KR100852038B1 - Data processing apparatus - Google Patents

Abstract

In order to enable continuous reproduction of content and the like, a technique of efficiently writing data on a recording medium is provided. More specifically, it is assumed that the FAT (File Allocation Table) of the recording medium is read in units of a part thereof, and data is written by a method suitable for the reading method. The data processing apparatus writes a data stream of the content into a recording medium whose storage location of data is defined based on a FAT (File Allocation Table). The data processing apparatus includes a control unit for determining the amount of data that needs to be continuously read until the data stream to be reproduced over the read interruption time of the data stream including at least the read time of the partial FAT that is part of the FAT; In a partial area managed by one partial FAT, an area detecting unit detects a free area where data of data amount can be stored, and a recording unit for writing a data stream of content in the free area. This makes it possible to read the data stream and reconstruct the contents based on the partial FAT.

Description

Data Processing Unit {DATA PROCESSING APPARATUS}

The present invention relates to a technique for recording a data stream of a content and reproducing the content on a recording medium in which a FAT file system is constructed. More specifically, the present invention relates to a data stream recording process and a reproduction process for continuously reproducing a content such as a moving picture or audio from a data stream recorded on a recording medium.

Background Art In recent years, digital apparatuses (optical disk recorders, camcorders, and the like) capable of writing and storing digital data of content on media such as optical disks such as DVDs, magnetic disks such as hard disks, and media such as semiconductor memories have become popular. Such content is, for example, video and audio photographed by a broadcast program or a camcorder.

In recent years, the recording, reproducing, and editing functions of the contents have been implemented in the PC, and the PC can be included in the above-mentioned digital apparatus. In the PC, in order to record data such as document data, media such as a hard disk, an optical disk, a semiconductor memory and the like have conventionally been used. Therefore, in such media, a file system using a data management structure that can be linked with a PC, for example, FAT (File Allocation Table), is adopted. In the FAT32 file system which is widely used at present, a file having a size of up to 4 gigabytes per one can be handled, and a medium having a maximum recordable capacity of 2 terabytes can be managed.

With the increase in the maximum recordable capacity of the media, the total recording time of the content is getting longer. Since optical discs, hard discs, semiconductor memories and the like are so-called random-accessible media, it is convenient to be able to reproduce them from any position of the contents when storing the data stream of the contents for a long time in such media.

For example, Patent Document 1 generates time map information that defines the correspondence between a playback time and a storage address of AV data reproduced at that time at regular time intervals from the head of the data stream. The contents can be reproduced from the time by converting each of the user specified start time and end time into the start address and the end address with reference to the time map information, and reading the data stored at the address. By the way, a lot of recording media on which FAT file systems are constructed are currently sold. For example, a removable semiconductor memory (memory card) is generally managed by a FAT file system.

In a semiconductor memory, a write destination address is designated in units of 512 bytes called sectors. Each address is assigned a logical address in units of one sector.

On the other hand, in the FAT file system, the recording area is managed in units called clusters, and the use / nonuse situation is managed. For example, if the storage capacity of the semiconductor memory is 2 GB or less, the data size of one cluster is 32 sectors (that is, 16 kilobytes). In this case, a file system called FAT16 is used. On the other hand, if the storage capacity of the semiconductor memory exceeds 2 gigabytes, the data size of one cluster is 64 sectors (that is, 32 kilobytes). In this case, a file system called FAT32 is used.

When writing a data stream to such a semiconductor memory, the write speed is changed depending on the degree of continuity of the plurality of sectors to be written. For example, when the sector numbers to be written are respectively, the recording speed is lowered. The reason for this is that, for example, when both the sectors to be written and the sectors to be newly written are mixed in the same cluster, it is necessary to read the data once written, and then rewrite the recorded data and write the new data. This is because a delay in processing occurs.

On the contrary, if recording is continuously performed in a plurality of consecutive sectors or clusters, data can be written at a speed faster than the recording speed assumed for normal use.

Patent Document 1: Japanese Patent Application Laid-Open No. 11-155130

Disclosure of the Invention

Problems to be Solved by the Invention

With the recent increase in the capacity of recording media, it is assumed that various problems will occur.

For example, as the capacity of a recording medium increases, the data size of a FAT also increases according to its capacity. When the recording capacity is 32 gigabytes, the data size of the FAT may be 4 megabytes. If the device needs to read and store all of these FATs having a large data size, an appropriate internal memory is required for this, which greatly increases the manufacturing cost. In addition, the user waits for the entire reading, and the response of the device to the user's operation is deteriorated. Therefore, there is a need for an improved method of reading FAT.

In order to avoid the problem of cost, a method of reading only a part of the FAT and storing it in the cache memory can be considered. However, according to this method, the FAT table provided in the cache memory is burdened with the tracking of the FAT chain at the time of reproduction, and the possibility of continuous playback of contents cannot be increased. Specifically, if the recording position of the content data falls in the middle, it is necessary to frequently execute a process of re-registering the FAT table in the read cache memory. In particular, since the reading of the contents is stopped during the reading period of the FAT, it is conceivable that the video data / audio data accumulated in the buffer is completely reproduced. At this time, the coma drop of the moving image and the interruption of the audio occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently writing data onto a recording medium in which a FAT file system is constructed in order to enable continuous reproduction of contents and the like, and to provide an apparatus for executing the method. . Another object of the present invention is to read the data written by such a method and apparatus, and to reproduce the content without interruption.

Means to solve the problem

The data processing apparatus according to the present invention writes a data stream of content on a recording medium whose storage location of data is defined based on a FAT (File Allocation Table). The data processing apparatus is further configured to determine an amount of data that needs to be read continuously until the data stream to be reproduced over the read interruption time of the data stream including at least the read time of the partial FAT that is part of the FAT is obtained. A control unit for determining, an area detecting unit for detecting a free area in which the data of the data amount can be stored in the partial area managed by one partial FAT, and a recording unit for writing the data stream of the content in the free area. Equipped. This enables reading of the data stream and reproduction of the content based on the partial FAT.

The recording medium has a predetermined continuous data unit which can be read at a speed higher than the reproduction speed of the data stream, and the partial region is a set of the continuous data units. The area detection unit may detect the empty area including one or more of the continuous data units from the partial area.

The area detection unit may detect a free area in the partial area managed by any partial FAT.

The area detector is a blank area continuously present in the partial area, and may detect a blank area whose area length is equal to or larger than the data amount.

The area detection unit may detect a plurality of free areas in which the total value of the area length of each free area is equal to or larger than the data amount as a plurality of free spaces present discretely in the partial area.

If the transfer rate of the data read out from the continuous recording unit is Vr, the read time of the partial FAT is t, and the bit rate of the data stream to be recorded is Vo, the control unit sets the amount of data that needs to be continuously read to Vr × Vo. It is determined that xt / (Vr-Vo) or more, and the recording unit may write data of the data amount.

The area detecting unit is a free area existing in the partial area managed by one partial FAT, and the area lengths may be summed to detect the free area of the data amount.

The recording unit may write the data stream of the content to all or part of the blank area.

The recording unit may write at least one of data at the beginning of the data stream and data at the end in a part of the detected empty area.

Another data processing apparatus according to the present invention is a reproduction unit for reading a partial FAT which is a part of the FAT from a recording medium whose storage location of data is defined based on a FAT (File Allocation Table), and based on the partial FAT. And a control unit for instructing the reproduction unit to read the data stream of the content recorded on the recording medium, and a decoding unit for reproducing the content based on the read data stream. After the reading of the first data stream of a predetermined amount or more based on the first partial FAT is completed, while the reproduction processing by the decoding section is continued, the reproducing section reads the second partial FAT subsequent to the first partial FAT. The control unit instructs the reproduction unit to read the second data stream based on the second partial FAT. The predetermined amount is an amount of data required to continue reading until a data stream to be reproduced over the read interruption time of the data stream including at least the read time of the second partial FAT is secured.

The recording medium has a predetermined continuous data unit which can be read at a speed higher than a reproduction speed of the data stream, and each partial area managed based on the first partial FAT and the second partial FAT includes the continuous data unit. Is a set of. The control unit may instruct the reproduction unit to read the data stream based on the partial FAT, and the reproduction unit may read the data stream at a speed equal to or higher than the reproduction speed of the data stream.

(Effects of the Invention)

According to the present invention, assuming that the FAT is read in units of a part thereof, data is written to the recording medium. That is, the recording apparatus calculates the data amount of the content to be reproduced over the time required to read a part (partial FAT) of the FAT, and stores a data area of the data in the recording area of the recording medium. Is detected. Then, the data stream of the content is written in the blank area. The free area is reserved in the partial area managed by one partial FAT.

As a result, even if the FAT alternately reads the partial data and reads the data stream, the data necessary for the reproduction processing can be securely ensured. Therefore, the content can be continuously played back from the data stream without interruption. In addition, since the FAT can be read out little by little, the memory capacity for retaining the FAT may be very small compared with the data capacity for retaining the FAT entirely on the memory. As a result, the cost of the buffer memory required for the device can be reduced.

In addition, compared with the case where all FATs are read once and the reproduction processing is started, a part of the FATs may be read, so that the waiting time of the user can be significantly reduced.

1 is a diagram showing the configuration of a recorder 10 according to the first embodiment;

2 is a diagram showing a data management structure of the memory card 130;

3 is a diagram showing data management of a FAT file system in the memory card 130;

4 is a diagram showing an example of the hierarchical structure of the file system of the memory card 130;

5 shows the data structure of a data stream file 2 0;

6 is a diagram illustrating an example of management information of a program stream;

7 shows a reproduction model of a data stream using the buffer memory 71 and the decoder 72;

FIG. 8 is a diagram showing a time transition of the amount of data stored in the buffer memory 71 when the reproduction model shown in FIG. 7 is used;

9 is a diagram showing an example of conditions for securing a free area at the time of moving picture recording;

10 is a flowchart showing a procedure of initialization processing for the memory card at the time of startup of the recorder 10;

11 is a flowchart showing a procedure of recording processing of the recorder 10;

12 is a diagram showing an example of data arrangement in the memory card 130 after the recording process;

13 is a flowchart showing a procedure of a reproduction process of the recorder 10;

14 is a diagram showing a recording model of data in each embodiment;

FIG. 15 is a diagram showing a transition example of the amount of data stored on the buffer memory 74 of the recording model shown in FIG. 14;

16 is a flowchart showing the procedure of recording processing by the recording control unit 161 according to the second embodiment;

17 is a diagram showing an example of a recording position and a data size of a data stream according to the third embodiment;

18 is a diagram showing a configuration in which a memory for storing a partial FAT is provided;

19 shows an example of a relationship between a partial FAT and a memory space;

20 is a diagram showing another example of the relationship between the partial FAT and the memory space.

Explanation of the sign

10: recorder

100: video signal input unit

101: video compression unit

102: voice signal input unit

103: voice compression unit

104: system encoding unit

110: video signal output unit

111: image extension

112: audio signal output unit

113: voice extension

114: system decode section

120: record

121: playback unit

130: removable memory card

160: continuous data area detection unit

161: recording control unit

162: playback control unit

163: logical block management unit

164: edit control unit

170: MPEG encoder

171: MPEG Decoder

175: media control unit

180: system control unit

181: CPU

182: ROM

183: RAM

Implement the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, the Example of the data processing apparatus which concerns on this invention is described, referring an accompanying drawing.

1 shows the configuration of the recorder 10 according to the present embodiment. The recorder writes a data stream (video stream) of a moving picture including video and audio onto the memory card 130 (recording function), reads the video stream written on the memory card 130, and reproduces the moving picture. Function (playback function) and a function (edit function) for editing the moving picture stream written in the memory card 130. The recorder 10 is, for example, a stationary recording device for recording a portable camcorder, a television program, or the like.

Hereinafter, the components of the recorder 10 will be described. The recorder 10 includes a video signal input unit 100, an audio signal input unit 102, a video signal output unit 110, an audio signal output unit 112, an MPEG encoder 170, and an MPEG decoder 171. ), A media control unit 175, a system control unit 180, and a CPU 181.

The memory card 130 is inserted into the recorder 10 in a detachable form so that a moving picture can be recorded on the memory card 130. In addition, the memory card 130 is not an essential component of the recorder 10.

The video signal input unit 100 is, for example, a video input terminal (not shown) connected to a CCD camera or an antenna (not shown). The audio signal input unit 102 is, for example, a voice input terminal (not shown) connected to a microphone or an antenna (not shown).

The MPEG encoder 170 (hereinafter referred to as "encoder 170") has a video compression unit 101, an audio compression unit 103, and a system encoder 104. The video compression unit 101 receives a video signal from the video signal input unit 100 and compressively encodes the video signal based on the MPEG standard. The audio compression unit 103 receives the video signal from the audio signal input unit 102 and encodes (compresses) the signal based on the MPEG standard. As a result, video data and audio data are output.

The system encoder 104 interleaves the video data and the audio data to generate a moving picture stream. More specifically, the system encoder 104 generates a packet storing video data and audio data, respectively, and arranges the packets to generate a moving picture stream. At this time, further data (character data, management information, etc.) can also be packetized and arranged as part of the moving picture stream.

The media control unit 175 has a recording unit 120 and a playback unit 121, and controls the writing and reading of moving picture streams and other data to the memory card 130, respectively.

In this embodiment, the memory card 130 is assumed to be a recording medium conforming to a standard such as an SD memory card. The moving picture stream written to the memory card 130 is assumed to be a program stream conforming to the MPEG2 standard. The program stream is composed of fixed-length data units called "packs." A "pack" is known as one exemplary form of packet. The configuration of the memory card 130 and the data structure of the program stream will be described later in detail with reference to Figs.

The other component of the recorder 10 is demonstrated. The MPEG decoder 171 (hereinafter referred to as "decoder 171") has a video expansion unit 111, an audio expansion unit 113, and a system decoder 114. In the order of processing, the system decoding unit 114 separates the moving picture stream, that is, the program stream according to the type of packet, sends the packet of the video data to the video decompression unit 111, and audio-extends the packet of the audio data. Send to section 113. The image extending unit 111 decompresses the video data based on the MPEG standard and sends the video data to the image signal output unit 110. The voice decompression unit 113 decompresses the audio data based on the MPEG standard or the like and sends it to the voice signal output unit 112.

The video signal output unit 110 is, for example, a terminal for outputting a video signal when the recorder 10 is a camcorder and a liquid crystal display screen when the recorder is a recorder. The audio signal output unit 112 is, for example, a terminal for outputting a speaker or an audio signal.

The system control unit 180 has a CPU 181, a ROM 182, and a RAM 183. The CPU 181 can realize various functions by, for example, reading a computer program stored in the ROM 182, expanding it on the RAM 183, and executing it. For example, the CPU 181 functions as the continuous data area detection unit 160, the recording control unit 161, the reproduction control unit 162, the logical block management unit 163, and the editing control unit 164. In the following, each function realized by the CPU 181 is treated as an independent component. The transfer of data between each component corresponds to the data exchange between programs.

Before the recording control unit 161 starts recording of the program stream, the recording control unit 161 activates the continuous data area detection unit (hereinafter referred to as "area detection unit") 160 to search for an empty area. The area detection unit 160 searches for a continuous free area from the free area management table created in the initialization process by using the FAT read from the memory card 130 in advance. Then, recording of the program stream is started on the free area detected as a result of the search. Until the writing of the program stream into the detected free area is completed, the next free area is continuously searched to continue recording the program stream.

When the user selects the content to be played back during playback, the playback control unit 162 controls the management information of the program stream corresponding to the content to be read from the management file via the playback unit 121. The program stream is further read with reference to the address information described in the management file. The program stream is separated into a video signal and an audio signal by the system decoder 114, and each of them is passed through the video extension 111 and the audio extension 113 to the video signal output unit 110 and the audio signal output unit ( To 112).

When editing a moving image, the editing control unit 164 receives, for example, an editing instruction for a part of the recorded content from the user. At this time, the editing control unit 164 instructs the reproduction unit 121 to read the editing target portion of the data stream or its management data. For example, in editing to delete a part of content, the editing control unit 164 specifies a part to be deleted from the read data and deletes the part. The editing control unit 164 instructs the recording unit 120 to write data left undeleted or its management data to the memory card 130.

2 and 3, a data management structure and a logical structure of the memory card 130 will be described. 4 to 6, an example of the data structure of the data stream written to the memory card 130 will be described.

2 shows a data management structure of the memory card 130. In the present embodiment, the memory card 130 has a recording capacity of 32 gigabytes, and it is explained that the file is managed by the FAT32 file system.

In the memory card 130, the smallest unit in which data can be written and read is the sector 131. An address is assigned to each sector 131, and a sector can be uniquely identified using the address. The data size of each sector 131 is 512 bytes.

A plurality of sectors 131 are integrated to form a cluster 132 called a logical block. The cluster 132 is a management unit of the free area and is a writing / reading unit of the area. It is assumed that the number of sectors constituting the cluster 132, in other words, the data size of the cluster 132 is determined according to the recording capacity of the memory card. For example, when the recording capacity of the memory card 130 is 1 gigabyte or less, the data size of one cluster is 16 kilobytes, and when it exceeds 1 gigabyte, it is assumed that it is 32 kilobytes. In this embodiment, one cluster is composed of 64 sectors, and its data size is 32 kilobytes.

In addition, a continuous recording unit 133 is defined in the memory card 130. The continuous recording unit 133 is a data unit to be accessed as a contiguous sector or a contiguous cluster region designated by the memory card 130 as a condition that can achieve its write performance value. The data size of the continuous recording unit 133 can be determined in advance, for example, and is held in a predetermined register (not shown) in the card. In the present embodiment, the continuous recording unit 133 is composed of two consecutive clusters, and the data size thereof is 64 kilobytes.

The memory card 130 also defines a continuous playback unit. The continuous playback unit is a data unit that the memory card 130 should access as a continuous sector or a continuous cluster area, which has designated the read performance value as a condition that can be achieved. The data size of the continuous playback unit can be determined in advance, for example, or is held in a predetermined register (not shown) in the card or is determined in advance. In this embodiment, the continuous playback unit is assumed to have a continuous data size of 16 kilobytes. Moreover, in general, the writing speed is slower than the reading speed, so that the continuous recording unit often has a larger data size than the continuous reproduction unit.

In the memory card 130, it is assumed that a value of a data read time of four sectors or eight sectors of an arbitrary logical address is predetermined, for example, held in a predetermined register in the card. This is especially necessary to ensure partial read speed of directory entries or FATs.

The memory card 130 is also determined in advance that the value of the write buffer size is also held in a predetermined register in the card. In addition, it is assumed that the processing time until the data write processing for this buffer size is completed is also predetermined, and is held in a register inside the memory card.

The recording area of the memory card 130 composed of continuous clusters of at least the data size of the continuous recording unit 133 is called a continuous recording area. The data size of the continuous recording unit is said to be in the range of 16 kilobytes to 2 megabytes depending on the performance of the memory card.

3 shows data management of the FAT16 file system in the memory card 130. First, the configuration of the recording area of the memory card 130 will be described. The memory card 130 has a boot record area 135, a FAT area 136, a directory management area 137, and a data area 138.

In the boot record area 135, for example, a boot record of an OS, information of a file system type for each partition, and the like are stored. The information recorded on the memory card is recorded as a file of an arbitrary directory, and the directory constitutes a hierarchical structure consisting of an arbitrary tree structure with the root directory as the vertex.

There are two FATs (FAT1 and FAT2) in the FAT area 136. FAT2 is a copy of FAT1 and is provided as a spare. Each FAT is defined as a table of cluster numbers. The cluster number set in the FAT is called a FAT entry.

In the directory management area 137, data of the root directory is recorded. If a subdirectory exists, the data of that subdirectory is recorded in the data area 138. Referring to the directory data 140 shown in FIG. 3 as an example, the directory data 140 is configured as a table of one or more directory entries. Each directory entry has fields for storing a file name, an extension, a file attribute, an update time, a file size, a storage destination cluster number, and the like, respectively. In FIG. 3, a file name field 141 indicating the contents of the written data and a head cluster number field 142 are shown.

Finally, in the data area 138 of the memory card 130, data of the directory management area of the directory lower than the root and the contents of the file are written.

The procedure for reading the file "xxx.yyy" is described below using FAT. First, with reference to each directory data in the directory management area 137, the entry file name field 141 in which "xxx.yyy" is described is specified. Then, the value is read from the head cluster number field 142 corresponding to the field 141. In this example, the head cluster number value is "2". This value indicates that data at the head of the file "xxx.yyy" is written in the cluster "2". Therefore, reading of data from the cluster is started.

Next, FAT1 is referred to, and a table value corresponding to cluster 2 is obtained. In the example shown in FIG. 3, the table value of the position shown by the arrow is referenced, and "3" is acquired. This value represents the cluster number value in which consecutive data is stored. Therefore, what is necessary is just to read the data of cluster "3" next. Subsequently, with reference to FAT1, table value "4" corresponding to cluster 3 is obtained, and data is read from cluster "4". When a predetermined table value ("FFFF" in Fig. 3) appears, it indicates that the cluster is the last cluster of the file "xxx.yyy".

As described above, when the FAT is traced, it is specified in what order the cluster storing the data of the file should be read. In other words, the FAT manages the relationship of data distributed in a plurality of clusters. As is apparent from the above description, in the FAT file system, a file is managed using two directories and a FAT.

4 to 6, an example of the data structure of the data stream written to the memory card 130 will be described.

4 shows an example of the hierarchical structure of the file system of the memory card 130. In this example, a subdirectory DVD_RTAV is provided under the root directory ROOT. It is assumed that a management file and a data stream file are stored in the subdirectory.

As shown in Fig. 4, for example, the management file for the data stream VRMOV001.MPG is VRMAN001.IFO. Similarly, the management file for the data stream VRMOV002.MPG is VRMAN002.IFO.

The directory structure shown in FIG. 4 is reflected in the directory management area 137 of the memory card 130 described in FIG. In addition, the order in which data constituting each file is written into the cluster is specified based on FAT1.

Hereinafter, the data structure of the data stream file will be described with reference to FIG. 5. After that, the data structure of the management file will be described with reference to FIG.

5 shows the data structure of the data stream file 20. In this embodiment, the data stream is a program stream of MPEG2 standard. The data structure described below is based on the DVD video recording standard for recording moving pictures on an optical disc such as a DVD-RAM or a DVD-RW. In this DVD video recording standard, only one stream file and one management file are defined. However, as shown in Fig. 4, in this embodiment, one stream file and a management file related thereto are recorded each time recording is started and stopped.

The data stream file 20 contains a plurality of VOBs (Video Objects) shown in the MPEG program stream 21, for example. Each VOB is composed of one or more video object units (hereinafter referred to as "VOBU").

Each VOBU is composed of a pack, which is a lower layer of an MPEG program stream in units of 2048 bytes, and contains 0.4 to 1 second of data as a video playback time.

Hereinafter, the VOBU 22 will be described as an example. The VOBU 22 includes two types of a video pack (V_PCK) 23 in which compressed video data is stored, and an audio pack (A_PCK) 24 in which compressed audio data is stored. When the video data of all the video packs (V_PCK) 23 in the VOBU 22 is reproduced, the above-described video of 0.4 to 1 second is obtained. In addition, the audio data in the VOBU 22 is used for decoding each audio frame. Data of one voice frame is not stored beyond the VOBU boundary.

The real-time data information pack (RDI_PCK) may be recorded at the head of each VOBU. In the RDI pack, management information (for example, letter box information) for managing reproduction is stored as necessary.

The program stream 21 stores time information such as system time reference SCR, video / audio decoding time information (DTS), and output time information (PTS). The system time reference SCR is used to set a reference value in the STC register of the playback apparatus. Based on this reference value, a synchronization signal STC is generated, and video and audio are decoded at timings at which the value of the synchronization signal STC and the value of the decode time information DTS coincide with each other. The video and audio are output at timings at which the value of the synchronization signal STC and the value of the output time information PTS coincide. In the present embodiment, it is assumed that the values of the system time reference SCR, video decoding time information DTS, and output time information PTS in one continuous program stream VOB are continuously changed at predetermined cycles. .

The video pack 23 at the head of each VOBU includes a pack header 25 and pack data (video data) 26. The video data 26 also includes a sequence header 28, a GOP header 29, and compressed I picture data 30. In the figure, another PES header and P picture frame data 31 are shown.

In addition, the data size of I picture data is generally large and may exceed 2048 bytes significantly. Therefore, in most cases, only part of the I picture data (for example, the head part) is stored in the video data 26.

A plurality of pictures from the I picture 32 to the picture 33 constitute one GOP (Group Of Picture). A GOP is a playback unit in which a plurality of video frames including a P picture and / or a B picture, up to an I picture 32 that is a video frame that can be reproduced alone and a picture 33 immediately before the next I picture, are integrated. to be.

Next, the data structure of the management file will be described with reference to FIG. 6 shows an example of management information of a program stream. Management information is generated for each VOBU. According to FIG. 6, it is shown that management information exists corresponding to each VOBU.

As the management information, the VOBU data size of each VOBU, the address offset value of the pack including the I picture end of the head of the VOBU, and the number of video fields included in the VOBU are specified. As apparent from Fig. 5, when there are a plurality of VOBs, a set of management information shown in Fig. 6 exists in accordance with the number of VOBs.

Next, the process of the recorder 10 will be described. The recorder 10 according to the present embodiment writes the data stream of the moving image to the memory card 130 in consideration of the reproduction processing. Thus, the following describes the playback process for establishing a playback process first, and then ensuring that playback of content is not interrupted by such playback process.

7 shows a reproduction model of a data stream using the buffer memory 71 and the decoder 72. The buffer memory 71 corresponds to the memory in the buffer memory shown in FIG. 1, and the decoders 72 correspond to the decoder 171 shown in FIG. 1, respectively. However, the MPEG decoder 171 may have a memory corresponding to the buffer memory 71 therein.

The data read rate from the memory card 130 to the buffer memory 71 is now Vr, and the maximum data transfer rate (maximum reproduction rate) from the buffer memory 71 to the decoder 72 is Vo.

FIG. 8 shows the worst case time transition of the amount of data stored in the buffer memory 71 when the reproduction model shown in FIG. 7 is used. The vertical axis represents the data amount and the horizontal axis represents the time.

In the reproduction processing according to the present embodiment, not all the FATs are read from the memory card 130 at the start of reproduction, but a part thereof is read. This is because, for example, in the 32-gigabyte memory card 130, since the data size of the FAT may be 4 megabytes, the cost increases if the recorder 10 provides a memory for holding such a FAT. In addition, at the start of the reproduction processing, the user is waited for the entire reading, and the response of the device to the user's operation is deteriorated. The start of the playback process is, for example, when the user turns on the power of the recorder 10 and selects the playback mode according to the selection of a mode switch (not shown). In parallel with the process, all the readings of the FAT are assumed, since the card access is not concentrated at the start of the recording process as compared with the start of the playback process).

In the following description, a part of the FAT to be read is called "partial FAT". The data size of the partial FAT is, for example, 4 kilobytes. 4 kilobytes is 8 sectors of data.

In the reproduction processing, reading of the 4-kilobyte partial FAT and reading of the data stream from the cluster managed by the partial FAT are alternately performed. Then, the decoder 72 receives and decodes the read data stream so that video, audio, and the like are reproduced.

In the recording area managed by the 4-kilobyte partial FAT, since the memory card is managed by FAT32 and the data size of the partial FAT is 4 kilobytes, 1 cluster size x (4 kilobytes / 4) = 32 kilobytes x 1024 = 32 megabytes. In the following description, the recording area managed by this partial FAT is called a window, and its size is called a window size.

Referring to Fig. 8, the section a after the start of the reproduction process corresponds to the reading time of the partial FAT before the start of decoding (the maximum values of the sections a, c, and e are equivalent and are all expressed as t _FR ). The interval b then corresponds to the read time of the data stream based on the partial FAT. The time length of the interval b is represented as t _S.

In the section b, the buffer memory 71 sends the already stored data stream to the decoder 72 and at the same time accumulates the data stream from the memory card 130. Therefore, the data stream is accumulated in the buffer memory 71 at the speed of Vr-Vo. The data stream read from the memory card 130 is stored in a window managed by the partial FAT.

The interval c corresponds to the read time of the next partial FAT. The time length of the interval c is equal to the time length of the previous interval a.

In the section c, the buffer memory 71 only transmits the data stream to the decoder 72 and does not accumulate the data stream from the memory card 130. Therefore, the amount of data accumulated in the buffer memory 71 decreases at the speed of Vo. The interval d, the interval e, and the subsequent times are the repetitions of the interval b and the interval c, and the times of t _S and t _FR are required.

Note the section c here. In the period c, the amount of data in the buffer memory 71 decreases at the speed of Vo, so that the data amount in the buffer memory 71 becomes zero at the same time as the end of the period c so as not to interrupt the reproduction of the content. The amount of data needs to remain. Therefore, at the start time of the section c (that is, the end time of the section b), the buffer memory 71 needs to accumulate at least the data amount corresponding to (Vo x t _FR ). For that purpose, the data of the data amount must be stored continuously or discretely in a window managed by the already read partial FAT.

Explaining using the equation, Vo × t _FR is

It can be obtained as By this,

Can be obtained. Therefore, the continuous read data amount SR is

Is applied.

As a result, at the time of recording the data stream, it can be said that at least a free area of the data amount SR described above can be secured and written in the window by each partial FAT. The recorder 10 according to the present embodiment finds such a blank area and writes data. As a result, even if the FAT is read in units of partial FATs, the content can be reproduced without interruption.

The minimum structural unit of the empty area is the above-described 16 kilobyte continuous playback unit. In this embodiment, it is assumed that the read speed of Vr is assured when data is written by securing a continuous playback unit of this size.

Hereinafter, a specific example is given and described. 7 and 8, the transfer rate Vr from the memory card 130 to the buffer memory 71 is 4 megabytes / second, and the maximum transfer rate Vo from the buffer memory 71 to the decoder 72 is 30. In terms of megabits / second, t _FR is referred to as 4 ms.

Then, according to the equations (1) to (3), SR = 246 kilobytes. Therefore, if there is a free area of at least 246 kilobytes or more in one window area, the content can be reproduced without interruption under the above-described conditions. However, in the present embodiment, since a margin of processing is provided, if a free area of 1 megabyte or more remains, the data stream may be written.

9 shows an example of a condition for securing a free area at the time of moving picture recording. In the recording area (logical address space) of the memory card 130, the recorder 10 is free of a predetermined amount (e.g., 1 megabyte in total) of an area capable of storing data in a window 90 having a size of 32 megabytes. If so, it is determined that recording is possible, and the streams are sequentially written to the area.

As long as the total size of the free area is 1 megabyte, either of the continuous playback unit or the continuous recording unit may be configured (of which FIG. 9 shows an example in which the continuous recording unit constitutes 1 megabyte or more in total). . Moreover, not all of them may be arranged continuously. That is, as the two empty areas 91 and 92 of FIG. 9 are shown, a set of continuous recording units may exist discretely in the window. The reason is that in the window 90 managed by the partial FAT, there is no need to read another partial FAT, and the processing delay for trapping the FAT does not substantially occur.

Since there are many kinds of memory cards, there are also some write / read speeds slower than those of the memory card of this embodiment. In such a memory card, in order to guarantee a writing speed of 4 megabytes per second in real time, a data length longer than the data length (64 kilobytes) of the above-described continuous recording unit must be adopted. For example, the recording length (minimum continuous recording length) of the continuous recording unit needs to be about 640 kilobytes.

Hereinafter, the specific processing at the time of recording of the recorder 10 according to the present embodiment will be described in detail. First, the starting process of the recorder 10 will be described with reference to FIG. 10, and then the recording process will be described with reference to FIG.

10 shows the procedure of the initialization process relating to the memory card at the start of the record process of the recorder 10. The start of the recording process is, for example, when the user turns on the recorder 10 and selects the recording mode by selection of a mode switch (not shown). The logical block management unit 163 of the recorder 10 instructs the reproduction unit 121 to read all FAT1 of the memory card 130. Based on FAT1, the logical block manager 163 generates a free area management table indicating the condition of free areas for all clusters. More specifically, the logical block management unit 163 generates an empty area management table in which an empty cluster is set to a value of 1, a cluster in use is 0, and compressed into 1 bit per cluster. This generation process is performed sequentially while reading the partial FAT. This free area management table is held in the RAM 183. As a result, the entire size of FAT1 is compressed and stored 1/32 times. At the time of moving picture recording, the area detection unit 160 detects the free area by referring to this free area management table.

Next, the recording process of the recorder 10 will be described. In the recording process, the recorder 10 presumes that the information of the size of the partial FAT read at the time of reproduction and the information of the time required to read the partial FAT are obtained from the register of the memory card 130.

11 shows a procedure of recording processing of the recorder 10. When the user receives an instruction to start moving picture recording, the recording control unit 161 and the area detection unit 160 operate to detect an empty area (S100). Specifically, the recording control unit 161 calculates the data amount of the content to be reproduced over the time required for reading the partial FAT. The data amount is 1 megabyte as described so far. In doing so, the area detection unit 160 searches the empty area management table and detects at least one window including a total of one or more empty areas in one window (32 megabytes) (S100).

Next, the recording control unit 161 starts the MPEG encoder 170 and the recording unit 120 (S110), and starts writing the data stream into the detected empty area (S120). In addition, although the process of actually writing is performed by the recording part 120 based on the instruction | indication from the recording control part 161, it is described below as what the recording control part 161 writes for convenience of description.

If the user continues recording (NO in S130) and if it is possible to add to the area being written (YES in S140), the recording control unit 161 continues to write the data stream in the area (S120). . On the other hand, if it is determined that the addition is impossible (No in S140), the area detection unit 160 detects the next empty area (S150). At this time, the conditions of the empty area to be detected are the same as in S100. The recording control unit 161 writes the data stream using the newly detected free area as the next recording destination (S120).

When the user performs a recording stop operation and instructs a stop (YES in S130), the recording control unit 161 writes the data stream remaining on the temporary memory into the memory card without writing (S160).

Subsequently, data of the management data file VRMAN001.IFO is written to the memory card 130 (S170). Then, all FAT1 corresponding to the area where the data files of VRMOV001.MPG and VRMAN001.IFO are written are read out (S180). For example, if the data stream is 2 gigabytes, the FAT of the corresponding FAT32 file system is at least 256 kilobytes.

Next, in order to reflect the situation of the cluster in which the data stream has been written and is in use, the recording control unit 161 stores FAT information (FAT chain) corresponding to VRMOV001.MPG and VRMAN001.IFO on the FAT. The directory entry is written (S190). This completes the recording process.

12 shows an example of data arrangement in the memory card 130 after the recording process. In the memory card 130, the logical addresses are stored in descending order from the boot record, the FAT1, the FAT2, the data area of the root directory, and the data area of the DVD_RTAV directory. In addition, on the subsequent logical address, a data stream file, a management file of the data stream, and the like are recorded. The DVD_RTAV directory stores directory entries such as a VRMOV001.MPG file and a VRMAN002.IFO file.

The recording area shown as window # 1 of the memory card 130 includes a use area, an area in which some data # 001 of the moving image file VRMOV001.MPG is stored, and another use area. The data size of the area in which the data of the moving image file is stored is 1 megabyte or more. As described above, this area may exist discretely in the window # 1.

The recording area shown as window # 100 is composed of a use area, a part of data # 100 of the moving image file (VRMOV001.MPG), a VRMAN001.IFO file, and an unused area. Moreover, although the data of a moving image file is divided and stored into # 1-# 100, this is an example. This number changes depending on the file size (all data amounts in the data stream).

Next, a process of reading the data stream written to the memory card 130 by the above-described recording process and reproducing contents such as video and audio will be described.

13 shows a procedure of the reproduction process of the recorder 10. First, the reproduction control unit 162 reads the directory entry of the data stream file selected by the user (S300). Incidentally, the actual reading process is performed by the reproducing unit 121 based on the instruction from the reproducing control unit 162. Hereinafter, the reproducing control unit 162 reads for convenience of description.

Next, the reproduction control unit 162 reads the partial FAT of 4 kilobytes (S310). This partial FAT manages a cluster for storing the leading part of the data stream stored in the read directory entry.

Next, the reproduction control unit 162 reads out the continuous recording unit for storing the data stream by a predetermined number from the window area corresponding to the 4-kilobyte FAT (S320) and stores it in the temporary memory (S320). Then, playback is instructed to the decoder 171 (S330). The amount of data to be read before the start of reproduction is, for example, an amount equal to or larger than the size in which the amount of video data equal to or larger than the VBV buffer size is accumulated on the temporary memory.

The reproduction control unit 162 selects and reads one continuous recording unit in which the data stream is stored from within the window area managed by the partial FAT. In this case, the decoder 171 starts decoding, thereby starting the reproduction of the content (S340).

Subsequently, the reproduction control unit 162 further tracks the FAT chain by referring to the FAT to detect the cluster number corresponding to the next continuous recording unit (S350). If the end of the data stream being read has not been reached (NO in S360), the reproduction control section 162 checks whether there are any continuous recording units not yet read in the window (S370). If it remains (NO in S370), it continues reading (S340). If not remaining (YES in S370), the FAT chain is traced to read a partial FAT for the next 4 kilobytes (S380), and one continuous data stream is stored in the window area managed by the partial FAT. The recording unit is continuously read (S340).

On the other hand, if the end of the data stream has not been reached continuously (YES in S360), the reading of data ends. After the reproducing process of the data read so far is finished, the reproducing process is stopped (S390).

According to the reproduction processing described above, even if the recorder 10 alternately reads the partial data of the FAT and the data stream, the desired transfer speed required for the reproduction processing can be ensured. As a result, content can be continuously played back from the data stream without interruption.

Since the FAT can be read out little by little, the memory capacity for retaining the read FAT should be secured at least by the read size. Therefore, a very small memory capacity is sufficient as compared with the data capacity for holding the entire FAT. For example, a 32-gigabyte memory card can be reduced to 512 bytes as compared to 4 megabytes. As a result, the cost of the memory required for the recorder 10 can be reduced.

In addition, compared with the case where all FATs are read once and the reproduction processing is started, only a part of FATs can be read, so that the waiting time of the user can be significantly reduced. For example, in the case of a 32-gigabyte memory card, it can be reduced to a state of 0.01 seconds, compared to reading a 4-megabyte FAT in 3 seconds.

By adopting the above-described process, the playback apparatus can play back the content without interruption regardless of the maker. In addition, even a large capacity memory card or a relatively low performance memory card, continuous playback is easy to be realized.

In addition, the window area mentioned above can be set on arbitrary data addresses. Since it is determined whether or not to write data based on the total size of the free areas in each window area, even if the free areas are discrete in each window area, those areas can be effectively utilized.

The processing according to the present embodiment is also applicable to the writing and reproduction of a plurality of data streams. In this case, however, it should be noted that the total data size of the free area to be secured in the window size increases. The calculation method conforms to the above-mentioned equations 1 to 3.

The method of reading a FAT by dividing it into partial FATs according to the present embodiment is fundamentally different from the conventional method of reading out a FAT and then starting to read a moving image stream. The apparatus may be configured to cope with both the reading method according to the present embodiment and the reading method according to the conventional FAT file system. At this time, the identification information may be provided so that the apparatus can adopt a more appropriate reading method. For example, when a moving picture stream has been recorded assuming a reproduction method according to the present embodiment, the apparatus may separately describe a management file in the card including identification information indicating the same. By this method, the playback apparatus can determine whether to reproduce the contents by partially reading the FAT or reading the FAT collectively in accordance with the presence or absence of the identification information. In addition, the read size of the assumed partial FAT may be described separately.

(Example 2)

The difference between the present embodiment and the first embodiment is that FAT information is written during recording of the data stream, and that the size of the blank area required in the window area is increased. In the latter case, it is 1 megabyte in Example 1, but is 8 megabytes in this example.

In addition, the structure of the recorder which concerns on a present Example is the same as the recorder 10 which concerns on Example 1, unless there is particular notice.

14 shows a recording model of data in this embodiment. It is assumed that the encoder 73 corresponds to the encoder 170 shown in FIG. 1, and the buffer memory 74 is included in the recording unit 120. However, the encoder 170 may have a memory corresponding to the buffer memory 74 therein. It is assumed that the recorder 10 shown in FIG. 14 also satisfies the recorder 10 of the first embodiment which performs recording based on, for example, the MPEG standard.

The data stream generated by the encoder 73 is input to the buffer memory 74 at the maximum speed Vi. The data stream is then written from the buffer memory 74 to the memory card 130 at a speed Vw or higher.

FIG. 15 shows an example of transition of the amount of data stored on the buffer memory 74 of the recording model shown in FIG. At the same time as the start of the recording process, the data stream is written to the memory card (section a) for at least the continuous recording time t, and then a portion of FAT1 (for 4 kilobytes) that needs to be updated of the data stream file, and the directory entry information. Read a portion (for 4 kilobytes) (section b). Then, the FAT information (the update required portion of FAT1, the update required portion of FAT2, and the directory entry) of the data stream file is updated (section c). If the window boundary is crossed immediately after the writing of a very small amount of data stream after the interval c (not shown), the FAT information of the data stream file (parts required to update the FAT, FAT2) is repeated as in the intervals d and e. Update required portion, and directory entry). In the next continuous writing section f, the data stream in the buffer memory is reduced at the rate of Vw-Vi. Thereafter, the sections b to f appear repeatedly.

16 shows the procedure of recording processing by the recording control unit 161 according to the present embodiment. Compared with FIG. 11 regarding Embodiment 1, steps S410, S420, S430, S440, S460, S470, S480, and S490 of FIG. 16 are the same as those of FIG. On the other hand, in steps S400 and S450, a difference of detecting an 8 megabyte free area among 32 megabyte window areas is different.

In addition, steps S500 to S550 in FIG. 16 are also different from the processing shown in FIG. Specifically, after writing the data stream (S420), when 8 megabytes of continuous writing is completed (YES in S500), the FAT1 corresponding to the window area and the directory entry DIR are read out (S510). Next, using the data read in step S510, the FAT1, FAT2, and directory entries of the data stream file (VRMOV001.MPG) are updated to reflect the data size, recording time, FAT chain, etc., recorded on the memory card ( S520).

If writing is possible in the window (YES in S440), writing is continued. If it is impossible to record in the window (No in S530, No in S440), the FAT information of the data stream file is updated as in steps S510 and S520 (S540 and S550).

In addition, in order to determine whether 8MB of data has been written in step S500, when the step S510 or step S540 is completed, the total of the written data streams may be reset to zero.

In the above configuration, the minimum data size required in the window area is the maximum transfer rate Vi = 30 megabits / sec from the encoder to the buffer memory in FIG. 16, and the transfer rate Vw = 4 from the buffer memory to the memory card. Megabytes / sec, FAT1 per 4 kilobytes, or read speed tFR = 4 milliseconds for directory entries, total write time tFW = 110 milliseconds for FAT1, FAT2, and directory entries, as shown in FIG. When the continuous writing time is t _s and the continuous writing data size is SW, the following relationship is established.

From this,

therefore,

It becomes This results in Sw = 7.96 megabytes <8 megabytes.

Therefore, if the write operation is continuously performed for 8 megabytes in one window area, the data stream can be written while updating the FAT information of the data stream. At the same time, one megabyte or more of data streams of the first embodiment may also exist in the window size, and continuous reading is possible by the same playback process as in the first embodiment.

In the present embodiment, the FAT information is updated during the recording of the data stream. However, the present invention is not limited thereto, and may be assumed to write or reproduce another data stream. Also, writing or reproduction of a plurality of data streams may be performed. In this case, however, the total data size of the free area to be secured in the window size becomes larger.

In addition, when the data size Sw that needs to be continuously written is smaller than the continuous recording unit for guaranteeing the transmission speed Vw determined by the performance of the card, the data that must be continuously recorded for the value of the continuous recording unit It is good to make size.

(Example 3)

In this embodiment, a modification of the data storage method will be described. Except that there is no description, either the recorder according to the first embodiment or the recorder according to the second embodiment may be used.

17 shows an example of the recording position and data size of a data stream according to the present embodiment. Part (a) of FIG. 17 shows a FAT that defines the relationship of data between windows, and part (b) shows the relationship between the window area and the data size in the area.

The data stream is divided into windows # 1 to # 10 and recorded. Windows # 1 contains 20 kilobytes of data streams. A total of 8 megabytes or more of data streams are recorded in the windows # 1 to # 9, respectively. In Windows # 10, a 50 kilobyte data stream is stored.

In Examples 1 and 2, it is assumed that at least the continuous recording unit stores a data stream. However, in the present embodiment, data need not be stored in all the continuous recording units with respect to the window in which the data of the head of the data stream file is stored. For example, when the continuous recording unit is 64 kilobytes, the window # 1 may be 32 kilobytes which cannot fill the 64 kilobytes.

However, assuming that the data stream head exists in a state where the data stream head does not fill in the continuous recording unit outside the window area in this manner, the following processing is required. In other words, it is necessary to read many data streams into the buffer memory shown in Fig. 14 before starting decoding of data for reproduction processing. The purpose is to ensure that the buffer memory does not underflow during one reading time of the partial FAT. For example, it is sufficient to start decoding after reading Vo × t _FR data in Example 1 before starting decoding.

If the data does not need to be stored in all the continuous recording units in the window, the head of the data stream file is suitable in the following cases. That is, a case of dividing a data stream file into two files or a case of forward deleting. In these cases, the data streams before and after the split point may not fill the total data size in one window area by the division process and the forward erase process. In the splitting process, the cluster including the splitting point includes the splitting point as a data stream file before the splitting point or as a data stream file after the splitting point. After copying the required portion of the cluster, it needs to be included as part of at least either file (part before or after the splitting point).

Similarly, the window area including the head portion of the data stream file does not need to contain a predetermined amount of data (1 megabyte of Example 1 or 8 megabytes of Example 2). Also in this case, when the division processing and the forward deletion processing are assumed, some correspondence is required in the reproduction processing. That is, before starting the data decoding process, it is necessary to read many data streams in the buffer memory shown in Fig. 7 so that the buffer memory does not underflow even if one partial FAT is read.

With the above configuration, it is possible to easily complete the division process, and it is possible to easily ensure continuous reproduction even in the data stream file after the division.

Similarly with regard to the window storing data at the end of the data stream file, the data need not be stored in all the continuous recording units in the empty area. For example, the data stream does not have to be recorded after halfway through the free area. This is because the data size of the data stream becomes an arbitrary data size, and backward erase processing occurs.

In the description of the above-described embodiment, the window size is 32 megabytes. However, in S310 and S380 of the reproduction processing in Fig. 13, the partial FAT for managing the area of 16 kilobytes is used instead of 4 kilobytes. In this case, the empty area may be found with a window size of 128 megabytes. In this case, however, the t _FR of Equation 1 or 4 needs to be quadrupled.

In addition, if the partial FAT which manages the continuous area of 8 kilobytes instead of 4 kilobytes is read, the memory area can be used more effectively. More specifically, the vicinity of the end (near the 4 kilobytes) of the memory area managed by the partial FAT can be effectively used. The reason is that when the free areas are near the end of the memory area managed by the partial FAT and near the front end of the next memory area managed by the next partial FAT, the sum of them is taken as the value of the free area. Because it can manage.

In addition, in description of an Example, it was assumed that the partial FAT and each memory area referred to by the partial FAT do not overlap as shown in FIG. However, the partial FAT may be a contiguous area of 4 kilobytes from the FAT entry corresponding to the head address of the data stream file, and the memory areas managed by the partial FAT may overlap. This means that the area managed by the partial FAT or the head position of the partial FAT can be arbitrarily determined as shown in FIG. This also means that the starting sector managed by the partial FAT has coincident with the sector boundary, but does not have to match.

In the description of the above-described embodiment, the processing delay time generated in the memory card interface has not been mentioned, but in view of the processing delay time t _oh , the equation (1) may be changed as shown in the equation (7).

Further, in consideration of the processing delay time occurring in the memory card interface, for example, the maximum value of Vo may be limited slightly to about 80% of Vr.

In the description of the above-described embodiment, the memory storing the partial FAT is not specified in the model of FIG. 18 shows a configuration in which a memory for storing a partial FAT is provided. Although the partial FAT is said to be composed of consecutive sectors, for example, the partial FAT may be selected in units of 4 kilobyte partial FATs.

In addition, the process of compressing and recording a moving picture in real time has been described so far. However, the SD card may be attached to a memory card reader connected to a PC, and the moving picture data may be recorded in the data area in the window in real time. In this case, for example, the recording may be performed such that the total value of the continuous playback units is 1 megabyte or more in the window, as compared with the first embodiment.

In addition, the operation during the normal reproducing process has been mainly described. However, in high-speed playback using only I frames, the update rate of I frames can be shortened.

In the above description of the embodiment, although the transmission rates Vi and Vo of the data stream are set to 30 Mbps, a lower value may be used. In this case, however, the total amount of the free space required in the window area is at least smaller, and may be the same as that of the time of 30 Mbps.

In the description of the above-described embodiments, the time at which reading of the data stream file is stopped during reproduction is equal to the time for reading the partial FAT. However, for example, the time for reading other data or writing other data may be included. . In other words, any processing time may be used as long as the reading of the data stream to be reproduced is interrupted.

In addition, although the memory card 130 was said to be removable, this is an example. If the file is managed by the file system described above, another semiconductor recording medium (e.g., FeRAM, MRAM) may be used, and an optical disc (e.g., DVD-RAM, MO, DVD-R, DVD-RW, DVD +). RW, DVD + R, CD-R, CD-RW). The non-removable media such as a hard disk built into the recorder 10 may also be used.

Although the FAT32 file system is taken as an example, the FAT16 or FAT12 file system may be used. The file management structure identical to that of FAT32 / FAT16 / FAT12 may be another file system.

Each functional block of FIG. 1 or the like is typically realized as a chip of an integrated circuit (LSI) represented by the CPU 181. These may be single-chip individually, or may be single-chip so that some or all may be included. For example, in FIG. 1, the MPEG encoder unit 170 and the system control unit 180 are shown as separate functional blocks. These may be mounted as separate semiconductor chips, or may be realized by physically the same chip. In addition, the functions of the system control unit 180, the MPEG encoder 170, and the MPEG decoder 171 may be integrated and realized as one chip circuit. However, for example, only a memory storing data to be encoded or decoded may be excluded from the integration.

In addition, "LSI" mentioned above may be called IC, system LSI, super LSI, and ultra LSI according to the difference of integration degree. The integrated circuit method is not limited to the LSI, and may be realized by a dedicated circuit or a general purpose processor. After manufacture of the LSI, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor capable of reconfiguring the connection and setting of circuit cells inside the LSI may be used.

Alternatively, if the technology of integrated circuitry, which is replaced by LSI due to the advancement of semiconductor technology or other derived technology, appears, the function block may be integrated. For example, you may integrate as what is called a bio element using biotechnology.

In this specification, the data stream has been described as a program stream. However, it may be a bit stream such as a transport stream or a PES stream. The video may be an MPEG-2 video stream or an MPEG-4 video stream or an MPEG-4 AVC stream. The voice may also be a linear PCM audio stream or an AC-3 stream. It may also contain multimedia information of other types (graphic information, text information, etc.) other than video and audio.

Although all program streams (all VOBs) are stored in one data stream file, they may be separated as different data stream files. In addition, although all management data regarding a data stream file is stored in one management gjl file, you may separate as a management data file of another data stream file.

By recording a data stream on a recording medium (such as a memory card) using the apparatus and method according to the present invention, it is possible to easily secure a desired transfer rate at the time of reproduction. Therefore, when the content is played back, it is possible to continuously play the content without freezing the processing of the playback device and to prevent the drop of the coma drop and the voice in the moving picture. Since the data stream is recorded in accordance with the operation speed of the recording medium, it is easy for the maker to ensure compatibility of continuous playback between different playback devices as long as it is a playback device that can read the data properly. In addition, even with a large capacity memory card or a relatively low performance memory card, continuous playback compatibility can be easily achieved. In addition, while maintaining the transmission rate of the data stream, the free area can be used as a recording destination of the data area in smaller units than in the prior art.

Claims (13)

A data processing apparatus for writing a data stream of a content in a recording medium whose storage location of data is defined based on a file allocation table (FAT), A control unit for determining an amount of data that needs to be read continuously until at least the read time of the partial FAT, which is a part of the FAT, to secure the data stream to be reproduced over the read interruption time of the data stream; An area detecting unit for detecting a free area in which the data of the data amount can be stored in the partial area of the recording medium managed by the partial FAT; A recording unit for writing a data stream of the content in the blank area With And a data processing apparatus that enables reading of the data stream and reproduction of the content based on the partial FAT. The method of claim 1, The recording medium has a predetermined continuous data unit which can be read at a speed higher than a reproduction speed of the data stream, A partial region of the recording medium is a set of the continuous data units, The area detection unit detects the free area including one or more of the continuous data units from a partial area of the recording medium. Data processing unit. The method of claim 2, And the area detection unit detects an empty area in the partial area of the recording medium managed by any one partial FAT. The method of claim 3, wherein And the area detection section detects a blank area that is continuously present in a partial area of the recording medium, and whose area length is equal to or larger than the data amount. The method of claim 3, wherein And the area detection unit detects a plurality of free areas that are discretely present in a partial area of the recording medium, wherein a total value of the area lengths of each free area is equal to or larger than the data amount. The method of claim 2, If the transfer rate of the data read from the continuous data unit is Vr, the read time of the partial FAT is t, and the bit rate of the data stream to be written is Vo, The controller determines the amount of data for which subsequent reading is required to be equal to or greater than Vr × Vo × t / (Vr−Vo), The recording section writes data of the data amount. Data processing unit. The method of claim 6, And the area detection unit is a blank area existing in the partial area of the recording medium managed by one partial FAT, and the area length is summed to detect the blank area of the data amount. The method of claim 2, And the recording unit writes the data stream of the content to all or part of the blank area. The method of claim 8, And the recording unit writes at least one of data at the beginning of the data stream and data at the end in a part of the detected empty area. A reproducing unit which reads a partial FAT which is a part of the FAT from a recording medium whose storage location of data is defined based on a FAT (File Allocation Table); A control unit for instructing the reproduction unit to read a data stream of the content recorded on the recording medium based on the partial FAT; Decode section for playing back content based on the read data stream Provided with After the reading of the first data stream of a predetermined amount or more based on the first partial FAT is completed, while the reproduction processing by the decoding unit is continued, the reproducing unit reads the second partial FAT subsequent to the first partial FAT. and, The control unit instructs the reproducing unit to read a second data stream based on the second partial FAT, The predetermined amount is an amount of data that requires continuous reading until a data stream to be reproduced over the read interruption time of the data stream including at least the read time of the second partial FAT is obtained. Data processing unit. The method of claim 10, The recording medium has a predetermined continuous data unit which can be read at a speed higher than a reproduction speed of the data stream, A partial area of each recording medium managed based on the first partial FAT and the second partial FAT is a set of the continuous data units, The control unit instructs the reproduction unit to read a data stream based on the partial FAT, The reproducing section reads the data stream at a speed equal to or higher than a reproduction speed of the data stream. Data processing unit. A method for writing a data stream of content on a recording medium whose storage location of data is defined based on a file allocation table (FAT), comprising: Determining an amount of data that needs to be read continuously until at least the read time of the partial FAT, which is part of the FAT, to secure the data stream to be reproduced over the read interruption time of the data stream; Detecting a free area capable of storing data of the data amount in a partial area of the recording medium managed by the partial FAT; Writing a data stream of the content in the blank area Including, Thereby enabling reading of the data stream and reproduction of the content based on the partial FAT. Reading a partial FAT that is a part of the FAT from a recording medium in which a storage location of data is defined based on a file allocation table (FAT); Instructing reading of a data stream of content recorded on the recording medium based on the partial FAT; Playing content based on the read data stream As a method comprising: The reading step includes: a second continuous to the first partial FAT while the reproduction processing by the reproducing step is continued after the reading of the first data stream of a predetermined amount or more based on the first partial FAT is completed; Read the partial FAT, The indicating step may include reading a second data stream based on the second partial FAT, The predetermined amount is an amount of data that requires continuous reading until the data stream to be reproduced over the read interruption time of the data stream including at least the reading time of the second partial FAT is secured. How data is processed.

Images