JPH11345457A - Audio reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio reproducing device which can easily display a bit rate of an audio stream. SOLUTION: The audio reproducing device successively gains many packs belonging to a DTS data stream, and gains the packet data in them to convert them to a regenerative signal. Respective audio packets contain frame information and a packet header, and an audio frame is stored in the data, and the number of headers of this frame are described to the frame information, and a PES packet length and a PES header data length are described to the packet header. The number of headers of the frame are detected, and the number of frames are gained, and the PES packet length and the PES header data length are detected, and an audio data length is calculated, and the number of bytes of one frame is calculated by a calculation part 119, and a transfer bit rate is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio reproducing apparatus, and more particularly to an audio reproducing apparatus for reproducing or processing audio data.

[0002]

2. Description of the Related Art In recent years, an optical disk reproducing apparatus for reproducing an optical disk on which audio or video data is digitally recorded has been developed, and is widely used as a reproducing apparatus for movie software or karaoke. An optical disc, particularly a DVD disc, has a large storage capacity, so that a maximum of eight audio streams can be recorded, and the audio stream is not limited to the MPEG audio stream, but may be an AC-3 audio stream or
It is also possible to record a linear PCM audio stream. In addition to these audio streams, a new standard DTS (Digital
THEATER SYSTEM) audio streams can also be recorded, and DVD discs on which DTS audio stream data is recorded are on the market.

[0003] Conventionally, DVD playback devices, particularly DV (Digital Video), have been used to deal with various digital audio streams.
The D player is provided with a decoder corresponding to the audio stream, and is designed as a system that decodes data of the selected audio stream and outputs a high-quality audio signal.

[0004] As described above, a DVD reproducing apparatus having an audio decoder capable of selecting and reproducing a plurality of audio streams has a codec of an audio stream selected from attribute information recorded in a management area of a DVD disc. It is possible to acquire and display the format, the number of channels, and the language, but since the bit rate of the audio stream data is not described in the attribute information, the bit rate is given to the user. It is not possible to inform. Audio encoding methods include AC-3, MPEG, and DTS, and the sound quality depends on the bit rate. It is said that the higher the bit rate, the better the sound. Some of the already proposed DVD players try to display the bit rate, and the bit rate is the data including all of the video (video), audio (audio), and sub-picture (sub-picture) from the DVD disc. Is the transfer rate of
The bit rate of the audio itself is said to be unknown.

[0005] In addition, a player for decoding DTS requires high-performance hardware, in other words, a digital sound processor (DSP) capable of high-speed processing.
In general, encoded data is digitally output, decoded by an external DTS decoder, and reproduced. A DTS according to the DVD format can output encoded data digitally without knowing the DTS algorithm.
However, knowing the bit rate requires a unit having a decoding function that can interpret the algorithm.

Further, the conventional audio reproducing apparatus can display the encoding system, the number of channels, and the language of the selected audio stream, but cannot know the information of all the audio streams at once, so If the stream is not switched by the user, the information of the audio stream cannot be confirmed, which is said to be inconvenient.

[0007]

As described above, in the conventional audio reproducing apparatus, the bit rate of the audio stream cannot be displayed, and the encoding method, the number of channels, and the language of all the audio streams are collectively described. Has a problem that cannot be displayed. Also, there is a problem that the bit rate display of the DTS has a high performance and is therefore difficult without a high-cost decoding device.

The present invention has been made in view of such circumstances, and has as its object to provide an audio reproducing apparatus capable of easily displaying the bit rate of an audio stream.

Another object of the present invention is to be able to display the bit rate of an audio stream and to simultaneously display the encoding method, the number of channels, or the language.
It is an object of the present invention to provide an audio reproducing apparatus capable of displaying all audio streams at once and displaying the DTS bit rate easily without a DTS decoding function.

[0010]

According to the present invention, there is provided an audio pack comprising a pack header and an audio packet, wherein the audio packet is composed of a packet header, a sub-stream ID, and an audio frame. Information and audio data, wherein the pack header and the packet header are MP
An audio frame is stored in the audio data, the number of headers of the audio frame is described in audio frame information, and the packet length is defined as a pack header and a packet header defined by the EG system layer. Extracting the packet data from the audio pack, wherein the PES packet length for the PES and the PES header data length for the data length of the packet header are described in the packet header;
In an audio playback device that decodes and outputs the data,
First detecting means for detecting the number of headers of an audio frame from the audio frame information to obtain the number of frames;
Second detecting means for detecting an S packet length and a PES header data length to calculate an audio data length; and a first detecting means for calculating the number of bytes of one audio frame from the number of frames and the audio data length.
Calculating means for determining the bit rate from the number of bytes of one frame selected from the calculating means; converting means for converting the bit rate obtained from the determining means into a display signal for displaying; An audio reproducing device comprising:

Further, according to the present invention, in an audio reproducing apparatus for transferring and reproducing audio data from a recording medium on which one or a plurality of audio data streams are recorded, the audio data is transferred when the audio data is transferred. An audio reproducing apparatus comprising: a detecting unit that detects a bit rate; and a generating unit that generates a display signal for displaying a bit rate of audio data according to audio data to be reproduced. Provided.

Further, according to the present invention, in a sound reproducing apparatus for transferring and reproducing audio data from a recording medium on which one or a plurality of audio data streams are recorded, the type of the audio data is detected. First detecting means for detecting the bit rate of the audio data, second detecting means for detecting the bit rate of the audio data, and displaying the encoding method or the number of channels or the language or the bit rate of the audio data according to the audio data to be reproduced And a generating means for generating a signal for the sound reproduction.

Still further, according to the present invention, one or a plurality of audio data streams are recorded, and this audio data stream is composed of a number of packs, each pack being composed of a pack header and a packet. Audio reproducing apparatus for transferring and reproducing audio data from a recording medium, comprising: first detecting means for detecting the type of audio data; at least one packet from each audio data; And a generating means for generating a signal for simultaneously displaying the encoding method or the number of channels or the language or the bit rate of all the audio data. A playback device is provided.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an optical disc according to an embodiment of the present invention, that is, a DVD disc. FIG. 2 shows a reproducing apparatus and a DVD player for reproducing the DVD disc shown in FIG.

The DVD disk 10 has various structures. As shown in FIG. 1, for example, as shown in FIG.
8 and an adhesive layer 20 interposed between the composite disc layers 18
It is composed of Each of the composite disc layers 18
It comprises a transparent substrate 14 and a recording layer, that is, a light reflecting layer 16. The disk layer 18 is arranged such that the light reflection layer 16 contacts the adhesive layer 20. The DVD disk 10 is provided with a center hole 22, and around the center holes 22 on both sides thereof, there are provided clamping regions 24 for holding the DVD disk 10 during rotation. In the center hole 22, the disc 1 is inserted into the DVD disc device.
0 is loaded when the spindle motor 1 shown in FIG.
While the second spindle is inserted and the disc is rotated,
The DVD disk 10 is clamped by the clamping area 24.

The DVD disc 10 has an information area 25 on the both sides of the clamping area 24 on which information can be recorded on the optical disc 10. Each information area 25 has its outer peripheral area defined as a lead-out area 26 where information is not normally recorded, and its inner peripheral area adjacent to the clamping area 24 is similarly defined as a lead-in area 27 where information is not normally recorded. The data recording area 28 is defined between the lead-out area 26 and the lead-in area 27.

In the recording layer 16 of the information area 25, usually, tracks are continuously formed in a spiral shape as areas in which data is recorded, and the continuous tracks are divided into a plurality of physical sectors. The sectors are numbered consecutively, and data is recorded based on the sectors.
The data recording area 28 of the information recording area 25 is an actual data recording area, in which reproduction information, video data, sub-picture data, and audio data are similarly recorded as pits (that is, physical state changes). . In the read-only DVD disk 10, a pit array is previously formed on the transparent substrate 14 by a stamper, and a reflective layer is formed by vapor deposition on the surface of the transparent substrate 14 on which the pit array is formed. Will be formed. In the read-only DVD disk 10, no groove is usually provided as a track, and a pit row formed on the surface of the transparent substrate 14 is defined as a track.

The data recording area 28 has a volume structure defined in the DVD format as shown in FIG. 3, and is called a so-called volume space. In this volume structure, a volume file structure 30 for a UDF (Universal Disk Format) bridge structure defined by international standards for disks is allocated after the lead-in area 27. The recording area between the volume file structure 30 and the lead-out area 26 is defined as a DVD area. The DVD area includes a DVD video area 31 and a DVD.
There is an area 32 for other DVDs such as audio,
The video area 31 is a video manager (VMG) 33
Followed by one or more video title sets 34 (VT
S) is arranged. Video Manager (VMG) 33
The video title set 34 (VTS) has a file structure defined as two or three or more files as shown in FIG.

As shown in FIG. 4, the video manager (V
The MG 33 stores video manager information 35 in which control data of the video area 31 is described, a video title set, and menu data for selecting an audio stream and a sub-picture stream. Video object set for menu (VMG
M_VOBS) 36 and video manager information (VM
GI) backup 37. The video manager information 35 includes, more specifically, V
MG identifier and video title set 34 (VT
Management information (VMGI_MAT) describing the number of S), etc.,
Search information (TT_SRPT) for searching the video title set 34 (VTS), video for each video title set 34 (VTS), and video in which attribute information of audio and sub-picture data streams are stored. -Title set attribute table (VTS_AT)
R) and the like, and the video manager information (VMGI) 35 and the video object set (V
The MGM_VOBS 36 and the video manager information (VMGI) backup 37 are each composed of one file.

Video title set 34 (VTS)
Is the video title set 3 as shown in FIG.
4 (VTS), video title set information (VTSI) 38 in which control data is stored, selection of the video title set 34, for example,
Selection of audio stream and sub-picture stream,
Alternatively, a backup 41 of a video object set (VTSM_VOBS) 39 storing menu data for selecting a certain chapter in a video title and the like, and a video title set information (VTSI) 38
It is composed of The video title set information (VTSI) 38 has a management table (VTSI_
MAT), a video title set program chain information table (VTS_PGCIT) in which reproduction information of the video title set 34 is described, and the like. The video title set information management table (VTSI_MAT) includes the video title
Search information describing the identifier of the set 34 (VTS), the address of each table in the video title set,
The attribute information (VTS_ATR) of the video, audio, and sub-picture data streams of the video title set 34 (VTS) is stored. In the program chain information table (VTS_PGCIT), reproduction information of a program chain defined as a set of cells 51 is described, and the reproduction order of the cells 51 is specified by the cell number as the reproduction information.

In the other area 32 of the DVD shown in FIG. 3, for example, DVD audio is stored. Even when this area is provided for audio, the audio data corresponding to the VMG is provided similarly to the DVD video area. An audio title set corresponding to the manager and the VTS will be provided. These areas store audio-related data as well as video-related data shown in FIG.

Although not shown, in the video title set information (VTSI) 38, attribute information for the video title set (VTS) 34 is described in its management table (VTSI_MAT), and the video manager The information (VMGI) 35 has a video title set attribute table (VTS_ATRT) in which attribute information of all video title sets (VTS) 34 is described for each video title set (VTS) 34. ing. Of course, the management table (VTSI_MAT) of the video title set information (VTSI) 38
And the attribute information on the title set in the video title set attribute table (VTS_ATRT) are the same, and the decoder of the DVD player must be set regardless of which attribute information is obtained. Can be.

The attribute information includes video attribute information (V
TS_V_ATR), audio attribute information (VTS_
AST_ATR) and attribute information of sub-picture (VTS_SP)
_ATR). The video attribute information includes video attributes (VTS_V_ATR) related to the video compression mode, TV system (NTSC or PAL system), aspect ratio, display mode, and the like. Audio attribute information (VTS_AST_ATR) includes audio / video The attribute is described for each stream, and the attribute (VT
S_AST_ATR) as an audio coding mode, for example, MPEG compression mode, Dolby A
C3 compression mode, linear PCM encoding mode, or DTS compression mode, audio type,
For example, an audio type indicating whether or not a language is included, an audio application mode, for example, an audio application mode such as karaoke, surround or not specified, and the number of audio channels are described. Further, the attribute information (VTS_SP_ATR) of the sub-picture is described for each sub-picture stream, and the attribute information (VTS_SP_AT)
As R), a coding mode of the sub-picture, for example, run-length compression, and a type of the sub-picture, for example, whether or not a language is used are described.

FIG. 4 shows an example of the video object set (VOBS) 36, 39, 40. This video object set (VOBU) 36,3
9 and 40 are defined in a structure composed of packs of video, audio and sub-picture data as shown in FIG. Here, the video object set (VOB)
S) 40 includes three types of video object sets (VOB) for two menus and a title.
S) 36, 39, 40. The object set (VOBU) 36, 39, 40 for video usually includes a video pack, and additionally includes audio and / or audio.
Alternatively, it is composed of a pack of sub-picture data. On the other hand, an audio object set (VOBU)
36,39,40 usually include audio packs,
In addition to this, it is composed of packs of sub-picture data and / or video.

The following is a description of the video object set (VOBS) 40, but it should be understood that other types of video object sets (VOBS) have a similar structure. As shown in FIG. 5, the video object set (VOBS) 40 is defined as a set of one or more video objects (VOB) 50, and the video objects 83 in the video object set (VOBS) 40 are the same. Of use.

An identification number (IDN # j) is given to the video object (VOB) 50, and the video object (VOB) 50 can be specified by the identification number. Video object (VOB) 5
0 is composed of one or more data cells 51.
An identification number (C_IDN # j) is assigned to the cell, and the cell 51 is specified by the cell identification number (C_IDN # j). Each cell 51 is composed of one or a plurality of video object units (VOBU) 51, usually a plurality of video object units (VOBU) 52. Here, the video object unit (VOBU) 52 includes one navigation pack (N
(V pack) 53 is defined as a pack sequence having a head at the top. That is, the video object unit (VOB)
U) 52 is defined as a set of all packs recorded from a certain navigation pack 53 to immediately before the next navigation pack. This video object
The playback time of the unit (VOBU) 52 corresponds to the playback time of video data composed of one or more GOPs included in the video object unit (VOBU), and the playback time is 0.4 seconds or more. It is determined not to be longer than 1.2 seconds. In MPEG,
One GOP is usually 0.5 seconds, and is defined as compressed screen data for reproducing about 15 images during that time.

As shown in FIG.
When the unit (VOBU) 52 includes video data, a video pack (V pack) 54, a sub-picture pack (SP pack) 55, and an audio pack (A pack) specified by the MPEG standard, that is, the MPEG system layer, are used. A video data stream is formed by arranging GOPs composed of GOPs 56. Regardless of the number of GOPs, a video object unit (VOBU) 52 is determined based on the playback time of the GOPs. At the beginning, always a navigation pack (NV pack) 5
3 are arranged. In addition, even in the case of reproduction data of only audio and / or sub-picture data, reproduction data is configured with this video object unit as one unit. That is, even if the video object unit 52 is composed of only the audio pack 56, the audio to be reproduced within the reproduction time of the video object unit to which the audio data belongs, similarly to the video object of the video data The pack is the video
Stored in the object unit.

The navigation pack 53 and the video / audio and sub-picture packs 53, 55 and 56 will be described below. Navigation pack 53 and video / audio and sub-picture pack 5 described below
3, 55, and 56 all have the same pack length (2048 bytes), the navigation pack 53 has a structure in which two packets are stored in one pack, and the video / audio and sub-picture packs 53 and 55 have the same structure. , 56 have a structure in which one packet is stored in one pack in principle.
As described with reference to FIG. 5, the cell 51 is a set of video object units (VOBU) 52,
The video object unit (VOBU) 52
It is defined as a pack sequence starting from the navigation (NV) pack 53. Therefore, the start address (C_FVOBU_SA) of the first video object unit (VOBU) 52 in the cell 51 is the NV pack 53
Represents the start address. As shown in FIG. 6, the NV pack 53 includes a pack header 61, a system header 62, and two packets serving as navigation data, that is, a reproduction (presentation) control information (PCI) packet 63 and a data search information (D).
SI) packet 64, and the number of bytes as shown in FIG. 6 is assigned to each part, and one pack is defined as 2048 bytes corresponding to one logical sector. The NV pack is arranged immediately before the video pack including the first data in the group of picture (GOP). Even when the object unit 52 does not include a video pack, the NV pack is placed at the head of the object unit including the audio pack and / or the sub-picture pack. As described above, even when the object unit does not include the video pack, the reproduction time of the object unit is determined based on the unit in which the video is reproduced, similarly to the case where the object unit includes the video pack.

The pack header 61 and the system header 62 of the NV pack 53 are defined by an MPEG2 system layer. The pack header 61 includes a pack start code,
Information of a system clock reference (SCR) and a multiplexing rate are stored, and a bit rate and a stream ID are described in a system header 62. Packet header 6 of PCI packet 63 and DSI packet 64
The packet start code, the packet length, and the stream ID are stored in the packet headers 5 and 66, respectively, as defined in the MPEG2 system layer.
Sub stream IDs 73 and 74 are described after the sub streams 5 and 66.

The PCI data of the PCI packet 63 (PC
I) 67 includes a presentation in synchronization with the playback state of the video data in the VOB unit (VOBU) 52,
That is, navigation data for changing the content of the display is stored. That is, the PCI data (PCI) 67
Contains PCI general information (PC
I_GI) and angle information (NSMLS_ANGL) as each destination angle information at the time of angle change
I) is described. PCI general information (PCI_G
I) includes the PCI 6 as the relative number of logical blocks from the logical sector of the VOBU 52 in which the PCI 67 is recorded.
7, the address (NV_PCK_LBN) of the NV pack (NV_PCK) 53 in which 7 is recorded.
The VOBU is included in the PCI general information (PCI_GI).
52 categories (VOBU_CAT), VOBU52
The reproduction start time (VOBU_S_PTM) and the reproduction end time (VOBU_EPTM) are described. Here, the start PTS of the VOBU 52 (VOBU_SP
TS) indicates the reproduction start time (start presentation time) of the video data in the VOBU 52 including the PCI 65. This playback start time is
This is the first playback start time in VOBU85. Normally,
The first picture corresponds to a reproduction start time of an I picture (Intra-Picture) in the MPEG standard. End PTS of VOBU 52 (VOBU_EP
TS) indicates the playback end time (end presentation time) of the VOBU 52 including the PCI 67. Further, the PCI general information (PCI_GI) includes the playback end time (VOV) of the video data including the PCI.
BU_SE_E_PTM) and the corresponding video from the first video frame in the display order in the cell containing the PCI.
The relative time (C_ELTM) up to the first video frame in the display order in the VOBU including the CI is described.

The DS of the DSI packet 317 shown in FIG.
The I data (DSI) 68 is a VOB unit (VOB
U) Navigation data for executing the search of 52). The DSI data (DSI) 52 includes DSI general information (DSI_GI) and seamless playback information (SML_
PBI), angle information (SML_AGLI), VOB
Information for searching for units (VOBU_SRI)
And synchronous reproduction information (SYNCI).

The DSI general information (DSI_GI) describes information on the entire DSI data 68. That is,
The DSI general information (DSI_GI) includes the NV pack 53
The system time reference value (NV_PCK_SCR) is described. This system time reference value (NV_
PCK_SCR) is stored in a system time clock (STC) incorporated in each unit shown in FIG. 2. Based on the STC, a video, audio, and sub-picture pack is decoded by a video, audio, and sub-picture decoder. An audio signal is output. DSI
The general information (DSI_GI) includes the start address of the NV pack (NV_PCK) 53 in which the DSI 68 is recorded by the relative logical sector number (RLSN) from the first logical sector of the VOB set (VOBS) 52 in which the DSI 68 is recorded. (NV_PCK_LBN) is described and V
The address (VOBU_EA) of the last pack in the VOB unit (VOBU) 52 in which the DSI 68 is recorded is described by the number of logical sectors (RLSN) from the first logical sector of the OB unit (VOBU).

Further, in the DSI general information (DSI_GI), the VOB unit (VO
BU) relative number of logical sectors from the first logical sector (R)
V pack (V_PCK) 5 in which the last address of the first I picture in this VOBU is recorded in LSN)
No. 4 (VOBU_IP_EA), the identification number (VOBU_IP_IDN) of the VOBU 52 in which the DSI 68 is recorded, and the DSI 68
Number (VOBU_C_ID) of the cell in which is recorded
N).

DSI search information (VOBU_SRI)
Describes addresses of a predetermined number of navigation packs. With reference to this address, the video is fast forwarded or the like. The synchronization information (SYNCI) includes D
Address information of sub-picture and audio data to be reproduced in synchronization with the reproduction start time of the video data of the VOB unit (VOBU) including the SI 68 is described. That is,
NV pack in which the DSI 68 is recorded (NV_PC
K) The start address (A_SYNCA) of the target audio pack (A_PCK) 56 is described by the relative number of logical sectors (RLSN) from 53. When there are a plurality of (up to 8) audio streams, synchronization information (SYNCI) is described for the number. The synchronization information (SYNCI) includes a VOB unit (VOB) including a target audio pack (SP_PCK) 56.
U) The address (SP_SYNCA) of the NV pack (NV_PCK) 53 of 52 is N in which the DSI 68 is recorded.
The number is described by the relative number of logical sectors (RLSN) from the V pack (NV_PCK) 53. When there are a plurality of sub-video streams (up to 32), the synchronization information (SYNCI) is described by the number.

The video pack 54 is composed of a pack header 70, a packet header 71 and a video packet 72 in which corresponding data is stored in a manner similar to that defined in the MPEG2 system layer, as shown in FIG. The pack length is set to 2048 bytes. The pack header 70 of the video pack 54 is MP
Defined by the system layer of EG2, the pack header 70
Stores information on a pack start code, a system clock reference (SCR), and a multiplexing rate. The packet header 71 of the video packet 73 includes
Similarly, the packet start code, the packet length, and the stream I as defined in the MPEG2 system layer.
D is stored. The packet data 72 of the video packet 73 stores video data obtained by compressing the video data by MPEG.

As shown in FIG. 8, the sub-picture pack 55
A pack header 76 and a packet header 77, followed by a sub-stream ID 78 and a video packet 79 storing the corresponding data, as defined in the PEG2 system layer, have a pack length of 2048 bytes. Stipulated. Sub-picture pack 5
The pack header 76 of No. 5 is defined by the MPEG2 system layer. The pack header 76 stores information of a pack start code, a system clock reference (SCR), and a multiplexing rate. Sub-picture packet 80
The packet header 77 has a packet start code, as defined in the MPEG2 system layer,
The packet length and the stream ID are stored. In the packet data 79 of the sub-picture packet 80, sub-picture data in which the sub-picture data is normally run-length compressed is stored. The substream ID 78 will be described later in relation to the audio substream ID.

For an audio packet in which MPEG-compressed audio data is stored as packet data, a video pack 54 shown in FIG.
Since it has a structure substantially similar to that described above, the description thereof is omitted. Dolby AC-3 or DTS audio data is stored in a pack 56 having a structure as shown in FIG. That is, as shown in FIG.
The pack 56 includes a pack header 82 and a packet 87 in the same manner as defined in the MPEG2 system layer. Packet 87 is packet header 8
3, followed by a video packet 86 storing a substream ID 84, audio frame information 85, and audio data. As described above, the pack length of the pack 56 is set to 2048 bytes. The pack header 82 of the audio pack 56 is defined by an MPEG2 system layer. The pack header 82 stores information of a pack start code, a system clock reference (SCR), and a multiplexing rate. In the packet header 83 of the audio packet 87, a packet start code, a packet length, and a stream ID are stored similarly as defined in the MPEG2 system layer. Dolby AC is included in the packet data 86 of the audio packet 87.
-3 or DTS-compressed audio data is stored. The sub stream ID 85 will be described later in relation to the stream ID and the sub stream ID.

The linear PCM audio pack is shown in FIG.
Although the packet structure is different as shown in FIG. 0, the packet structure is substantially the same as the pack structure shown in FIG. FIG.
The packet data 86 of the linear PCM audio pack 90 shown in FIG. 7 is data encoded but not compressed data unlike Dolby AC3 and DTS. Linear PCM Audio Pack 9
0 is composed of a pack header 82 and a packet 90, and the packet 90 is the packet header 8 already described.
3 is followed by a sub stream ID, audio frame information 85, and audio packet data 92. If the linear PCM audio packet 90 matches, the audio frame information 85 and the audio packet data 92 Audio frame information 91 is provided.

The audio frame information 91 of the linear PCM includes information on the audio of the linear PCM, for example, the frame number of the audio frame to be accessed first in the audio frame group, mute on, or , Audio mute flag indicating mute off, 16 bits, 20
Indicates the quantized word length indicating whether the audio data sampled in bits, 24 bits or other bits is quantized, the sample frequency indicating whether it was sampled at 48 kHz and 96 kHz, and the number of audio channels. It describes the dynamic range control which describes the control information of the number of audio channels and the dynamic range.

The above-mentioned audio packets 80 and 90
Packet header is a 16-bit PES packet
Length (PES_packet_length) and 8-bit PES header data length (PES_packet_length)
header_length). here,
PES packet length (PES_packet_l
length) indicates the data length from the next data following the PES packet length to the end of the audio packets 80 and 90, and the PES header data length (PES_header_length) indicates the PES header data length. It indicates the data length from the next data following the length to the end of the packet header. Linear PCM, Dolby AC3 and DTS audio
The frame information 85 describes the number of frame headers and the first access unit pointer.
Here, the number of frame headers is equal to the number of headers of audio data frames included in the audio packet data 86 and 92 (Number_of_fra).
me_headers), in other words, the number of frames is described. Also, audio packet data 86 and 92 are stored in the first access unit pointer.
Describes the address of the audio frame that is accessed first. This address is
It is described by the relative address from the last byte of the access unit pointer, more precisely, by the relative block number. When the packet data 86, 92 does not include the audio frame unit to be accessed first, "000000000h" indicating that there is no audio frame unit is described. In the audio packet data 86, 92 of the linear PCM and Dolby AC3, the packet data 86,
Since the data length of N.92 does not correspond to an integral multiple or a fraction of an audio frame, its first
The access unit pointer is undefined.
On the other hand, in the DTS audio packet data 86, since the data length of the packet data 86 is an integral multiple of the audio frame, in other words, a plurality of DTSs are included in the packet data 86. Since the audio frames are stored consistently, D
“0001b” is always described in the first access unit pointer of the TS.

Next, a method of determining which stream the packet data belongs to with reference to the stream ID and the sub-stream ID will be described. FIG.
Include packet headers 65, 66, 71, 77, 83
2 shows the data of the stream ID described in.
When "11100000b" is described in the stream ID in the packet header 71 of the pack 54 shown in FIG. 7, the packet data is video packet data as shown in FIG. -It belongs to the stream. The stream ID in the packet header 71 of the pack 54 is “110X0 **”.
If "* b" is described, the packet data is MPEG audio packet data and belongs to the MPEG audio stream as shown in FIG. “b” indicates an audio stream number.

"10111111b" is described in the stream ID in the PCI packet 65 and the DSI packet 66 of the navigation pack 53 shown in FIG. 6, and it is clearly indicated that the packet data 67 and 68 belong to the private stream 2. Is done. Then, as shown in FIG. 12, “00000000b” is described in the sub stream ID 73 following the PCI packet header 65, and it is determined that the PCI packet data 67 belongs to the PCI stream. Further, “00000001b” is described in the sub stream ID 74 following the DSI packet header 66 as shown in FIG. 12, and it is found that the DSI packet data 68 belongs to the DSI stream. Note that “0111111” is added to the sub stream ID.
1b "indicates that the stream is a stream uniquely defined by the provider.

In the sub-picture pack 55 shown in FIG.
"10" is added to the stream ID in the packet header 77.
111101b "is described, and the packet data 7
9 belongs to private stream 1. The sub-stream ID 73 following the packet header 77 has "001 **" as shown in FIG.
*** b "is described, and it is determined that the packet data 79 belongs to the sub-picture data stream, where" *** b "indicates the sub-picture data stream number.

The audio signals shown in FIG. 8, FIG. 9 and FIG.
In the pack 56, “10111101b” is described in the stream ID in the packet header 83,
It is specified that the packet data 86, 92 belongs to the private stream 1. The sub-stream ID 84 following the packet header 83 is shown in FIG.
When "10000 *** b" is described as shown in (1), it is determined that this packet data 86 belongs to the audio data stream of Dolby AC3.
Also, the sub-stream I following the packet header 83
When "10001 *** b" is described in D84 as shown in FIG.
It is determined that it belongs to the audio data stream of S. Further, as shown in FIG. 13, "10100 ***" is added to the sub-stream ID 84 following the packet header 83.
b "is described, the packet data 92
Belong to the audio data stream of the linear PCM. Here, “*** b” indicates an audio data stream number.

As described above, it is determined to which of the data stream belongs by the combination of the stream ID and the sub-stream ID. Audio packet 8 described above
0,90 PES packet length (PES_pac
ket_length), PES header data length (PES_header_length), and number of frame headers (Number_of_frame)
_Headers), the transfer rate can be obtained by calculation. The principle will be described with reference to the structure of the DTS audio pack shown in FIG. As described above, the DTS audio data is always frame-aligned in the audio data 86. The pack header length is 14 bytes, the pack header length is variable, and the substream ID length is 1 byte.
The audio frame information length is 3 bytes. The packet header 83 first has 4 bytes of data, then has 2 bytes of PES packet length (PES_packet_length), then has 2 bytes of data, and then has 1 byte of PES header data length ( PES_header_length
h), followed by variable length data.
The PES packet length indicates the data length from the next data to the end of the audio packet, and the PES header data length indicates the data length from the next data to the end of the packet header. Therefore, the audio data length (a) of the DTS is calculated as follows.

A = b-2-c-4 a: DTS audio data length b: Pes packet length c: Pes header data length Also, audio frame information 85
Since the number of frames (the number of frame headers) is described at the beginning, it is possible to know how many DTS frames are included.

Since the DTS pack of the DVD has the above structure, the DTS pack detects the packet header and
For the audio data length of S, the number of DTS frames is obtained by detecting audio frame information, and the bit rate is determined from both values. The bit rate is determined by obtaining the data length of one frame from these two values. That is, the data length of one frame = the audio data length of DTS (a) ÷ the number of DTS frames. Since the DTS of a DVD has a sampling frequency of 48 kHz and one frame has 512 samples,
The bit rate is the data length of one frame ÷ (512 × 4) × 153600
0 can be calculated. Even if calculation is not performed, there are only six types of DTS bit rates for DVD, as described below. Therefore, if a table corresponding to the data length of one frame is stored in a ROM or the like in advance, the bit rate can be easily obtained. be able to.

The audio data 86 of the packet 87 is (1) 1509 and 750 kbps when one audio frame is stored, and (2) 754 when two audio frames are stored. , 5
00 kbps, (3) 503,250 kbps when 3 audio frames are stored, (4) 377,250 kbps when 4 audio frames are stored, (5 ) If 6 audio frames are stored, 251
250 kbps, and (6) 188,250 kbps when 8 audio frames are stored.

Since the DTS audio data is always frame-aligned in the audio data 86, the bit rate can be accurately calculated. Although the Dolby AC-3 audio data is not necessarily frame-aligned in the packet data 86, the approximate bit rate can be calculated in a similar manner. When the bit rate is not displayed as a numerical value, if the approximate bit rate can be calculated, for example, the approximate bit rate can be displayed as a graph. The transfer rate of the Dolby AC-3 audio data is obtained as follows.

The audio data of Dolby AC-3 is
Since the audio data 86 is not necessarily frame-aligned, the bit rate is obtained as an approximate number. In the Dolby AC-3 audio pack, the pack header length is 14 bytes, the pack header length is variable, and the substream ID length is 1 byte.
The byte and the audio frame information length are 3 bytes. The packet header 17 first has 4 bytes of data, and then has 2 bytes of PES packet length (PES_packet_length).
h) is followed by 2 bytes of data, followed by 1 byte of pes
Header data length (PES_header_l)
length), and is composed of variable-length data. Pes packet length indicates the data length from the next data to the end of the audio packet,
The PES header data length indicates the data length from the next data to the end of the packet header. Therefore, the audio data length (a) of the DTS is calculated as follows.

A = b-2-c-4 a: Audio data length of Dolby AC-3 b: Pes packet length c: Pes header data length Audio frame information 85
Since the number of frames (the number of frame headers) is described at the beginning of the table, it is possible to determine how many Dolby AC-3 frames are included.

Since the Dolby AC-3 pack of the DVD has the above structure, the audio data length of the Dolby AC-3 is detected by detecting the packet header, and the DTS is determined by detecting the audio frame information. , And the bit rate is determined from both values. The bit rate is determined by obtaining the data length of one frame from these two values. That is, the data length of one frame is obtained by the following equation: audio data length of AC-3 (a) ÷ number of frames of AC-3. DVD Dolby AC-3 is 48kHz
Since one frame is 1536 samples at the sampling frequency of, the bit rate is: data length of one frame ÷ (1536 × 4) × 15360
00 can be calculated.

It is to be noted that an approximate number of transfer bit rates can be calculated for MPEG audio in the same manner as in the case of AC-3 described above. In the case of linear PCM audio, the transfer rate is determined by the sampling frequency and the quantization number, and the sound quality is determined by both.
Since the sampling frequency and the quantization number are described in the audio data information 91, the transfer rate and the sound quality can be displayed only by acquiring the audio data information 91.

In an AC-3 audio packet, synchronization information is included in encoded data in a bit stream as a set of the packets, and a frame size code (frame) in the synchronization information is included. siz
e code), and the bit rate can be obtained from the code. In the case of an MPEG audio packet, a bit stream index (bitrate_index) in a header in the encoded data is used.
Since x) can be read and the bit rate can be obtained from the data, the bit rate may be calculated from the data.

An outline of the operation of the DVD player will be described with reference to FIG. An optical pickup 101 is provided to face the DVD disk 10.
1, data is read in units of physical sectors from a DVD disk 10 rotated by a motor 12, and the data is read by a DVD digital signal processing unit (DVD
(DSP) 102. V of DVD disk 10
The MG 33 is read and stored in the RAM of the host microcomputer 104,
Each part is set by the microcomputer 104. Thereafter, when the title is determined by referring to the menu or the like, the VT of the VTS 34 corresponding to the determined title is determined.
The SI 38 is read, and the VTSI 38
The title is stored in the RAM of the microcomputer 104, and the reproduction preparation of the title is prepared. Thereafter, the VOBUs 52 are successively read from the title VOBS 40 as actual data with the data cell 51 as a unit of reproduction with reference to the VTSI 38 stored in the RAM. The leading navigation pack 53 from the read VOBU 52 is supplied to the host microcomputer 104 and stored in its RAM.

The other packs 54 and 5 in the VOBU 52
5 and 56 are demultiplexers 10 of the decoder 103.
5, the demultiplexer 105 refers to the stream ID and the substream ID, and outputs the packets of the packs 54, 55, and 56 to the corresponding decoder units. That is, video pack 5
Packet 73 of the video decoder unit 10
6 and the video packet data is expanded and output to the video mixer 107. The packet 80 of the sub-picture pack 55 is
08, the control data relating to the sub-picture is extracted from the packet 80, sent to the sub-picture decoder unit 109 together with the display information, and the sub-picture data is run-length expanded. The run-length-extended sub-picture data is supplied to the video mixer 107, where the sub-picture data is mixed with the video data so that the sub-picture is displayed in an area or the like specified by the display information, and the mixed video is mixed. A digital signal is supplied to the encoder 110; The encoder 110 converts this video / digital signal into an analog signal and outputs it as an analog video signal. Further, packet 8 of audio pack 56
6, 92 are supplied to the audio decoder unit 111, and their stream ID and sub-stream ID
The audio data 86 and 92 in the packets 87 and 90 are decoded according to the encoding type of the data determined by (1). That is, any one of MPEG decoding, linear PCM decoding, AC-3 decoding, or DTS decoding is performed in the audio decoder unit 111. The decoded audio data is
The signal is converted into an analog audio signal by the D / A converter 99, and the analog audio signal is output from the D / A converter 99.

The audio packets 86 and 92 are also supplied to a bit rate determination unit 100, the bit rate of which is calculated, and the calculation result is transmitted to the sub-picture decoder 1.
09 and the bit rate information is mixed with the video data in the video mixer 107 as sub-picture data. Therefore, when an image is displayed on a monitor (not shown) by a video signal, its bit rate is displayed numerically or graphically, and the user can know the bit rate of the audio.

In addition to displaying the bit rate on the monitor, the output from the bit rate determination unit 100 is displayed on the display unit provided on the front panel 98 by the host.
The information may be displayed by the microcomputer 104.

The bit rate determination unit 100 may be specifically configured as shown in FIG. 15 as an example. As shown in FIG. 15, the data on the DVD disk 10 is demodulated by a demodulation unit 112 in the DVD DSP 102, error-corrected by a signal processing unit 113, and controlled by a host microcomputer 104. The audio / attribute information extracting unit 114 and the audio stream separating unit 115 of the demultiplexer 105 are sent.
The audio stream separation unit 115 extracts only the audio stream from the audio and video data, and
The stream is transferred to the audio stream selection unit 116. The audio attribute information extracting unit 114 sends the audio stream number designated by the user, for example, the audio stream number in which the DTS audio data is recorded, to the audio stream selecting unit 116. The audio stream selection unit 116 selects only the audio stream having the same number as the audio stream number from the audio attribute information extraction unit 114, sends the DTS data to the packet header detection unit 117 and the audio frame information detection unit 118, and sends one frame. It is sent to the sampling circuit 121.

The packet header detection unit 117
Packet length (b) and PES header data
The length (c) is detected, and the audio frame information detection unit 118 extracts the number of audio frames, for example, the number of DTS audio frames, from the audio frame information. The already described equation (a = b-2-
The audio data length (a) of the DTS is determined from c-4), and both values are output to the bit rate determination unit 119. The bit rate calculator 119 obtains the data length of one frame from both values. That is, the data length of one frame = the audio data length of DTSＳthe number of frames of DTS. Since the DTS of a DVD has a sampling frequency of 48 kHz and one frame has 512 samples, the bit rate is the data length of one frame ÷ (512 × 4) × 153600.
0 can be calculated.

Since the DTS audio data has only six types of bit rates as described above, the bit rate can be obtained by referring to the table for the number of frames by the bit rate calculator 119.

The bit rate obtained by the bit rate calculator 119 is sent to a display signal generator 120, converted into a display signal, and this display signal is supplied to the sub-picture decoder unit 109 and displayed on a monitor. Alternatively, it is supplied to the host microcomputer 104 and displayed on the front panel.

One frame of the audio stream output from the audio stream selection unit 116 is extracted by a one-frame extraction circuit 121 for extracting one frame in the audio decoder unit 111, and an amble adding circuit 122 immediately extracts the frame. After the padding data is added immediately after the frame by the padding adding circuit 123, the data is converted into a digital audio interface standard by the IEC958 conversion circuit 124 and taken out from the bit stream output terminal 125. This signal is decoded by an audio decoder and D /
It is reproduced via the A converter 130.

Although the circuit shown in FIG. 15 has been described as a circuit for dealing with DTS audio data, it is apparent that the circuit shown in FIG. 15 uses a PES packet length (AC) in an AC-3 audio packet. b) and the PES header data length (c) and the number of audio frames from the audio frame information in the AC-3 audio packet to obtain an estimate of the bit rate and display it.

Further, if the audio data is a linear PCM
If the audio data information is found to be
The frequency and the number of sampling quantization bits may be displayed.

FIG. 16 shows an outline of a system including a bit rate judgment unit according to another embodiment. This figure 1
In the circuit shown in FIG. 6, the data on the recording medium 10 is demodulated by the demodulation unit 112, error-corrected by the signal processing unit 113, and sent to the audio attribute information extraction unit 114 and the audio stream separation unit 115. The audio stream separation unit 115 extracts only the audio stream from the audio and video data, and transfers this audio stream to the audio stream selection unit 116. Voice attribute information extraction unit 11
In step 4, the audio stream number is sent to the audio stream selection unit 116. The audio stream selection unit 116 selects only the audio stream having the same number as the audio stream number from the audio attribute information extraction unit 114,
Only the S packet is sent to the packet header detection unit 117 and the audio / frame information detection unit 118, and is also sent to the one-frame extraction circuit 121. DTS
Is processed as described above to generate a display signal.

Audio packets other than DTS are 1
It is sent to the frame extraction circuit 121 and the audio decoding unit 129. This audio packet other than DTS is
In the decoding process performed by the audio decoding unit 129, the bit rate is detected in the case of AC-3 by detecting the frame size code (framesi) in the synchronization information in the encoded data.
ze code) and obtain the bit rate from the code. For MPEG audio packets,
The bit stream index (bitrate_index) in the header in the encoded data is read, and the bit rate can be obtained from the data. Therefore, the data is output to the display signal generator 120 via the bit rate calculator 119. And the display is possible.

On the other hand, in the selected audio stream, the data encoded by the audio decoding unit 129 is decoded and returned to the original data, and the audio stream is sent from the audio output terminal 132 via the D / A converter 130 and the amplifier 131. A signal is output.

One frame of the audio stream is extracted by a one-frame extracting circuit 121, amble data is added immediately before the frame by an amble adding circuit 122, and padding data is added immediately after the frame by a padding adding circuit 123. After being added, IEC95
The data is converted into a digital audio interface standard by an 8-conversion circuit 124 and taken out from a bit stream output terminal 125. This signal is decoded by a decoder and reproduced as an audio signal.

FIG. 17 shows still another embodiment. The difference from the embodiment shown in FIG. 16 is that the audio attribute information extraction unit 114 extracts the audio attribute information (VTS
_AST_ATR) to obtain the audio data encoding method, the number of channels, or the language, and send the data to the display signal generator 120. Therefore, it is possible to display the encoding method, the number of channels, the language, or the bit rate of the currently reproduced audio.

FIG. 18 shows still another embodiment. Data on the DVD disk 10 is transmitted to the demodulator 112
After that, the signal is corrected by the signal processing unit 113 and sent to the audio attribute information extracting unit 114 and the audio stream separating unit 115. Audio stream separation unit 115
Then, only the audio stream is extracted from the audio and video data, and this audio stream is transferred to the audio stream selection unit 116. Voice attribute information extraction unit 11
In step 4, the audio stream number is sent to the audio stream selection unit 116. In the audio stream selection unit 116,
Only the audio stream having the same number as the audio stream number from the audio attribute information extracting unit 114 is selected and sent to the one-frame extracting circuit 121 and the audio decoding unit 129. The circuits subsequent to the one-frame extraction circuit 121 and the audio decoding unit 129 are the same as those in FIG.

On the other hand, the audio stream separation unit 115 sends at least one packet of each audio stream to the packet header detection unit 117, the audio frame information detection unit 118, and the audio decoding unit 119, and obtains the bit rate as described above. be able to. Voice attribute information (VT
S_AST_ATR) describes the encoding system, the number of channels, or the language of each audio stream, so that the display signal generator 120 collectively stores the encoding system, the number of channels, the language, or the bit rate of all audio data. Can be displayed.

The voice attribute information (VTS_AST_A)
TR) also describes the audio stream number, so that the encoding method, the number of channels, the language, or the bit rate of the audio data in which the audio stream numbers of all the audio data are added to the display 120 are collectively shown. Can be displayed at the same time.

[0074]

As described above, according to the present invention, the bit rate of an audio stream can be displayed, the encoding method, the number of channels, and the language can be simultaneously displayed. It is possible to provide a very good sound reproducing apparatus that can perform DTS bit rate display easily without a DTS decoding function.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a DVD disk loaded in an audio reproducing apparatus according to one embodiment of the present invention.

FIG. 2 is a block diagram schematically showing an audio reproducing apparatus according to one embodiment of the present invention.

FIG. 3 is a plan view showing a format structure of a recording area of the DVD disk shown in FIG. 1;

FIG. 4 is a plan view showing a DVD video area having the format structure shown in FIG. 3 in more detail;

FIG. 5 is a plan view showing a hierarchical structure of the video object set shown in FIG.

FIG. 6 is a plan view showing the structure of the navigation pack shown in FIG.

FIG. 7 is a plan view showing the structure of the video pack shown in FIG.

8 is a plan view showing the structure of the sub-picture pack shown in FIG.

FIG. 9 is a plan view showing the structure of the audio pack shown in FIG. 5;

FIG. 10 is a plan view showing the structure of the audio pack shown in FIG. 5;

FIG. 11 is a table showing a description of a stream ID provided in the packet header shown in FIGS. 6 to 10;

FIG. 12 is a table showing a description of a sub-stream ID shown in FIG. 6;

FIG. 13 is a table showing a description of a sub-stream ID shown in FIGS. 8 to 10;

FIG. 14 is a plan view showing the structure of a DTS audio pack.

FIG. 15 is a block diagram showing an audio reproducing device according to an embodiment of the present invention in more detail;

FIG. 16 is a block diagram showing an audio reproducing apparatus according to another embodiment of the present invention in more detail.

FIG. 17 is a block diagram showing an audio reproducing apparatus according to another embodiment of the present invention in more detail.

FIG. 18 is a block diagram showing an audio reproducing apparatus according to another embodiment of the present invention in more detail.

[Explanation of symbols]

 Reference Signs List 10 DVD disk 25 Information area 28 Data recording area 30 Volume file structure 33 Video manager information (VMGI) 34 Video title set (VTS) 36 Video object set (VOB) 52 Video object unit (VOBU) 53 Navigation pack 54 Video pack 55 Sub-picture pack 56 Audio pack 99 D / A converter 100 Bit rate determination unit 101 Optical pickup 102 DVD · DSP 104 · Host microcomputer 105 · Demultiplexer 106 · DVD decoder unit 107 · Video mixer 109 · Sub-picture decoder unit 110 · Encoder 111 · Audio decoder unit G 112 demodulation unit 113 signal processing unit 114 audio attribute information extraction unit 115 audio stream separation unit 116 audio stream selection unit 117 packet header detection unit 118 audio frame information detection unit 119 bit rate determination unit Reference Signs List 120 display signal generator 121 1 frame extraction circuit 130 amble addition circuit 131 padding addition circuit 124 IEC958 conversion circuit 125 bit stream output terminal 129 audio decoding unit 130 D / A converter 131 amplifier 132 Audio output terminal

Claims (5)

[Claims] 1. An audio pack comprising a pack header and an audio packet, the audio packet comprising a packet header, a sub-stream ID, audio frame information and audio data, Pack header and packet
The header is a pack header and a packet header defined by the MPEG system layer. The audio data stores an audio frame, and the number of headers of the audio frame is described in the audio frame information. The PES packet length relating to the packet length and the PES header data length relating to the data length of the packet header are described in the packet header. In the reproducing apparatus, first detecting means for detecting the number of headers of an audio frame from the audio frame information to obtain the number of frames; A second detecting means for detecting an audio data length by detecting the number of frames; a first calculating means for calculating the number of bytes of one audio frame from the number of frames and the audio data length; An audio reproducing apparatus comprising: a judging means for judging a bit rate from the number of bytes of one frame; and a converting means for converting the bit rate obtained from the judging means into a display signal for displaying. . 2. One or a plurality of audio data
From the recording medium on which the stream is recorded,
In an audio reproducing apparatus for transferring and reproducing data, detecting means for detecting a bit rate at the time of transferring audio data and generating a display signal for displaying a bit rate of the audio data in accordance with the reproduced audio data. A sound reproducing device comprising: 3. One or a plurality of audio data
From the recording medium on which the stream is recorded,
In an audio reproducing apparatus for transferring and reproducing data, a first detecting means for detecting a type of audio data, a second detecting means for detecting a bit rate of the audio data, Generating means for generating a signal for indicating the encoding method or the number of channels or the language or the bit rate of the audio data,
An audio playback device comprising: 4. One or a plurality of audio data
A stream is recorded, and this audio data stream is composed of a number of packs, and in an audio reproducing apparatus that transfers and reproduces audio data from a recording medium in which each pack is composed of a pack header and a packet, First detection means for detecting the type of audio data; second means for capturing at least one packet from each audio data and obtaining a bit rate in the encoded data; Generating means for generating a signal for simultaneously displaying the number of channels, the language, or the bit rate. 5. The reproducing apparatus according to claim 4, wherein a display signal is generated corresponding to the audio stream number.