JP2006054629A - Data recording / reproducing method and recording / reproducing apparatus - Google Patents

Abstract

【Task】
In the method in which the decoding means is incorporated in the reproduction apparatus, only a predetermined CODEC can be handled, and a newly developed CODEC cannot be adopted. Further, when the number of types of CODECs increases, it is necessary to incorporate a large number of decoders in the playback device, which causes a problem of cost increase and makes verification complicated.
[Solution]
When the encoded data is converted into a packet format of a predetermined length and recorded on the recording medium, decoding software for decoding the encoded data is recorded on the recording medium. At the time of reproduction, the decoding software is read from the recording medium, and the decoding software is incorporated into a decoder that decodes the encoded data.
[Selection] Figure 5

Description

  The present invention relates to a recording medium in which encoded data is converted into a packet format having a predetermined length and recorded, and a reproducing apparatus for reproducing the recording medium.

  An example of a DVD playback apparatus that supports a plurality of audio CODECs is described in Patent Document 1. The reproduction apparatus described in Japanese Patent Laid-Open No. 2004-228561 is adapted to an extended CODEC by adding a decoder board corresponding to a nonstandard CODEC.

Japanese Patent Laid-Open No. 10-21648

  When recording video and audio on a recording medium, data is not recorded as it is, but data compression is performed by a predetermined CODEC (encoding and decoding method) to reduce the amount of data. Thereby, the time which can be recorded on a recording medium can be extended significantly.

  There are various video and audio compression methods, and research and development are still underway. Conventionally, various proposed CODECs were compared and examined, and some excellent ones were selected and used. On the recording medium, data encoded by a predetermined CODEC is recorded. On the other hand, the playback apparatus incorporates a hardware decoder or software decoder corresponding to the CODEC to be used, and decodes data reproduced from a recording medium and decodes video and audio.

  However, the method in which the decoding means is incorporated in the playback apparatus can only deal with a predetermined CODEC, and cannot adopt a newly developed CODEC. Further, when the number of types of CODECs increases, it is necessary to incorporate a large number of decoders in the playback device, which causes a problem of cost increase and has a drawback that verification is complicated.

  An object of the present invention is to provide a playback apparatus that can easily cope with a plurality of different CODECs and can cope with even when a new CODEC is developed.

  In order to solve the above-described problem, a decoding software for decoding the encoded data is recorded on the recording medium when the encoded data is converted into a packet format of a predetermined length and recorded on the recording medium. Keep a record. At the time of reproduction, the decoding software is read from the recording medium, and the decoding software is incorporated into a decoder that decodes the encoded data.

  According to the present invention, when the encoded data is converted into a packet format of a predetermined length and recorded on the recording medium, decoding software for decoding the encoded data is recorded on the recording medium. When recording and reproducing, the decoding software is read from the recording medium, and the decoding software is incorporated into a decoder that decodes the encoded data, so that it is easy to change the decoding method of the encoded data, It is possible to deal with various types of CODECs. Further, even when a new CODEC is developed, if decoding software corresponding to these CODECs is recorded on a recording medium, it is possible to cope without changing the reproducing apparatus.

  FIG. 1 shows a first embodiment of a reproducing apparatus according to the present invention. In FIG. 1, 101 is an optical disk, 102 is an optical pickup that reads a signal from the optical disk, 103 is a reproduction signal processing circuit that reproduces data by performing predetermined demodulation processing on the signal reproduced from the optical disk, and 104 is a reproduction signal at a predetermined timing. An output control unit that performs packet processing, 105 is a servo unit that controls the rotation speed of the optical disk and the position of the optical pickup, 106 is a drive control unit that controls the servo unit and the reproduction signal processing circuit, 107 is an audio decoder that decodes an audio signal, 108 is an audio output terminal for outputting the decoded audio signal, 109 is a video decoder for decoding the video signal, 110 is a video output terminal for outputting the decoded video signal, 111 is a system control unit for controlling the entire playback device, 112 is a remote control receiver for receiving signals from the remote control. .

  FIG. 2 shows a block diagram of the audio decoder unit. In FIG. 2, 201 is a packet input terminal, 202 is a DSP (Digital Signal Processor), 203 is a RAM, 204 is an audio signal output terminal, and 205 is a program input terminal.

  The DSP is a processor (arithmetic processing device) dedicated to signal processing, and is configured to perform signal processing efficiently. In the example of FIG. 2, a program for controlling the operation of the DSP is recorded on the RAM, and the DPS performs arithmetic processing according to this program. The program on the RAM can be rewritten from an external system control unit via a program input terminal.

  Hereinafter, an operation during reproduction of the optical disc will be described. First, the user turns on the power of the playback apparatus and sets the optical disc 101. The system control unit 111 in the playback apparatus recognizes that the optical disk has been set, and reads file management information in the optical disk. Here, the file management information is recorded at a predetermined position on the optical disc in accordance with, for example, a file management system represented by UDF (Universal Disk Format). File management information manages each piece of information recorded on the optical disc as a file. Specifically, the file identifier (file name), recording start sector number, file length, additional information, etc. of each file are recorded.

  After the file management information is read, the system control unit 111 reads a file necessary for reproducing the optical disc in accordance with the file management information.

  A file as shown in FIG. 3 is recorded on the optical disk to be reproduced. In FIG. 3, reference numeral 301 denotes info. The dvr file 302 is a menu.menu. Java file, 303 is a playlist file in which information such as the playback position and order and mark position of video is recorded, 304 is a clip information file in which information such as playback time and its packet position on the stream file is recorded, and 305 is video A stream file in which information packets such as voice and audio are recorded, and a program file 306 in which decoding software is recorded.

  Here, the stream file 305 will be described. The video information is recorded after the data amount is reduced by the MPEG2 system which is one of the image information compression techniques, converted into the transport stream (TS) format. MPEG2 can reduce the amount of data even for high-quality HD images represented by NTSC format and high-definition images, and reduces the data amount to about 1/10 to 1/50 of the original image. It can be reduced. For example, sufficient image quality can be obtained with a data amount of about 6 Mbps for NTSC format images and about 20 Mbps for HD images. Image compression by MPEG2 is widely used for image storage media such as DVD and digital broadcasting.

  Here, the MPEG2 format will be described as an example, but it goes without saying that data may be encoded using another image compression method.

  As with video, audio information is also compressed using an audio compression technique. There are various compression techniques such as MPEG1 audio and AAC format used in BS digital broadcasting. Also, since audio information has a smaller data amount than video information, it is possible to record data in a linear PCM format without compression. Here, it is assumed that the data is recorded in the MPEG1 audio format.

  The encoded video information and audio information are multiplexed as a transport stream and recorded as one file so that transmission and storage are easy. Specifically, each information is converted into a 188-byte packet. At this time, a PID (packet ID) for packet identification is added to each packet. By adding a single PID to a series of information, packets can be easily separated during reproduction.

  In addition to video / audio, various information packets such as caption information, graphic information, and control commands can be multiplexed in the transport stream. Furthermore, packets such as PMT (Program Map Table) and PAT (Program Allocation Table) representing the relationship between each PID, and PCR (Program Clock Reference) representing time information are multiplexed. The transport stream in which information is multiplexed in this way is recorded on the optical disc as a transport stream file 305.

  Next, the clip information file 304 will be described. As described above, video information is recorded after MPEG2 format image compression. In the MPEG2 format, the data amount is reduced by using the correlation between successive images. Specifically, processing is performed in which the data of the immediately preceding image is used as it is without retransmitting the information of a portion that does not change between consecutive images. For this reason, image data in which only changes are encoded has a drawback that information on all pixels cannot be decoded from the data. Therefore, the only images that can be played back by fast-forwarding, skipping operation, or the like are images in which all pixels are encoded.

  In general, image compression in the MPEG2 format is often performed by combining about 15 images. This set of images is called GOP (Group Of Pictures). If playback is performed from the beginning of this GOP, the image can be played back immediately.

  In the clip information file, the packet position at the tip of the GOP is recorded together with the encoding time of the image (corresponding to the value of Presentation Time Stamp). Thereby, it is possible to easily search for a position where reproduction is started by searching or skipping.

  The clip information file has a one-to-one correspondence with the transport stream file. 01000. Corresponding to a transport stream file called m2ts, 01000. If a clip information file called clpi is recorded, correspondence between files can be easily identified.

  Next, the playlist file 303 will be described. The playlist file is a file in which information defining the playback order of the transport stream file is recorded. In the playlist file, one or more sets of information such as the file identifier, the playback start time, and the playback end time of the stream file to be played are recorded as play item information. At the time of reproduction, the stream file is sequentially reproduced according to the play item information in the designated playlist file.

  The system control unit first reads the “info.dvr” file, and obtains information such as the file name of the menu display program, the file name of the decoding software, the number of playlists, and each file name recorded on the disc.

  Next, based on the information of the “info.dvr” file, the decoding software corresponding to the audio CODEC is downloaded and set. Specifically, the system control unit 111 reads the “audio.dsp” file 306 recorded on the optical disc and writes it to the RAM 203 in the audio decoder 109. As a result, the decoding software corresponding to the audio CODEC is introduced into the DSP 202 in the audio decoder, and the audio can be decoded. The DSP 202 of the audio decoder unit starts an operation according to the program on the RAM 203. When a packet is input from the packet input terminal 201, the DSP 202 extracts data from the input packet and performs a predetermined decoding process according to the CODEC. The audio data is decoded and output to the audio signal output terminal 110 via 204.

  Next, the menu display program 302 is read and executed. The menu display program is programmed to display a menu that allows selection of content recorded on the optical disc and various settings. Here, the menu display program is the “menu.java” file in FIG. The menu display program is read into a memory in the system control unit 111 and executed by a so-called virtual machine which is a program execution environment.

  The user selects desired content from the displayed menu using a remote controller (not shown), and instructs the start of reproduction. The system control unit 111 reads a playlist file 303 corresponding to the content that the user has instructed to reproduce from the optical disc. One or a plurality of play item information is recorded in the playlist, the stream file corresponding to the play item information is read out, and the reading is performed from the packet of the packet number specified in the play item information. . Specifically, the system control unit 111 instructs the drive control unit 106 to read the information of the sector in which the packet to be read is recorded. The drive control unit controls the servo unit 105 so that the instructed sector can be read, and performs control so that the disk rotation speed and the position of the optical pickup 102 become predetermined values. When a recording signal is read from the optical disc by the optical pickup 102, signal processing such as error correction processing and data rearrangement is performed by the reproduction signal processing unit 103 and input to the output control unit 104 as sector data. The output control unit 104 outputs the packets at the time corresponding to the time stamp added to each packet in order from the packet having the packet number designated by the system control unit 111.

  Here, the recording format of the packet recorded on the optical disc is shown in FIG. In FIG. 4, 401 is a packet header, and 402 is an MPEG packet.

  Each MPEG packet is recorded with a 4-byte (32-bit) packet header added thereto. 30 bits in the packet header are used as a time stamp indicating the timing of outputting the packet. The time stamp represents the time counted with a 27 MHz clock as a reference.

  The MPEG packet is 188 bytes long, and the first byte is a synchronization byte. Further, the packet includes a 13-bit PID (packet ID) for identifying the type of the packet.

  The output control unit 104 has a 27-MHz 30-bit counter inside, compares the value counted by this counter with the value of the time stamp added to each packet, and outputs the packet when they match. To control. Thereby, the output timing of the packet can be controlled. When a packet is output from the output control unit 104, the packet header is removed and only the MPEG packet is output.

  The MPEG packet output from the output control unit 104 is input to the audio decoder 107 and the video decoder 109. Each packet includes a 13-bit PID that determines the packet type as described above, and this determines the type of PCR packet, audio data packet, video data packet, and the like. Thereby, each decoder takes out only the packet necessary for decoding from the stream and uses it.

  The stream data in the stream file to be reproduced includes time information called PCR (Program Clock Reference), and video and audio are output in synchronization with this time information. Each decoder performs video and audio decoding processing based on the PCR value (time information).

  The video decoder 107 decodes the video packet in the stream and outputs a video signal to the video signal output terminal 108. On the other hand, the voice packet is input to the voice decoder 109. As described above, the DSP 202 in the audio decoder is preinstalled with decoding software corresponding to CODEC at the start of reproduction, performs predetermined decoding processing on the input packet, and outputs an audio signal. The audio signal output from the audio decoder is connected to an external television or the like via the audio output terminal 110.

  As described above, the audio can be decoded by using the decoding software 306 recorded on the disc, and the audio can be decoded. What is necessary is to record the decoding software according to the CODEC, and when using a different CODEC, the software decoder corresponding to the CODEC is recorded on the disc together with the data encoded by the CODEC. If this is done, it is possible to correspond to an arbitrary CODEC. Of course, this CODEC does not need to be an existing one, and even when a new CODEC is developed, it is possible to make it compatible with the new CODEC by creating a disc on which a software decoder corresponding to the CODEC is created. Become.

  In the above embodiment, software executed by the DSP is recorded as a file, but various modifications can be made. For example, the decoding software is described in a general-purpose software language such as C language or JAVA (registered trademark) language, the decoding software is compiled by the system control unit 111, transferred to the DSP 202, and controlled to be executed. Also good. Furthermore, if a compiler or interpreter is prepared in the DSP, the stream can be decoded by downloading the decoding software directly to the DSP and executing it.

  In the optical disc described above, CODEC decoding software is recorded as an independent file, but this is not a limitation. For example, by including audio CODEC decoding software as user data in the audio stream, the decoding software can be downloaded simultaneously with the reproduction of the audio stream. This method is particularly effective when the DSP has a compiler or interpreter. In addition, it is possible to easily cope with a case where a stream encoded with a different CODEC is provided for each audio channel.

  FIG. 5 shows an example of a stream when decoding software is inserted into an audio stream. In FIG. 5, 501 is a PAT (Program Allocation Table), 502 is a PMT (Program Map Table), 503 is a program packet including decoding software, and 504 is an audio packet including audio data. Here, the description will be made in a form including only audio packets, but there is of course no problem even if video packets are included. The audio stream is recorded as a stream file 305 on the disc.

  FIG. 6 shows a block diagram of a second reproducing apparatus according to the present invention. In FIG. 6, reference numeral 116 denotes a second audio decoder, and the other symbols are the same as those in FIG.

  FIG. 7 shows a block diagram of the second audio decoder. In FIG. 7, reference numeral 701 denotes a ROM (Read Only Memory), and other reference numerals are the same as those in FIG.

  When the user selects the stream shown in FIG. 5 and performs reproduction, the stream shown in FIG. 5 is output from the output control unit and input to the video decoder and the audio decoder.

The DSP in the audio decoder starts the discrimination process of the input packet according to the program written in the ROM. First, the PAT 501 and the PMT 502 in the stream shown in FIG. 5 are input to the audio decoder, and the DSP program determines the PIDs of the program packet 503 and the audio packet 504 included in the reproduction stream. Here, the PID of the program packet is assumed to be 0x01FF, and the PID of the voice packet is assumed to be 0x1200. Of course, this is only an example, and any PID can be used.
Following PAT 501 and PMT 502, a program packet 503 is input. In this program packet, decoding software to be executed by the DSP is recorded. The DSP 202 extracts the decoding software from the input program packet 503 and stores it in the RAM 203. When the input of the program packet is completed, the DSP starts executing the decoding software stored on the RAM. As a result, the DSP starts the operation according to the decoding software recorded in the stream file.

  After the decoding software is read, an audio packet 504 is input as audio data. The DSP in the audio decoder performs the decoding operation of the input audio packet according to the read decoding software, and outputs the decoded audio signal from the output terminal 204. This audio signal is output from the audio output terminal 112 of the playback apparatus to an external amplifier (not shown) and reproduced as audio.

  As described above, it is possible to record or transmit a stream including audio decoding software.

  Here, the decoding software and the audio data have been described as being recorded as packet data having different PIDs, but various modifications are possible. For example, as shown in FIG. 9, the decoding software and the audio data can be handled as a single data. In this case, each of them may be recorded as separate sequence data so that the decoding software and the audio data can be separated. Specifically, a sequence header 901 is added to the head of the decoding software, and subsequently, a sequence number 902 indicating decoding software and decoding software 903 are recorded. After that, a sequence header 901, a sequence number 904 indicating audio data, and audio data 905 are recorded in succession. As a result, at the time of data reproduction, it is possible to detect the sequence header in the data and determine whether the subsequent data is the decoding software or the audio data based on the subsequent sequence number. Audio data can be separated.

  A single data stream including decoding software and audio data can be converted into a packet format, added with a single PID, and recorded in a single stream file.

  As described above, the decoding software and the audio data recording method of the present invention can separate the decoding software and the audio data regardless of whether they are recorded in a single file or as separate files. If it is possible, the present invention can be realized, and the present invention can be applied regardless of the data separation method.

  In the above embodiment, audio decoding has been described, but this is not a limitation. For example, with regard to decoding of video signals and display of subtitles, similarly to the above embodiment, by recording the decoding software on the disc together with the stream, it is possible to easily reproduce even if the CODEC is different for each disc. It is possible to cope with the case where CODEC is newly developed or improved.

Block diagram of a playback device that performs data playback Block diagram of a decoder that performs audio decoding Data file structure on optical disc Packet structure Packet arrangement of stream file Second block diagram of reproducing apparatus for reproducing data Second block diagram of decoder for performing audio decoding Second packet placement of stream file Decoding software and audio data recording example

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Optical disk, 102 ... Optical pick-up, 103 ... Reproduction signal processing circuit, 104 ... Output control circuit, 105 ... Servo, 106 ... Drive control part, 107 ... Video decoder, 108 ... Video signal output terminal, 109 ... Audio decoder, 110 DESCRIPTION OF SYMBOLS ... Audio signal output terminal, 111 ... System control unit, 112 ... Remote control receiving unit, 201 ... Stream input terminal, 202 ... Digital signal processor, 203 ... RAM, 204 ... Audio signal output terminal, 205 ... Program input terminal, 301 ... Disc Information file 302 ... menu file 303 ... playlist file 304 ... clip information file 305 ... stream file 306 ... decode software file 401 ... time stamp 402 ... MPEG-TS packet 403 ... packet 404: Packet ID, 405 ... Data recording area, 501 ... PAT, 502 ... PMT, 503 ... Decode software packet, 504 ... Audio data packet, 701 ... ROM, 901 ... Sequence header, 902 ... Sequence number of decode software, 903 ... Decoding software, 904 ... Sequence number of audio data, 905 ... Audio data

Claims (12)

A data recording method for converting encoded data into a packet format of a predetermined length and recording it on a recording medium,
A data recording method, wherein decoding software for decoding the encoded data is recorded on the recording medium. The data recording method according to claim 1,
A data recording method, wherein the decoding software converts the packet format into a predetermined length and records it. The data recording method according to claim 2, wherein
A packet ID for identifying a packet including the encoded data;
A data recording method, wherein a packet ID for identifying a packet including the decoding software is different. The data recording method according to claim 2, wherein
The decoding software and the encoded data are recorded in different sequences,
A data recording method comprising: recording a sequence in which the encoded data is recorded following a sequence in which the decoding software is recorded. A recording medium on which encoded data is converted into a packet format of a predetermined length and recorded,
A recording medium for recording decoding software for decoding the encoded data. The recording medium according to claim 5,
A recording medium, wherein the decoding software records the packet after converting it into a packet format of a predetermined length. The recording medium according to claim 6,
A packet ID for identifying a packet including the encoded data;
A recording medium having a different packet ID for identifying a packet including the decoding software. The data recording method according to claim 6, wherein
The decoding software and the encoded data are recorded in different sequences,
A recording medium for recording the sequence in which the encoded data is recorded following the sequence in which the decoding software is recorded. Reproducing apparatus A reproducing apparatus that converts encoded data into a packet format of a predetermined length and records the data, and reproduces the data from a recording medium on which decoding software for decoding the encoded data is recorded. And
The playback device has a decoder that decodes the encoded data,
The decoder can change the decoding processing content by software change,
Prior to reproduction of the encoded data, the decoding software is read from a recording medium, and the decoding software is incorporated into the decoder. The playback apparatus according to claim 9, wherein
The decoding software is recorded on a recording medium in a packet format of a predetermined length,
A reproducing apparatus for reproducing packet-format data recorded with decoding software on a recording medium from the recording medium, extracting the decoding software from the packet-format data, and incorporating the decoding software into the decoder. The playback device according to claim 10, wherein
A packet separation means for determining the type of the packet based on the packet ID included in the packet;
A reproduction apparatus characterized in that a packet recorded with the decoding software and the encoded data are separated by a packet ID, and the decoding software is separated and extracted from reproduction data. The playback device according to claim 10, wherein
Having sequence separation means for separating the sequence of data;
A reproducing apparatus, wherein the decoding software and the encoded data are separated by a sequence, and the decoding software is separated and extracted from reproduction data.

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