And the quantization word length “2” of the 4-bit group “2”
A 4-bit audio sampling frequency fs1 of group "1"; a 4-bit audio sampling frequency fs2 of group "2"; a 4-bit reserved area; and 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 a signal processing circuit of FIG. 32 in detail. In FIG. 32, the analog audio signal A is A /
Sampled by the D converter 31 at a sufficiently high sampling frequency (sampling period Δt), for example, 192 kHz, for example, a 24-bit high-resolution PCM
Xb1, x1, xa1, x2, xb2, x3, xa2,..., X
bi, x2i-1, xai, x2i,... This data sequence (xbi, x2i-1, xai, x
2i) 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 unit 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 present embodiment, the PCM data converted by the A / D converter 31 is directly applied to the allocation circuit 40, and the audio data (linear PC) shown in FIG.
M), and then the DVD formatting unit 3
4 to format A pack shown in FIG.

On the other hand, when performing compression, first,
Low-pass filter (LPF) that passes a half band
36, for example, by using an FIR filter, a high-resolution curve α
From the data sequence (xbi, x2i-1, xai, x2i), the data sequence xc1, *, *, *, xc2, *, *, *, xc3, corresponding to the band-limited low-resolution 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. Here, the data sequence xci is a data sequence in which the digital data A / D converted by the A / D converter 31 is band-limited and the sampling frequency is reduced to 1/4.

The data sequence (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, the adder 39 acting as a difference calculator calculates the difference xbi−xci = Δ1i xai−xci = Δ2i. 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 converts the data string xci and the difference data Δ1i, Δ2i into user data (FIG. 13).
(1 packet = 2034 bytes), and the user data is stored in the DVD formatter 34.
Output to

The video signal V is supplied to the A / D converter 31V
Then, the digital video signal is encoded into an MPEG format by a V encoder 32V, and then packed into user data shown in FIG. Then, the DVD formatting unit 34 performs packing in the format described above. This DVD
The data formatted by the formatting unit 34 is modulated by a modulation circuit 35 in a modulation method according to the disk, and a disk is manufactured based on the modulated data.

FIG. 34 shows an apparatus for reproducing the disk of the reference example shown in FIG.
Has data of the above structure EFM-modulated and recorded in the form of pits. When music 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 playback device 17 in accordance with the operation. During playback, pit data recorded on the DVD audio disk 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.
Detects NT pack and sets control parameters in parameter section 8
And the V pack controlled by the CONT pack is sequentially written into 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 stored in the pack order by the buffer extracting unit 5 based on the SCR (see FIG. 13) in the V pack, and in the CONT pack. PTS (Pr
(Esentation TimeStamp), and then output as an analog video signal via the image converter 6, the D / A converter 7, and the video output terminals 15, 15 '.

The A-CONT pack detecting section 9 detects the A-CONT pack in the reproduced data, sets the control parameters in the parameter section 14, and sets the A-CONT pack.
The A pack controlled by the T pack is sequentially written into the A pack buffer 10. The user data (audio signal) in the A pack written in the A pack buffer 10 is
The buffer extracting unit 11 extracts the audio search data ASD in the A-CONT pack in the order of packs and the output time based on the current time (see FIG. 17) of the audio search data ASD in the A-CONT pack.
The signal is output as an analog audio signal via the conversion unit 13 and the audio output terminal 16. Also, A-CONT
The display data (the audio character display information ACD shown in FIGS. 15 and 16) in the pack is sent to the display signal generator to generate a display signal.

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

In FIG. 35, the control means 23 is the operation unit 1
When a command signal for reproducing the target music is transmitted from the remote control device 8 or the remote control device 19, an address control information signal corresponding to the reproduction command is transmitted to the reproducing means 2 so that the target music is reproduced from the DVD audio disk 1. Reproduce. The reproduced signal processing / separating means A separates the reproduced data to A
-Send the CONT information to the control means 23, send the audio signal to the audio signal output means (12, 13), and send the character information to the character information output means 20. The reproduction signal processing separation means V separates the reproduction data and sends CONT information to the control means 23, and converts the video signal and the sub-picture information into 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, and the beginning of a song may be performed.

FIGS. 36 and 37 show an apparatus for reproducing a disc (format shown in FIG. 24) applied to the present invention. When performed, the control unit 23
Controls the drive device 2 and the playback device 17 in accordance with the operation. During playback, 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 detectors 9. When the V pack is recorded on the disk 1, the V pack detection unit 3 detects the V pack in the reproduced data, sets the control parameters 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 stored in the pack order by the buffer extracting unit 5 based on the SCR (see FIG. 13) in the V pack, and in the CONT pack. PTS (Presentation
(Time Stamp), and are taken out in order of output time, and then the image converter 6, the D / A converter 7, and the video output terminal 1
It is output as an analog video signal via 5, 15 '.

The A and D pack detecting section 9 detects the A and D packs in the reproduced data, sets the control parameters in the parameter section 14, and stores the A and D packs in the A and D pack buffers 10. Write sequentially. A
The user data (audio signal) in the A pack written in the D pack buffer 10 is extracted by the buffer extracting unit 11 in the order of packs and in the order of output time, 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. The display signal is output via the display signal output terminal 22 or is output to the built-in character display unit 21. You.

[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 of the multi-channels can be arbitrarily selected by the recording side, and the digital The audio signal and its quantization bit number and sampling frequency are recorded on a 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 quantization bit number and sampling frequency. So that the recording side has different recording time and sound quality,
In addition, we can record at approximately constant recording time,
Even if the recorded audio signal differs in the recording time and sound quality, it can be reproduced by one type of player.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a format of an audio manager (AMG) of FIG. 1 in detail.

FIG. 3 is an explanatory diagram showing a format of an audio title set (ATS) of FIG. 1 in detail.

FIG. 4 is an explanatory diagram showing a format of audio manager information (AMGI) of FIG. 2 in detail.

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

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

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

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

FIG. 9 shows the audio title set menu, audio stream, and attribute data (ATSM) shown in FIG.
FIG. 2 is an explanatory diagram showing (AST-ATR) in detail.

FIG. 10 shows an audio title set audio stream attribute table (ATS-AS) shown in FIG.
FIG. 4 is an explanatory diagram showing the format of (T-ATRT) in detail.

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

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

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

FIG. 14 shows the audio control (A-CO) shown in FIG.
It is explanatory drawing which shows the format of NT) pack in detail.

FIG. 15 is an explanatory diagram showing in detail a format of an audio character display (ACD) area in FIG. 14;

FIG. 16 is an explanatory diagram showing an example displayed by the namespace information of FIG. 15;

17 is an audio search data (ASD) shown in FIG. 14;
It is explanatory drawing which shows the format of an area in detail.

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

FIG. 19 is an explanatory diagram showing the relationship between the channel, the number of quantization bits, the sampling frequency, and the 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.

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

FIG. 23 is an explanatory diagram showing a basic format of a DVD-Audio disc applied to the present invention.

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

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

FIG. 28 is an explanatory diagram showing AOTT-AOB-ATR in a DVD-audio disc applied to the present invention.

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

FIG. 30 is an explanatory diagram showing a format of an audio (A) pack of a linear PCM of a DVD audio disc applied to the present invention.

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 device 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 according to a reference example of the present invention.

FIG. 35 is a block diagram functionally showing the playback device of FIG. 34.

FIG. 36 is a block diagram showing a DVD-Audio disc reproducing apparatus applied to the present invention.

FIG. 37 is a block diagram functionally showing the playback device of FIG. 36.

[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

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H04N 5/92 G10L 9/18 M EF term (Reference) 5C053 FA24 GA06 GB05 GB11 GB32 5D044 AB06 BC03 CC06 DE02 DE15 DE44 DE54 DE59 GK08 GK12 GL22 5D045 DA06 DA11 5D090 AA01 BB02 DD05 FF42 GG21 GG36

Claims (2)

[Claims] 1. A recording area for an auxiliary signal and a recording area for a main signal are continuously arranged, and a recording area for the main signal includes a first group of analog audio signals and a second group of multi-channel audio signals. Digital audio signal sampled at a different sampling frequency for each of the channels and quantized with a different number of quantization bits for each of the first group of channels and the second group of channels and coded in a predetermined coding mode An audio area recorded as: a sampling frequency and a quantization bit number for each of a first group of channels and a second group of channels of the digital audio signal recorded in the audio area; and a first group of channels Control for recording the assignment of the channel of the second group and the coding mode Steps and encoding method of the audio signal consisting of recording the broadcast area, the formatted by a predetermined format. 2. A decoding method for decoding an audio signal recorded by the encoding method according to claim 1, wherein a channel of a first group of digital audio signals recorded in the quantization control information area and a second channel of the digital audio signal are recorded. Sampling frequency and quantization bit number for each channel of group 2;
Based on the assignment of the first group of channels and the second group of channels and the coding mode,
An audio signal decoding method for decoding digital audio signals of a first group of channels and a second group of channels recorded in the audio area.