JP2004080796A - Device and method for encoding and decoding data, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable quick searches by finding an access point of video data quickly. <P>SOLUTION: A device for encoding data is equipped with an encoder 1 which encodes input video data into a bit stream made from in-frame and interframe encoded pictures, an entry packet generation part 32 which generates an entry packet having location information on the in-frame encoded pictures, and a multiplexer 6 which multiplexes the generated entry packet so that it is placed in front of the in-frame encoded pictures in the bit stream. The entry packet is composed of location information on a plurality of in-frame encoded pictures selected discretely. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention is a data encoding apparatus and method, a data decoding apparatus and method, which are suitable for use when a moving image and audio are compressed and time-division multiplex-recorded on a disc and a predetermined image is searched at high speed. It relates to a recording medium.

FIGS. 6 and 7 show examples of the conventional encoding device and decoding device. In FIG. 6, a video signal is compressed and encoded (encoded) by a video encoder 1 and input to a code buffer 4 in a multiplexer 3. The audio signal is compressed and encoded by the audio encoder 2 and input to the code buffer 5 of the multiplexer 3.

The output terminals of the code buffers 4 and 5 are connected to the input terminals E1 and E2 of the switching circuit 6, respectively. The output terminal F of the switching circuit 6 is connected to the input terminal of the header adding circuit 7. The output of the header adding circuit 7 is supplied to a drive device (DSM) 10 for a recording medium including, for example, a magneto-optical disk, a magnetic disk (hard disk), or the like. The control device 8 receives the system clock output from the multiplexed system clock generation circuit 9 and sequentially connects the input terminals E1 and E2 of the switching circuit 6 to the output terminal F at a predetermined cycle, thereby setting the code buffer 4 Alternatively, data from 5 is sequentially taken out and time-division multiplexed.

The control device 8 controls the switching circuit 6 and the header adding circuit 7 so that a bit stream is generated according to the format shown in FIG.

That is, as shown in FIG. 8, in the multiplexing method of ISO11172 (MPEG), one multiplexed bit stream is composed of one or more packs (PACK) and one ISO_11172_end_code. ISO_11172_end_code is a 32-bit code, and is 0x000001b9 in hexadecimal. Here, x means indefinite.

One pack is composed of a header composed of Pack_Start_Code, SCR (System Clock Reference), and MUX_Rate, and one or more packets. Pack_Start_Code of the header is a 32-bit code, which is 0x000001b4 in hexadecimal. The length of the pack is defined as a variable length, but is set to a maximum of 2048 bytes.

(1) One packet includes a header including Packet_Start_Code_Prefix, Stream_ID, Packet_length, PTS (Presentation Time Stamp), DTS (Decoding Time Stamp), and packet data (Code Data). Packet_Start_Code_Prefix is a 24-bit code and is 0x000001. Stream_ID is an 8-bit code and represents the type of packet as shown in FIG. Packet_length (16 bits) indicates the length of a subsequent packet.

(4) In the Code Data of each packet, audio data (audio stream) or video data (video stream) is recorded. Further, since 32 types of audio streams and 16 types of video streams have different stream ids, a plurality of audio signals and video signals up to this number can be multiplexed.

The reserved stream has data such as subtitles. The use of private_stream_1 and private_stream_2 is not defined. padding_stream is used to increase the amount of data.

{Circle around (2)} According to the above-mentioned format, the control device 8 performs processing of adding a header and reading a code using an algorithm as shown in FIG. 10 so that the interval between packs becomes 2048 bytes.

First, the control device 8 instructs the header adding circuit 7 to add a pack header (step S1). Then, the process waits until the sum of M4 and M5 becomes equal to or larger than the code data amount D included in one pack (step S2). That is, the process waits until data enough to be stored in one pack is accumulated in the code buffers 4 and 5.

Here, M4 is the amount of data written to the code buffer 4, and M5 is the amount of data written to the code buffer 5. D indicates the total amount of data included in one pack. Here, for simplicity, it is assumed that D is a constant, that is, the size of the pack (2048) minus the size of the pack header, the size of the video packet header, and the size of the audio packet header.

Next, the amount P1 of video data contained in the pack and the amount P2 of audio data contained in the pack are calculated according to the following equation (step 3). P1 = D × M4 / (M4 + M5) P2 = D-P1 Here, the total amount D of the code data included in the pack is simply distributed according to the ratio of the data amount of each of the code buffers 4 and 5.

(4) When the data amount is determined, the control device 8 instructs the header adding circuit 7 to output a video packet header (step S4). Next, the P1 byte video data is read from the code buffer 4 and output to the driving device 10 (step S5). Similarly, an audio packet header is added (step S6), and P2-byte audio data is read from the code buffer 5 and output to the driving device 10 (step S7). In the drive device 10, these input data are recorded on a built-in disk.

デ ー タ The data recorded on the disk in this manner is decoded by the decoding device shown in FIG. That is, the header separation circuit 22 of the separation device 21 separates the pack header and the packet header from the data read from the driving device 10 and supplies them to the control device 24, and also converts the time-division multiplexed data into the switching circuit 23. To the input terminal G. Output terminals H1 and H2 of the switching circuit 23 are connected to input terminals of a video decoder 25 and an audio decoder 26, respectively. The control device 24 of the demultiplexer 21 sequentially connects the input terminal G and the output terminals H1 and H2 of the switching circuit 23 according to the stream id of the packet header supplied from the header demultiplexer 22, and outputs the time-division multiplexed data. Are correctly separated and supplied to the corresponding decoder.

(4) When the multiplexed video data is compressed by the MPEG coding method, random access and search operations are restricted. That is, in MPEG, there are an intra-frame coded picture (I (intra) picture) and an inter-frame coded picture (P (forward prediction) picture, B (bidirectional prediction) picture). Since the coding of an I picture is performed using only the data in the image (frame or field), the data compression efficiency is low. This I picture itself can be decoded. Since the P picture and the B picture are obtained by encoding the difference signal from the preceding and succeeding pictures, the data compression efficiency increases. In order to decode this P picture or B picture, an earlier or later predicted image is required. For this reason, normally, about two I-pictures appear per second to balance the random accessibility and the compression efficiency.

FIG. 11 shows a conceptual diagram of a bit stream including an I picture, a P picture, and a B picture recorded on a disk by the drive device 10. A series of video bit streams is divided into one or more GOPs (Group of Pictures). The GOP has an I picture at the head. When the video data is compressed at a fixed rate, the I picture periodically appears at a predetermined position, so that the position can be obtained by calculation and accessed. However, when variable rate compression is being performed, the position of the I picture is undefined, making it difficult to access.

That is, when the search command is received in the multiplexed data decoding device of FIG. 7, the main control device (not shown) instructs the control device 24, the video decoder 25, and the audio decoder 26 to transition to the search mode. I do. In the search mode, the video decoder 25 decodes only I-picture data from the input video data. Alternatively, only the I picture data is selected by the separating device 21 and input to the video decoder 25. The video decoder 25 decodes the input data.

In the search mode, the control device 24 commands the drive device 10 to move the data reading position on the disk forward (or backward). The moving amount of the reading position at this time depends on the search speed, the coding rate, and the like. In general, the higher the search speed and the higher the coding rate, the larger the moving amount. When the reading position has moved to a predetermined position, the data output from the driving device 10 is input to the separation device 21. The header separation circuit 22 separates the video data and supplies it to the video decoder 25. The video decoder 25 decodes and outputs the first appearing I picture. In the search mode, the audio decoder 26 is in a muted state.

サ ー チ Thus, the search operation (continuous reproduction of I pictures) is realized as repetition of random access. That is, when the user instructs, for example, a high-speed search in the forward direction, the video decoder 25 skips data of a predetermined number of frames among the input data, searches for an I picture, decodes and outputs the picture. Alternatively, an I-picture search is performed by the driving device 10, and only the I-picture data is supplied to the video decoder 25 and decoded. By repeating such operations, a search operation (continuous reproduction of I pictures) is realized.

As described above, in the conventional apparatus, since the position (access point) of the I picture cannot be known, it is necessary to wait for the access point after moving the reproduction position to some extent. For this reason, there has been a problem that the repetition period of the search operation becomes long and it is difficult to perform a quick search operation.

The present invention has been made in view of such a situation, and is to quickly find an access point of video data and enable a quick search.

An encoder for encoding input video data into a bit stream composed of an intra-frame coded picture and an inter-frame coded picture, and a position of the intra-frame coded picture. An entry packet generation unit that generates an entry packet having information; anda multiplexer that multiplexes the generated entry packet so as to be arranged before an intra-frame coded picture in the bit stream. The entry packet is characterized by comprising position information of a plurality of intra-frame coded pictures discretely selected.

It is preferable that the entry packet includes at least the position information of the adjacent forward and backward intra-coded pictures. Further, it is preferable that the entry packet includes position information of an intra-frame coded picture selected such that an adjacent distance increases as the distance increases. Further, it is preferable that the entry packet include, together with the position information of the intra-frame coded picture, information indicating how far the intra-frame coded picture is arranged.

An encoding step for encoding input video data into a bit stream consisting of an intra-coded picture and an inter-coded picture, and a position of the intra-coded picture. An entry packet generating step of generating an entry packet having information; anda multiplexing step of multiplexing the generated entry packet so as to be arranged before an intra-frame coded picture in the bit stream. The entry packet is characterized by comprising position information of a plurality of intra-frame coded pictures discretely selected.

The data decoding apparatus according to claim 6 decodes an intra-frame coded picture and an inter-frame coded picture from a bit stream multiplexed such that an entry packet is arranged before an intra-frame coded picture. Decoding means, and control means for controlling a reading position from a recording medium based on position information of an intra-frame coded picture obtained from the entry packet, wherein the entry packet includes a plurality of discretely selected entry packets. . Is characterized by the position information of the intra-coded picture.

A data decoding method according to claim 10, wherein an intra-coded picture and an inter-coded picture are decoded from a bit stream multiplexed such that an entry packet is arranged before an intra-coded picture. A decoding step, and a control step of controlling a reading position from a recording medium based on position information of an intra-frame coded picture obtained from the entry packet, wherein the entry packet includes a plurality of discretely selected entry packets. . Is characterized by the position information of the intra-coded picture.

The recording medium according to claim 11, wherein the moving image is an intra-frame coded picture, wherein the moving image is mounted on a playback device, and the reading position is controlled to be read based on the recorded address information. And an entry packet comprising position information of a plurality of discretely selected intra-coded pictures is encoded and recorded as a bit stream composed of inter-coded pictures, and the intra-frame encoding in the bit stream is performed. It is characterized by being multiplexed and recorded so as to be arranged before a picture.

According to the data encoding device and the data encoding method of the present invention, input video data is encoded into a bit stream including an intra-frame coded picture and an inter-frame coded picture, and the position information of the intra-frame coded picture is encoded. And multiplexing the generated entry packet such that it is placed before the intra-coded picture in the bitstream, wherein the entry packet comprises a plurality of discretely selected intra-frame codings. Since the position information is composed of the position information of the picture, the positions of a plurality of intra-frame coded pictures can be sequentially and quickly searched in accordance with the entry packet. Thus, an access point of the video data can be quickly found, and a quick search can be performed.

Further, according to the data decoding device and the data decoding method of the present invention, an intra-coded picture and an inter-frame are converted from a bit stream multiplexed so that an entry packet is arranged before an intra-coded picture. The coded picture is decoded, and the read position from the recording medium is controlled based on the position information of the intra-frame coded picture obtained from the entry packet. The entry packet includes a plurality of discretely selected intra-frame codes. Since the position information is composed of the position information of the coded pictures, the positions of a plurality of intra-frame coded pictures can be sequentially and quickly searched. Thus, an access point of the video data can be quickly found, and a quick search can be performed.

Further, according to the recording medium of the present invention, in a recording medium which is mounted on a reproducing apparatus and whose reading position is controlled and read based on the recorded address information, the moving image is an intra-coded picture. And an entry packet consisting of position information of a plurality of discretely selected intra-coded pictures, which is encoded and recorded as a bit stream composed of inter-coded pictures, Since the data is multiplexed and recorded so as to be arranged before the picture, the positions of a plurality of intra-frame coded pictures can be quickly and sequentially searched in response to the entry packet. Thus, an access point of the video data can be quickly found, and a quick search can be performed.

FIGS. 1 and 2 are block diagrams showing a configuration of an embodiment of a data encoding device and a data decoding device according to the present invention. The same components as those in FIGS. 6 and 7 are denoted by the same reference numerals. Is attached.

In the encoding device of FIG. 1, the output terminal of the video encoder 1 is connected to the input terminal of the video entry point detection circuit 31, and the output terminal is connected to the input terminal of the code buffer 4. The entry packet generating circuit 32 receives a control input of the control device 8 and supplies its output to the input terminal E3 of the switching circuit 6. Further, the control device 8 receives the input of the system clock output from the multiplexed system clock generation circuit 9 and sequentially connects the input terminals E1, E2, E3 of the switching circuit 6 to the output terminal F at a predetermined cycle, and Data is sequentially taken out from the buffers 4 and 5 or the entry packet generating circuit 32, time-division multiplexed, and output to the header adding circuit 7.

The control device 8 controls the header adding circuit 7 to add a video packet header to the video data read from the code buffer 4. An audio packet header is added to the audio data read from the code buffer 5.

Further, the control device 8 receives an input of an entry point generation signal generated at the generation timing of the I picture from the video encoder 1 or the video entry point detection circuit 31, controls the entry packet generation circuit 32, and An entry packet is inserted at a predetermined position. When the video encoder 1 is configured to output an entry point generation signal, the video encoder 1 outputs an entry point generation signal at an I picture generation timing.

In the case where the video encoder 1 cannot output an entry point generation signal or when multiplexing an already encoded video bit stream, the video entry point detection circuit 31 outputs An entry point generation signal is generated, or an entry point is detected from video data input from the video encoder 1, and an entry point generation signal is output. The entry point storage device 33 is a memory readable and writable by the control device 8, and stores the position of the detected entry point. Other configurations are the same as those in FIG.

も Also in the embodiment shown in FIG. 1, the multiplexed bit stream is composed of at least one pack and ISO_11172_end_code. Each pack has a format as shown in FIG. 3, for example.

That is, first, as in the case of FIG. 8, a Pack_Header (header) composed of Pack_Start_Code, SCR, and MUX_Rate is arranged. Next, Video_Packet_Header is further arranged. They are arranged in a packet structure. Next to the video data, an Entry_Packet is placed, followed by a Video_Packet_Header, and then a video data including an I picture is placed in a packet structure. That is, the Entry_Packet is arranged immediately before the video data including the I picture (entry point) (immediately before the Video_Packet_Header). Then, in the case of this embodiment, Audio_Packet_Header is arranged next to the video data, and audio data having a packet structure is arranged next to the audio data.

Entry_Packet (entry packet) has a format shown in FIG. This format corresponds to the format of the private_stream_2 packet among the MPEG packets. At the beginning, Packet_Start_Code_Prefix is arranged, followed by stream_id which is set to 0xbf in hexadecimal. Next to that, a length indicating the length of the subsequent packet is arranged. The above arrangement is the same as that in the packet header in FIG.

に お い て In this embodiment, next, sony_id is arranged. This indicates that the private packet is in the applicant's own format. Next to this, a sony_packet_type is arranged, which indicates the classification in the private packet format unique to the applicant, and is set to 0xff in the case of an entry packet. Further, current _ # _ data_streams, current _ # _ video_streams, and current _ # _ audio_streams that are sequentially arranged next to the data packet are multiplexed from immediately after this entry packet to immediately before the next entry packet. The numbers of video packets and audio packets are respectively shown.

Next, entry_packet_-3, entry_packet_-2, entry_packet_-1, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3 are sequentially arranged. The position of the previous, the previous, the first, the second, and the third entry packet, and the relative distance between the entry packets and the number of sectors of the disk driven by the drive device 10 are recorded. ing.

Next, the operation of the embodiment of FIG. 1 will be described. The control device 8 receives the entry point generation signal from the video encoder 1 or the video entry point detection circuit 31, and inserts an entry packet immediately before the video entry point (FIG. 3). That is, when an entry point generation signal is received, the entry packet generation circuit 32 generates an entry packet, switches the switching circuit 6 to the input terminal E3 side, and supplies the input terminal E3 to the header addition circuit 7 so that the code buffer 4 , 5 are multiplexed with the video and audio data.

As shown in FIG. 4, in each entry packet, the positions of the entry packets three, two, one, one, two, and three ahead of the entry packet are indicated by the entry. _Packet_-3, entry_packet_-2, entry_packet_-1, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3. The positions of the previous (past) entry packets (three before, two before, and one before) are stored in the entry point storage device 33 so that they can be known when the current entry packet is recorded. (So it can be supplied to the drive 10 and recorded on a disc at this timing, if necessary).

However, the position of the previous (future) entry packet cannot be known at this time. For this reason, the control device 8 stores all the positions of the entry points in the entry point storage device 33, and after all the multiplexing is completed (after the recording of the bit stream of the video data and the audio data to the disk is completed). ), The positions of the entry packets three, two, one, one, two, and three ahead of each entry packet are read out from the entry point storage device 33, and are read out from the drive device 10. To record (append) each entry packet on the disk.

The video encoder 1 and the audio encoder 2 respectively encode the video signal and the audio signal at a variable rate. The control device 8 controls the header adding circuit 7 so that the pack interval becomes 2048 bytes. Add a pack header. For this reason, the control device 8 controls the processing of adding a header, reading a code, and inserting an entry packet using, for example, an algorithm as shown in FIG.

Here, M4 is the amount of data stored in the code buffer 4, and M5 is the amount of data stored in the code buffer 5, as in the case of the processing in FIG. D indicates the total amount of data included in one pack. Here, for simplicity, it is assumed that D is a constant, that is, the size of the pack (2048) minus the size of the pack header, the size of the video packet header, and the size of the audio packet header. D2 indicates the total amount of data in the pack including the entry packet. That is, the size of the entry packet and the size of the video packet header are reduced from D.

First, the control device 8 instructs the header adding circuit 7 to add a pack header (step S11). Then, the process waits until the sum of M4 and M5 becomes equal to or larger than the amount D of the code data included in one pack (step S12). That is, the process waits until data enough to be stored in one pack is accumulated in the code buffers 4 and 5.

Next, the amount P1 of video data contained in the pack and the amount P2 of audio data contained in the pack are calculated by the following equation (step S13). P1 and P2 are obtained by distributing the total amount D of the code data included in the pack in the ratio of the data amounts M4 and M5 of the respective code buffers 4 and 5.
P1 = D × M4 / (M4 + M5)
P2 = D-P1

Next, the control device 8 checks whether or not the data up to the first P1 byte of the M4 data has a video entry point (step S14). When the video entry point is not included in the pack, the control device 8 instructs the header adding circuit 7 to output the video packet header (step S15). Next, the P1 byte video data is read from the code buffer 4 and output to the driving device 10 (step S16). Similarly, an audio packet header is added (step S17), and the P2 byte audio data is read from the code buffer 5 and output to the driving device 10 (step S18).

If the video entry point is not included in the pack, the above processing is repeated. This processing is the same as the processing in the case of FIG.

On the other hand, when the video entry point is included in the pack, the control device 8 first causes the entry point storage device 33 to store the current position of the pack. Then, the amount P1 of video data and the amount P2 of audio data to be stored in the pack are calculated according to the following equation (step S19).
P1 = D2 × M4 / (M4 + M5)
P2 = D2-P1
After performing the calculation in step S13, the same calculation is further performed here, because the pack includes the entry packet, so that the data capacity is reduced. Here, P1 and P2 are obtained by distributing D2 in the ratio of the data amounts M4 and M5 of the code buffers 4 and 5, respectively.

Next, the video packet header is output from the header adding circuit 7 to the driving device 10 (step S20). Subsequently, the video data up to immediately before the video entry point is stored in the video encoder 1, the video entry point detection circuit 31, the code buffer 4, The signal is output to the driving device 10 via the input terminal E1, the output terminal F of the switching circuit 6, and the path of the header adding circuit 7, and is recorded on a disk (step S21). Next, the entry packet is output by the entry packet generation circuit 32 and recorded on the disk (step S22). However, at this time, the relative position information of the entry packet is not yet written on the disk.

Then, the video packet header is output and recorded again (step S23), and the remaining video data is output and recorded (step S24). Then, the process proceeds to steps S17 and S18, where an audio packet header is added, and P2 bytes of audio data are recorded.

(5) The algorithm of FIG. 5 is repeated, and when there is no more input to the video encoder 1 and the audio encoder 2, the position data is written to the entry packet already recorded on the disk. That is, the control device 8 reads the position of the pack including the entry packet from the entry point storage device 33 and writes the position of the pack including the preceding and following three entry packets into each entry packet of the disk of the drive device 10.

Next, an apparatus for decoding data encoded in the embodiment of FIG. 1 will be described with reference to FIG. The header separation circuit 22 of the separation device 21 separates a pack header, a packet header, and an entry packet from the data read from the driving device 10 and supplies them to the control device 24. 23 input terminal G. Output terminals H1 and H2 of the switching circuit 23 are connected to input terminals of a video decoder 25 and an audio decoder 26, respectively.

{Circle around (4)} The control device 24 reads information (entry packet information) related to the entry point from the data input from the header separation circuit 22, supplies the information to the entry point storage device 41, and stores it. Since the control device 24 is supplied with information on the current readout position from the drive device 10, the control device 24 can store the position of the entry point and its content in association with each other.

The control device 24 of the separation device 21 sequentially connects the input terminal G and the output terminals H1 and H2 of the switching circuit 23 in accordance with the stream id of the packet header supplied from the header separation circuit 22, and outputs the time-division multiplexed data. , And video data is supplied to the video decoder 25 and audio data is supplied to the audio decoder 26.

Next, the operation of the multiplexed data decoding apparatus shown in FIG. 2 when a search operation is instructed will be described. When a search operation is instructed, a main controller (not shown) instructs controller 24, video decoder 25, and audio decoder 26 to transition to the search mode. Further, the control device 24 reads the current read position from the output of the drive device 10 and extracts an entry point near the position from the entry point storage device 41. The entry point storage device 41 stores information on entry packets reproduced in the reproduction mode as needed. Alternatively, at a predetermined timing, such as when the power of the apparatus is turned on, when a disk is mounted, or when a reproduction is instructed, all or a predetermined range recorded on the disk mounted on the drive device 10 Can be read out and stored in advance.

When the control device 24 finds an entry point, it sends a search command to the drive device 10 to move the reading position to the entry point at high speed. When the movement is completed, the drive device 10 reproduces data from the entry point and supplies the data to the separation device 21. As described with reference to FIG. 3, the entry packet is located immediately before the video data in which the I picture is recorded. Therefore, when the video data following the entry packet is separated by the header separation circuit 22 and supplied to the video decoder 25, the first picture of the video data is an I picture. The video decoder 25 immediately decodes and outputs the first appearing I picture. In the search mode, the audio decoder 26 is in a muted state.

(4) Since the position information of the three entry points before and after the entry packet is recorded in the entry packet, the control device 24 searches for the next entry packet from the position information and repeats the operation of reproducing. As a result, the I pictures are rapidly and successively reproduced.

When the search speed is high, the control device 24 accesses a farther entry point, and when the search speed is low, the control device 24 accesses a closer entry point. Since three entry points are recorded in each of the forward direction and the reverse direction, three or more search speed variations can be provided depending on the combination of the selected entry points.

As described above, when the entry packet is first sent to the drive device 10 first, the control device 8 does not know the position of the (future) entry packet at the previous position, and the control device 8 finishes all multiplexing. Later, using the information recorded in the entry point storage device 33, the position information of the entry packet, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3, are stored in the entry in the multiplexed bit stream of the activation device 10. Append to the packet.

However, if the capacity of the entry point storage device 33 is sufficient or not at all, the position information of the entry packet at the previous position cannot be held sufficiently or at all, so that the entry packet in the multiplexed bit stream recorded in the driving device 10 Can not be added. If there is no capacity in the entry packet storage device 33 at all, when the first entry packet is sent to the driving device 33, the position information of the entry packet at the previous position, entry_packet_-3, entry_packet_-2, entry_packet_- Cannot write 1. In such a case, since the value contained in the position information of the entry packet in the completed multiplexed bit stream cannot be predicted, an unexpected operation may occur if a search is performed based on such a value. There is.

Therefore, a flag indicating the validity of the position information of the entry packet is provided. Specifically, the format of the entry packet generated by the entry packet generation circuit 32 is the format shown in FIG. 12 or FIG. The format of FIG. 12 is a method of expressing the validity of the position information of all the entry points included in the entry packet by one 1-bit flag. In the case of FIG. 13, a flag indicating the validity is set for each entry point. It is a method of adding.

When an entry packet of the format shown in FIG. 12 is used, at the stage where multiplexing is performed and the multiplexed bit stream is first sent to the driving device 10, the position information of the entry packet cannot be completely written. The enable flag is set to 0 meaning "invalid" in the enable flag, and is recorded in the drive device 10. After the recording of all multiplexed data, when additional writing is performed on the entry packet using the position information of the entry packet recorded in the entry point recording device 33, for the entry packet in which all the position information can be written, The control device 8 updates the Enable Flag in the entry packet to 1 meaning “valid”.

In the case of using the entry packet of the format shown in FIG. 13, at the stage of performing multiplexing and first transmitting the multiplexed bit stream to the driving device 10, of the enable flags of Enable Flag−3 to EnableFlag + 3, writing was possible. The validity flag corresponding to the position information is set to 1 indicating "valid", and the validity flag corresponding to the position information that could not be written is set to 0 indicating "invalid" and recorded in the drive device 10. . After the recording of all the multiplexed data is completed, when additional writing is performed on the entry packet by using the position information of the entry packet recorded in the entry point recording device 33, the control device 8 performs Updates the corresponding valid flag to 1 meaning “valid”.

In FIG. 13, consider that enable_flag_N and entry_packet_N (−3 ≦ N ≦ + 3) are continuous bit strings and that this bit string represents one number, instead of providing a position information valid flag of an entry packet, The packet position information itself is equivalent to expressing the validity of the value. In other words, when valid position information cannot be written, a function equivalent to adding a position information valid flag can be realized by writing a value in a specific range or an invalid value as position information. When a specific value is written in the position information of the entry packet to indicate that each entry point is invalid, a plurality of types of specific values indicating invalidity can be provided. For example, different values are used when the information of the entry point is invalid simply because the recording of the location information of the entry point has failed, and when the reading position is intentionally prohibited from being moved to the entry point. By writing to the entry packet, it is possible to notify the multiplexed data decoding device.

Next, a multiplexed data decoding apparatus that performs a search operation using an entry packet position information valid flag as shown in FIG. 12 or 13 will be described with reference to FIG. The control device 24 supplies the information of the entry packet read from the header separation circuit 22 to the entry point storage device 41 and stores it. At this time, as shown in FIG. 12 or 13, when the entry packet position information valid flag is added to the entry packet, the control device 24 supplies the entry packet including the flag to the entry point storage device 41. , And the entry point storage device 41 stores it.

When the search operation is instructed, the main controller (not shown) instructs the controller 24, the video decoder 25, and the audio decoder 26 to shift to the search mode. The control device 24 reads the current read position information read from the output of the drive device 10 and the position information of the entry packet read from the entry point storage device 41 to read to the drive device 10 to instruct a search operation. Get the position. At this time, the control device 24 determines the validity of the position information of the entry packet from the entry point storage device 41, and does not instruct the drive device 10 to perform a search operation for an invalid entry point. Alternatively, if the position of the entry point can be calculated by interpolation, estimation, or the like from the position information or the like of another entry point, the driving device 10 may be searched for the position of the entry point thus obtained. it can.

The entry_packet_-3, entry_packet_-2, entry_packet_-1, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3 of the entry packet shown in FIG. The relative positions of the entry points before, one before, one ahead, two ahead, and three ahead are recorded (in sector numbers), but the relative positions of the entry points to be written here are not necessarily relative to the entry packet. It is not necessary to be the entry point at the position of -3, -2, -1, + 1, + 2, + 3, for example, -25, -8, -1, + 1, + 5, + 20 , The relative position of any entry packet can be recorded.

Thus, the relative position of the entry point to be written can be determined for each recording device, for each multiplexed data, for each entry packet, according to various characteristics such as the type of recording media, the signal format of the multiplexed bit stream, and the characteristics of the video or audio data to be multiplexed. The search speed can be adjusted by changing each time. For example, in a multiplexed bit stream defined by ISO11172 (MPEG), the number of pictures from an I picture to the next I picture is variable. In such a case, if the entry point at the position of -3, -2, -1, +1, +2, +3 is always written in the entry packet, in a bit stream in which the number of I-pictures differs, Although the speed of the search playback with respect to the real-time playback changes, the search speed is adjusted by changing the relative position of the entry point and recording it in the entry packet according to the number of pictures between I pictures, A constant search reproduction speed can be realized between bit streams having different numbers of I pictures.

The relative position of the entry point to be written in the position information of the entry packet does not necessarily need to be the position of the entry point at the position of -3, -2, -1, +1, +2, +3 with respect to the entry packet. For example, the relative position of any entry packet can be recorded, for example, -25, -8, -1, +1, +5, +20. In the case of performing special reproduction such as an operation, the position of the entry point at the position of -1, +1 before and after may be required.

Therefore, with respect to the bit stream requiring such special reproduction, the positions of the entry points to be recorded in the entry_packet_-1 and the entry_packet_ + 1 are limited, and the entry points at the positions before and after -1, +1 are always set. May be written. As described above, in the case where the position information of the entry point ahead or ahead by an arbitrary number is recorded in the entry packet, for example, -25, -8, -1, +1, +5, +20 ahead In the case of recording the relative position of the entry packet of FIG. 4, if the entry packet of the format as shown in FIG. 4 is used, the multiplexed data decoding as shown in FIG. It is not possible to determine how many positions the previous or previous entry point relates to. Therefore, when the relative position information is used for the search operation, there is a problem that it is impossible to predict how much search speed can be realized.

Therefore, the entry packet has a format as shown in FIG. 19, and entry_packet_-3, entry_packet_-2, try_packet_-1, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3 are respectively several times before or Entry Point Position -3, Entry Point Position -2, Entry Point Position -1, Entry Point Position +1, Entry Point Position +2, Entry Point Position +3 It can also be recorded in the entry packet.

For example, entry_packet_-3, entry_packet_-2, entry_packet_1, entry_packet_ + 1, entry_packet_ + 2, and entry_packet_ + 3 are respectively -25, -8, -1, + 1, + 5, + To record the position information of the entry point 20 points ahead, Entry Point Position -3, Entry Point Position -2, Entry Point Position -1, Entry Point Position +1, Entry Point Position +2, Entry
Record -25, -8, -1, + 1, + 5, + 20 at Point Position + 3 respectively. The operation of the multiplexed data decoding apparatus shown in FIG. 2 when a search is performed using the information of Entry Point Position -3 to +3 will be described.

The main control device (not shown) gives a target value of the search speed to the control device 24 and instructs a search operation. The header separation circuit 22 determines an entry packet from the multiplexed bit stream sent from the DSM 10 and sends the contents of the entry packet to the control device 24. The controller 24 selects one of Entry Point Position -3, Entry Point Position -2, Entry Point Position -1, Entry Point Position +1, Entry Point Position +2, and Entry Point Position +3 in the entry packet. The one that realizes the speed closest to the search speed instructed by the main controller (not shown) is selected, and the position information of the corresponding entry points is entered as entry_packet_-3, entry_packet_-2, entry_packet_-1, entry_packet_ +. 1, obtained from entry_packet_ + 2, entry_packet_ + 3. The control device 24 instructs the DSM 10 to search for the next entry point using the position information of the entry point selected in this way.

In this way, using the information indicating the position of the entry point or the position of the previous entry point, the entry point position information that realizes the search speed closest to any desired search speed is obtained. You can choose. The entry packet has the format shown in FIG. 14, and the data size I-picture length of the I picture immediately following the entry point or the position I-picture of the pack in which the end of the data of the I picture is multiplexed. Picture END sector-No., or both, can be recorded in the entry packet.

FIG. 15 shows the configuration of a multiplexer for recording the I-picture length and I-picture END sector-No. In the entry packet. The I-picture end point detection circuit 51 has a function of searching for the end of I-picture data from the bit stream sent from the video encoder 1 and informing the control device 8 of the position. The entry point storage device 33 stores, in addition to the position of the entry packet and the value of the entry point (entry_packet_-3, entry_packet_-2,..., Entry_packet_ + 3) written in the entry packet, It has a function of holding the data length I-picture length of the immediately following I picture and the position information I-picture END sector-No. Of the pack in which the end of the data of the I picture is multiplexed. The functions of the other blocks are the same as those in FIG.

The control device 8 detects the position of the entry point and the position of the end point of the data of the I picture immediately following the entry point from the video encoder 1, the video entry point detection circuit 31, and the I picture end point detection circuit 51. Since the position of the entry point is the position of the start point of the data of the I picture, the control device 8 calculates the difference between the position of the end point of the data of the I picture and the position of the entry point, thereby obtaining the length of the data of the I picture. Calculate the I-picture length.

Since the length of the data of the I picture may be larger than the storage capacity of the code buffer 4, when multiplexing the entry packet and writing it to the drive circuit 10, the length of the data of the I picture to be written in the entry packet I-picture length may not be calculated yet. In such a case, 0 or a specific value indicating uncalculated is written in the I-picture length portion of the entry packet and recorded in the driving device 10. The control device 8 records the I-picture length of the I-picture data in the entry point storage device 33 at the time when the length of the I-picture data is calculated, and when adding the entry packet later, , The value of the I-picture length is supplied to the drive device 10 and recorded.

(4) The end position I-pictureEND sector-No. Of the pack in which the data of the I picture is multiplexed can be obtained as follows. The control device 8 multiplexes data by the algorithm shown in FIG. 5 according to the data amounts M4 and M5 stored in the code buffer 4 and the code buffer 5, and the control device 8 is shown in FIG. Apart from the processing described in the algorithm, it is determined for each pack whether the video data of the pack includes the end point of the I picture. When the end point of the data of the I picture is included in the pack, the control device 8 records the position of the pack in the entry point storage device 33. When the data is recorded in the entry point storage device 33, the data is stored so as to correspond to the data written in the entry packet multiplexed immediately before the I picture.

The position I-picture END sector-No. Of the pack including the end position of the data of the I picture recorded in the entry point storage device 33 is the same as the length I-piturelength of the data of the I picture. Is performed, the value is supplied to the driving device 10 and recorded. At this time, the I-picture END sector-No. Is given to the driving device 10 by a relative distance from the position of the pack where the multiplexing of the data of the I-picture is started, that is, the position of the multiplexed pack of the entry packet. Written.

Next, an example of a multiplexed data decoding device that performs a high-speed search using the I-picture END sector-No. Written in the entry packet as described above will be described with reference to FIG. A video decoder based on ISO11172 (MPEG) has a video code buffer inside the decoder in order to guarantee a decoding operation even for a bit stream having a different amount of data for each picture. The bit stream that has entered the video decoder 25 is first temporarily stored in the video code buffer, and then decoded at a necessary timing.

Conventionally, in order to continuously reproduce I pictures, the control device 24 monitors whether the decoding of the I pictures by the video decoder 25 has been completed, and after confirming that the decoding has been completed, issues a search command for the next I picture to the drive device. 10 was performed. At this time, if the video decoder 25 has a video code buffer, and the decoding unit of the video decoder 25 has finished decoding the I-picture, the video decoder 25 The data of the P and B pictures are stored, and the data is read from the driving device 10 even though they are not decoded. In many cases, the search speed is governed by the time required to read data from the driving device 10 rather than the time required for decoding by the video decoder 25. Therefore, the useless loading of P and B pictures reduces the search speed. .

By using the I-picture END sector-No. Information written in the entry packet, the amount of useless reading of P and B pictures is minimized, and the data of the I picture to be displayed next is video decoder. Since the data can be read in advance into the video code buffer in the multiplexed data buffer 25, a higher-speed search operation can be realized in a multiplexed data separation device in which the search speed is governed by the speed of reading from the drive device 10.

During the search operation, the control device 24 instructs the drive device 10 to perform a search based on the information recorded in the entry point storage device 41. The driving device 10 sends the multiplexed bit stream to the header separation circuit 22 from the designated position. When an entry packet is detected in the transmitted multiplexed bit stream, the header separation circuit generates an interrupt to the control device 24 to notify it. In response to the interrupt, the control device 24 reads out the current readout position information from the drive device 10 and records it in the entry point storage device 41 as the current entry point position.

{At the same time, the control device 24 extracts the position information of the entry point written in the entry packet from the header separation circuit and records it in the entry point storage device. At this time, information written in the entry packet at a position relative to the pack position at the beginning of the current entry point, such as I-picture END sector-No. The relative position information is converted into absolute position information by adding the relative position information to the position information of the current entry point read from the entry 10 and recorded in the entry point storage device 41, and recorded in the entry point storage device 41. I do.

(4) As the driving device 10 continues to supply the multiplexed bit stream to the header separation circuit 22, the read position information of the driving device 10 increases with time. The control device 24 reads the read position information from the drive device 10 at regular intervals, and compares the read position information with the I-picture END sector-No. Converted into the absolute position information stored in the entry point storage device 41. At this time, if the readout position information obtained from the drive device 10 exceeds the I-picture END sector-No., The necessary readout of the I picture has been completed, and the P, B picture, etc. It determines that unnecessary data has been loaded, and immediately instructs the drive device 10 to perform a search for reading the next I picture.

Also, the data size I-picture length of the I picture and the position I-picture END sector-No. Of the pack in which the end of the I picture data is multiplexed, written in the entry packet in this manner, are shown. An example of a multiplexed data decoding device capable of performing a search at a more constant search speed will be described with reference to FIG. In the multiplexed data decoding device shown in FIG. 2, when the search operation starts, the control device 24 determines the I picture data based on the entry point position information stored in the entry packet storage device 41. The pack with the head is read from the driving device 10. An entry packet is always multiplexed in the read pack, so the I-picture length and I-picture END sector-No. The amount can be read.

The control device 24 determines whether the I-picture length and I-picture END sector-No. Written in the entry packet exceed a certain threshold, and how many I-pictures exceeding the threshold continue. I do. If the number of I-pictures whose data amount exceeds the threshold value continues for a certain number or more, it takes time to read data from the driving device 10 and decode processing by the video decoder 25, and the search speed becomes slow. Since it can be estimated, the delay is corrected by temporarily stopping the decoding of the I picture or changing the entry point to be selected among the entry points from -3 to +3. The suspension of the decoding of the I-picture is realized by instructing the driving device 10 to search for the next entry point before data is supplied to the video decoder 25 and the audio decoder 26. The change of the position of the entry point to be selected is realized by causing the driving device 10 to search for an entry point that performs a search faster than the search performed so far when searching for the next I picture. For example, if a search using entry_packet_ + 2 is being performed, the search is temporarily changed to a search using entry_packet_ + 3.

According to the above procedure, when the search speed temporarily decreases, the search operation immediately after is temporarily omitted or speeded up, and a search closer to a constant speed can be realized. Also, the format of the entry packet is as shown in FIG. 16, and not only the I-picture length and I-picture END sector-No. Related to the I picture following the entry packet but also entry_packet_-3 to entry_packet_ + 3 An I-picture length and an I-picture END sector-No. Related to an I picture following the indicated entry packet can be recorded in the entry packet. That is, I-picture length_-3 to I-picture length_ + 3 and I-picture END sector-No ._- 3 to I-picture END sector-No ._ + 3 are written in the entry packet.

Thus, when reading a new I picture, the control device can know the length of the I picture and the end position on the drive device before reading the entry packet multiplexed immediately before the I picture. Therefore, a higher-speed search can be realized. The entry packet has a format as shown in FIG. 16, and a video stream number and a Video stream-No. Can be recorded. A maximum of 16 video data is allowed to be multiplexed in a multiplexed bit stream defined in ISO11172 (MPEG). When a plurality of video streams are multiplexed in one multiplexed bit stream, and it is conceivable to perform a search operation on two or more multiplexed video streams, the position of the entry point differs for each video stream. , It is necessary to record entry point information for each bit stream.

In the conventional entry packet format, only entry packets for one video stream could be multiplexed. However, video stream-No. Information is recorded in entry packets, and entry packets for each video stream must be multiplexed. Enables the decoding device to select an entry packet for a required video stream, and realizes a search operation for an arbitrary video stream even in multiplexed data in which a plurality of video streams are multiplexed. it can.

In the multiplexer shown in FIG. 17, there are n video encoders 1, video entry point detection circuits 31, I picture end point detection circuits 51, and n code buffers 4 and 5, respectively. In the case of such a multiplexing device, the control device 8 switches the video or audio bit stream stored in each code buffer by the switching circuit 62 and supplies it to the header adding circuit to add a video packet header or an audio packet header, The data is recorded in the drive unit 10 in pack units.

If the pack to be recorded in the drive device 10 includes an I picture of any video stream, the entry packet is multiplexed immediately before the I picture. At this time, the control device 8 supplies the entry point generation circuit 32 with which video stream the entry packet is for, and records it in the Video stream-No. Of the entry packet.

In the multiplexed data decoding device shown in FIG. 2, the control device 24 reads out the Video stream-No. Of the entry packet from the header separation circuit 22, and when the value matches the video stream number for which the search operation is to be performed, The entry point information and the like recorded in the entry packet are stored in the entry point storage device 41. If they do not match, the entry point information and the like are discarded. As described above, an entry packet is provided for each video stream to be multiplexed, and a search operation can be realized for all multiplexed video streams by including an identifier indicating which video stream corresponds to the entry packet.

(4) The entry packet has a format as shown in FIG. 16, and a copy management flag and a copy management flag can be recorded. The Copy Management Flag realizes the same function as SCMS (Serial Copy Management System) used for CDs (Compact Discs) and DATs (Digital Audio Tapes). Is a flag that specifies that

In the data multiplexing device shown in FIG. 1, the control device 8 instructs the entry packet generation circuit 32 for a bit stream whose copying is to be prohibited, and sets a value indicating the copy prohibition in the Copy Management Flag of the generated entry packet. Set. In the data decoding device shown in FIG. 2, the control device 8 reads the Copy Management Flag of the entry packet from the header separation circuit 22, and if a value indicating copy prohibition is set here, treats the video stream as copy prohibition. . When the decoding device has an external output terminal, the decoding device does not output the bit stream data to the external output terminal or sends the bit stream data to the video stream that is treated as copy prohibited when the decoding device has the external output terminal. A value indicating copy prohibition is set in an area indicating copy prohibition of the bit stream to notify the destination device that the bit stream is copy prohibition.

(4) The Copy Management Flag can record not only information on whether or not copying is prohibited, but also information on the number of times copying is permitted. This makes it possible to create a copy by copying the bit stream, but it is possible to prohibit a copy based on the copy, that is, a copy by a grandchild copy. As described above, a bit stream whose copying is to be prohibited due to a copyright claim or the like can be clearly indicated to the decoding device or a device connected thereto.

When performing the search operation, the decoding apparatus continuously displays the I pictures using the entry packet information. In this case, pictures that are not temporally continuous are displayed. Looking at images that are not temporally continuous for a certain period of time or more in this manner may cause extreme eye fatigue. Therefore, as shown in the multiplexed data decoding device shown in FIG. 18, the control device 24 can send a brightness control signal to the video decoder 25, and reduce the brightness of the display screen during the search to reduce eye fatigue. Can be measured. The control device 24 sends a control signal for lowering the luminance to the video decoder 25 when a search operation is started by a command from a main control device (not shown). Upon receiving the brightness control signal, the video decoder 25 lowers the brightness of the display screen and darkens the display screen. When the search operation is completed, the control device 24 sends a control signal for returning the brightness to normal. The video decoder 25 returns the luminance of the display screen to a normal state according to the signal.

(4) As a result, the search operation is performed, and while a temporally discontinuous image is displayed, the brightness of the displayed image can be reduced, and eye fatigue during the search operation can be reduced.

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a data encoding device according to the present invention. FIG. 2 is a block diagram illustrating a configuration of an embodiment of a data decoding device according to the present invention. FIG. 3 is a diagram showing a pack format among data formats of a disk driven by the driving device 10 of the embodiment of FIGS. 1 and 2. FIG. 4 is a diagram illustrating a format of an entry packet of FIG. 3. 2 is a flowchart illustrating the operation of the embodiment in FIG. 1. FIG. 14 is a block diagram illustrating a configuration of an example of a conventional data encoding device. FIG. 29 is a block diagram illustrating a configuration of an example of a conventional data decoding device. FIG. 8 is a diagram illustrating a format of a bit stream in the examples of FIGS. 6 and 7. FIG. 9 is a diagram illustrating the stream ID of FIG. 8. 7 is a flowchart illustrating the operation of the example of FIG. 6. FIG. 8 is a diagram illustrating a bit stream on a disk driven by the drive device 10 of FIGS. 6 and 7. FIG. 3 is a diagram illustrating a format of an entry packet in a bit stream. FIG. 9 is a diagram for explaining another format in a bit stream of an entry packet. FIG. 11 is a diagram illustrating still another format in a bit stream of an entry packet. FIG. 3 is a block diagram illustrating a configuration of an example of a multiplexing device for recording data in an entry packet. FIG. 11 is a diagram illustrating still another format in a bit stream of an entry packet. FIG. 3 is a block diagram illustrating a configuration of an example of a multiplexing device for recording data in an entry packet. It is a block diagram which shows the structure of an example of the multiplexed data decoding apparatus which enables brightness control. FIG. 11 is a diagram illustrating still another format in a bit stream of an entry packet.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Video encoder 2 Audio encoder 3 Multiplexers 4 and 5 Code buffer 6 Switching circuit 7 Header adding circuit 8 Control device 9 Multiplexing system clock generation circuit 10 Driving device 21 Separating device 22 Header separating circuit 23 Switching circuit 24 Control device 25 Video Decoder 26 Audio decoder 31 Video entry point detection circuit 32 Entry packet generation circuits 33 and 41 Entry point storage device

Claims (14)

In the data encoding device,
An encoder for encoding the input video data into a bit stream consisting of an intra-coded picture and an inter-coded picture;
An entry packet generation unit that generates an entry packet having position information of an intra-frame coded picture;
A multiplexer for multiplexing the generated entry packet so as to be arranged before the intra-frame coded picture in the bit stream. The entry packet includes a plurality of discretely selected intra-frame codes. A data encoding device comprising position information of a coded picture. The data encoding device according to claim 1,
The data encoding apparatus, wherein the entry packet includes at least position information of adjacent forward and backward intra-coded pictures. The data encoding device according to claim 2,
The data encoding device, wherein the entry packet includes position information of an intra-frame coded picture selected such that an adjacent distance increases as the distance increases. The data encoding device according to claim 2,
The data encoding device, wherein the entry packet includes information indicating how far the intra-frame coded pictures are arranged, together with the position information of the intra-frame coded pictures. In the data encoding method,
An encoding step of encoding the input video data into a bit stream consisting of an intra-coded picture and an inter-coded picture;
An entry packet generating step of generating an entry packet having position information of an intra-frame coded picture;
Multiplexing the generated entry packet so as to be arranged before the intra-frame coded picture in the bit stream. The entry packet includes a plurality of discretely selected intra-frame codes. A data encoding method comprising position information of a coded picture. In the data decryption device,
Decoding means for decoding an intra-coded picture and an inter-coded picture from a bit stream multiplexed such that the entry packet is arranged before the intra-coded picture;
Control means for controlling a reading position from a recording medium based on position information of an intra-frame coded picture obtained from the entry packet,
The data decoding device, wherein the entry packet includes position information of a plurality of intra-coded pictures discretely selected. The data decoding device according to claim 6,
The data decoding device, wherein the entry packet includes at least position information of adjacent forward and backward intra-coded pictures. The data decoding device according to claim 7,
The data decoding device, wherein the entry packet includes position information of an intra-frame coded picture selected such that an adjacent distance increases as the distance increases. The data decoding device according to claim 7,
The data decoding device, characterized in that the entry packet includes, together with the position information of the intra-coded picture, information indicating how far the intra-coded picture is located. In the data decryption method,
Decoding an intra-coded picture and an inter-coded picture from a bitstream multiplexed such that the entry packet is placed before the intra-coded picture;
Controlling the read position from the recording medium based on the position information of the intra-frame coded picture obtained from the entry packet,
The above-mentioned entry packet comprises position information of a plurality of discretely selected intra-frame coded pictures, wherein: In a recording medium mounted on the reproducing apparatus, the reading position is controlled and read based on the recorded address information,
A moving image is encoded and recorded as a bit stream including an intra-coded picture and an inter-coded picture, and
An entry packet comprising position information of a plurality of discretely selected intra-coded pictures is multiplexed and recorded so as to be arranged before the intra-coded pictures in the bit stream. Recording medium. The recording medium according to claim 11,
The recording medium, characterized in that the entry packet includes at least position information of adjacent forward and backward intra-coded pictures. The recording medium according to claim 12,
The recording medium according to claim 1, wherein the entry packet includes position information of an intra-frame coded picture selected such that an adjacent distance increases as the distance increases. The recording medium according to claim 12,
The recording medium according to claim 1, wherein the entry packet includes information indicating how far the intra-frame coded pictures are arranged, together with the position information of the intra-frame coded pictures.

Images