JP2002057991A - Data reproduction method and data recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data reproduction method by which only required data can be read at random access even in the case that coded data where a code quantity and a time are not proportional to each other are recorded. SOLUTION: This invention provides the data reproduction method by which at least video data or audio data are reproduced from a recording medium in which multiplexed data resulting from multiplexing audio coded data with video coded data including coded data of a key frame consisting of in-frame coded frames or frames subjected to forward prediction coded are recorded in addition to management data including position information denoting a position of the key frame on the multiplexed data, and the method includes a step where the management data are read from the recording medium, a step where the position of the key frame is obtained from the management data at random access and a step where the multiplexed data are read from the position of the key frame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is applied to a digital video recording / reproducing apparatus using a read-only recording medium such as a CD-ROM or a digital video recording / reproducing apparatus using a rewritable recording medium such as a magneto-optical disk. The present invention also relates to a preferable data reproducing method and data recording method.

[0002]

2. Description of the Related Art A disk medium such as a magnetic disk, an optical disk, and a magneto-optical disk can perform high-speed random access. If high-speed random access is used, data recorded in a discontinuous area can be reproduced as continuous data.

On the other hand, since moving image data has a very high data rate, it is difficult to record it on the disk medium without processing the data. However, by encoding moving picture data and audio data with high efficiency, the data rate can be reduced to a recordable rate on a disk medium without any visual or auditory deterioration.

As an example of the high-efficiency coding method, MPEG
(Moving Picture Experts Group: MPEG). MPEG is being standardized by ISO-IEC / JTC1 / SC29 / WG11, and relates to high-efficiency encoding of video and audio and a multiplexing method for synchronous reproduction thereof. In the MPEG video coding method, a unit such as 12 video frames or 15 video frames is called a GOP (Group Of Pictures), and predictive coding is performed within the GOP.

FIG. 20 is a diagram showing an example of the structure of a GOP. Video frames in a GOP are classified into I frames, P frames, and B frames. I-frames are intra-coded. The P frame is forward predictive coded from the I frame or forward predictive coded from the P frame. The B frame is located between the I frame and the P frame or between the P frames, and is predictively coded from both directions of the I frame and the P frame.

As described above, the P frame and the B frame are
In order to perform predictive encoding from a video frame predicted and encoded from a frame or an I frame, at the time of decoding, all video frames in a GOP cannot be decoded unless the I frame is first decoded. That is, when reproducing from the middle of a video sequence by random access or the like, it is necessary to decode from an I frame. Also, since the P frame uses only prediction from the forward direction, it can be decoded relatively easily.

In the following description, the I frame and the P frame will be referred to as key frames. The video sequence refers to temporally continuous video frames from the start of recording to the end of recording and corresponding coded data.

In MPEG video coding, the average code amount is almost constant, but the code amount is not proportional to time in a short time. Therefore, the interval between the video encoded data of each frame is not constant, and the recording position of the encoded data of each frame is not uniquely determined. For this reason, it is difficult to reproduce a discontinuous video frame such as high-speed reproduction.

[0009] As a conventional example of realizing high-speed reproduction using highly efficient encoded data, there is a method described in, for example, Japanese Patent Application Laid-Open No. 5-153577. This aims at realizing high-speed reproduction by increasing the data read speed of the disk medium during reproduction and selecting data necessary for high-speed reproduction from the obtained continuous data.

[0010]

However, in the method described in the above publication, the data reading speed is increased without using random access, and data necessary for high-speed reproduction is selected from data obtained more than usual. Although the speed of high-speed reproduction increases in proportion to the data reading speed, the data reading speed is limited. That is, the speed of high-speed reproduction also has a limit.

To realize higher-speed reproduction, it is conceivable to read out discrete data using random access. That is, data reading and high-speed jump are repeated, and the speed of high-speed reproduction can be changed depending on the amount of jump.

However, when reading highly efficient encoded data, the following problems occur during jumping. That is, when jumping and playing back from the middle of the video sequence, as described above, it is necessary to decode from the I frame, but since the code amount and time are not proportional, the encoded data of the I frame is recorded. The problem is that the starting point cannot be found.

As described above, the method described in the above-mentioned publication does not allow random access to data for a predetermined time, so that a function using random access to a disk, such as cueing and reproduction of pointer editing, which will be described later, is also realized. Can not. The cue function is a function of reproducing a video output and an audio output while synchronizing from a specified time, and requires random access to reproduce from a specified time.

In the prior art, since the position of the I frame is unknown, unnecessary data may be read out until the multiplexed coded data required for reproduction is read out, and there is a problem that it takes time to find the start. . In addition, the cue position cannot be precisely defined, and a rough position must be accessed.

[0015] High-speed reproduction of a disk medium can be realized by reproducing only key frames while thinning out video frames as described above. In this case, the reading of the video coded data and the high-speed random access are repeated. However, according to the conventional technique, the recording position of the video coded data of the key frame is not known. In addition, there is a problem that the number of video frames that can be reproduced per unit time is reduced because a wide range of multiplex encoded data is read.

Pointer editing is a function of designating a plurality of playback start and end points and connecting a plurality of temporally separated data with a logical pointer without copying them. During playback, video output and audio output are performed. Play while synchronizing.

In this case as well, it is necessary to make random access from the area specified during reproduction to the next area. In the decoder, it is necessary to output reproduced data even while data cannot be obtained, and to output the reproduced data as continuous reproduced data. Therefore, it is necessary to provide a code buffer and output reproduced data using the coded data stored in the code buffer while coded data cannot be obtained.

As described above, in the prior art, unnecessary data may be read out at random access, so that a code required for decoding is not obtained for a long time, and more code buffers are required. There was a point.
Since the data read from the disk medium is multiplex encoded data to which a header for multiplexing is added,
When the video output and the audio output are reproduced in synchronization, it is necessary to read from the header.

FIG. 21 is a diagram showing an outline of multiplex encoded data recorded by the MPEG system. Multiple encoded data is divided into units called packs, and the first
Is added. The pack is a group of data to which a second header is added for each of the divided video encoded data and audio encoded data.

The first header contains information for synchronizing the encoded video data and the encoded audio data, and the second header contains information indicating the type of data following the header. included. Therefore, in order to synchronously play back video and audio, it is necessary to read from the first header.

The present invention has been made in view of such circumstances, and even when coded data that is not proportional to the code amount and time is recorded, even at the time of random access,
It is an object of the present invention to provide a data reproducing method and a data recording method capable of reading out only necessary data.

[0022]

According to a first aspect of the present invention, there is provided video encoded data including encoded data of a key frame composed of an intra-coded frame or a forward prediction-coded frame. The multiplexed coded data obtained by multiplexing the audio coded data, from the recording medium recorded separately from the management data including the position information indicating the position of the key frame on the multiplexed coded data, at least video or audio A data reproducing method for reproducing one of the data, wherein the step of reading the management data from the recording medium, the step of obtaining a key frame position from the management data at the time of random access, and the step of performing the multiplex encoding from the key frame position. Reading the data.

According to a second aspect of the present invention, the position information includes video position information indicating a position of video encoded data of a key frame, audio position information indicating a position of audio encoded data corresponding to the key frame, and a key frame. If any of the multiplexed position information indicating the position of the multiplexed coded data that needs to be read in order to play back video and audio synchronously from, when playing back video and audio synchronously, Using multiplexed location information,
When the video encoded data of the key frame and the audio encoded data corresponding to the key frame are decoded and only the video is reproduced, the video encoded data of the key frame is decoded using the video position information. It is characterized by.

According to a third aspect of the present invention, the video position information includes a head position or a rear end position of audio encoded data of a key frame, and the audio position information includes a position of audio encoded data corresponding to the key frame. The multiplexed position information includes a start position or a rear end position of the multiplexed coded data that needs to be read out for synchronously reproducing video and audio from a key frame. Features.

According to a fourth aspect of the present invention, the management data is
The information processing apparatus further includes a step of obtaining concatenated information indicating a position of encoded data of the key frame before or after the encoded data of the key frame, and determining a key frame to be reproduced next from the linked information.

According to a fifth aspect of the present invention, video encoded data including encoded data of a key frame composed of an intra-coded frame or a frame encoded by forward prediction and audio encoded data are encoded. A multi-encoded data including, and management data including position information indicating the position of a key frame on the multi-encoded data, a data recording method for recording on a recording medium, when encoding the key frame, As the position information, position information where encoded data of a key frame is recorded, position information where audio encoded data corresponding to the key frame is recorded,
Detecting any one of the position information at which the multiplexed coded data corresponding to the key frame is recorded, and recording management data including the detected position information on the recording medium separately from the multiplexed coded data. And a step.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram for explaining an embodiment of a moving picture recording / reproducing apparatus according to the present invention.
Among them, 1 is a data processing unit, 2 is a recording (disk) medium, 3 is a recording media controller, 4 is an encoded data management unit, 5 is a memory controller, 5a is a video recording information management unit, and 5b is an audio recording information management unit. 5c, a multiplexed record information management unit; and 6, a memory.

The data processing section 1 divides the multiplexed coded data input from the encoder and the data input from the coded data management section 4 into sectors and outputs the data so as to be recorded in a predetermined sector of the recording medium 2. I do. The sector number is input from the recording media controller 3.

The recording medium controller 3 outputs recording medium control data for controlling reading and writing of the recording medium 2 and outputs a sector number on the recording medium 2 to which data is to be written or read to the data processing section 1. . The coded data management unit 4 stores management data corresponding to a video sequence that is recorded in advance on a recording medium or newly recorded on a recording medium.

The encoded data management section 4 has a memory controller 5 comprising a video recording information management section 5a, an audio recording information management section 5b, and a multiplex recording information management section 5c. It is connected and controls management data stored in the memory 6.

The coded data management unit 4 further comprises: video coded data obtained by coding video data with high efficiency; audio coded data obtained by coding audio data with high efficiency; The multiplexed coded data including the coded audio data and the additional data for multiplexing the coded audio data is managed to store the multiplexed coded data on a recording medium. A frame or a video frame predictively encoded from the forward direction is used as a key frame for management, and one of the video encoded data, the audio encoded data, and the multiplex encoded data corresponding to the key frame is used. One or two or all of the encoded data with the recording position information on the recording medium and the encoded data before and after It is intended to provide a binding information management data to.

In the embodiment described below, the MPEG method described in the example of the conventional coding method is used as the coding method, and the multiplex coded data input from the encoder has the structure shown in FIG. I do. In addition, a pack including a head position previously recorded among a head position of video encoded data of a key frame and a head position of audio encoded data corresponding to the key frame is referred to as a key pack.

First, the operation when a recording medium is inserted into a recording / reproducing apparatus will be described. The recording medium controller 3 outputs recording medium control data so as to read out management data recorded on the recording medium 2. Management data is input from the recording medium 2 to the data processing unit 1 and output to the encoded data management unit 4. The encoded data management unit 4 records the input management data at a predetermined address.

Next, the operation of recording encoded data will be described. This operation is not an operation for a moving image reproducing apparatus, but an operation for a recordable apparatus. First, the data processing unit 1 divides the multiplexed coded data input from the encoder into sector units. Then, according to the sector number input from the recording media controller 3,
The encoded data is output so as to be recorded in a predetermined sector on the recording medium 2.

When recording the multiplexed coded data input from the encoder on the recording medium 2, the data processing section 1 divides the first sector number and the last sector number of the portion where the recording area is continuous into coded data. Management unit 4
Output to At the time of recording, some recording devices can divide a temporally continuous video sequence into a plurality of areas and record them, while others can only record in a continuous area. In the former case, if the data is divided into a plurality of areas and recorded, the first sector number and the last sector number are output to the encoded data management unit 4 for each area.

Further, the data processing unit 1 detects the first header of FIG. 21 added by the encoder, detects the video encoded data of the key frame and the start of the audio encoded data corresponding to the key frame. A detection unit for detecting the end is provided, and position information on a recording medium on which video coded data and multiplexed coded data corresponding to the key frame are recorded is output to the coded data management unit 4.

Here, the start and end of the video coded data of the key frame can be detected by detecting a header present in video coded data in the video coded data. Also, the start and end of the audio encoded data corresponding to the key frame can be known from the time information added to the video encoded data and the audio encoded data.

A flag indicating the start of the first header,
If the encoder is configured to output a flag indicating the start and end of the video encoded data of the key frame and the audio encoded data corresponding to the key frame, an output unit that detects the first header in the data processing unit 1; It is not necessary to provide a detector for detecting the start and end of the video encoded data of the key frame and the audio encoded data corresponding to the key frame.

The memory controller 5 in the encoded data management unit 4 generates connection information from the data input from the data processing unit 1. At this time, the recording position information of the video encoded data is managed by the video recording information management unit 5a, the recording position information of the audio encoded data is managed by the audio recording position information managing unit 5b, and the recording position information of the multiplex encoded data is managed. Are managed by the multiplexed record information management unit 5c.

Then, a video sequence, a recording area on a recording medium, and link information of key frames recorded in the recording area are generated from the contents of the memory 6 and recorded in the memory 6 together with recording position information. With this operation, when encoded data is newly recorded on the recording medium 2, the latest management data corresponding to the encoded data recorded on the recording medium 2 is always recorded in the encoded data management unit 4. Will be.

When new data is recorded on the recording medium 2, the latest management data is recorded on the encoded data management section 4, but the management data recorded on the recording medium 2 is not updated. Therefore, for example, when the recording is completed or when the recording medium 2 is taken out of the apparatus, it is necessary to record the management data recorded in the encoded data management unit 4 on the recording medium 2. Further, even while the encoded data is being recorded on the recording medium 2, the recording medium 2 may be controlled to periodically update the management data.

This procedure is performed by the recording media controller 3
Controls the recording medium 2 so that the management data is written to the recording medium 2, and controls the data of the encoded data management unit 4 to be sequentially input to the data processing unit 1. The data processing unit 1 outputs the data input from the encoded data management unit 4 to the recording medium 2.

Next, the operation during normal reproduction will be described. Here, it is assumed that management data read from the recording medium 2 has already been recorded in the encoded data management unit 4.
First, the first sector number and the last sector number where multiplexed coded data to be reproduced are recorded are read out from the coded data management section 4 and input to the recording media controller 3.

The encoded data may be divided into a plurality of areas on the recording medium 2 and recorded. In this case, the first sector number and the last sector number of the area are recorded for each recording area. Is input from the encoded data management unit 4 to the recording media controller 3.

FIG. 2 is a diagram showing an example in which the encoded data is divided into two areas indicated by oblique lines and recorded. The actual recording area of the recording medium 2 has a plurality of concentric or spiral shapes, but here, the horizontal axis represents the time axis.

Assuming that the encoded data is read out in the order of 1 and 2 in FIG.
The sector number at the position b is output, and then the sector number at the positions c and d is output. Recording media controller 3
Outputs recording medium control data such that multiplexed coded data is read from the recording medium 2 according to the sector number input from the coded data management unit 4. The data processing unit 1 receives continuous multiplexed encoded data from the recording medium 2 and outputs the data to a decoder.

Next, the operation at the time of cueing will be described.
At the time of cueing, information on the recording position on the recording medium of the multiplexed coded data corresponding to the key frame to be reproduced is output from the coded data management unit 4 to the recording medium controller 3. The recording medium controller 3 uses the input recording position information to control the recording medium 2 so as to access the sector where the encoded data of the key pack is recorded. The operation of the data processing unit 1 is the same as that of the normal reproduction.

Next, the operation during high-speed reproduction will be described. During high-speed playback, the recording media controller 3
The recording medium is controlled so as to continuously access the encoded data corresponding to the key frame. In the MPEG system, there are B frames to be predictively coded in both forward and backward directions between key frames, but during high-speed playback, video coded data of the B frames is not read.

First, when high-speed reproduction is designated, the encoded data management unit 4 outputs the position information of the key frame to be reproduced on the recording medium to the recording medium controller 3 in order. In the recording media controller 3,
Using the input recording position information, the recording medium 2 is controlled so as to access the sector where the video encoded data of the key frame is recorded.

The operation at the time of reproduction of pointer editing is almost the same as that of high-speed reproduction. In the case of high-speed reproduction, random access is made to encoded data corresponding to a key frame in order. Makes random access to the encoded data recorded in the discontinuous area according to the connection information indicated by the management data.

As described above, in this embodiment, since the recording position of the data to be read at the time of random access on the recording medium is stored as management data in the coded data management unit 4, almost all unnecessary data is read. And high-speed random access is possible.

Next, another embodiment of the present invention will be described. The block diagram of this embodiment is the same as the block diagram shown in FIG. In the present embodiment, the management data recorded in the encoded data management unit 4 includes, as recording position information of the multiplexed encoded data on the recording medium, a sector number indicating the head position of the key pack, a medium of the video encoded data. The above recording position information includes a sector number indicating a head position and a tail position of video encoded data of a key frame.

FIGS. 3A and 3B are diagrams showing examples of the head position of the key pack. The key pack indicates a pack including the first position recorded first among the head position of the video encoded data of the key frame and the head position of the audio encoded data corresponding to the key frame. FIG.
3A shows a case where the head of video encoded data of a key frame is recorded first, and FIG. 3B shows a case where the head of audio encoded data corresponding to the key frame is recorded first. It is an example. In the figure, m1, m2, ..., m
8 is multiplexing additional data.

FIG. 4 is a block diagram of a header detection circuit of the data processing unit in FIG. 1. In FIG. 4, reference numeral 7 denotes a first header detection unit, 8 denotes a video header detection unit, 9 denotes an audio header detection unit, and 10 denotes an audio header detection unit. Is a judgment circuit. The data processing unit 1 of this embodiment has a header detection circuit for detecting a header as shown in FIG. 4, and when recording encoded data, the first sector number in which the key pack is recorded and the encoded data of the key frame. And outputs to the encoded data management unit 4 the sector number in which the head and tail of the sector are recorded.

The header detection circuit shown in FIG. 4 comprises a first header detection unit 7, a video header detection unit 8, an audio header detection unit 9, and a judgment circuit 10, and the first header detection unit 7, The multiplexed coded data is input from the encoder to the video header detection unit 8 and the audio header detection unit 9, and the first header, the header added to the head of the video frame, and the head of the audio frame shown in FIG. Detects the header added to.

When a header is detected, a flag is input to the determination circuit 10. In the determination circuit 10, the first
From the headers input from the header detection unit 7, video header detection unit 8, and audio header detection unit 9 and the sector numbers input from the recording media controller 3, the first sector number in which the key pack is recorded and the key frame A sector number in which the head and tail of the video encoded data are recorded is output to the encoded data management unit 4.

The header detected in the example shown in FIG. 4 is added by an encoder at a stage preceding the data processing unit 1. Accordingly, the flag indicating that the first header, the header added to the head of the video frame, and the header added to the head of the audio frame are input from the encoder to the data processing unit 1 is input. In this configuration, the data processing unit 1 includes the first header detection unit 7, the video header detection unit 8, and the audio header detection unit 9 shown in FIG.
It is not necessary to provide.

At the time of reproduction, data read from the recording medium 2 is usually obtained in sector units.
If the head of the multiplexed coded data required for reproduction is recorded in the middle of a sector, there is unnecessary data first. Therefore, the decoder at the subsequent stage of the data processing unit 1 has the same circuit as the first header detection unit 7, video header detection unit 8, and audio header detection unit 9 shown in FIG. It is necessary to remove unnecessary data obtained before.

However, when the data processing unit 1 is provided with the circuit shown in FIG. 4 as in this embodiment, unnecessary data obtained before the header can be removed by the data processing unit 1. It is not necessary to provide a subsequent decoder with a detection circuit for detecting the header.

As described above, in this embodiment, the head or tail of each coded data corresponding to a key frame is used for managing video coded data, audio coded data, and multiplex coded data corresponding to a key frame. Since the sector number to be recorded is used, access to the key frame can be performed efficiently. That is, access to a recording position corresponding to a key frame necessary for performing cueing, high-speed reproduction, and pointer editing becomes possible by using the management data.

At this time, if both video and audio are to be output, only the management data related to multiplexed coded data need be used, and management data related to video coded data and audio coded data is unnecessary. is there. On the other hand, when accessing only the video coded data or only the audio coded data, management data related to the video coded data and the audio coded data is used.

Next, another embodiment of the present invention will be described. The block diagram of this embodiment is the same as the block diagram shown in FIG. 1, but the operation of the encoded data management unit 4 is different. In the present embodiment, of the playback involving random access, in the case of playback of cueing and pointer editing, the multi-encoded data is read out using the recording position information of the multi-encoded data on the recording medium, and the high-speed playback is performed. In such a case, the encoded video data is read out using the recording position information of the encoded video data on the recording medium.

Therefore, in the case of reproduction of the head search and pointer editing, the sector number indicating the head position of the key pack is input from the encoded data management unit 4 to the recording medium controller 3, and in the case of high-speed reproduction, the key frame is reproduced. A sector number indicating the head position and tail position of the video encoded data is input.

This is because it is necessary to synchronize the audio output with the video output in the case of the reproduction of the cue and the pointer edit, and in the case of the high-speed reproduction, only the video output. According to the present embodiment, at the time of high-speed reproduction, unnecessary audio encoded data is not read out, and the number of images that can be reproduced per unit time is increased.

In the above-described embodiment, as the position information of the multiplexed coded data on the recording medium in the management data, the sector number in which the head position of the key pack is recorded is described.
As the position information of the video encoded data on the recording medium, a sector number indicating a start position and a tail position of the video encoded data of the key frame is used.

Further, as another embodiment, as the management data, the starting position of the key pack and the sector number indicating the tail position of the video encoded data of the key frame are used, and the sector indicating the starting position of the video encoded data of the key frame is used. Embodiments that do not use numbers are also conceivable. In this case, whether the audio output and the video output are reproduced synchronously or only the video output is used, the head position of the key pack is accessed at the time of random access.

Therefore, when only video output is required, unnecessary audio coded data may be read out. For example, in the case of high-speed reproduction, the number of video frames that can be reproduced per unit time is reduced. The data capacity can be reduced.

If a flag indicating the end of a video frame is input from the video decoder during reproduction, it is not necessary to record the tail position of the video encoded data of the key frame, and the management data can be further reduced. Can be. In this case, only the sector number indicating the head position of the key pack is used as the management data.

Next, another embodiment of the present invention will be described. FIG. 5 is a block diagram of the encoded data management unit in FIG. 1. In FIG. 5, reference numeral 11 denotes a memory controller, and 12 to 14 represent memories.

As shown in FIG. 5, the coded data management section 4 has three memories 12, 13, 1 for storing management data.
4 and a memory controller 11 for controlling them. In the memories 12, 13, and 14, a first table (hereinafter, referred to as a sequence table) for managing a video sequence and a second table (hereinafter, referred to as an area table) for managing a recording area on a recording medium are provided. And a third table (hereinafter, referred to as a key frame table) for managing video encoded data, audio encoded data, or multiplex encoded data corresponding to the key frame.

FIG. 6 shows an example of the contents of the management data recorded in each memory shown in FIG. 5. In FIG. 5, 21 is the next sequence address, 22 is the area table address,
23 is the address of the next area, 24 is the starting sector number, 2
5 is the end sector number, 26 is the start frame address, 2
7 is a next frame address, 28 is a pack start sector number, 29 is a key start sector number, 30 is a key end sector number, addresses 21, 22, 23, 26, and 27 are pointers (connection information) and sector numbers. 24, 25, 2
8, 29 and 30 are recording position information.

The sequence table of the memory 12 has one word of data for one video sequence.
One-word data includes a pointer “next sequence address” 21 indicating the next word and a pointer “area table address” 22 indicating the position of the area table.

The "next sequence address" 21 indicates the reproduction order of the video sequence, and the "region table address" 22 indicates the address of the region table corresponding to the video sequence. Here, "next sequence address"
21 indicates an address of the memory 12, and the last data connected by the pointer "next sequence address" 21 has a special value indicating "end".

The area table of the memory 13 has one word of data for each continuous recording area on the recording medium. One-word data includes a pointer “address of next area” 23 indicating the next word, a “start sector number” 24, which is the first sector number of a continuous recording area, and a “last sector number”, which is the last sector number of a continuous recording area. End sector number 2
5. Pointer "start frame address" 26 indicating the start address of the key frame table corresponding to the key frames included in the continuous recording area.

The area table corresponding to one word data of the sequence table is obtained by converting the area table address indicated by “area table address” 22 in the sequence table into a series of area tables connected by the pointer “address of next area” 23. Becomes

The “address of the next area” 23 is the memory 1
The last data connected by the pointer "address of the next area" 23 has a special value indicating "end". When a key frame is not recorded in the area from the start sector number to the end sector number indicated by one word data in the area table, the “start frame address” 26 has a special value indicating “no data”.

The key frame table in the memory 14 includes:
There is one word of data for each key frame. One word data includes a pointer "next frame address" 27 indicating the next word, a "pack start sector number" 28 indicating the sector number in which the head of the key pack is recorded, and the head of video encoded data of the key frame. Are the "key start sector number" 29 indicating the sector number in which is recorded, and the "end key sector number" 30 indicating the sector number in which the rear end is recorded.

The "next frame address" 27 indicates the address of the memory 14, and the last data connected by the pointer "next frame address" 27 has a special value indicating "end".

In the example of FIG. 6, there is no information indicating whether the data recorded in the key frame table of the memory 14 of FIG. 5 indicates coded data of an I frame or P frame. Therefore, as described later,
A flag indicating whether the I-frame video encoded data or the P-frame video encoded data is indicated for each word data of the key frame table is added, or the key frame table is added to the I frame table and the P frame.
The technique of separating into frame tables is used.

FIG. 7 is a diagram showing the relationship between the management data recorded in each table of the memory shown in FIG. 5 and the recording area. A plurality of video sequences can be recorded on the recording medium 2, and one video sequence may be recorded in a continuous recording area on the recording medium 2 or divided into a plurality of recording areas. It may be done.

In the example of FIG. 7, three video sequences are recorded, and video sequence 1 is divided into three regions and recorded. It is assumed that the reproduction order is the sequence of the video sequences 1, 2, and 3.

In the case of the example of FIG. 7, the sequence table includes three 1's corresponding to video sequences 1, 2, and 3, respectively.
There will be word data. The first one-word data is data corresponding to the video sequence 1, the “next sequence address” of the video sequence 1 indicates one-word data corresponding to the video sequence 2, and the “next sequence address” of the video sequence 2 Indicates one-word data corresponding to the video sequence 3. The “area table address” of the sequence table indicates the address of the first area table data corresponding to the video sequence.

In the area table, one word data corresponds to a continuous recording area on the recording medium 2. That is,
In the case of FIG. 7, there are three 1-word data of the area table corresponding to the video sequence 1. As described above, when there are a plurality of area tables, the “address of the next area” of the area table indicates the next area table data.

Of the 1-word data in the area table,
“Start sector number” indicates the first sector number of the continuous recording area, and “end sector number” indicates the last sector number. In this continuous recording area, encoded data of a plurality of key frames is recorded. Among them, the sector number in which the encoded data of the first key frame is recorded is managed by a key frame table indicated by “start frame address”.

In one word data of the key frame table, “pack start sector number” indicates a sector number in which the head of the key pack is recorded, and “key start sector number”
Indicates the sector number at which the head of the video encoded data of the key frame is recorded, and “key end sector number” indicates the sector number at which the tail of the video encoded data is recorded. The “next frame address” indicates the next key frame table data.

FIG. 8 is a diagram showing an example of a special case in which encoded data of the same key frame extends over an area managed by a plurality of area tables. In the example of FIG. 8, the encoded data of the key frame i is recorded over three recording areas of the recording area 1, the recording area 2, and the recording area 3.

In the case of FIG. 8, the “key start sector number” of the last key frame table corresponding to the recording area 1 includes
The sector number indicating the head of the video encoded data of the key frame i is recorded, the sector number indicating the tail is recorded in “key end sector number”, and the “key end sector number” is the sector number of the recording area 3. .

Since there is no key frame table corresponding to the recording area 2, data indicating "no data" is recorded in the "start frame address" of the recording area 2. The “start frame address” of the recording area 3 indicates the key frame table of the key frame i + 1.

At the time of high-speed reproduction, the “key start sector number” and the “key end sector number” recorded in the key frame table are input to the recording media controller 3.
The recording medium controller 3 controls the recording medium 2 so as to read data from “key start sector number” to “key end sector number”.

At this time, when the key frame i shown in FIG. 8 is reproduced, as described above, the “key start sector number” corresponding to the key frame i in the key frame table is used.
And the “key end sector number” indicate different recording areas. However, even in such a case, it can be known that reproduction is performed in the order of the recording area 1, the recording area 2, and the recording area 3 based on the information recorded in the area table.

Therefore, the recording medium controller 3 accesses the recording medium 2 in the order of the recording area 1, the recording area 2, and the recording area 3, and reads out data up to the “key end sector number”.

If the video sequence is divided into a plurality of areas and is not recorded, but is recorded only in a continuous area, and editing is not performed during reproduction and the order is not changed,
For example, in FIG. 6, if the “address of the next area” 23 in the area table indicates the playback order of the video sequence, the sequence table becomes unnecessary.

Next, the operations of the memory controller and the memory shown in FIG. 5 will be described in more detail. When the recording medium 2 is inserted into the device, the management data recorded on the recording medium 2 is sequentially input. Therefore, the memory controller 11 controls the memories 12 and 13 to record the management data in a predetermined memory. , 14 are controlled.

FIG. 9 is a flowchart for explaining the operation of the memory when recording encoded data on a recording medium. Here, it is assumed that each table is based on the structure of FIG. 6, and how the management data changes is shown in FIG.

In the sequence table of the memory 12 of FIG. 6, one word of data is added to the end of the already recorded data, and the area table of the memory 13 corresponding to the added data of the sequence table and the Record additional data of the key frame table. In FIG. 10, the solid line portion is the management data already stored, and the dotted line portion is the management data to be additionally recorded.

In the following description, ad12, adl
12, are the addresses of the memory 12, ad13, adn1
3 denotes an address of the memory 13, and ad14 and adn14 denote addresses of the memory 14, respectively. When recording, the recording media controller 3 of FIG. 1 manages the empty area of the recording medium 2 based on the management data in advance, and controls to record data in each sector of the empty area.

Hereinafter, each step (S) will be described in order according to the flowchart of FIG. First, a sequence table in the memory 12 is set in steps S101 to S104. Free area of memory 12 and memory 1
A search is made for an empty area of No. 3 and these are set as ad12 and ad13, respectively (S101). Then, the “area table address” of ad12 is set to ad13, and the “next sequence address” is set to “end” (S102).

Next, the address of the last data among the data connected by the pointer "next sequence address" in the sequence table of the memory 12 is set to adl12 (S103). Then, the “next sequence address” of adl12 is set as ad12 (S104). With the above operation, new one-word data ad12 is added to the rear end of the sequence table.

Next, an area table of the memory 13 is set. Since the first sector number of the continuous recording area on the recording medium 2 is input to the encoded data management unit 2, this input data is set as the “start sector number” of ad13 (S105). Then, an empty area of the key frame table in the memory 14 is searched and is set as ad14 (S10).
6). Then, the “start frame address” of ad13 is set as ad14 (S107).

Next, three sector numbers, ie, a sector number in which the head of the key pack is recorded and a sector number indicating the head and tail of the video coded data of the key frame are input. (S108), "pack start sector number", "key start sector number", and "key end sector number".

Then, it is determined whether or not the continuous recording area of the recording medium 2 is completed (S109). If not completed, a free area of the memory 14 is searched for and set as adn14 (S110). Then, the "next frame address" of the ad14 is set as the and14, and the ad14 is updated to indicate the adn14 (S111).

Next, the process returns to step S108. Recording media 2 in a loop of steps S108 to S111
The sector number indicating the encoded data of the key frame recorded in the continuous recording area is written in the key frame table.

If the continuous recording area of the recording medium 2 is completed in step S109, the last sector number of the recording area which is the input sector number is stored in the area table ad13.
(S112), and the "next frame address" of the key frame table ad14 is set to "end". Step S105 to step S113
Thus, the data of the one-word area table is set.

Next, in step S114, it is determined whether or not the input data is completed. If the input data is not completed, a free area in the area table is searched for and set as adn13 (S115).
The “address of the next area” of d13 is set as adn13, and the ad13 is updated so as to indicate the adn13 (S1).
16).

Then, the flow returns to step S105. In the loop of steps S105 to S116, new area table data connected by a pointer is created from the previous area table data, and the sector numbers are recorded in a series of key frame tables indicated by the area table data. If it is determined in step S114 that the data is completed, the “address of the next area” of ad13
Is set to 'end' (S117), and the operation ends.

Next, the operation during normal reproduction will be described. At the time of normal reproduction, the “start sector number” and the “end sector number” of the area table corresponding to the video sequence to be reproduced are output to the recording media controller 3. FIG.
FIG. 7 is a diagram showing an operation at the time of normal reproduction in a flowchart.

Here, the sequence table and the area table corresponding to the data being reproduced are referred to as “sequence address” and “area address”.
Use two pointers. Each table is based on the structure shown in FIG.

Hereinafter, description will be made in order according to each step (S). First, "sequence address" and "area address" are set (S121 to S122). Next, the value of the “start sector number” and the value of the “end sector number” of the “area address” are output to the recording media controller 3 (S123, S124).

The recording media controller 3 uses the first sector number and the last sector number of the continuous recording area input from the encoded data management unit 4 to read data recorded in the continuous recording area. To control the recording medium 2.

Then, it is determined whether the "address of the next area" of the "area address" is "end" (S12).
5). If it is determined that it is not “end”, since the area table data corresponding to the “sequence address” remains, the “area address” is set as the “address of the next area” of the “area address”, and the pointer is advanced ( S126),
It returns to step S123.

In the loop of steps S123 to S126, the first sector number and the last sector number of the recording area are sequentially output for each of a plurality of continuous recording areas on the recording medium 2 corresponding to one word data of the sequence table. Is done.

If it is determined in step 125 that it is “end”, it is determined whether the “next sequence address” of the “sequence address” is “end” (S127).
If it is determined that the video sequence is not “end”, since the video sequence recorded on the recording medium 2 remains,
The “sequence address” is set as the “next sequence address” of the “sequence address”, and the pointer is advanced (S
128), and the process returns to step S122.

In the loop of steps S122 to S128, the first sector number and the last sector number are sequentially output for each continuous recording area until the video sequence recorded on the recording medium 2 ends.

FIG. 12 is a flowchart for explaining the operation in the case of high-speed reproduction. At the time of high-speed reproduction, a sector number in which the head and tail of the video encoded data of the key frame recorded in the key frame table are recorded is read out and output to the recording media controller 3.

Here, a "sequence address" indicating the address of each of the sequence table, area table and key frame table corresponding to the data being reproduced,
3 called "area address" and "key frame address"
Use two pointers.

Hereinafter, each step (S) will be described in order. First, “sequence address”, “area address”, and “key frame address” are set (S13).
1 to S133). Next, the "key start sector number" and the "key end sector number" of the "key frame address" are output to the recording media controller 3 (S134).

The recording medium controller 3 controls the recording medium 2 so as to read the video encoded data of the key frame from the first sector number and the last sector number input from the encoded data management section 4.

Then, it is determined whether the "next key frame address" of the "key frame address" is "end" (S135). If it is not 'end', since the sector number to be accessed next is recorded in the 'next key frame table', set 'key frame address' to 'next key frame address' of 'key frame address', The pointer is advanced (S136), and the process returns to step S134.

In the loop of steps S134 to S136, a plurality of sector numbers recorded in the key frame table corresponding to one word data of the area table are output to the recording media controller 3.

If it is determined in step S135 that "end", it is determined whether the "next area address" of "area address" is "end" (S137). If it is determined that it is not “end”, since area table data corresponding to “sequence address” remains, “area address” is set to “next area address” of “area address”, and the pointer is advanced (S138). ), And returns to step S133.

In the loop from step S133 to step S138, the sector numbers for the video encoded data of the key frame corresponding to one word data of the sequence table are sequentially output.

If it is determined in step S137 that the processing is "end", it is determined whether the "next sequence address" of the "sequence address" is "end" (S139).
If it is determined that the video sequence is not “end”, since the video sequence recorded on the recording medium 2 remains,
The “sequence address” is set as the “next sequence address” of the “sequence address”, and the pointer is advanced (S
140), and return to step S132.

Until the video sequence recorded on the recording medium 2 ends in the loop of steps S132 to S140, sector numbers corresponding to the video encoded data of the key frames are sequentially output.

In the example of FIG. 12, all the sector numbers recorded in the key frame table are output. That is,
All key frames are reproduced, but when the speed of high-speed reproduction is high, some frames may be thinned and output.

Here, in order to decode a P frame,
A decoded image of a past I frame or P frame is required. Therefore, when an I frame or a P frame in a GOP is thinned, P frames subsequent to the thinned frame in the GOP cannot be decoded.

For example, in the case of the GOP structure as shown in FIG. 13, when the frame (c) is thinned, the frame (d)
Is not decoded because a decoded image of the referenced frame (c) cannot be obtained. Similarly, when the frame (b) is thinned, the frames (c) and (d) cannot be decoded. When the frame (a) is thinned, the frames (b) and (b) are not decoded.
(C) and (d) cannot be decoded. As described above, since the number of frames that cannot be decoded differs depending on the frames to be decimated, which frame to be decimated is calculated from the speed of high-speed reproduction.

FIG. 14 is a diagram showing another example of management data recorded in the coded data management section of FIG. 1, and the reference numerals in FIG. 14 are the same as those in FIG. This is an example in which a signal indicating the end of the key frame is input from the decoder. The example of the management data recorded in the encoded data management unit 4 shown in FIG. Sector number ”. Therefore, in this embodiment, the capacity of the encoded data management unit 4 is smaller.

The operation in this example is different from the operation in FIG.
Different only for high-speed playback. That is, in the example of FIG.
At the time of high-speed playback, the "key end sector number" of the key frame table is output, and the recording media controller 3 can detect the end of the key frame with this data. In this example, the data indicating the end of the key frame is obtained from the key frame table. Is not output and the recording media controller 3
Detects the end of a key frame by an input signal from a decoder. In the case of normal reproduction or reproduction of pointer editing, the end position of the key frame does not need to be used, and the operation is the same as that in the example of FIG.

FIG. 15 is a diagram showing another example of the management data. The reference numerals in FIG. 15 are the same as those in FIG. In this method, a signal indicating the end of a key frame is input from a decoder, and the head position of the key pack is accessed at random access when audio output and video output are reproduced synchronously or when only video output is performed.

As described above, in this example, when only video output is required, unnecessary audio encoded data may be read. For example, in the case of high-speed reproduction, reproduction is performed per unit time. Although the number of possible video frames is reduced, the capacity of management data can be further reduced.

In cueing, high-speed reproduction, and pointer editing reproduction, it is necessary to know which of the managed key frames is an I frame. When only the I frame is managed by the key frame table, it is possible to know which key frame is the I frame in the examples of FIGS. 6, 14, and 15, but the I frame and the P frame are determined by the key frame table. In the case of management, see FIG. 6, FIG. 14, FIG.
In the example, it is difficult to know whether the key frame is an I frame or a P frame.

Therefore, for example, as shown in FIG. 16, if a 1-bit flag 31 indicating whether the data is I-frame data or P-frame data is added to each word data of the key frame table, the key frame becomes It can be seen whether it indicates an I frame or a P frame.

FIG. 16 is a diagram in which a 1-bit flag 31 is added to the key frame table shown in FIG.
Similarly, a 1-bit flag is added to the key frame tables of FIGS.
Frames can be distinguished.

Next, still another embodiment of the present invention will be described. FIG. 17 is a block diagram showing another example of the encoded data management unit shown in FIG. 1. In FIG. 17, reference numeral 32 denotes a memory controller, reference numerals 33 and 34 denote memories, and other parts having the same functions as those in FIG. The code is attached. The encoded data management unit 4 includes four memories 12, 13, 33, and 34 and a memory controller 32 that controls them.

The memories 12 and 13 are the same as those in FIG. 5, and the memory 33 has a fourth table (hereinafter referred to as an I-frame key) for managing the recording position information of the I-frame on the recording medium among the key frames. The memory 34 stores a fifth table (hereinafter, referred to as a P-frame key frame table) for managing the recording position information of the P-frame on the recording medium.

FIG. 18 is a diagram showing an example of data to be recorded in the I-frame key frame table and the P-frame key frame table. In FIG. 18, reference numeral 41 denotes the next frame address of I, 42 denotes the pack start sector number, 43 is the key start sector number of I, 44 is the key end sector number of I, 4
5 is a frame address of P, 46 is a frame address next to P, 47 is a key start sector number of P, 48 is a key end sector number of P, and addresses 41, 45, and 46 are pointers (connection information). Sector numbers 42, 43, 4
4, 47 and 48 are recording position information.

The structure of each table is the same as that of the key frame table shown in FIG. 6. The only difference is that the I frame key frame table has a pointer indicating the address of the P frame key frame table. The key frame table for the P frame is different only in that there is no pack start sector number. Since it is assumed that the P-frame key frame table is used only for high-speed reproduction, no key pack position information is required.

In the example of FIG. 18, the key frame table corresponding to one I frame is composed of one word data of the key frame table for the I frame and the P frame address indicated by the “P frame address” 45 of the data. From the data in the key frame table, "frame address next to P"
The word data of a series of P-frame key frame tables connected by 46 are provided.

In a moving picture recording / reproducing apparatus using the present invention,
When changing or erasing the playback sequence of a video sequence or a part thereof, it is only necessary to change the sequence table of the memory 12, the area table of the memory 13, and the key frame table of the memory 14, which are recorded on the recording medium. There is no need to change the encoded data. For example, when erasing one video sequence, it is only necessary to remove one word data of the sequence table corresponding to the video sequence to be erased from the pointer connected by the “next sequence address”.

To change the reproduction order of the video sequence, it is only necessary to change the order of the pointers connected by the "next sequence address" in the sequence table. When a part of the sequence is to be left and the remaining part is deleted, the data of the area table corresponding to the part to be deleted is removed from the pointer connected by the “table address of the next area”, and “ It is only necessary to newly set the “start sector number” and the “end sector number”.

In the case of pointer editing, management data indicating a new playback order after editing is reconstructed from the original management data and stored separately from the original management data.
Various playbacks are possible while maintaining the original playback order.

To write new data in each table, it is necessary to manage unused addresses in each table. As a method of managing unused addresses, there is a method in which a table for managing free addresses is provided for each table, and a method of finding an unused address by following a pointer of each table to check a used address is conceivable. As in 19, unused addresses can also be managed.

Next, another embodiment of the present invention will be described. FIG. 19 is a diagram in which a 1-bit flag indicating whether the data is used or unused is added to each word data of each table.
In FIG. 9, reference numerals 51 to 53 denote flags indicating whether they are used or not used, and other parts having the same functions as those in FIG.

In the embodiment shown in FIG. 19, flags 51 to 53 indicating whether the word is used or not are added to each word of the configuration example shown in FIG. 6, but FIGS. 14, 15, 16, and 18
The same can be applied to the example shown in FIG.

In the above-described embodiment, management data is constructed at the time of recording encoded data, and reproduction with random access is performed at high speed using the management data. Therefore, in the case of a medium on which management data is not recorded at the time of recording encoded data, it is necessary to construct management data.

Next, means for constructing management data in the embodiment of FIG. 1 will be described below. First, the recording medium controller 3 outputs recording medium control data so that data recorded on the recording medium 2 is read from the beginning to the end.

In the data processing section 1, a video sequence,
A detection circuit for detecting the start and end of each of the pack and the key frame is provided, the sector number where the beginning and the end of the video sequence are recorded, the sector number where the beginning of the key pack is recorded, and the video code of the key frame. It outputs the sector number in which the head and tail of the encoded data are recorded to the encoded data management unit 4. The coded data management unit 4 additionally records management data in the same order as when recording coded data.

In the above embodiment, the sector number is used as the recording position information on the recording medium. However, the present invention is not limited to this. Depending on the recording media,
There may be another notation such as a set of a track number and a sector number. In such a case, the notation according to the recording medium may be used.

As apparent from the above description, the present invention has the following effects. In order to store, as management data, recording position information of video encoded data, audio encoded data, and multiplexed encoded data corresponding to a key frame on a recording medium, the reproduction of a key frame to be accessed in the case of random access is performed. The position on the recording medium is known. Therefore, high-speed random access can be performed without reading unnecessary data at the time of random access.

By using the start position and the tail position of the video coded data and the multiplexed coded data corresponding to the key frame as the management data, unnecessary data is not read out at the time of random access, and high-speed cueing is performed. Becomes possible. In other words, at the time of high-speed reproduction, the number of video frames that can be reproduced per unit time increases, and at the time of reproduction of pointer editing, access to a joint position of scenes can be efficiently performed.

When the video output and the audio output are reproduced synchronously, the multiplexed coded data necessary for synchronous reproduction is accessed, and when only the video output is reproduced, only the coded video data is accessed. Then, when only video output is required, such as in high-speed reproduction, more images can be reproduced per unit time.

As management data, the first layer is a video sequence, the second layer is a recording area on a recording medium,
By using a hierarchical structure in which the hierarchy is a key frame position recorded in the recording area, even when a new video sequence is recorded or deleted, or when the reproduction order is changed,
Management data can be easily updated.

If management data corresponding to a key frame recorded in the recording area is recorded in a hierarchical structure of an I frame and a P frame following the I frame, the I frame and the P frame can be managed separately. . Therefore, for example, at the time of high-speed reproduction, the type of the I frame and the P frame and the recording position on the recording medium can be known, so that the frame to be used can be flexibly selected according to the high-speed reproduction speed.

Further, since the pointer indicating the reproduction order in each table and the pointer indicating the connection relationship between the tables are used as the connection information in each layer of the management data and between the layers, it is necessary to change these pointers. Thus, recording, erasing, changing the playback order of the video sequence, erasing a part of the video sequence, changing the playback order, and the like can be easily performed.

If a 1-bit flag indicating whether the word is used or unused is added to each word of the management data,
Since it is possible to know whether the memory for recording the management data is used or free, it is easy to manage the free area of the memory.

Even if the management data is not recorded,
If the management data is newly constructed, even with a recording medium on which no management data is recorded, reproduction with random access can be performed at high speed.

As described above, in order to use inter-frame prediction for moving picture coding such as the MPEG method, if random access is allowed only for a specific key frame, video coded data or audio coding for the key frame is performed. Since the recording positions of the coded data and the multiplexed coded data are managed, a desired key frame can be directly accessed. Therefore, high-speed reproduction and pointer editing can be performed easily and efficiently, and a moving image accompanied by audio can be handled, so that the effect is remarkable.

[0159]

According to the present invention, when multiplexed data including video encoded data and audio encoded data is recorded on a recording medium, position information indicating the position of a key frame on the multiplexed data is managed. By recording the data on a medium and accurately accessing the key frame using the management data during reproduction, it is possible to realize functions such as cueing, high-speed reproduction, and editing.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a moving image recording / reproducing apparatus according to the present invention.

FIG. 2 is a diagram for explaining a position on a recording medium of a sector number input from an encoded data management unit in FIG. 1;

FIG. 3 is a diagram showing a head of a key pack according to the present invention.

FIG. 4 is a diagram illustrating a header detection circuit of the data processing unit in FIG. 1;

FIG. 5 is a block diagram of an encoded data management unit in FIG. 1;

6 is a diagram showing an example of the content of management data recorded in a memory in FIG.

FIG. 7 is a diagram illustrating a relationship between management data recorded in an encoded data management unit and a recording area on a recording medium according to the present invention.

FIG. 8 is another diagram showing a relationship between management data recorded in an encoded data management unit and a recording area on a recording medium according to the present invention.

FIG. 9 is a flowchart for explaining the operation of the encoded data management unit when recording encoded data in the moving picture recording / reproducing apparatus according to the present invention.

FIG. 10 is a diagram illustrating updating of an encoded data management unit when encoded data is recorded in the present invention.

FIG. 11 is a flowchart showing the operation of the encoded data management unit during normal reproduction according to the present invention.

FIG. 12 is a flowchart showing the operation of the encoded data management unit at the time of high-speed reproduction according to the present invention.

FIG. 13 is a diagram for explaining frames to be thinned out in a GOP and frames that cannot be decoded in the present invention.

FIG. 14 is a diagram illustrating another example of management data recorded in an encoded data management unit according to the present invention.

FIG. 15 is a diagram illustrating another example of management data recorded in an encoded data management unit according to the present invention.

FIG. 16 is a diagram showing another configuration example of the key frame table according to the present invention.

FIG. 17 is a block diagram showing another embodiment of the encoded data management unit in FIG. 1;

FIG. 18 is a diagram showing an example of data recorded in an I-frame key frame table and a P-frame key frame table in the present invention.

FIG. 19 is a diagram in which a 1-bit flag indicating whether the word data is used or unused is added to each word data of each table in the present invention.

FIG. 20 is a diagram illustrating a configuration example of a conventional GOP.

FIG. 21 is a diagram showing an example of conventional multi-encoded data.

[Description of Codes] 1 Data processing unit 2 Recording medium 3 Recording media controller 4 Encoded data management unit 5 Memory controller 5a Video recording information management unit 5b Audio recording information management unit 5c Multiplexed recording information Management section 6 Memory 7 First header detection section 8 Video header detection section 9 Audio header detection section 10 Judgment circuit 11 Memory controller 12, 13, 14 Memory 32 Memory controller 33, 34 Memory 21 Next sequence address 22 ... Area table address 23 ... Next area address 24 ... Start sector number 25 ... End sector number 26 ... Start frame address 27 ... Next frame address 28 ... Pack start sector number 29 ... Key start sector number 30 ... key end sector number 31 ... I frame or P frame Flag indicating whether frame is present 41 ... Next frame address of I 42 ... Pack start sector number 43 ... Key start sector number of I 44 ... Key end sector number of I 45 ... P frame address 46 ... P next frame address 47 ... P key start sector number 48 ... P key end sector number 51-53 ... Flag indicating whether it is used or not used

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 27/10 H04N 5/781 Z H04N 5/781 5/85 A 5/85 5/93 Z 5/92 5/92 HF term (reference) 5C052 AA01 AA02 AA03 AB03 AB04 AC01 CC05 CC11 DD04 DD06 5C053 FA23 FA27 GB06 GB11 GB37 HA21 KA05 5D044 AB05 AB07 BC02 CC04 DE03 DE12 DE14 DE24 DE25 DE37 DE49 DE53 DE58 EF05 FG18 GK12 BA CB06 DC10 DC16 DE13 EA13 EA33 EA34 5D110 AA14 AA27 AA29 BB04 DA01 DA11 DA12 DA15 DB03 DB05 DC05 DC15 DE02 DE04 DE06

Claims (5)

[Claims] 1. A multiplex coding method that multiplexes coded video data and coded audio data including coded data of a key frame composed of an intra-coded frame or a forward predicted coded frame. The data is,
A data reproducing method for reproducing at least one of video and audio from a recording medium recorded separately from management data including position information indicating a position of a key frame on the multiplexed coded data, comprising: A data reproducing method comprising: reading the management data; obtaining a key frame position from the management data at random access; and reading the multiplexed coded data from the key frame position. . 2. The data reproduction method according to claim 1, wherein the position information indicates video position information indicating a position of video encoded data of a key frame, and indicates a position of audio encoded data corresponding to the key frame. Includes either audio position information or multiplexed position information indicating the position of multiplexed coded data that must be read from keyframes for synchronized playback of video and audio, and plays back video and audio in synchronization If you do
Using the multiplexed position information, video encoded data of a key frame and audio encoded data corresponding to the key frame are decoded, and when only video is reproduced, the key frame is decoded using the video position information. A data reproducing method characterized by decoding video encoded data of (1). 3. The data reproducing method according to claim 2, wherein the video position information includes a start position or a rear end position of video encoded data of a key frame, and the audio position information corresponds to the key frame. The multiplexed position information includes the start position or the end position of the multiplexed coded data that needs to be read from the key frame in order to reproduce the video and the audio synchronously. A data reproducing method comprising an edge position. 4. The data reproduction method according to claim 1, wherein the management data is linked information indicating a position of encoded data of a key frame before or after encoded data of a key frame. And a step of obtaining a key frame to be reproduced next from the connection information. 5. Multiple encoded data including video encoded data including audio encoded data and video encoded data including encoded data of a key frame composed of an intra-frame encoded frame or a forward predicted encoded frame. A management data including position information indicating a position of a key frame on the multiplexed coded data, a data recording method for recording on a recording medium, at the time of encoding the key frame, as the position information,
Detects any one of the position information where the encoded data of the key frame is recorded, the position information where the audio encoded data corresponding to the key frame is recorded, and the position information where the multiplex encoded data corresponding to the key frame is recorded. And a step of recording management data including the detected position information on the recording medium separately from the multiplexed coded data.