JP2006014179A - Apparatus and method for transmitting data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable remarkable reduction of hardware and configuration with an inexpensive memory by remarkably reducing a memory access rate. <P>SOLUTION: An image recording/reproducing apparatus records a data unit into a recording medium 107, transmits a set of data unit and management information to a receiver via an ISO transfer IF 110 synchronously with a recording operation of the data unit into the recording medium 107. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data transmission apparatus and a data transmission method applicable to an image recording / reproducing apparatus such as a digital camera.

  Conventionally, MPEG2 is known as an encoding method of an image recording / reproducing apparatus, a Transport Stream (hereinafter referred to as TS) suitable for transmission, a Progaraming Stream (hereinafter referred to as PS) suitable for recording, and a stream between the two streams. Packetize Elementary Stream (hereinafter referred to as PES) is defined as an intermediate stream used for conversion or the like. In addition, a plurality of inventions regarding a configuration method and a conversion method according to these purposes are disclosed (for example, see Patent Document 1). Conventionally, in a recording / reproducing apparatus, a TS converter or the like is required when recording with transmission output.

  In addition, the image recording / playback apparatus in PS recording generally records management information collectively at the end of recording, but the management information cannot be recorded due to unexpected power failure during recording. In this case, there is a problem that the data recorded so far cannot be managed, that is, cannot be reproduced. In order to deal with this problem, for example, in Motion JPEG 2000, a method called Fragmented movie has been proposed (see, for example, Patent Document 2).

  A Movie atom that manages information common to the entire file is arranged at the top, followed by a Movie data atom that stores partial AV stream data (hereinafter referred to as Movie fragment), and a Movie fragment atom that manages the Movie fragment Are alternately arranged.

  By recording on the media in this order during recording, even if the power is cut off during recording, the movie fragment atom recorded on the media immediately before and the movie fragment managed by it remain on the media, It can be played back later.

JP-A-11-45512 JP 2003-22621 A

  However, in the above-described conventional configuration, a conversion processing circuit is required to realize synchronous transfer output, and an increase in hardware amount or an expensive processor is required. In addition, the access rate to the buffer memory is increased, and it is necessary to have a high-speed buffer configuration, and there is a problem that an expensive high-speed memory is required.

  SUMMARY OF THE INVENTION An object of the present invention is to make it possible to significantly reduce hardware, to significantly reduce the memory access rate, and to configure an inexpensive memory.

  The data transmission apparatus according to the present invention includes a data unit generation unit that generates a plurality of data units from a series of input audio data and video data, a management information generation unit that generates management information related to one data unit, A recording unit that records a plurality of data units including a series of audio data and video data on a recording medium, and a transmission unit that adds the management information to each data unit and transmits the data unit to a receiving device. And

  The data transmission method of the present invention is a data transmission method by a data transmission apparatus, and includes a data unit generation step for generating a plurality of data units from a series of input audio data and video data, and management related to one data unit. A management information generating step for generating information; a recording step for recording a plurality of data units including the series of audio data and video data on a recording medium; and a receiving apparatus that adds the management information to each data unit A transmission step of transmitting to the network.

  A program according to the present invention causes a computer to execute the data transmission method.

  The computer-readable recording medium of the present invention is characterized in that the program is recorded.

  According to the present invention, since the management information is added to each data unit and transmitted to the receiving device, the hardware can be greatly reduced, the memory access rate can be greatly reduced, and the cost can be reduced. It is possible to configure with a simple memory.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments to which the invention is applied will be described in detail with reference to the accompanying drawings.

-First embodiment-
FIG. 1 is a diagram showing a schematic configuration of an image recording / reproducing apparatus according to the first embodiment of the present invention.
101 is a video encoding unit, 102 is an audio encoding unit, 103 is a buffer, 104 is a Progaraming Stream converter (hereinafter referred to as a PS converter), and 105 is a Post Recording Unit addition unit (hereinafter referred to as a PRU addition unit). , 106 is a medium recording unit, 107 is a recording medium, and the output of the PRU adding unit 105 is input to the Media recording unit 106 and the management information adding unit 109, respectively.

  The video signal to be encoded and recorded on the recording medium is encoded by a video encoding unit 101 by a known encoding method such as MPEG and stored in the buffer 103. At the same time, the audio signal is also encoded by the audio encoding unit 102 by a known encoding method and stored in the buffer 103. The accumulated data is converted by the PS converter 104 into a known general PS format with reference to the management information 108. Thereafter, a PRU unit for after-recording including after-recording data is added by the PRU adding unit 105, and processing appropriate or necessary for the recording medium is performed by the medium recording unit 106 and recorded on the recording medium 107. At this time, since the PRU is an after-recording area, it is general that the PRU is in an unrecorded state.

  On the other hand, in the management information adding unit 109, data corresponding to a certain amount of time in a predetermined GOP (Group Of Picture) unit in which post-record data is added to the encoded data by the PRU adding unit 105 is managed corresponding to that from the management information 108. Data is added and output to the synchronous transmission interface, ISO transfer IF 110. The management information to be added at this time is management information related to the data to be added, so that the same effect as that of the Fragmented movie is obtained in that unit. In this case, it can be realized by adding the management information in PRU units, that is, in Record Unit units. Since the data to which the management information is added is data for a certain time in the added unit, this data is transmitted in the existing synchronous transmission (ISO) format by the ISO transfer IF 110, and the receiving side performs time synchronization from the management information. Thus, synchronous transmission can be realized.

  FIG. 2 shows the data format. In the figure, ES (201) is an elementary stream and has a structure in units of GOP, which is a unit of MPEG encoding. SH is a Sequence Header, SE is a Seaquence Extension, and GH is a GOP Header, which is management information. Subsequent I, B, and P form a frame structure for image coding. Generally, 15 frames are set as 1 GOP, but this is not a limitation.

  In the figure, PES (202) is a Packetize Elementary Stream, which is a stream obtained by packetizing the ES (201). At the beginning of each packet, there is a PH packet header, followed by header and data in units of frames. One packetized packet is Video PES (V_PES) in the case of a video data packet, and Audio PES (A_PES) in the case of audio data.

  In the figure, PS (203) is a Program Stream, and has a configuration in which a plurality of V_PES or A_PES corresponding to one GOP of the aforementioned PES (202) are collectively packed.

  In the figure, reference numeral 204 denotes a Video Unit by adding a predetermined number of GOP-unit PSs together with a packet header PH.

  In the figure, a Movie File (205) forms a Record Unit by adding PRU to the above-mentioned Video Unit, and records this data on a recording medium. Such management information is recorded as a separate file or subsequent data. This management information is created after all video data is recorded as described above.

  Although the contents of PRU are not described, PRU Header, Post Audio data, and unused part are composed of Padding Data.

  At the time of post-recording, the PRU part is rewritten to realize post-recording. Therefore, in order to facilitate post-recording processing, the system is configured so that the video time of the data content of the above-mentioned Recording Unit is constant. In other words, a PRU is added for each predetermined number of GOPs using GOP as a unit. In this way, it is possible to easily encode an audio signal at regular intervals and insert it into the PRU.

  Movie File (205) is ISO output (206). The Movie File (205) is composed of a unit of Record Units (RU) to constitute one video clip, and management information for the entire clip is attached. On the other hand, the ISO output divides the above-mentioned Record Unit by the unit, creates management information (moof) of the fragmentation recording method for the divided Record Unit, and outputs in a configuration in which moof is added after each Record Unit. . By repeating the transmission from # 1 to #n in the figure, it is possible to perform synchronous transfer synchronized in units of Record Units.

  In this case, the entire management information becomes unnecessary because it is substituted by moof. When transmitting in the existing synchronous transmission format, it is important to synchronize the Record Unit of the Movie File (205) and the RU of the ISO output (206), which can be easily realized by synchronizing the start of each. is there. Of course, the same effect can be obtained by synchronizing the predetermined positions. Each of them may be in a synchronized state even if it has a predetermined constant delay. Further, by setting the relationship between the ISO output RU or moof capacity n (n is a natural number) and the transmission packet capacity m (m is a natural number) to n: m, the processing becomes easy and efficient transmission is possible. Become.

  Next, the operation of the image recording / reproducing apparatus according to the present embodiment will be described in detail with reference to FIG.

  Step S301 is start, step S302 is RU recording start determination processing, step S303 is RU ISO transfer start processing, step S304 is RU ISO transfer end determination processing, step S305 is moof ISO transfer start processing, and step S306 is moof ISO transfer end determination processing, step S307 is file end determination processing, and step S308 is end.

  First, in step S301, it is determined whether or not RU recording has started in the RU recording start determination process in step S302. If NO, the process returns to step S302 and is executed again. If YES, the process proceeds to step S303.

  In step S303, ISO transfer of the RU is started in synchronization with the start of RU recording, and the process proceeds to step S304. In step S304, it is determined whether the ISO transfer of the transferring RU is completed. If NO, the process returns to step S304 and is executed again. If YES, the RU has completed the transfer and proceeds to step S305.

  In step S305, moof ISO transfer is started, and the process proceeds to step S306. In step S306, it is determined whether the ISO transfer of the transferring moof has been completed. If NO, the process returns to step S306 and re-executes. If YES, the moof transfer is complete and the process proceeds to step S307.

  In step S307, it is determined whether the file has been completed. If NO, the file has not ended and RU continues, so the process returns to step S302 to re-execute a series of operations. If YES, the file transfer is completed, so the process proceeds to step S308 and ends.

  In the series of operations described above, the RU data and the moof data can be sequentially and synchronously transferred in synchronization with the start of RU recording. On the receiving side, management information is obtained from moof in units of RU, which is a unit of synchronization, and decoding and reproduction can be performed while obtaining video synchronization. At this time, in order to match the reception times of the RU data and the moof data, it can be realized by using a buffer corresponding to the synchronization unit time. In the above description, the management information is expressed as moof. However, the present invention is not limited to this, and mov may be used as long as the content is the same.

-Second Embodiment-
Next, a second embodiment of the present invention will be described. The configuration of the image recording / reproducing apparatus according to the present embodiment is the same as that of the first embodiment shown in FIG. FIG. 4 is a diagram showing a data format in the second embodiment of the present invention. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The steps up to Movie File (205) are the same as those in the first embodiment, but the part for outputting the ISO (401) is different. The Movie File (205) is composed of a unit of Record Units (RU) to form one video clip, and management information for the entire clip is attached. On the other hand, the ISO output divides the above-mentioned Record Unit by the unit, creates management information (moof) for the divided Record Unit, and adds the moof first to each Record Unit and outputs it. By repeating the transmission from # 1 to #n in the figure, it is possible to perform synchronous transfer synchronized in units of Record Units.

  In this case, the entire management information is unnecessary because it can be substituted by moof. When transmitting in the existing synchronous transmission format, it is important to synchronize the Record Unit of the Movie File (205) and the RU of the ISO output (401). The fixed amount of moof information and the Record Unit of the Movie File (205) This can be easily realized by synchronizing the beginnings of. Of course, the same effect can be obtained by synchronizing the predetermined positions. Each of them may be in a synchronized state even if it has a predetermined constant delay. By transmitting the Moof information first, it is possible to reduce the buffer amount at the receiving decoder.

  In FIG. 4, the start positions of the Movie File (205) and the ISO output (401) are set the same. However, in real time, the moof information includes information obtained after obtaining the Record Unit. , Output will be delayed by that amount. If this delay is constant, there is no problem. It is also possible to adopt a configuration that can eliminate the delay in other parts such as a buffer.

FIG. 5 is a flowchart showing the operation of the image recording / reproducing apparatus according to the present embodiment.
Step S501 is start, step S502 is RU recording start determination processing, step S503 is moof ISO transfer start processing, step S504 is moof ISO transfer end determination processing, step S505 is RU ISO transfer start processing, and step S506 is RU. ISO transfer end determination processing, step S507 is file end determination processing, and step S508 is end.

  First, in step S501, it is determined in the RU recording start determination process in step S502 whether RU recording has started. If NO, the process returns to step S502 and is executed again. If YES, the process proceeds to step S503. Here, as described above, the determination is made at the end time of the RU in real time. However, the processing is performed in synchronization with the start of the RU, assuming that the buffer memory absorbs the time.

  In step S503, the ISO transfer of moof is started, and the process proceeds to step S504. In step S504, it is determined whether the ISO transfer of the transferring moof has been completed. If NO, the process returns to step S504 and re-executes. If YES, moof has finished transferring and proceeds to step S505.

  In step S505, ISO transfer of the RU is started, and the process proceeds to step S506. In step S506, it is determined whether the ISO transfer of the transferring RU is completed. If NO, the process returns to step S506 and re-executes. If YES, the RU transfer is completed and the process proceeds to step S507.

  In step S507, it is determined whether the file has been completed. If NO, the file has not ended and moof continues, so the process returns to step S502 to re-execute a series of operations. If YES, the file transfer is complete, so the process proceeds to step S508 and ends.

  In the above series of operations, the moof data and the RU data can be sequentially synchronously transferred in synchronization with the start of recording of the Record Unit. On the receiving side, it is possible to decode and reproduce while obtaining video synchronization by obtaining management information from moof in units of Record Units which are units of synchronization. At this time, in order to match the reception times of the RU data and the moof data, it can be realized by using a small buffer for the moof information.

  As described above, according to the above embodiment, synchronous transfer can be realized by simple additional means, and at the same time, the hardware can be greatly reduced, and the memory access rate can be greatly reduced. Configuration is possible. Furthermore, power consumption can be reduced.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (basic system or operating system) running on the computer based on the instruction of the program code. Needless to say, a case where the functions of the above-described embodiment are realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion board or function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows schematic structure of the image recording / reproducing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the format of the data in the 1st Embodiment of this invention. 3 is a flowchart showing an operation of the image recording / reproducing apparatus according to the first embodiment of the present invention. It is a figure which shows the format of the data in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the image recording / reproducing apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Video encoding part 102 Audio encoding part 103 Buffer 104 Progaraming Stream converter 105 Post Recording Unit addition part 106 Medium recording part 107 Recording medium 108 Management information 109 Management information addition part 110 ISO transfer IF

Claims (12)

Data unit generating means for generating a plurality of data units from a series of input audio data and video data;
Management information generating means for generating management information relating to one data unit;
Recording means for recording a plurality of data units including the series of audio data and video data on a recording medium;
A data transmission apparatus comprising transmission means for adding the management information to each data unit and transmitting the data to a reception apparatus.   The data transmission apparatus according to claim 1, wherein the transmission unit starts transmission of the set of the data unit and the management information in synchronization with the recording start of the data unit by the recording unit.   The data transmission apparatus according to claim 1 or 2, wherein the data unit generation unit generates one data unit from the video data for a predetermined period.   The data transmission apparatus according to claim 1, wherein the transmission unit transmits the data unit earlier than the management information.   4. The data transmission apparatus according to claim 1, wherein the transmission unit transmits the management information before the data unit.   The relationship between the capacity of the data unit or the management information and the capacity of the transmission packet is a relationship of n (n: natural number): m (m: natural number). The data transmission device according to item.   The data transmission apparatus according to claim 1, wherein the data unit includes after-recording data.   8. The data transmission apparatus according to claim 1, wherein the management information includes management information of a fragmentation recording method.   The management information generating means further generates overall management information relating to the entire plurality of data units including the series of video data and audio data, and the recording means includes the overall management information together with the plurality of data units in the recording medium. The data transmission apparatus according to claim 1, wherein the data transmission apparatus records the data. A data transmission method by a data transmission device,
A data unit generating step for generating a plurality of data units from a series of input audio data and video data;
A management information generating step for generating management information related to one data unit;
A recording step of recording a plurality of data units including the series of audio data and video data on a recording medium;
A data transmission method comprising: a transmission step of adding the management information to each data unit and transmitting the data to a receiving device.   A program for causing a computer to execute the data transmission method according to claim 10.   The computer-readable recording medium which recorded the program of Claim 11.

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