JP2000173248A - Time obtaining method based on digital audio data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method through which a present reproducing time of digital versatile disk audio data being reproduced, total reproducing time of the tracks and remaining reproducing time are obtained. SOLUTION: In the method, track starting time data (FAC-S-PTM), reproducing timing data (PTS) of the pack presently being reproduced, and total reproducing time data (ATS-PG-PB-TM) of the tracks are obtained from digital audio data or control information. Then, based on the data obtained, present reproducing time and remaining reproducing time are obtained using a prescribed computational equation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for playing back digital audio data, and more particularly to a method for acquiring time information such as a current playback time while playing back digital audio data.

[0002]

2. Description of the Related Art A DVD video disk has been developed as an optical disk capable of recording video (moving images) with high image quality and high density and recording various information such as multi-angle video, sub-video, multi-lingual audio, and multi-channel audio. As a result, the spread and penetration into the general market has begun (DVD stands for Digital Versatile Disc).

[0003] However, the DVD video specifications are rather created with priority on video rather than audio, and the DVD video is not limited to the sampling frequency and the number of quantization bits, but also to the number of recordable channels and recordable time.
Expectations for audio priority over video audio specifications are also expected.

In response to the above expectations, a DVD audio specification has been produced (although the DVD audio specification is not yet a prior art). In this DVD audio specification, 48K to 96K employed in DVD video are used.
As a matter of course, it is possible to support up to 192 kHz sampling and 24-bit linear PCM.

[0005] Packed PCM in which audio information is packed (compressed) into a compact data size while maintaining the same high quality as linear PCM by performing lossless encoding / decoding is also supported.
Further, there is a possibility that a specification capable of higher sound quality will be introduced in a future version upgrade of the DVD audio specification.

[0006] As described above, the DVD audio system can cope with future scale-up because a D-picture capable of recording a large amount of data including a digital high-definition image is included in the target.
This is because DVD audio has a part that can be commonly used with VD video.

[0007]

In a DVD video capable of reproducing digital audio, there are four types of data to be reproduced (Nv_PCK, A_PCK, V_PCK,
SP_PCK), and the bit transfer rates of the four types of packs are different from each other, so that a method of acquiring time using the packs has not been realized.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to provide a method for obtaining a current reproduction time, a total reproduction time of a track, and a remaining reproduction time during reproduction of digital audio data in DVD audio. Aim.

[0009]

In order to achieve the above object, a digital audio time obtaining method according to the present invention comprises a method of obtaining a start time of a track from digital audio data or management information; And the total playback time is obtained, and based on the obtained information, the current time during playback is obtained using a predetermined calculation formula.

That is, data PTS that manages the time to be played back from the pack of digital audio data, the track playback start time and the total playback time of the track are obtained from the management information, and the current playback time and the remaining playback time are obtained. Calculate the playback time.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. In order to avoid redundant description, common reference numerals are used for functionally common parts in a plurality of drawings.

FIG. 1 is a diagram showing a recording format of information recorded on a DVD optical disk, and particularly showing a recording format of information recorded on a DVD audio zone. As shown in FIG. 1, this format includes a lead-in area 27, a volume space 28, and a lead-out area 29. The volume space 28 includes a volume / file structure area 70, a DV
A D audio zone 71, a DVD video zone 72, and another recording area 73 are included.

The volume / file structure area 70 has I
It corresponds to a management area defined in SO9660 and UDF bridge. Based on the description of the area 70, the contents of a simple audio manager or audio manager described later are stored in a system memory inside a DVD audio player (not shown).

The DVD audio zone 71 includes a simple audio manager (SAMG) 710, an audio manager (AMG) 711, an audio still video set (ASVS) 713, and one or more audio title sets (ATS # m) 712. (Maximum number m of audio title sets is 99). However, ASVS 713 is optional data and DV
In some cases, the data is not recorded in the D audio zone 71.

The SAMG 710 is a table indicating the contents (stereo or monaural) of linear PCM data or lossless packed PCM data, and is composed of eight simple audio reproduction pointer tables.

AMG 711 is a DVD audio zone 7
1, which is composed of an audio manager information (AMGI) file, a video object set for audio manager menu (AMGM_VOBS) file, and an audio manager information backup (AMGI_BUP) file (not shown). You.

Each ATS 712 includes an audio title set information (ATSI) file 7120, an audio only title audio object set (AOTT_AOBS) file 7121, and an audio title set information backup (ATSI_BU).
P) file 7123.

Although the AOTT_AOBS 7121 is composed of 1 to 9 files, these are optional files and may not be present.

The ASVS 713 disposed after the AMG 711 (before the ATS 712) is a DVD audio player (video-capable audio player: VCAP for short) capable of handling video.
A logical unit indicating a set of still pictures (audio still video: ASV for short) that can be reproduced together with the audio data in 712.

If there is an audio still video ASV, the ASVS 713 is recorded in the DVD audio zone 71 together with SAMG, AMG, and ATS.

In a DVD audio-only player (audio only player: AOP for short),
Even if it is recorded, the ASVS 713 is ignored and the audio still video ASV is not reproduced.

The DVD video zone 72 includes a video manager VMG and a video title set VT (not shown).
It has the same hierarchical structure as the DVD audio zone including S # 1 to #n. For details of the DVD video zone 72,
It is omitted here for simplicity.

In the other recording area 73, information usable in the video title set VTS of the DVD video zone 72 or other information unrelated to the video title set can be recorded. This area 73 is not essential, and may be deleted if not used.

Returning to the description of FIG. 1, AOTT_AO in FIG.
The BS 7121 defines a group of one or more audio objects AOTT_AOB #, as shown in FIG. Each AOTT_AOB is one or more audio cells A
A set of TS_C # is defined. A program is constituted by a group of one or more cells ATS_C #, and a program chain PGC is constituted by a group of one or more programs. The PGC constitutes a logical unit indicating the whole or a part of the audio title.

In the example of FIG. 2, each audio cell ATS
_C # is an audio pack A with a size of 2048 bytes
It is composed of a set of PCKs. These packs are the minimum units when performing data transfer processing. The minimum unit for performing the logical processing is a cell unit, and the logical processing is performed in this cell unit.

In another example of FIG. 2, the audio cell ATS_
The C # is composed of an audio pack A_PCK including a real-time information pack RTI_PCK having real-time information RTI as appropriate.

As an option, a part of the audio packet (see FIG. 3A) constituting the audio pack of FIG. 2 may have a sampling frequency of 192 kHz or more (for example, 384 kHz) and a quantization bit number of 16 bits or less. It is also possible to store audio data of only a super-high frequency component that has been compressed (lossless compression or lossy compression).

The sub-stream ID of the audio packet containing the data of the super high frequency component includes information indicating that the packet is audio data for the super high frequency band, its compression method, sampling frequency, number of quantization bits, and the like. Can be described.

When a general DVD audio player does not have a function of decoding the super high frequency audio packet, the super high frequency audio packet is ignored by the player.

If the DVD audio player is a high-end model and has a function of decoding the audio packet for the ultra-high frequency band, the content (compression method, sampling frequency, , Quantization bit number, etc.), and can decode the ultra-high frequency audio data.

The decoded ultra-high frequency audio data (for example, 384 kHz, 8-bit non-linear compressed audio) is synthesized with ordinary decoded DVD audio data (for example, 96 kHz, 24-bit linear PCM audio).

As a result, for example, audio data of 5 Hz to 40 kHz is reproduced as a 96 kHz, 24-bit linear PCM audio, and the linear PCM audio has a frequency of 40 kHz.
The super high frequency components of z to 160 kHz are superimposed and reproduced.

The super-high frequency component of 40 kHz to 160 kHz is inaudible to human ears as a single tone (single tone), but the envelope of the super-high frequency component is 20 kHz.
When the following amplitude change component is included, it can be detected by human hearing (as a subtle nuance change or a feeling of air at the recording site).

FIG. 3A shows the configuration of the audio information pack A_PCK of FIG. 2, and FIG. 3B shows the configuration of the real-time information pack RTI_PCK of FIG.

In FIG. 3A, the audio information pack is 2048 bytes, and the pack header includes:
Pack start code, system clock reference SCR, marker bit, maximum rate of program (10.08 Mbp
s), and information such as the stuffing length of the pack.

In the packet header of the audio packet, a prefix of a packet start code, a stream ID (private stream 1 indicating the total of the reproduction data buffer <Note 1 of AU7-54>), a presentation time stamp (PTS), a marker bit Are stored.

The PTS indicating the reproduction timing of the audio frame is described in each audio packet including the first data of the audio frame.

Audio packet substream ID
Stores, for example, a code (1010 0000b) indicating a linear PCM audio stream.

UPC_EAN_I of audio packet
SRC includes Used Parameter C
ontrol; UPC) International Standard Record Code (Internationa
l Standard Recording Code (ISRC) information is stored.

In the private header length of the audio packet, the number of bytes of the private header is described.

In the first access unit pointer of the audio packet, the address of the first byte of the first access unit is described. Here, the first access unit has the first byte of the audio frame and is specified by the presentation time stamp of the audio packet.

The audio data information portion of the audio packet includes an audio emphasis flag, downmix mode, downmix code validity, downmix code, equalize word length 1, equalize word length 2, audio sampling frequency 1, audio sampling frequency. 2. Information such as multi-channel format, bit shift of channel group 2, channel assignment, dynamic range control, and the like are described.

In the stuffing byte of the audio packet, a predetermined 8-bit value (0000 0000b) is written to adjust the pack length (the stuffing byte is 0 to 7 bytes).

The audio data portion of the audio packet includes linear PCM data of 44.1 kHz to 192 kHz / 16 to 24 bits (or lossless packed P
CM data) is stored. An audio stream for each audio data is composed of a group of one or more audio packs, and is recorded in AOTT_AOB of FIG.

In FIG. 3B, the real-time information pack is also 2048 bytes, and the pack header stores information having the same contents as the pack header of the audio pack.

In the packet header of the real-time information packet, information having the same configuration as the packet header of the audio packet is stored.

A code (0100 1000b) indicating a real-time information stream is stored in the sub-stream ID of the real-time information packet.

The number of bytes of the private header is described in the private header length of the real-time information packet.

RTI information I of real-time information packet
D describes the type of real-time information included in this packet.

In the stuffing byte of the real-time information packet, a predetermined 8-bit value (0000 0000b) is written to adjust the pack length (the stuffing byte is 0 to 7 bytes).

On the DVD audio disc, certain information that can be reproduced in real time can be recorded together with the audio content as needed.

Specifically, in the data portion of the real-time information packet shown in FIG. 3B, various data that can be reproduced in synchronization with audio data can be stored. Typical examples of real-time data that is reproduced in synchronization with audio data include real-time text data such as a message to a user and lyrics of a song. In addition, various real-time information for different uses is shown in AOTT_AO of FIG.
B can be recorded.

Hereinafter, as a typical example of the real-time information,
The contents of the real-time text data will be briefly described.

A DVD audio disk has one or more audio text data language units (ATXTDT_L).
When U) is provided, text data used for lyrics, explanations to the user, and the like can be recorded as real-time text data (RTXTDT).

Real-time text data RTXTDT
Is displayed on the display screen as a “page”.
One page can be composed of 4 lines of 30 characters per line (for 1-byte characters) or 2 lines of 15 characters per line (for 2-byte characters). When the player has a function of playing RTXTDT, the player writes the contents of RTXTDT in page units.
It is displayed on a display screen (a display panel of an audio player not shown or a TV monitor screen connected to the player).

In DVD audio, up to eight languages can be used as real-time text.

In the case of DVD audio, the management structure of recorded contents from the software production side includes albums,
It has a hierarchical structure consisting of groups, tracks and indexes.

Here, the album, group, track and index can all be accessed by the user of the DVD audio player, but the group and track can be accessed only by the user. On the other hand, the head group of the album / the head index of the head track can be stored in the DVD even if the user does nothing.
The audio player itself can access it automatically.

An album corresponds to one side of a DVD audio disc, and is described in, for example, “First Beethoven Works Collection”.
Volumes "can be assigned to this album. In this case, this album can be composed of, for example, the first symphony group # 1 to the ninth symphony group # 9.

Each group (for example, group # 1)
It is composed of tracks # 1 to # 4 corresponding to the first to fourth movements of the corresponding symphony (Symphony No. 1). Further, each track is constituted by indexes # 1 to #i obtained by appropriately dividing the content into i.

Each group corresponds to a group of one or more audio titles ATT #. These ATTs are:
It is used only as an internal logical unit indicating recorded contents.

When a user plays a DVD audio disc, the user sets the disc 10 in a DVD audio player (not shown), and then operates a remote controller (not shown) to set the group # 1 and / or group # 1. Track # 1 can be selected.

When the user presses the play button on the remote controller after making this selection, the DVD audio player starts playing from the beginning of the first movement of Beethoven's symphony No. 1. When the user further designates a specific index from the remote controller, the designated index portion is searched and reproduced from that portion. (The default index playback of the first index portion of the first track of the first group of the album is performed without any user specification.) FIG.
FIG. 3 is a diagram for describing recorded contents of an audio title set (ATS) in a DVD audio zone of FIG.

The audio title set ATS includes audio title set information ATSI and an audio object set AOT for audio only title.
It is composed of T_AOBS and a backup ATSI_BUP of audio title set information.

Audio title set information ATSI
Is an audio title set management table ATSI_
MAT and audio title set program chain information table ATS_PGCIT.

The audio title set program chain information table ATS_PGCIT includes an audio title set program chain information table information ATS_PGCITI and an audio title set program chain information search pointer ATS_PG.
CI_SRP and one or more audio title set program chain information ATS_PGCI.

FIG. 4 shows the recorded contents of the audio title set information management table ATSI_MAT of FIG.

That is, the audio title set information management table ATSI_MAT includes the audio manager information management table AMGI_MAT.
Audio title set identifier (ATS_ID); end address of audio title set (ATS_E)
A); End address of audio title set information (ATSI_EA); Version number of the adopted audio standard (VERN); End address of audio title set information management table (ATSI_MAT_)
EA); start address (VTS_) of audio-only title AOTT video title set VTS
SA); Start address (AOTT_AO) of audio object set for audio only title
BS_SA) or the start address (AOTT) of the video object set for the audio-only title
_VOBS_SA); Start address (AT) of the program chain information table for audio title set
S_PGCIT_SA); attribute of audio object set for audio only title (AOTT_
AOBS_ATR) or attributes of the video object set for audio-only titles (AOTT_VO)
BS_ATR) # 0 to # 7; audio title set data mix coefficient (ATS_DM_COEFT) # 0
~ # 15: Other reserved areas are provided.

When the ATS does not have AOTT_AOBS, the start address VTS_SA of the VTS for AOTT contains VTSTT_ATS used for AOTT.
The start address of the VTS including the VOBS is written. When ATS has AOTT_AOBS, "000
“00000h” is written to this VTS_SA.

The above AOTT_AOBS_SA contains AT
When S has AOTT_AOBS, AO is represented by the number of logical blocks relative to the first logical block of ATS.
The start address of TT_AOBS is written. On the other hand, when the ATS does not have AOTT_ABOS, ATS
In OTT_VOBS_SA, the start address of VTSTT_VOBS is the VTS used for ATS.
Written with the number of logical blocks relative to the first logical block of the VTS including TT_VOBS.

The ATS_PGCIT_SA contains AT
The start address of ATS_PGCIT is written with the number of relative logical blocks from the first logical block of SI.

The above AOTT_AOBS_ATR or A
Eight OTT_VOB_ARTs are prepared from # 0 to # 7. When the ATS has AOTT_AOBS, the attribute of AOTT_AOB recorded in the ATS is AOTT_AOBS.
Written to TT_AOBS_ATR. On the other hand, ATS
Does not have AOTT_AOBS, AOTT_V
The attribute of the audio stream in the VOB used for AOTT_VOB in the ATS is written in OB_ART. The adopted sampling frequency (44 kHz to 192 kHz) and the number of quantization bits (16 to 24 bits) are written in AOTT_AOBS_ATR or AOTT_VOB_ART.

The ATS_DM_COEFT is AC-
Indicates a coefficient when audio data having a multi-channel output (5.1 channel output) such as 3 or DTS is mixed down to a 2-channel output, and is used only for one or more AOTT_AOBs recorded in the ATS. Is done. 1 if ATS does not have AOTT_AOBS
“0h” is written to all bits of each of the six (# 0 to # 15) ATS_DM_COEFTs. This one
Areas for six (# 0 to # 15) ATS_DM_COEFTs are constantly provided.

FIG. 5 shows an audio title set program chain information table (ATS_PGCI) included in the audio title set information (ATSI) of FIG.
T), an audio title set cell playback information table (ATS_C_PBIT), and an audio title set audio still video playback information table (ATS).
_ASV_PBIT).

As shown in FIG. 5, ATS_PGCIT
Is the audio title set program chain information table information ATS_PGCITI and the audio title set program chain information search pointer AT
S_PGCI_SRP and audio title set program chain information ATS_PGCI.

The ATS_PGCI_SRP is one or more audio title set program chain information search pointers (ATS_PGCI_SRP # 1 to ATS).
_PGCI_SRP # j), and the ATS_PGC
I is the same number of ATS_PGCI_SRP and audio title set program chain information (ATS_PGC
I # 1 to ATS_PGCI # j).

Each ATS_PGCI functions as navigation data for controlling the reproduction of the audio title set program chain ATS_PGC.

Here, ATS_PGC is an audio
A unit that defines only title AOTT, AT
S_PGCI and one or more cells (A in AOTT_AOBS or A
OTT_VOBS).

Each ATS_PGCI contains general information (ATS_P) of an audio title set program chain.
GC_GI), an audio title set program information table (ATS_PGCIT), and an audio title set cell playback information table (ATS_C_
PBIT) and a reproduction information table (ATS_ASV_P) of the audio still video for the audio title set.
BIT).

The ATS_PGIT contains one or more audio title set program information (ATS_PGI #).
1 to ATS_PGI # n) (n ≦ 99);
TS_C_PBIT is the same number of audio title set cell playback information (ATS_C_PBI) as ATS_PGI.
# 1 to ATS_C_PBI # k) (k ≦ 2
55).

Reproduction information table ATS_ASV_PBI of audio still video for audio title set
T is each program PG in the program chain PGC
Describes the display state (display number, display timing, etc.) of the audio still video ASV with respect to.

FIG. 6 shows the contents of the audio title set program information ATS_PGI of FIG.

This ATS_PGI is the content of the audio title set program (ATS_PG_CNT).
And the entry cell number of ATS_PG (ATS_PG_
EN_CN), the reproduction start time of the first audio cell in the ATS_PG (FAC_ST_PTM), and the ATS
_PG playback time (ATS_PG_PB_TM) and A
Pause time of TS_PG (ATS_PG_PA_TM)
Etc. are included.

The ATS_PG_CNT includes the following contents: a description (relation allocation) indicating a physical arrangement relationship between the preceding program and the current program; and a reproduction time stamp between the preceding program and the current program. Description indicating relationship (temporal continuity) (discontinuous flag of system time clock STC); A
Description (ATRN) indicating the attribute of the OB or the attribute of the audio stream in the VOB of ATS_PG; description indicating how many bits are shifted from the sample data in channel group 2 (bit shift of channel group 2); Description of whether stereo output is allowed (downmix mode); DM_COE
Description of whether FTN is valid (DM_COEFT
N validity); AT defined by ATSI_MAT
Coefficient table number (DM_COEFTN) for downmixing AOB in ATS_PG using S_DM_COEFT number; ATS is AOTT_AO
In the case of having a BS, RTS is included in AOB of ATS_PG.
A real-time information packet (R) having a TI_id value of [n]
TI_PKT) (RT_PKT)
_Flag_n).

The ATS_PG_EN_CN is the ATS
_PG number of the first ATS cell (1 to 25)
5 ATS_CN). Note that A
ATS_PG_EN_CN for TS_PGI # 1 is “1”, and ATS_P of subsequent ATS_PGI #
G_EN_CN increases.

The FAC_ST_PTM is such that ATS
In the case of having the OTT_AOBS, the description includes the lower 32 bits of the reproduction time stamp (presentation time stamp PTS) described in the first audio packet of the first audio cell in the ATS_PG.

The ATS_PG_PB_TM is the ATS
_PG describes the total playback time of each cell. This total playback time (seconds) is ATS_PG_
It is obtained as a value obtained by dividing PB_TM (32-bit data) by 90000.

The ATS_PG_PA_TM is the ATS
Has AOTT_AOBS, ATS_P
It describes the pause time that can be defined at the beginning of G. This pause time (seconds) is ATS_PG_
It is obtained as a value obtained by dividing PA_TM (32-bit data) by 90000. If the ATS does not have AOTT_AOBS, ATS_PG_PA_TM contains “0000”.
0000h ”is written.

FIG. 7 is a block diagram exemplifying a part of a configuration of a device (DVD audio player) for reproducing recorded information in the audio zone of FIG. 1 from a DVD optical disk. This playback device may take the configuration of a DVD video / DVD audio compatible player capable of playing back video as well as audio. Further, the playback device may be configured to be able to play an existing CD.

The playback apparatus (DVD audio player) shown in FIG. 7 is roughly divided into a disk drive section for rotating the DVD audio disk 10 and reading recorded data therefrom, and a still picture, sub-picture or menu from the read data. And a video-based decoder for decoding and outputting a music signal and related text from the read data.

The disk drive unit is driven D
An optical pickup 102 for detecting a corresponding optical signal from the recording pits of the VD audio disk 10, a demodulation unit 104 for demodulating the detected optical signal, and an error correction unit (ECC unit) 106 for the demodulated signal. I have. ECC
The data (no error) recorded in the lead-in area, the data recording area (volume space) 28, and the lead-out area in FIG. The retrieved data is the SAMG 710 of FIG.
AMG 711, ASVS 713, ATS 712, and the like are included.

Now, a DVD audio player capable of reproducing not only audio but also video (still image) is called a video-capable audio player (VCAP). In this VCAP, before the reproduction of the audio object AOB accompanied by the still image display is started, the program chain information AT of the audio title set is started.
Each pack in ASVU indicated by S_PGCI is D
It is read from the VD audio disc and stored in a specific buffer. ASVU
It is called a buffer.

The system control section 160 shown in FIG. 7 includes a control information reading section 160a.
The data of the audio still video ASV and the related sub-picture data are extracted from a predetermined recording position of the VS 713 and taken into the ASV buffer 110.

Further, the control information reading section 160a
Audio data (FIG. 3A) or real-time text data (FIG. 3B) is extracted from a predetermined recording position 712 (hierarchical configuration in FIG. 2), and is taken into the track buffer 140.

The data taken into the ASV buffer 110 is supplied to the ASV object demultiplexer 112. The demultiplexer 112 determines the type (such as a still image or a sub-image) of various packets included in the data reproduced from the disk 10, and separates and extracts the data in the packets. In the separated and extracted data, transfer time data and ID data indicating the type of data are recorded for each type of packet.

The demultiplexer 112 refers to these transfer time data and ID data and transfers the data to the corresponding input buffer. That is, the video data (still picture data) and the sub-picture data separated and extracted by the demultiplexer 112 are supplied to the input buffer via different signal paths.

In this input buffer, the separated video data (still picture data) is
4 is temporarily stored in the sub-picture buffer 11.
6 is stored once. The video data (still image data) once stored in the video buffer 114 is decoded by the video decoder 124 and converted into, for example, an NTSC analog video signal (ASV signal) having an aspect ratio of 4: 3. The sub-picture data once stored in the sub-picture buffer 116 is decoded by the sub-picture decoder 126,
It is converted into a video signal that can be superimposed on the ASV signal.

The decoded ASV signal and sub-picture signal are combined at a predetermined timing in the video mixer 130, and output to a monitor (not shown) outside the player.

This monitor unit is used not only as a playback video monitor for a DVD audio disk with a still picture, but also as a display means such as an on-screen display OSD. The monitor unit is not limited to a direct-view display such as a CRT display, a liquid crystal display, and a plasma display. In addition, various images including OSD information on a large screen (a menu screen, a relaxing scenery image, a recording site) Video projector that projects a still image or other single image or multi-divided image that captures the above situation.

On the other hand, the data taken into the track buffer 140 is the audio data demultiplexer 1.
42. The demultiplexer 142 determines the type of various packets (such as an audio packet and a real-time information packet) included in the data reproduced from the disk 10, and separates and extracts the data in the packet.

In the separated / extracted data, transfer time data and ID data indicating the type of data are recorded for each type of packet.

The demultiplexer 142 refers to the transfer time data and the ID data and transfers the data to the corresponding input buffer.

That is, audio data (monaural, 2-channel stereo or multi-channel surround audio data) separated and extracted by the demultiplexer 142 and real-time information data (RT
I data) are supplied to the input buffer via separate signal paths.

In this input buffer, the separated audio data is temporarily stored in the audio buffer 144, and the real-time information data is stored in the RTI buffer
6 is stored once.

The audio data once stored in the audio buffer 144 (for example, 96 kHz 24-bit 2-channel stereo data) is
4 and converted into a high-quality 2-channel analog audio signal.

Real-time information data (for example, text data of lyrics corresponding to a decoded audio signal) once stored in RTI buffer 146 is decoded by RTI decoder 156.

The decoded audio signal is sent to an audio system (a stereo system including a control amplifier, a power amplifier, a speaker, etc.) (not shown), and at the same time, the decoded text data is sent to the external monitor (not shown). Sent.

The audio signal reproduced from the DVD audio disk 10 is reproduced as high-quality stereo sound by the above-mentioned audio system.
The image of the lyrics is projected on a monitor TV or a projector screen.

[0109] Although not shown, user operation information from a remote controller attached to the DVD audio player is notified to a system control unit 160 which controls the operation of the entire player. The control unit 160 includes a microcomputer, a ROM storing a control program executed by the microcomputer, a RAM serving as a work area of the microcomputer, and other peripheral circuits.

The microcomputer displays the player's operation status (various setting status and DVD audio disc playback information) corresponding to the user's operation on a display panel (not shown) of the player as appropriate.

Although not shown, the control information reading section 160a includes a system time clock (STC) for providing the operation timing of each section of the player, and a register for temporarily storing commands and information from the microcomputer. I have. The control information reading unit 16 determines at what timing the player processes various data (audio data, still image data, highlight information, text data, etc.) read from the DVD audio disk 10.
The microcomputer 0a can make the determination with reference to the STC time. The timing for starting the time measurement of the STC can be determined by setting the contents of the system clock reference (SCR) included in the header of each pack read from the disk in the STC.

The playback time calculation unit 161 is a component according to the present invention, and includes the system control unit 160 and the ECC unit 10.
6. Input various control information from the audio decoder 154 and calculate time information such as the current reproduction time and the remaining reproduction time.

Next, a digital audio time acquisition method according to the present invention and a configuration to which the acquisition method is applied will be described.

Three embodiments for realizing the reproduction time from the start of reproduction of the currently reproduced track (hereinafter, referred to as the current track) to the present time and the remaining reproduction time of the current track will be described below. ATS_AOBS that contains only digital audio objects in all acquisition methods
(Audio Object Set for Aud
io Only Title). Therefore, the ATS type of the set of audio titles is type
Valid only when 1. The type 1 is an ATSI (Audio) indicating title information of audio as shown in FIG.
TitleSet Information), AO
TT_AOBS1, ATSI backup ATSI
_BUP (Backup of Audio Title)
e Set Information)
TS. type2 is ATSI, ATSI_B
AOTT_AOBS1 does not exist.

The audio pack A_PCK shown in FIG.
Is a set of audio data, and the real-time information pack RTI_PCK is a set of real-time information. Audio object AOTT_AOB of audio only title
Is a set of packs (A_PCK, RTI_PCK). The audio object set AOTT_AOBS of the audio-only title is a set of audio objects AOTT_AOB. As described above, the real-time information is information such as character data used in synchronization with the reproduction of audio data.

As shown in FIG. 2, an audio object AOTT_AOB (Audio Object) for digital audio only title is provided.
For Audio Only Title), there are two types: a case composed of only an audio pack A_PCK (essential) and a case composed of an audio pack A_PCK (essential) and a real-time information pack RTI_PCK (optional).

FIGS. 8 to 10 are diagrams for explaining the digital audio time obtaining method according to the first embodiment. FIG. 8 is a flowchart showing the operation of the first embodiment, and FIG. FIG. 10 is a graph showing the relationship between a track and its reproduction time. FIG. 10 is a diagram schematically showing a configuration for calculating and displaying the reproduction time using the management information of the DVD audio disk 10.

First, the system control unit 160 acquires the total reproduction time of each track and the start time of the current track (step S1). The total playback time of the track is represented by ATS_PG_P in the audio title set program information ATS_PGI of FIG.
B_TM (ATS_PG Playback Tim
Obtain and request the information of e). The start time of the current track is represented by FAC_S_PTM [bits 31 to 0] (St
art Presentation Timeoff
he first Audio-Cell in AT
S_PG).

Next, the system control section 160 determines the timing at which the target data in each packet of the audio pack and the real-time information pack shown in FIG. 3 should be reproduced, that is, the PTS [bit 31] indicating the reproduction time. ~ 0] (Presentation
Time Stamp) (Step S)
2).

The reproduction time calculation unit 161a calculates the start time FAC_ of the current track from the current reproduction time PTS.
By subtracting ST_PTM, the current playback time can be calculated (step S3). The remaining time of the track being reproduced is the total reproduction time ATS_ of the track.
The current playback time PTS is subtracted from PG_PB_TM to calculate (step S4).

The points A (PTS) to B (FA) shown in FIG.
The time up to C_S_PTM is the playback time of the currently playing track, and the remaining time of the playing track can be obtained by subtracting point A (PTS) from point C (ATS_PG_PB_TM). As shown in FIG. 10, after performing the time calculation, the reproduction time calculation unit 161a sends the result to the display controller 162. Display controller 162
Displays the reproduction time of the current track, the remaining time, and the total reproduction time of each track on the display device 163 capable of displaying time (step S5).

Next, as in step S6, if the reproduction of the current track is not completed, the flow returns to step S2, and if the reproduction of the current track is completed, it is determined whether the next track is to be reproduced continuously (step S6). S7). When reproducing the next track, steps S1 to S6 are executed again.

Note that the calculation of the reproduction time includes the pause time ATS_PG_PA_ of the ATS_PG described in the audio title set program information ATS_PGI in FIG.
The playback time including the pause time can be calculated and displayed by incorporating the TM.

FIGS. 11 and 12 are diagrams for explaining a digital audio time obtaining method according to the second embodiment. FIG. 11 is a flowchart showing the operation of the second embodiment, and FIG. FIG. 3 is a diagram schematically illustrating a configuration for calculating and displaying a reproduction time using a decoder.

As shown in FIG. 3, one pack of the audio pack A_PCK of digital audio data and the real-time information pack RTI_PCK is composed of two packs.
048 bytes. Further, since the decoder unit 154 counts the number of decoded packs, the number of packs can be obtained.

First, the system control unit 160 determines the total reproduction time ATS_P of the track as in step S1 described above.
G_PB_TM is obtained (step S10), the number of packs is obtained from the decoder unit 154 (step S11), and the data is provided to the reproduction time calculation unit 161b. By calculating the number of packs × the data amount of one pack, the reproduced data amount can be calculated. Therefore, the playback time calculation unit 1
61b calculates “the number of packs × the data amount of one pack (2048 bytes) × 8 (bits)” to obtain the reproduced data amount (the number of bits) (step S12).

Further, system control section 160 controls audio title set information management table ATSI_MAT of audio title set information ATSI shown in FIG.
AOTT_AOB that describes the audio attributes of
_ATR / AOTT_VOB_ATR # 0 to # 7 (At
tribute of AOBs for AOTTo
r Attribute of Audio stream
am of VOBs for AOTT), the number of quantization bits (Q
of Channel Group, Q of C
channelGroup2) and channel group 1,
2 Each sampling frequency (fs of Cha)
nnel Group, fs of Channel
Group 2) is obtained, and the playback time calculation unit 1
61b. FIG. 13 shows AOTT_AOB_ATR
It is a figure which shows the detail of # 0- # 7.

In the case of DVD audio, when the number of channels in the audio stream is three or more, the plurality of channels are classified into channel group 1 (CH_GR1) and channel group 2 (CH_GR2). FIG. 14 is a diagram showing standards related to channel groups. The number of quantization bits of each channel belonging to the same channel group must be the same. Also,
Channel groups 1 and 2 may have different sampling frequencies and / or different numbers of quantization bits.

The system control unit 160 controls the AOTT of FIG.
_AOB_ATR # 0 to # 7 to assign channels (Ch
inner Assignment) [bits 92 to 8
8] is read, the number of channels in each channel group is determined, and provided to the reproduction time calculation unit 161b. FIG. 15 is a diagram showing the assignment of each channel defined in the channel assignment bits [b92 to b88].

After obtaining the amount of data, the number of quantization bits (Q), the sampling frequency (fs), and the number of channels, the reproduction time calculation unit 161b, as shown in FIG. Data volume ×
The current playback time is obtained by dividing “α” by “quantization bit number × sampling frequency × channel number” (step S13). α is a constant determined from the number of quantization bits (Q), the sampling frequency (fs), and the number of channels.

As described above, according to the present application, even when the digital audio data has a plurality of channels and is classified into two channel groups, it is possible to obtain and provide the current playback time from the number of decoded packs. it can.

The remaining time of the track being reproduced is obtained from the total reproduction time of the track (ATS_PG_PB_TM).
It is obtained by subtracting the current time obtained as described above (step S14). The playback time calculation unit 161b
After calculating the time, the result is displayed on the display controller 162.
Send to The display controller 162 causes the display device 163 capable of displaying time to display the reproduction time of the current track, the remaining time, and the total reproduction time of each track (step S15).

Next, if the reproduction of the current track is not completed as in step S16, the flow proceeds to step S11.
When the reproduction of the current track is completed, it is determined whether to continue reproduction of the next track (step S17).
When reproducing the next track, steps S10 to S16
Are performed again.

FIGS. 16 and 17 are diagrams for explaining a digital audio time acquiring method according to the third embodiment. FIG. 16 is a flowchart showing the operation of the third embodiment, and FIG. FIG. 4 is a diagram schematically illustrating a configuration for calculating and displaying a reproduction time using a track buffer.

As shown in FIG. 3, one pack of the audio pack of digital audio and the real-time information pack is 2048 bytes. Further, the track buffer 140 counts the number of effective packs (the number of sectors) to be sent to the subsequent stage, so that the number of packs can be obtained.

First, the system control unit 160 determines the total reproduction time ATS_P of the track as in step S1 described above.
G_PB_TM is obtained (step S20), and the number of packs is obtained from the track buffer 140 (step S2).
1) The data is provided to the reproduction time calculation unit 161b.

The reproduction time calculation unit 161b calculates “the number of packs × 1
Pack data amount (2048 bytes) x 8 (bits) "
Is calculated, and the reproduction data amount (the number of bits) is obtained (step S22).

[0138] Further, the system control section 160 controls the audio title set information management table ATSI_MAT of the audio title set information ATSI shown in FIG.
AOTT_AOB that describes the audio attributes of
From the _ATR / AOTT_VOB_ATR # 0 to # 7, the number of quantization bits of each of the channel groups 1 and 2 and the sampling frequency of each of the channel groups 1 and 2 are acquired and provided to the reproduction time calculation unit 161b.

Next, the system control unit 160 executes the processing shown in FIG.
The channel allocation is read from OTT_AOB_ATR # 0 to # 7, the number of channels in each channel group is determined, and the number is provided to the reproduction time calculation unit 161b.

When the data amount, the number of quantization bits (Q), the sampling frequency (fs), and the number of channels are obtained, the reproduction time calculation unit 161b, as shown in FIG. Data volume ×
The current playback time is obtained by dividing “α” by “quantization bit number × sampling frequency × channel number” (step S23).

As described above, according to the present invention, even when the digital audio data has a plurality of channels and is classified into two channel groups, the current reproduction time is obtained from the number of packs output from the track buffer. Can be provided.

The remaining time of the track being reproduced is calculated from the total reproduction time of the track (ATS_PG_PB_TM).
It is obtained by subtracting the current time obtained as described above (step S24). The playback time calculation unit 161b
After calculating the time, the result is displayed on the display controller 162.
Send to The display controller 162 causes the display device 163 capable of displaying time to display the reproduction time of the current track, the remaining time, and the total reproduction time of each track (step S25).

If the reproduction of the current track is not completed as in step S26, the flow proceeds to step S21.
When the reproduction of the current track is completed, it is determined whether or not to continue reproduction of the next track (step S27).
If the next track is to be reproduced, steps S20 to S26
Are performed again.

[0144]

According to the present invention, the reproduction time of the current track, the remaining time, and the total reproduction time of each track can be obtained, and the obtained information can be provided to the display device.

[Brief description of the drawings]

FIG. 1 is a view for explaining recorded contents of an audio title set (ATS) in a DVD audio zone.

FIG. 2 shows recorded contents (A of a DVD audio zone in FIG. 1);
FIG. 4 is a view for explaining the data structure of (OTT_AOBS).

FIG. 3 is a view for explaining the configuration of an audio information pack and a real-time information pack of FIG. 1;

FIG. 4 shows the audio title set information (ATS) shown in FIG.
The figure explaining the recording content of the audio title set information management table (ATSI_MAT) included in I).

FIG. 5 shows the audio title set information (ATS) shown in FIG.
Audio title set program chain information table (ATS_PGCIT) and audio title set cell playback information table (ATS_C_
PBIT) and audio title set audio still video playback information table (ATS_ASV_PB)
The figure explaining the content of IT).

FIG. 6 is an exemplary view for explaining the contents of audio title set program information (ATS_PGI) in FIG. 5;

FIG. 7 is a block diagram illustrating a part of the configuration of a device (DVD audio player) for reproducing recorded information in the audio zone of FIG. 1 from a DVD optical disk.

FIG. 8 is a flowchart showing the operation of the first embodiment.

FIG. 9 is a diagram showing a relationship between a track and a reproduction time.

FIG. 10 is a schematic diagram in a case where time information is obtained using disk management information.

FIG. 11 is a flowchart showing the operation of the second embodiment.

FIG. 12 is a schematic diagram when time information is acquired using a decoder.

FIG. 13 is a diagram showing details of AOTT_AOB_ATR # 0 to # 7.

FIG. 14 is a diagram showing standards related to channel groups.

FIG. 15 is a diagram showing assignment of each channel defined in channel assignment bits [b92 to b88].

FIG. 16 is a flowchart showing the operation of the third embodiment.

FIG. 17 is a schematic diagram when time information is acquired using an error correction unit.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koji Maruyama 70 Yanagimachi, Saiwai-ku, Kawasaki-shi, Kanagawa F-term in Toshiba Yanagimachi Plant (reference) 5D077 AA23 DC05 DC11 DC39 DC01 DD01 EA22 EA35

Claims (2)

[Claims] 1. A reproduction time acquisition method for an apparatus for reproducing digital audio data recorded in a data recording area ATS, wherein the data recording area ATS controls a digital audio data area AOTT_AOBS and the digital audio data. And the digital audio data has a pack structure, and the pack structure has a pack A_P
A set of CK and RTI_PCK, in which a pack header and a packet header are sequentially recorded at the head of the pack, and in the packet header, a reproduction indicating the timing at which the digital audio data in the pack is to be reproduced. Timing data PTS is recorded, the control information area is recorded before the digital audio data area, and the control information area includes reproduction start time data FAC_ST_PT and total reproduction time data ATS_
PG_PB_TM is recorded; the reproduction start time data and the total reproduction time data in the control information area are obtained; the reproduction timing data in the packet header is obtained at the time of reproducing the digital audio data; A digital audio data time acquisition method, wherein a current playback time is calculated based on time data and the playback timing data. 2. A reproduction time acquisition method for an apparatus for performing error correction processing on digital audio data recorded in a data recording area ATS, decoding and reproducing the error-corrected data, and comprising: Includes a digital audio data area AOTT_AOBS and a control information area ATSI in which information for controlling the digital audio data is recorded. The digital audio data has a pack structure, and the pack structure has a pack A_P
CK, RTI_PCK, wherein the control information area is recorded before the digital audio data area, and the control information area is the total playback time data ATS.
Information area ATS_PG including _PG_PB_TM
I and the attribute AOTT of the digital audio data
Information area AT including _AOB_ATR # 0 to # 7
Reading an attribute of the digital audio data in the second information area, acquiring a quantization bit number, a sampling frequency, and a channel number of the digital audio data; Acquiring the number of reproduced packs indicating the number of the reproduced packs, calculating and providing a current reproduction time based on the number of quantization bits, the sampling frequency, the number of channels, and the number of reproduced packs. Digital audio data time acquisition method.