JP2006014256A - Video voice data recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generally deal with a plurality of video formats, a plurality of voice formats and a plurality of multiplex formats without depending on an encoding and decoding method. <P>SOLUTION: A recording and reproducing control device 2 comprises a file system interface library 5. The file system interface library 5 mediates a block (recording and reproducing device 2) depending on CODEC and a portion (file management device 3) independent of CODEC. Thus, the file management device 2 is separated from the recording and reproducing control device 3 and versatility of the recording and reproducing device is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a video / audio data recording / reproducing apparatus for managing video / audio data with a file structure suitable for special reproduction.

  Conventionally, a video / audio data recording apparatus that converts video / audio contents of various formats into a format that realizes special reproduction using random accessibility and records the data on a recording medium, and reproduces the video / audio content recorded in this format There is a video / audio data reproducing apparatus.

  FIG. 9 shows the configuration of a conventional video / audio data recording apparatus 100. The multiplexed video / audio data abstraction block 111 converts the input video / audio data into a format independent of CODEC (coding / decoding method) to generate packed video / audio data. The packed video / audio data management control block 112 performs file management of the packed video / audio data. The packed video / audio data management control block 112 determines the recording position of the recording medium. The recording medium control block 113 executes a recording process in accordance with an instruction from the packed video / audio data control management block 112.

  The multiplexed video / audio data abstraction block 111 and the system control block 110 are blocks dependent on CODEC. The multiplexed video / audio data abstraction block 111 receives attribute information of the video / audio data from the system control block. This attribute information includes information on which CODEC the video / audio data is encoded. The multiplexed video / audio data abstraction block 111 generates packed video / audio data independent of the CODEC from this information. The process of generating packed video / audio data depends on the CODEC.

  As described above, the conventional video / audio data recording apparatus 100 includes the system control block 110 and the multiplexed video / audio data abstraction block 111, which are dependent on the CODEC. There was a problem that it was not possible to respond flexibly to changes in the system.

  This problem also exists in the conventional video / audio reproduction device. A conventional video / audio data reproducing apparatus 200 has a configuration as shown in FIG. The multiplexed video / audio data configuration block 221 separates the packed video / audio data into video data, audio data, and playback time information, and reconstructs the video / audio data according to the multiplexing format specified by the system control block 220. Since the reconstruction of the video / audio data is processing dependent on the CODEC, the video / audio reproduction device 200 cannot flexibly cope with the change of the CODEC.

Japanese Patent Application No. 2003-128412

  SUMMARY OF THE INVENTION An object of the present invention is to provide a video / audio data recording / reproducing apparatus that is universally compatible with a plurality of video formats, a plurality of audio formats, and a plurality of multiplexed formats without depending on the encoding / decoding method.

  The video / audio data recording / reproducing apparatus according to the present invention includes a format conversion means for converting the video / audio data into a predetermined format independent of the multiplexing format of the video / audio data, and special reproduction of the video / audio data converted into the predetermined format. File management means for managing the file structure suitable for the above, and mediation means for mediating between the format conversion means and the file management means.

  The video / audio data recording / reproducing apparatus according to the present invention includes a format conversion means for converting the video / audio data into a predetermined format independent of the multiplexing format, and a file configuration suitable for special reproduction of the video / audio data converted into the predetermined format. The file management means, and the mediation means for mediating between the format conversion means and the file management means, so that the file management means is separated from the format conversion means, and the file management means becomes a multiplexed format of video and audio data. No longer depend on it.

  A video / audio data recording / reproducing system to which the present invention is applied will be described below with reference to the drawings. The video / audio data recording / reproducing system is a system for recording general video / audio data in a format suitable for special reproduction to improve the efficiency of special reproduction. The video / audio data recording / playback system converts video / audio data in a general format such as MPEG or DV stream into packed video / audio data independent of CODEC (coding / decoding method) when recording the video / audio data. The packed video / audio data is recorded in a file structure suitable for special reproduction. Also, the video / audio data recording / reproducing system reads packed video / audio data recorded on a recording medium and returns it to general video / audio data at the time of data reproduction.

  The process of converting the video / audio data into the packed video / audio data is a process dependent on CODEC. The process of recording the packed video / audio data in a format suitable for special reproduction is a process independent of CODEC. The present invention improves the versatility of a file management block by separating a block for converting video / audio data into packed video / audio data and a block for managing file of the packed video / audio data. .

  FIG. 1 is a block diagram showing a configuration of a video / audio data recording / reproducing system 1. The video / audio data recording / playback system 1 includes a recording / playback control device 2 that converts input video / audio data into packed video / audio data, and a file management device 3 that manages the packed video / audio data with a file configuration suitable for special playback. With. The recording / playback control device 2 is a portion that depends on the CODEC of the video / audio data, and the file management device 3 is a portion that does not depend on the CODEC. The recording / playback control device 2 is provided with a file system interface library 5. The file system interface library 5 mediates between blocks dependent on CODEC (recording / playback control device 2) and blocks not dependent on CODEC (file management device 3). As a result, the file management device 3 is separated from the recording / playback control device 2, and the versatility of the file management device 3 is improved.

  The recording / playback control apparatus 2 includes a video / audio data conversion unit 4 and a file system interface library 5 as shown in FIG. The recording / playback control device 2 is installed in a video / audio device such as a DVD player, a TV tuner, or a streaming client that records video / audio data or obtains the video / audio data. In the present embodiment, the description of the block for obtaining the video / audio data is omitted.

  The file system interface library 5 is provided by the vendor of the file management apparatus 3 to the developer of the video / audio equipment. The developer of the video / audio device creates the video / audio data conversion unit 4 using the function provided by the file system interface library 5. In addition to mediation with the file management device 3, the file system interface library 5 supports the development efficiency of the recording / playback control device 2 by componentizing modules necessary for mediation.

  The video / audio data conversion unit 4 is a multiplexed video / audio data abstraction block 41 that converts video / audio data into packed video / audio data, and a multiplex that converts packed video / audio data read from the recording medium 8 into video / audio data. And a system control block 42 for controlling the file management apparatus 3 using the functions of the file system interface library 5.

  The multiplexed video / audio data abstraction block 41 stores a control code for demultiplexing the video / audio data. The multiplexed video / audio data abstraction block 41 separates the video data and audio data of the input video / audio source in accordance with this control code. The multiplexed video / audio data abstraction block 41 has already recognized what multiplexed format is input by a command from the system control block 42. Multiplexed formats usually have time information for synchronizing video data and audio data, or have a mechanism that can be synchronized at least under certain conventions. For example, in the case of an MPEG-2 transport stream, PCR (Program Clock Reference) is included as a reference time, and PTS (in a certain unit) is the time at which video data and audio data should be started to be reproduced based on this reference clock. (Presentation Time Stamp) is included. Further, it is possible to calculate at what timing video or audio data should be reproduced from frame synchronization, sampling frequency, etc., even for video-only data or audio-only data without time information. In any case, the time at which video data and audio data should be reproduced can be obtained. Since this data has already been reduced to a format that has solved the multiplexing format, it is processed in a manner that does not depend on the multiplexing format.

  The multiplexed video / audio data abstraction block 41 separates video data and audio data into decoding units. Video data and audio data have units for decoding them. The encoded data can be decoded only when the data of the decoding unit is prepared, and the video frame and audio sample included in the unit can be decoded. The decoding unit differs depending on the encoding format. For example, the decoding unit of MPEG video is 1 GOP (Group Of Picture). Even if only data relating to a specific frame (or field) is extracted from this GOP, a video frame (or field) cannot be reproduced only from that data.

  Also, there is always a key frame in video data, and the frame from that key frame to the frame immediately before the next key frame can be considered as a decoding unit, and all frame data contained in that unit is decoded. can do. For example, in the case of MPEG video, a frame called an I frame corresponds to a key frame. In addition, audio data includes audio frames, and all sample data included therein can be decoded in units of audio data. In any case, video data and audio data can be separated into decoding units.

  The time information related to the reproduction of the video data and the time information related to the reproduction of the audio data are abstracted by combining the decoding units into one unit in the multiplexed video / audio data abstraction block 41. Also, the playback time information (abstracted video data time information and abstracted audio data time information) is attached to the abstracted video data and the abstracted audio data to generate packed video and audio data. For example, in the case of MPEG-2 video data, since GOP is a decoding unit, GOP data is extracted from video PES packet data, and the playback start time of the data and the I frame at the top of the GOP is set as abstract video data time information. And

  The multiplexed video / audio data configuration block 43 separates the packed video / audio data input from the file management device 3 into video data, audio data, and reproduction time information. The multiplexed video / audio data construction block 43 reconstructs the video / audio data multiplexed in a method according to the multiplexing format specified in the system control block 42 from the video data, the audio data, and their reproduction time information.

  The multiplexed video / audio data configuration block 43 can also perform special reproduction using the attribute information of the video / audio data in the recording medium management table 10. Special playback is designated as one of playback methods by an external command. The multiplexed video / audio data configuration block 43 determines which packed video / audio data should be read in order to realize special playback at the specified special playback type and speed. Based on this determination, the packed video / audio data required for the file management apparatus 3 is requested via the file system interface library 5. For example, the packed video / audio data is specified by specifying a time difference value from the most recent time at which multiplexing is completed. Alternatively, the desired time itself, the packed video / audio data number itself, or the packed video / audio data number difference value can be designated. By reading the packed video and audio data one by one as described above, special reproduction video and audio data in units of packed video and audio data can be acquired.

  The file system interface library 5 is incorporated in the same manner as the C language library, and provides the video / audio data conversion unit 4 with API (Application Programming Interface) functions similar to C language standard functions and system calls. The video / audio data converting unit 4 calls various API functions provided by the file system interface library 5 according to the processing purpose, thereby realizing recording / reproduction of the packed video / audio data.

  Data sent from the file system interface library 5 to the file management device 3 includes packed video / audio data to be recorded, a recording start command, a reproduction start command, a name of the video / audio data to be recorded, and video / audio data identification information to be reproduced. is there.

  The file management device 3 includes a packed video / audio data management control block 6 that manages a logical file configuration, and a recording medium control block 7 that manages a physical file configuration of the recording medium 8. The recording medium 8 may be built in the file management device 3 or externally attached. However, the recording medium 8 has different writing / reading performance (transfer rate) depending on its type. Since the transfer rate is greatly affected by the size of the packed video / audio data, the file management device 3 is informed of the optimal size of the packed video / audio data for the recording medium 8 connected to the recording / playback control device 2. This mechanism is necessary. This mechanism will be described later.

  When the packed video / audio data management control block 6 receives the packed video / audio data, it requests the recording medium control block 7 to allocate a recording area. The packed video / audio data management control block 6 executes alignment adjustment to the allocated recording area and writes the packed video / audio data to the allocated recording area as needed. When allocation to a new recording area becomes necessary, the recording medium control block 7 is requested to allocate a recording area.

  The packed video / audio data management control block 6 generates a sequence table describing each packed video / audio data start time (reproduction elapsed time), recording position, size, and the like. This sequence table is represented as a packed video / audio data management table 9. An example of the packed video / audio data management table 9 is shown in FIG.

  Further, the packed video / audio data management control block 6 generates a recording medium management table 10. The recording medium management table 10 is a management table positioned above the packed video / audio data management table 9 and is a table for managing all video / audio contents recorded in the recording medium 8. The simplest example is shown in FIG. The recording medium management table 10 in this example describes, for each content, an attribute of the video / audio data of the content, a name of the content, a recording position of the packed video / audio data management table 9, and the like. Information that is not included in the main body video / audio source, such as the attributes of video / audio data that is content and the name of the content, is acquired via the file system interface library 5.

  Hereinafter, recording / reproducing processing of video / audio data via the file system interface library 5 will be described with reference to FIGS. 4 and 5.

  FIG. 4 shows the procedure of the video / audio data recording process. The video / audio data is input to the multiplexed video / audio data abstraction block 41 of the video / audio data converter 4. When the multiplexed video / audio data abstraction block 41 reads the video / audio data (step S10), it converts the video / audio data into packed video / audio data (step S11). The system control block 42 monitors whether or not the packed video / audio data is completed. When the completion of the packed video / audio data is detected (step S12; YES), the system control block 42 requests writing of the packed video / audio data and The packed video / audio data is transferred to the file system interface library 5 (step S13). On the other hand, when the completion of the packed video / audio data is not detected (step S12; NO), the system control block 42 continues monitoring.

  The file system interface library 5 obtains the packed video / audio data write request and the packed video / audio data by the API function (step S14). The file system interface library 5 generates a file system access command for writing packed video and audio data based on the parameter of the file system access command acquired as an argument of the API function (step S15), and transfers it to the file management apparatus 3. (Step S16). The file management device 3 acquires a write access command (step S17). The file system interface library 5 transfers the packed video / audio data to the file management apparatus 3 following the transfer of the file system access command (step S18).

  The file management device 3 acquires the packed video / audio data transferred from the file system interface library 5 (step S19), and records it in the recording medium 8 with a file structure suitable for special reproduction (step S20). When the file management apparatus 3 completes the recording of the packed video / audio data, it transfers the response of the file system access command to the file system interface library 5 (step S21). The file system interface library 5 receives the response to the file system access command transferred from the file management device 3 (step S22). The file system interface library 5 transfers the response of the file system access command as an argument of the API function to the video / audio data converter 4 (step S23). The video / audio data converter 4 receives the response (step S24). Thereafter, these writing processes are repeated.

  As shown in the flowchart of FIG. 4, the video / audio data conversion unit 4 and the file management device 3 use the file system interface library 5 as an intermediary and do not exchange data directly. Thus, in the video / audio data recording / reproducing system 1 to which the present invention is applied, the file management apparatus 3 is separated from the video / audio data conversion unit 4 by providing the file system interface library 5.

  Next, the procedure of the video / audio data reproduction process will be described with reference to FIG.

  First, the system control block 42 of the video / audio data conversion unit 4 requests reading of packed video / audio data (step S30). The file system interface library 5 acquires a read request for the packed video and audio data (step S31). The file system interface library 5 generates a file system access command for reading packed video and audio data based on the parameter of the file system access command acquired as an argument of the API function (step S32), and transfers it to the file management device 3. (Step S33).

  Upon receiving the file system access command (step S34), the file management device 3 reads the packed video / audio data specified by the file system access command from the recording medium 8 (step S35), and reads the read packed video / audio data. Transfer to the file system interface library 5 (step S36). The file system interface library 5 acquires the packed video / audio data transferred from the file management apparatus 3 (step S37). When the transfer of the packed video / audio data is completed, the file management device 3 transfers the file system access command to the file system interface library 5 (step S38).

  When the file system interface library 5 receives the response of the file system access command transferred from the file management device 3 (step S39), the video / audio data conversion unit 4 packs the video / audio data and the file system as arguments of the API function. A response to the access command is transferred (step S40). The multiplexed video / audio data configuration block 43 of the video / audio data conversion unit 4 acquires the packed video / audio data transferred from the file system interface library 5 (step S41), and the acquired packed video / audio data is converted into the video / audio. The data is restored (step S42). The multiplexed video / audio data configuration block 43 of the video / audio data conversion unit 4 outputs the restored video / audio data to a reproduction processing unit or transmission processing unit (not shown) (step S43). Thereafter, these reading processes are repeated.

  As shown in the flowchart of FIG. 5, the video / audio data conversion unit 4 and the file management device 3 use the file system interface library 5 as an intermediary and do not exchange data directly. Thus, in the video / audio data recording / playback system 1 to which the present invention is applied, the file management device 3 is separated from the video / audio data conversion unit 4 by providing the file system interface library 5.

  By the way, the writing / reading performance (transfer rate) of the video / audio data greatly affects the size of the packed video / audio data, and the size of the packed video / audio data depends on the characteristics unique to the recording medium. In the video / audio data recording / playback system 1 to which the present invention is applied, the recording / playback control device 2 that generates packed video / audio data and the file management device 3 that manages the recording medium 8 are separated. I don't know how big the size of packed video and audio data should be. Therefore, a mechanism for transmitting the size of the packed video / audio data optimum for the recording medium 8 to the recording / reproducing control apparatus 2 is necessary.

  A method for determining the size of the packed video / audio data will be described below. First, in the first method, a rate table 11 representing the relationship between the transfer rate and the packed video and audio data size for realizing the transfer rate as shown in FIG. The contents of the rate table 11 differ depending on the type of recording medium (hard disk, memory, etc.) and the size of the recording medium (2.5 inch HDD, 3.5 inch HDD, etc.). The rate table 11 is created in advance by measuring the recording medium 8.

  The recording / playback control device 2 designates a necessary transfer rate for the file management device 3. The file management device 3 reads the rate table 11, searches for the size of the packed video / audio data necessary to realize the transfer rate specified by the recording / playback control device 2, and packs the video / audio data corresponding to the transfer rate. Is transferred to the recording / reproducing control apparatus 2. The size of the transferred packed video and audio data is a minimum size necessary for realizing the designated transfer rate. The exchange of the rate table 11 between the recording / playback control device 2 and the file management device 3 is also mediated by the file system interface library 5.

  FIG. 7 shows a procedure of processing for determining the size of the packed video / audio data using the rate table 11. The recording / reproducing control device 2 first obtains a transfer rate necessary for the video / audio data to be recorded (step S50). The recording / playback control apparatus 2 inquires the file management apparatus 3 about the size of the packed video / audio data that realizes a necessary transfer rate via the file system interface library (step S51). The file management device 3 receives the inquiry from the recording / playback control device 2 (step S52), and reads the rate table 11 from the recording medium 8 (step S53). The file management device 3 searches the rate table 11 for the size of the packed video / audio data that realizes the designated transfer rate (step S54). The file management device 3 transfers the size of the packed video / audio data via the file system interface library 5 (step S55). The recording / playback control apparatus 2 acquires the size of the packed video / audio data via the file system interface library 5 (step S56).

  Next, a second method for notifying the recording / playback control apparatus 2 of the size of the packed video / audio data will be described. The second method is a method of calculating the size of packed video / audio data from the transfer rate and the characteristic information unique to the recording medium by calculation. In this method, characteristic information unique to the recording medium is recorded in a predetermined fixed area (such as the beginning of the recording area) on the recording medium 8, and the transfer rate requested from the recording / reproduction control device 2 and the recording medium are recorded. The unique characteristic information is applied to the following calculation formula (1) to derive the size of the packed video / audio data.

Size of packed video / audio data = function (characteristic information specific to recording medium, requested transfer rate)
(1)
FIG. 8 shows a procedure for calculating the size of the packed video and audio data. The recording / reproducing control device 2 obtains a transfer rate necessary for the video / audio data to be recorded (step S60). The recording / playback control apparatus 2 inquires the file management apparatus 3 about the size of the packed video / audio data that realizes a necessary transfer rate via the file system interface library 5 (step S61). The file management device 3 receives the inquiry from the recording / playback control device 2 (step S62), and reads characteristic information specific to the recording medium from the recording medium 8 (step S63). The file management apparatus 3 applies the necessary transfer rate and the characteristic information specific to the recording medium 8 to the calculation formula (1), and the size of the packed video and audio data that is the minimum necessary to realize the requested transfer rate. Is derived from the calculation formula (1) (step S64). The file management device 3 transfers the size of the packed video / audio data via the file system interface library 5 (step S65). The recording / playback control apparatus 2 acquires the size of the packed video / audio data via the file system interface library 5 (step S66).

  As described above, the video / audio data recording / reproducing system 1 to which the present invention is applied includes the file system interface library 5 in the recording / reproducing control apparatus 2, and the recording / reproducing control apparatus 2 and the file via the file system interface library 5. The management device 3 communicates. As a result, the recording / reproduction control device 2 that is a CODEC-dependent portion and the file management device 3 that is a CODEC-independent portion are separated.

  Further, the video / audio data recording / reproducing system 1 inquires the file management apparatus 3 about the size of the packed video / audio data in order to ensure a transfer rate suitable for the video / audio data. The file management apparatus 3 reads the rate table 11 recorded on the recording medium 8 or the characteristic information of the recording medium 8 itself, and derives the size of the packed video / audio data based on these. Thereby, the transfer rate of video / audio data is ensured.

It is a block diagram which shows the structure of the video / audio data recording / reproducing system to which this invention is applied. It is a figure which shows the structure of a recording medium management table. It is a figure which shows the structure of a packed video and audio data management table. It is a flowchart explaining the procedure of a recording process. It is a flowchart explaining the procedure of a reproduction | regeneration process. It is a figure which shows the structure of a rate table. It is a flowchart explaining the procedure which determines the size of the packing audio-video data using a rate table. It is a flowchart explaining the procedure which determines the size of the pack video / audio data using the characteristic information of a recording medium. It is a block diagram which shows the structure of the conventional video / audio data recording device. It is a block diagram which shows the structure of the conventional video / audio data reproduction apparatus.

Explanation of symbols

1 video / audio data recording / playback system, 2 recording / playback control device, 3 file management device, 4 video / audio data conversion unit, 5 file system interface library, 6 packed video / audio data management control block, 7 recording medium control block, 8 recording Medium, 9-packed video / audio data management table, 10 recording medium management table, 11 rate table, 41 multiplexed video / audio data abstraction block, 42 system control block, 43 multiplexed video / audio data configuration block

Claims (3)

Format conversion means for converting the video / audio data into a predetermined format independent of the multiplexing format of the video / audio data;
File management means for managing the video and audio data converted into the predetermined format in a file configuration suitable for special reproduction;
A video / audio data recording / reproducing apparatus comprising: mediating means for mediating between the format converting means and the file managing means. The format conversion means analyzes the multiplexed data and separates the video data, audio data and video / audio data synchronization information included therein, and packs the video data and audio data independent of the multiplexing format. Packing means for converting into video and audio data,
The video / audio data recording / reproducing apparatus according to claim 1, wherein the file management means manages packed video / audio data using the synchronization information as an index. Transfer rate deriving means for deriving a transfer rate suitable for the video / audio data multiplexing format;
Size inquiry means for inquiring the file management means about the size of the packed video and audio data suitable for the transfer rate via the mediation means,
The file management means determines the size of the packed video / audio data suitable for the transfer rate and the characteristics of the recording medium for recording the packed video / audio data, and the size of the packed video / audio data through the mediation means. The video / audio data recording / reproducing apparatus according to claim 2, wherein:

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