JP2003052018A - Mpeg data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder capable of realizing the seamless and high fidelity reproduction of first MPEG picture data and second MPEG picture data without generating inconsistency in overflow or underflow at the time of connecting a VBV buffer. SOLUTION: The data of a linking section A of first MPEG picture data are decoded and re-encoded. The re-encoding of the data is executed so that the transition of a VBV buffer occupancy value can start from a VBV buffer occupancy value at the position of (a), and end at a VBV buffer occupancy value at the position of (d). Then, the first MPEG picture data are reproduced until the position of (a) of the first MPEG picture data, and then the re-encoded MPEG picture data of the linking section A are reproduced, and connected to the position of (d) of the second MPEG picture data. The second MPEG picture data following the position of (d) are reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first MP and a second MP which are image data encoded by the MPEG encoding system.
When the EG image data is reproduced by connecting it from the first MPEG image data to the second MPEG image data at a specified connection specified position in each MPEG image data,
The present invention relates to an MPEG data recording device for realizing seamless reproduction.

[0002]

2. Description of the Related Art The prior art used in this patent.
The MPEG will be briefly described.

Regarding MPEG, ISO-IEC11172-2, ITU-T H.
Since detailed explanation is given in 262 / ISO-IEC13818-2, only an outline is explained here. MPEG was 1988, ISO / IE
C JTC1 / SC2 (International Standards Organization / International Electrotechnical Standards Meeting Technical Committee 1 / Special Subcommittee 2, current SC29) The name of the organization that examines video coding standards (Moving Pictures)
Expert Group) is an abbreviation. MPEG1 (MPEG Phase 1)
Is a standard for storage media of about 1.5 Mbps, and JPEG for still image coding and H. for moving image compression for low transfer rates of ISDN video conferences and video phones.
It inherits the basic technology of 261 (CCITT SGXV, standardized by the current ITU-T SG15) and introduced a new technology for storage media. These are ISO / IEC 11172, August 1993.
Has been established as.

MPEG1 is created by combining several technologies. FIG. 5 shows a conventional MPEG encoder that performs encoding according to the MPEG encoding method, which will be briefly described below. The input image is decoded by the motion compensation predictor 1 and the difference between the input images is obtained by the difference unit 2 to reduce the time redundant part.

The direction of prediction is 3 from both past and future.
Mode exists. These are 16 pixel x 16 pixel MB (Mac
It can be switched for each roblock). The prediction direction is determined by the Picture Type given to the input image. A unidirectional inter-picture predictive coded image (P-picture) has two modes: a mode of coding by prediction from the past and a mode of independently coding the MB without prediction. In addition, bi-directional inter-picture prediction code is present in four modes: a mode for coding by prediction from the future, a mode for coding by prediction from the past, a mode for coding by prediction from both, and a mode for independent coding. Image (B-pict
ure). It is an intra-picture independent coded image (I-picture) that all MBs are coded independently.

In motion compensation, pattern matching is performed for each MB in a motion area to detect a motion vector with half-pel accuracy, and the motion vector is shifted by the motion amount before prediction. The motion vector has a horizontal direction and a vertical direction, and is transmitted as additional information of the MB together with the MC (Motion Compensation) mode indicating where the prediction is from.

Generally, a picture from an I picture to a picture before the next I picture is called a GOP (Group Of Picture). When used in a storage medium, generally about 15 pictures are included in one GOP section. Used as. (However, two or more I pictures may be included in one GOP section. In short, one or more I pictures may be included in one GOP section.) The DCT unit 3 orthogonally transforms the difference image. DCT (Discrete Cosine Transform) is an orthogonal transformation that performs discrete transformation of integral transformation with a cosine function as an integral kernel into a finite space. In MPEG, MB is divided into four and two-dimensional DCT is performed on an 8 × 8 DCT block. In general, a video signal has many low-frequency components and few high-frequency components, so when DCT is performed, the coefficients are concentrated in the low frequency range.

The DCT image data (DCT coefficient) is quantized by the quantizer 4. Quantization is a quantization matrix, which is a value obtained by weighting 8 × 8 two-dimensional frequencies with visual characteristics and a value obtained by multiplying by a value called a quantization scale that multiplies the whole by a scalar, and the DCT coefficient is quantized. Calculate by value. When inversely quantized by the MPEG decoder (decoder), a value that approximates the original DCT coefficient will be obtained by multiplying by the quantized value.

The quantized data is variable length coded by the VLC unit 5. The direct current (DC) component of the quantized value is one of the predictive coding DPCM (differential pulse).
se code modulation). In addition, Huffman encoding is performed by performing zigzag scan from low frequency to high frequency for the alternating current (AC) component, setting zero run length and effective coefficient value as one event, and allocating codes with shorter code length from those with high appearance probability. Done.

The variable-length coded data is stored in the temporary buffer 6 and output as coded data at a predetermined transfer rate. Further, the generated code amount of each macro block of the output data is transmitted to the code amount controller 21,
The code amount is controlled by feeding back the error code amount between the target code amount and the generated code amount to the quantizer 4 and adjusting the quantization scale.

The quantized image data is inversely quantized by the inverse quantizer 7, inverse DCT is performed by the inverse DCT device 8, temporarily stored in the image memory 10 via the adder 9, and then motion compensated. In the predictor 1, it is used as a reference decoded image for calculating a difference image.

FIG. 6 shows an MPEG decoder (decoder) that decodes the encoded data that has been MPEG encoded in this way.

The incoming coded data (stream) is buffered in the buffer 11, and the data from the buffer 11 is input to the VLD unit 12. The VLD unit 12 performs variable length decoding to obtain a direct current (DC) component and an alternating current (AC) component. The alternating current (AC) component data is zi from low to high
It is arranged in an 8x8 matrix in the order of gzag scan.
This data is input to the dequantizer 13 and dequantized by the quantization matrix. Inverse quantized data is inverse
It is input to the DCT unit 14, inverse DCT is performed, and output as image data (decoded data). The decoded data is temporarily stored in the image memory 16 and then used in the motion compensation predictor 17 as a reference decoded image for calculating a difference image.

In the case of video, the coded bit stream has a variable length code amount for each picture.
This is because MPEG uses information conversion such as DCT, quantization, and Huffman coding, and at the same time, it is necessary to adaptively change the code amount allocated for each picture in order to improve image quality. This is because the input image is coded as it is, and the difference image that is the difference between the predicted images is coded at some time, and the entropy of the coded image itself changes greatly.

In this case, most of the code amount control is performed while allocating to the entropy ratio of the image and keeping the buffer limit. The buffer manager monitors the relationship between the generated code amount and the coding rate and sets the target code amount so that the target code amount can be accommodated in a predetermined buffer. This value is fed back to the variable length encoder and enters the code amount controller, where the quantization value set in the quantizer is increased to suppress the generated code amount, or the quantization value is decreased to generate the generated code amount. Or make it smaller.

When such variable length data is encoded at a fixed transfer rate (encoding rate), assuming that the maximum buffer amount of the decoder is the upper limit value, the data is input at a constant speed and only a predetermined value is input. Since it has accumulated, it is possible to use a model that performs decoding at a predetermined time (1 / 29.97 sec unit for NTSC video signal) in an instant, and to encode so that the buffer does not overflow or underflow. Stipulated in. If this regulation (VBV buffer regulation) is observed, the rate in the VBV buffer will change locally, but if the observation time is long, it will be a fixed transfer rate, and in MPEG this is a fixed rate. It is defined.

In the case of a fixed transfer rate, when the generated code amount is small, the buffer occupancy amount is stuck to the upper limit value. In this case, it is necessary to increase the code amount by adding invalid bits to prevent overflow.

In the case of a variable transfer rate, the definition of this fixed transfer rate is expanded, and when the buffer occupancy rate reaches the upper limit value, the reading of the decoder is stopped so that overflow does not occur in principle. Is defined in. Such a buffer transition is shown in FIG. Even if the generated code amount is very small, the reading of the decoder is stopped, so that it is not necessary to insert an invalid bit as in the case of the fixed transfer rate. Therefore, encoding is performed so that only underflow does not occur.

The MPEG system defines a method of multiplexing a bit stream encoded by MPEG video and audio into one bit stream and reproducing the same while ensuring synchronization. The contents specified by the system are roughly divided into the following 5 points. 1) Synchronized reproduction of a plurality of encoded bitstreams 2) Multiplexing of a plurality of encoded bitstreams into a single bitstream 3) Initialization of a buffer at the start of reproduction 4) Continuous buffer management 5) Determining the time of decoding and reproduction It is necessary to packetize information in order to perform multiplexing in the MPEG system. Packet multiplexing refers to, for example, when video and audio are multiplexed, each is divided into streams of appropriate length called packets, and additional information such as headers is added to switch the video and audio packets as appropriate. This is a method of time division transmission. The header has information for identifying video, audio, etc., and time information for synchronization. The packet length depends on the transmission medium and application, and it ranges from 53 bytes like ATM to 4 Kbytes like optical disc. In MPEG, the packet length is variable and can be arbitrarily specified.

Data is packed and packetized, and one pack is composed of several packets. The pack start code and SCR (System Clock Referance) are added at the beginning of each P pack.
, The stream id and time stamp are described at the beginning of the packet. The time stamp describes time information for synchronizing audio, video, etc.
(Decoding Time Stamp), PTS (Presentation Time Stam
There are two types of p). PCR (Program Clock Referenc
e) is described with a time accuracy of 27 MHz and is information for locking the reference clock of the decoder. DTS indicates the decoding start time of the first access unit (1 picture for video, 1152 samples for audio, for example) in the packet data, and PTS indicates the display (playback) start time. As shown in FIG. 11, audio, video, and other decoders constantly monitor a common reference clock locked by PCR, and when they match the time of DTS or PTS, they are decoded and displayed. . The multiplexed data is buffered by each decoder, and a virtual decoder for performing synchronized display is used as the STD (System Target Deco
der), and this STD must be multiplexed so as not to cause overflow or underflow.

The MPEG system is roughly divided into TS.
(Transport Stream) and PS (Program Stream) exist. These are PES (Packetized Elementary Stream),
And other necessary information. PES is defined as an intermediate stream for enabling conversion between both streams, and is a packetized video stream, audio data encoded by MPEG, and a private stream.

The PS can multiplex video and audio of programs having a common reference time.
The packet layer is called PES, and this structure is used in common with TS described later, as shown in FIG. 12, to enable mutual compatibility between them. In the PS STD model, streams are switched by the stream id in PES packets.

Like the PS, the TS can also multiplex the video and audio of a program having a common reference time, but the TS has a multiple reference of multiple programs such as communication and broadcasting having different reference times. Is possible. The TS is composed of fixed length packets of 188 bytes in consideration of ATM cell length and error correction coding.
It is considered so that it can be used even in a system where an error exists. The structure of the TS packet itself is not so complicated, but its operation is complicated because it is a multi-program stream. What is characteristic compared to PS is that TS packets are (usually) shorter than PES packets even though they have a higher-level structure, and PES packets are divided and placed on TS packets for transmission. In the TS STD model, streams are switched by the PID (packet ID) in the TS packet.

The TS of the MPEG system has a mechanism for instructing which PID the packet relating to the information of the multiplexed program is. This will be described with reference to FIG. First
Search the TS packet group for PID = 0. It's PAT
An information packet called a (Program Association Table), in which information PID corresponding to the PROGRAM number PR is described in a linked form. Next, when I go to read the packet of PID corresponding to the target PR, PMT
There is an information packet called (Program Map Table), and the PID of the video packet of the program corresponding to the PR and the PID of the audio packet are described in the packet.

PAT and PMT are referred to as PSI (Program Specific
Information), and has an information system that allows access (entry) to the channel of the desired program.

Further, according to the invention of Japanese Patent Laid-Open No. 11-74799, when editing compressed data such as MPEG data recorded on a recording medium, the VBV buffer is used at the editing point in order to maintain continuity of the MPEG data. There is described a method of performing coding in consideration of continuity, such as controlling the amount of generated code so that is always fixed, or coding a GOP as a closed GOP.

Further, according to the invention of Japanese Patent Laid-Open No. 11-187354, the information indicating the data extracted as the editing material in the partial section of the coded data and the information thereof are placed without any restriction on the coded data. A method is described in which information about a reproduction order is described and video editing can be realized on a single recording medium without changing recorded data.

[0028]

However, in the above-mentioned conventional method, if MPEG image data is simply connected, the connection of the VBV buffer becomes inconsistent, resulting in overflow or underflow.

In the invention of Japanese Patent Laid-Open No. 11-74799, VBV is set for each GOP so that it can be edited anywhere.
Coding constraints that consider continuity, such as controlling the amount of generated code so that the buffer is always fixed, or encoding GOPs as closed GOPs, are disadvantageous factors in terms of encoding efficiency. Was there.

Further, in the invention of Japanese Patent Laid-Open No. 11-187354, the reproduction and display are performed as if they were edited, but the continuity at the editing points is incomplete, and temporary decoding such as initialization of the decoder buffer of MPEG data is performed. There was a possibility that a static phenomenon would occur.

According to the present invention, packet-multiplexed first MPEG multiplexed data including the first and second two MPEG image data (or the first MPEG image data as element encoded data), Packet-multiplexed second MPEG multiplexed data including two MPEG image data as element encoded data), at each designated connection designation position, from the first MPEG image data to the second MPEG image data. When playing back by connecting to MPEG image data (when playing back by connecting from the first MPEG multiplexed data to the second MPEG multiplexed data), an inconsistency of overflow or underflow occurs in the VBV buffer connection. It is an object of the present invention to provide an MPEG data recording device that can realize seamless and high-quality reproduction without the need.

[0032]

In order to solve the above problems, the present invention provides the following recording device. (1) The first and second MPEG image data, which are image data encoded by the MPEG encoding method, are
The second MPEG-encoded second data encoded as the data for connecting and reproducing the first MPEG image data to the second MPEG image data at the specified connection designated position in the MPEG image data. An MPEG data recording apparatus comprising recording means for generating and recording connection section re-encoded data, wherein the recording means sets the connection specified position in the second MPEG image data as a start position and the second
The second MPEG image data of the second connection section is decoded with the section having a position after the second predetermined time from the specified connection position of the MPEG image data as the end position as the second connection section. The second connection section decoded image data, which is the image data obtained by the above, is re-encoded by the MPEG encoding method to generate the second connection section re-encoded data, and the second re-encoding means is provided. The re-encoding means records the transition section re-encoded data in the recording medium, wherein the transition of the information value regarding the VBV buffer occupancy value is the first MPEG image data when the re-encoding is performed. Starting from an information value relating to the VBV buffer occupancy value at the time of encoding the first MPEG image data at a position corresponding to the specified connection position of the first MPEG image data, the first position at the position corresponding to the end position of the second connection section. 2 MPEG At the time of encoding of image data
An MPEG data recording device characterized by performing re-encoding by controlling a code amount so as to end up to an information value regarding a VBV buffer occupation value. (2) In the MPEG data recording device described in (1) above, the recording means includes the second connection section re-encoded data as element encoded data, and performs packet multiplexing according to the MPEG method to generate the packet. An MPEG data recording device, characterized in that MPEG multiplexed data of two connecting sections is recorded on a recording medium.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION First, the concept of connection reproduction that can be realized by the present invention will be described. As shown in FIG. 8, when the first MPEG image data, which is the image data encoded by the MPEG encoding method, and the second MPEG image data are the same, the middle of the first MPEG image data (specified Consider that the second MPEG image data is connected and reproduced from the specified connection position). Assuming that the connection point (the connection designated position in the first MPEG image data) is the position b, the first M
The PEG image data is reproduced up to the position b, and then the second MPEG image data is connected to reproduce the data. However, if the MPEG image data is simply connected, the connection of the VBV buffer becomes inconsistent, There is a problem that overflow or underflow will occur.

Therefore, first, when the first MPEG image data and the second MPEG image data are encoded by the MPEG encoding method, the information of the VBV buffer is given in a predetermined section unit (in the first MPEG image data, 1 predetermined section unit, 2nd
In the case of the MPEG image data, the second predetermined section unit) is generated as side information and described in the recording medium.

It is also possible to realize connection reproduction without describing the information of the VBV buffer in the side information. In this case, two methods are possible, which will be described later.

The information of the VBV buffer regarding the first MPEG image data is the VBV buffer at the beginning or end of the MPEG encoding of the last picture of the first MPEG image data in each of the first predetermined intervals. The first VBV buffer occupation value related information indicating the information value regarding the occupation value, and V
The first address information indicates at which position in the first MPEG image data the information value regarding the BV buffer occupation value is the information value regarding the VBV buffer occupation value.

The information of the VBV buffer regarding the second MPEG image data is the VBV buffer information at the start point or the end point of the MPEG encoding of the last picture of the second MPEG image data in each second predetermined section. Second VBV buffer occupation value related information indicating the information value regarding the occupation value, and V
And second address information indicating at which position in the second MPEG image data the information value regarding the BV buffer occupation value is the information value regarding the VBV buffer occupation value.

The information value regarding the VBV buffer occupation value is
For example, the VBV buffer occupancy value or V specified in MPEG
BV delay value.

Although one unit of the first and second predetermined sections is, for example, about 3 frames as will be described later, 1 GO
It may be about P. If the predetermined section unit is the first MPEG
In the image data, it is set between ab in FIG. 8 and in the second MPEG image data, it is set between cd in FIG.

In the information list of the VBV buffer, a
Information of the VBV buffer at the position (the boundary of the first predetermined section for the first predetermined time before the connection designated position in the first MPEG image data: that is, the start position of the section A described later), Position b (the specified connection position in the first MPEG image data: that is, the end position of section A described later)
The information of the VBV buffer is described. Further, the information of the VBV buffer at the position c of the second MPEG image data (the boundary position of the second predetermined section that is the second predetermined time before the connection designated position in the second MPEG image data). There is also information on the VBV buffer at the position of the connection point d (the specified connection position in the second MPEG image data: the boundary position of the second predetermined section in this example).

Therefore, the ab of the first MPEG image data
Data of a section (first connection section: here, section A) is once decoded to obtain decoded image data, and the decoded image data (first connection section decoded image data) is encoded by the MPEG encoding method. Re-encode. The re-encoded data created thereby will be referred to as re-encoded MPEG image data of the section A (first connection section re-encoded data).
In this re-encoding, the transition of the information value regarding the VBV buffer occupation value is started from the information value regarding the VBV buffer occupation value obtained based on the detected first VBV buffer occupation value related information at the position a. , D at the position of d, the rate control is performed so as to end up to the information value regarding the VBV buffer occupation value obtained based on the detected second VBV buffer occupation value related information, and re-encoding is performed by the MPEG encoding method. To do.

The first MPE, which is the conventional connection reproduction operation
Playback is performed up to position b of G image data, and then the second
The operation of connecting to the position d of the MPEG image data and reproducing the data is the following operation using the re-encoded MPEG image data of the section A. That is, the first M
The first MPEG image data is reproduced up to the position a of the PEG image data (the start position of the section A), and then the re-encoded MPEG image data of the section A is reproduced from the start position to the end position of the section. Then the second MPE
Connect to the d position (connection specified position) of the G image data and d
The following second MPEG image data is reproduced,
I will do the operation. This is realized by providing a connection reproducing means for performing this operation on the reproducing device side.

By performing this connection reproduction operation, the original first
Also, it is possible to realize seamless connection reproduction with the same content as the second MPEG image data and without the VBV buffer failure. It should be noted that when re-encoded MPEG image data of the connection section is obtained based on only the first MPEG image data side shown in FIG. 8, the position of the connection point d (the connection specified position in the second MPEG image data is specified). ) VBV buffer information is required. As described above, the information of the VBV buffer is the information at the start or end of the MPEG coding of the last picture of the predetermined section of the MPEG image data, and therefore the information at the boundary position of the predetermined section. Becomes Therefore, the position of the connection point (connection specified position) needs to be specified as the boundary of the second predetermined section at least in the second MPEG image data. (That is, the position of the connection point d in the second MPEG image data needs to be designated as the boundary of the second predetermined section.) Also, the recoding of the connecting section based only on the first MPEG image data side. In order to obtain the encoded MPEG image data, as described above, the position of a shown in FIG.
Information of the VBV buffer at the start position) is also required. However, since the position of a is specified as the boundary of the first predetermined section before the first predetermined time from the connection point (connection specified position) b in the first MPEG image data, it is set at the position of the connection point b. Regardless, the information of the VBV buffer can be obtained at the position a. Therefore, the position of the connection point b in the first MPEG image data does not necessarily have to be designated as the boundary of the first predetermined section.

Next, examples of its application are shown in FIGS. 9 (2) and 9 (3). The figure (1) is the same as the example shown in FIG. In the example shown in FIG. 8, the re-encoded MPEG image data in the splicing section is obtained based on only the first MPEG image data side to realize the splicing reproduction, but the splicing is performed only on the second MPEG image data side. It is also possible to obtain re-encoded MPEG image data of a section and realize connection reproduction. Figure 9 shows an example.
It is shown in (2), and re-encoded MPEG image data of the connecting section B in the second MPEG image data is used.

In FIG. 9B, the connection point (connection designation position) in the first MPEG image data is the position i, and the connection point (connection designation position) in the second MPEG image data is the position k. . One unit of the first and second predetermined sections, which is a unit having the information of the VBV buffer described above, is
In the second MPEG image data, it is between ij and in the second MPEG image data. The position of l is the second MPEG
Second from the connection point (connection specified position) k in the image data
Is the boundary position of the second predetermined section after a predetermined time. A section having the connection point k as the start position and the position of l as the end position is referred to as a connection section B (second connection section).

Connecting section B of the second MPEG image data
The data of (k-1 section) is once decoded to obtain decoded image data, and the decoded image data (second connection section decoded image data) is re-encoded by the MPEG encoding method. The re-encoded data created thereby will be referred to as re-encoded MPEG image data of the connecting section B (second connecting section re-encoded data). In this re-encoding, the transition of the information value regarding the VBV buffer occupation value is the first at the position of i.
Starting from the information value relating to the VBV buffer occupancy value obtained based on the VBV buffer occupancy value related information of V, the V obtained based on the second VBV buffer occupancy value related information at position l
The rate control is performed so that the processing is completed up to the information value related to the BV buffer occupation value, and re-encoding is performed by the MPEG encoding method.

Then, by using the re-encoded MPEG image data of the connection section B, the first MPEG image data to the second MPEG image data
The connection reproduction to the MPEG image data is performed. That is,
Connection point i of the first MPEG image data (connection specified position)
Up to the end position of the re-encoded MPEG image data of the section B, and then the second M image data is reproduced.
Position of l in PEG image data (end position of connecting section B)
The second MPEG image data after the position of l is reproduced and the operation is performed. This is realized by providing a connection reproducing means for performing this operation on the reproducing device side.

By performing this connection reproduction operation, the original first
Also, it is possible to realize seamless connection reproduction with the same content as the second MPEG image data and without the VBV buffer failure.

The second MPE shown in FIG. 9B is used.
Re-encoding MPEG of connecting section based only on G image data side
When obtaining image data, the position of the connection point i (first MP
Information on the VBV buffer at the specified connection position in the EG image data is required. As described above, the information of the VBV buffer is the information at the start or end of the MPEG coding of the last picture of the predetermined section of the MPEG image data, and therefore the information at the boundary position of the predetermined section. Becomes Therefore, the position of the connection point (connection specified position) is
At least in the first MPEG image data, it is necessary to specify it as the boundary of the first predetermined section. (That is, the first
The position of the connection point i in the MPEG image data is required to be designated as the boundary of the first predetermined section. ) See also
In order to obtain re-encoded MPEG image data of the connecting section based on only the MPEG image data side of FIG.
Information on the VBV buffer at the position of l (the end position of the connection section B) shown in (2) is also required. However, since the position of l is specified as the boundary of the second predetermined section after the second predetermined time from the connection point (connection specified position) k in the second MPEG image data, it is set at the position of the connection point k. Regardless, the information of the VBV buffer is obtained at the position of l. Therefore, the position of the connection point k in the second MPEG image data does not necessarily have to be designated as the boundary of the second predetermined section.

Next, an application example shown in FIG. 9C will be described. In this example, the first and second MPs before and after the connection point
The re-encoding MPEG image data of the connection section is obtained based on the EG image data to realize the connection reproduction.

In FIG. 9C, the connection point (connection designation position) in the first MPEG image data is the position n, and the connection point (connection designation position) in the second MPEG image data is the position p. . One unit of the first and second predetermined sections, which is a unit having the information of the VBV buffer described above, is
In the case of the second MPEG image data, it is between mn and in the second MPEG image data.

The position of m is the boundary position of the first predetermined section before the first predetermined time from the connection point (connection specified position) n in the first MPEG image data. A section in which the position of m is the start position and the position of the connection point n is the end position is connected to section A
(First connection section). The position of q becomes the boundary position of the second predetermined section after the second predetermined time from the connection point (connection specified position) p in the second MPEG image data. A section having the connection point p as the start position and the position of q as the end position is referred to as a connection section B (second connection section).

Connection section A of the first MPEG image data
The data of (m-n section) is once decoded to obtain decoded image data (connection section A decoded image data: first connection section decoded image data). Further, the data of the connecting section B (pq section) of the second MPEG image data is once decoded to obtain decoded image data (connecting section B decoded image data: second connecting section decoded image data). obtain.

The joint section A + B decoded image data (third joint section decoded image data) obtained by combining the joint section A decoded image data and the joint section B decoded image data is re-encoded by the MPEG encoding method. The re-encoded data thus created will be referred to as re-encoded MPEG image data of the connection section A + B (third connection section re-encoded data).
In this re-encoding, the transition of the information value related to the VBV buffer occupancy value is started from the information value related to the VBV buffer occupancy value obtained based on the first VBV buffer occupancy value related information at the position m, and q Re-encoding is performed by the MPEG encoding method by performing the rate control so that the processing is completed up to the information value regarding the VBV buffer occupation value obtained based on the second VBV buffer occupation value related information at the position.

Then, the re-encoding MPE of the connecting section A + B is performed.
The G image data is used to perform connection reproduction from the first MPEG image data to the second MPEG image data. That is, the first MPEG image data is reproduced up to the start position m of the connecting section A of the first MPEG image data, and then the re-encoded MPEG image data of the connecting section A + B ends from the start position of the section. The operation is performed such that the data is reproduced up to the position, and then the end position q of the connecting section B of the second MPEG image data is connected to reproduce the data of the second MPEG image data after the position of q. This is realized by providing a connection reproducing means for performing this operation on the reproducing device side.

By using this connection reproduction operation, the original first
Also, it is possible to realize seamless connection reproduction with the same content as the second MPEG image data and without the VBV buffer failure.

In the example shown in FIG. 9 (3), the information of the VBV buffer at the position m (start position of the connecting section A) is required as described above. Since the position of m is specified as the boundary of the first predetermined section before the first predetermined time from the connection point (connection specified position) n in the first MPEG image data, regardless of the position of the connection point n. Information of the VBV buffer is obtained at the position of m. Therefore, the position of the connection point n in the first MPEG image data does not necessarily have to be designated as the boundary of the first predetermined section.

As described above, as shown in FIG. 9 (3),
Information on the VBV buffer at the position q (the end position of the connecting section B) is also required. Since the position of q is specified as the boundary of the second predetermined section after the second predetermined time from the connection point (connection specified position) p in the second MPEG image data, regardless of the position of the connection point p. At the position of q, information of the VBV buffer is obtained. Therefore, the position of the connection point p in the second MPEG image data does not necessarily have to be designated as the boundary of the second predetermined section.

As described above, all of the methods shown in FIGS. 9 (1) to 9 (3) can be realized as seamless and high-quality connected reproduction as shown in FIG. , The first MPEG image data and the second MP
It is also possible to realize connection reproduction in which the EG image data and the third and fourth MPEG image data are branched midway as shown in the figure. Thus, using the present invention,
It is possible to freely connect to other MPEG data simply by generating and using re-encoded MPEG image data of the connecting section without processing the original MPEG image data itself, so a program that forms various branch stories. Even when encoding, the media can be used efficiently without recording redundant MPEG image data over the entire story for each branch story.
(By using the present invention, one set of each of the first to fourth MPEG image data and re-encoded MPEG image data of the connecting section for each branch story may be prepared.) Further, FIG. 9 (3) ), The position of the connection point in the first MPEG image data does not necessarily have to be specified as the boundary of the first predetermined section, as described above, and the connection in the second MPEG image data can be performed. Since the position of the point does not necessarily have to be specified as the boundary of the second predetermined section, the information of the VBV buffer is described as side information in predetermined section units, which is a finer precision than a predetermined section unit, for example, one frame unit. It can be applied when editing with. This example will be described with reference to FIG. The predetermined unit may be about 3 frames or 1 GOP, but here it is 1 GOP.

It is assumed that there are two MPEG streams to be connected as shown in FIG. At the points g and h indicated by arrows in the first MPEG stream, the information of the VBV buffer at the position of g is added to the information list of the VBV buffer.
Information of the VBV buffer at the position of h is described.
In addition, the VBV of the position i is also included in the second MPEG image data.
There is also information on the buffer and information on the VBV buffer at the position of j.

From the position p of the first MEPG stream 1,
When connecting to the beginning of the second MPEG stream, the data of the section A from g to p of the first MPEG stream is decoded, and further the data of the section B of i to j of the second MPEG stream is decoded, Re-encode both images so that the buffer transitions start at the buffer occupancy value at position g and become the buffer occupancy value at position j.

The data created thereby is section A +
When the re-encoded MPEG image data of B is called, the conventional reproduction operation is performed until the position p of the first MPEG image data is reproduced, and then the second MPEG image data is connected to reproduce the data. The action of doing is the first M
Playback is performed up to the position g of the PEG image data, then the re-encoded MPEG image data of the section A + B is played back, and then the data is played back by connecting to j of the second MPEG image data. By doing so, it is possible to perform seamless connection reproduction with the same content and without causing the VBV buffer to fail.

Next, two methods for realizing the same connection reproduction as in the above-described examples without describing the information of the VBV buffer as the side information will be described. (A method of calculating the information value regarding the VBV buffer occupation value, which is necessary when generating the re-encoded data of the connecting section will be described.) First, the first method will be described. In the MPEG standard, basically, in the case of a CBR (constant bit rate), that is, a fixed transfer rate, VBV indicating the buffer occupancy rate of the VBV buffer in the picture layer of the MPEG video is shown.
The delay value is specified. In this case, since the VBV delay value is described in picture units, by observing the MPEG image bit stream only with the picture header alone, the MPEG encoding start time point (or the MPEG encoding start time of the picture corresponding to the predetermined position of the MPEG image data (or (At the end)
The VBV buffer occupancy value at can be detected. In this case, for example, the function of the VBV buffer information detector 33 in FIG. 4, which will be described later, is to search a picture header of a bitstream (a 4-byte code of 0x00000100 in MPEG), and then to search for a 10-bit temporal reference of 10 bits, picture coding typ
This can be realized by detecting 16 bits of VBV delay following e3 bits. VBV delay value is defined by VBV delay = 90000 x B / R B: buffer occupancy value R: bit rate, so in case of fixed rate,
Using this bit rate, the VBV buffer occupancy value can also be calculated from the VBV delay value. (For example, it is calculated by the VBV buffer information detector 33 shown in FIG. 4.) MPE
In G, it is necessary to pay attention to the VBV delay value at the position of the vertex of the graph, as shown in FIG. 16 (2).

Next, the second method will be described. This is the case for variable transfer rates rather than fixed transfer rates. In the MPEG standard, basically VBR (variable bit
rate: variable transfer rate), the VBV delay value indicating the buffer occupancy of the VBV buffer in the picture layer of the MPEG video is all 1 (0xffff because all 16 bits are 1). Therefore, the first method cannot be used.

Therefore, the following calculation is performed from the information obtained by observing the MPEG image bit stream. First, it is assumed that the VBV buffer is occupied from the beginning of the bit stream to the maximum value defined by the MPEG (for example, 1.75 Mbit at the main profile main level). Next, the code amount of the first picture is subtracted. Next, using the transmission rate information of the peak rate in variable transfer rate encoding, the transmission amount when the time between display pictures has elapsed is added, and the code amount of the next picture is subtracted. By repeating such a series of addition and subtraction processes up to a predetermined bit stream position to be obtained, a picture corresponding to a predetermined position of MPEG image data can be obtained by simulating a graph as shown in FIG. The VBV buffer occupancy value at the MPEG encoding start point (or end point) can be calculated. The peak rate at the variable transfer rate is specified in MPEG in the syntax part called bit rate of the sequence header, and can be obtained by referring to it.

For example, the VBV buffer information detector 33 shown in FIG. 4, which will be described later, is realized by providing the above-mentioned MPEG image bit stream with an observation function and a calculation function. (In the case of the second method, the generated code amount of each picture must be observed and calculated from the beginning of the MPEG image bit stream, but as in the first method, information of the VBV buffer is previously used as side information. Next, a brief description will be given of the generation of the connection interval re-encoded data in the case of using the first and second methods described above. Note that the connection reproduction operation using the connection section re-encoded data is the same as the case of using the connection section re-encoded data generated from the information of the VBV buffer recorded in advance as the side information, and therefore, here, The description is omitted.

When re-encoded MPEG image data of the connecting section is obtained based on only the first MPEG image data side shown in FIG. 9A, a connection point (connection specifying position) in the first MPEG image data is obtained. A section in which the position a, which is a predetermined predetermined time before b, is the start position and the specified connection position b in the first MPEG image data is the end position is the first connection section (connection section A). The specification of the start position a of the connecting section A does not require the limitation such as the boundary of the first predetermined section as in the case of using the side information. Similarly, the second MP
The specification of the connection point (connection specification position) d in the EG image data does not require the limitation such as the boundary of the second predetermined section as in the case of using the side information.

Data in the ab section (connecting section A) of the first MPEG image data is once decoded to obtain decoded image data, and the decoded image data (first connecting section decoded image data) is MPEG encoded. Re-encoding is performed by the method to obtain re-encoded MPEG image data of the connection section A (first connection section re-encoded data). In this re-encoding, the VBV buffer occupation value transition is MPEG-encoded for the picture corresponding to the position of a calculated by the first or second method (the MPEG encoding when the first MPEG image data is generated). Start) from the VBV buffer occupancy value at the start time (or end time). Then, the transition of the VBV buffer occupancy value is the start point of the MPEG coding (MPEG coding at the time of generating the second MPEG image data) of the picture corresponding to the position of d calculated by the first or second method. It is re-encoded by the MPEG encoding method by performing rate control so that the VBV buffer occupancy value at (or at the end time) ends.
The obtained re-encoded MPEG image data of the connection section A (first connection section re-encoded data) is recorded on the recording medium.
(For example, it is recorded by the data writing unit 37 shown in FIG. 4 described later.) Next, the second MPE shown in FIG. 9B.
Re-encoding MPEG of connecting section based only on G image data side
The case of obtaining image data will be described. In FIG. 9 (2), the connection point (connection designation position) in the first MPEG image data is the position i, and the connection point (connection designation position) in the second MPEG image data is the position k. Connection point k
Is the start position, and the position of l, which is the position after the second predetermined time from the connection point (connection designation position) k, is the end position.
The section of the second MPEG image data is referred to as a connection section B (second connection section). To specify the end position l of the connecting section B,
The limitation such as the boundary of the second predetermined section as in the case of using the side information is unnecessary. Similarly, the first MPEG
When the side information is used to specify the connection point (connection specified position) i in the image data, the restriction such as the boundary of the first predetermined section becomes unnecessary.

Connection section B of the second MPEG image data
The data of (k-1 section) is once decoded to obtain decoded image data, and the decoded image data (second joint section decoded image data) is re-encoded by the MPEG encoding method to form the joint section B. Re-encoded MPEG image data (second connection section re-encoded data) is obtained. In this re-encoding, the transition of the VBV buffer occupation value is calculated by the first or second method, and the VBV buffer occupation at the MPEG encoding start time (or end time) of the picture corresponding to the position of i Start from the value. Then, the transition of the VBV buffer occupancy value is calculated by the first or second method, and the MPEG encoding start time (or end time) of the picture corresponding to the position of l is calculated.
The rate control is performed and re-encoding is performed by the MPEG encoding method so that the process ends up to the VBV buffer occupancy value. The re-encoded MPEG image data of the obtained connecting section B (second connecting section re-encoded data) is recorded on the recording medium. (For example, it is recorded by the data writing unit 37 shown in FIG. 4 which will be described later.) Next, the recoding of the connecting section based on the first and second MPEG image data before and after the connection point shown in FIG. 9C. A case of obtaining the encoded MPEG image data will be described.

In FIG. 9C, the connection point (connection designation position) in the first MPEG image data is the position n, and the connection point (connection designation position) in the second MPEG image data is the position p. .

The position before the first predetermined time from the connection point (connection designation position) n in the first MPEG image data is m. The section of the first MPEG image data having the position of m as the start position and the position of the connection point n as the end position
(First connection section). The position q after the second predetermined time from the connection point (connection specified position) p in the second MPEG image data is set. The section of the second MPEG image data having the connection point p as the start position and the position q as the end position is referred to as a connection section B (second connection section).

When the side information is used to specify the start position m of the connecting section A, it is not necessary to limit the boundary of the first predetermined section. Similarly, the end position q of the connecting section B
There is no need to limit the boundary of the second predetermined section as in the case of using the side information for the specification.

Connection section A of the first MPEG image data
The data in the (mn section) is once decoded to obtain decoded image data (connecting section A decoded image data: first connecting section decoded image data). In addition, the data of the connection section B (pq section) of the second MPEG image data is once decoded, and the decoded image data (connection section B decoded image data:
The second connection section decoded image data) is obtained.

Then, the joint section A + B decoded image data (third joint section decoded image data) obtained by combining the joint section A decoded image data and the joint section B decoded image data is re-encoded by the MPEG encoding method. The re-encoded data created thereby is used as re-encoded MPEG image data of the connection section A + B (third connection section re-encoded data). In this re-encoding, the transition of the VBV buffer occupation value is
Alternatively, it is started from the VBV buffer occupancy value at the MPEG encoding start point (or end point) of the picture corresponding to the position m calculated by the second method. Then, the transition of the VBV buffer occupancy value ends up to the VBV buffer occupancy value at the MPEG encoding start time (or end time) of the picture corresponding to the position of q calculated by the first or second method. As described above, rate control is performed and re-encoding is performed by the MPEG encoding method. The obtained re-encoded MPEG image data of the connection section A + B (third connection section re-encoded data) is recorded on the recording medium. (For example, FIG.
It is recorded by the data writing unit 37 shown in FIG. ) Figure 10
Also in the example shown in (1), it is of course possible to obtain the VBV buffer occupancy value at the required position by the above-described calculation method, and to obtain the desired connection interval re-encoded data).

Next, the VBV buffer information to be recorded on the recording medium by one embodiment of the recording / reproducing apparatus to which the present invention is applied (in every predetermined section of MPEG image data, the MPEG coding start time of the last picture of that section or VBV buffer occupancy value related information indicating the information value regarding the VBV buffer occupancy value at the end point and indicating at which position in the MPEG image data the information value regarding the VBV buffer occupancy value is the information value regarding the VBV buffer occupancy value Address information) and the recording structure for MPEG image data will be described in detail. MPEG image data, which is image data compressed by the MPEG encoding method, is recorded on the recording medium. The MPEG image data is recorded as a bit stream in which a plurality of continuously reproducible data coded and generated in one recording unit are continuously arranged.

Apart from the bit stream of these encoded MPEG image data, the VBV buffer value (occupied value) at the end of picture encoding one frame before the I picture in the bit stream of the MPEG image data and P The VBV buffer value (occupied value) at the end of picture coding one frame before the picture and each VBV buffer value are
Address information (in this example, a relative address from the beginning of the MPEG image data file) indicating which position of the MPEG image data is the VBV buffer occupation value is recorded. The data structure of VBV buffer information including these data is shown in FIG.

The VBV buffer information has a hierarchical structure. First there is the entry point information structure, and then there is the VBV information structure. In the entry point information structure, first, the number of entry point (EP) addresses is described in 32 bits, and then EPn (n is a natural number of 1 or more) addresses are described in 32 bits in order. EPn address is EPn information of VBV information structure (n is a natural number of 1 or more)
Indicates the position described in, and describes the relative address from the beginning of this VBV buffer information. On the other hand, the VBV information structure is described in order from the EP1 information, and the content of the EP1 information describes the relative address, the PTM value, and the VBV value in order.

The relative address in the EPn information of the VBV information structure is, as shown in FIG. 2, the picture coding end point of the I picture one frame before in the bit stream of the MPEG image data, and the picture one frame before the P picture. At the end of encoding and at the end of recording
This is a relative address from the beginning of the MPEG image data, and for example, the unit is bytes. When recorded on a disk medium, a sector or the like is used as a relative address.

The PTM value in the EPn information of the VBV information structure is 90 in the MPEG system standard (multiplexing standard).
It is a time stamp recorded with a clock of kHz or 27 MHz. According to the MPEG standard, PTS (Presentation Ti
It is called me Stamp) or DTS (Decoding Time Stamp). Here, I of the bit stream of MPEG image data
DTS is recorded as time information at the end of picture coding one frame before the picture, at the end of picture coding one frame before the P picture, and at the end of recording. One DTS is recorded in one picture, and N
In the case of a TSC video signal, 90KHz clock is recorded at intervals of 3003 clocks per picture.
Therefore, when an I picture or a P picture exists for every 3 pictures as in the present invention and the first one starts from 0, the PTM information is EPn information at intervals of 9009, 18018 .... Will be described in.

The VBV value in the EPn information of the VBV information structure is the virtual buffer occupation value of the decoder defined by MPEG. It can be calculated from the amount of generated code for each picture of MPEG image data and the value of the transfer rate.
As described above, the VBV occupancy value at the position of ◯ in the figure at the end of picture coding of the I picture and P picture of the compressed bit stream information one frame before is described. Alternatively, describe the VBV delay value specified by MPEG. This value is a value converted to the VBV occupancy value, which is the time required for the transfer rate at that time. In the present invention, any information may be used as long as it is information regarding the VBV buffer occupation value. VBV buffer occupancy value and VBV del
FIG. 17 shows the relationship between ay values. Occupied value of VBV buffer OCC
VBV delay = 90000 * O, where R is the coding rate
There is a relationship of CC / R, and 90000 is a value for indicating with a count number of 90 kHz.

In MPEG compression, coding is basically performed using a picture type of I or P in units of 3 frames such as IBB and PBB. In MPEG compression, B pictures may be predicted from both directions. Therefore, in the coding bitstream order, data joining is added only at the end of picture coding one frame before the I picture and P picture of the bitstream. Is not easy. Therefore, the present invention is described on the assumption that the VBV information is described at the end of picture coding of the I picture and P picture of the bit stream, which is one frame before.

However, the information value relating to the VBV occupation value may essentially have each picture. Further, the coding start point may be used instead of the picture coding end point.
FIG. 16 (1) is a conceptual diagram when the value of the coding end point is included in the list. In this case, since there is no information value regarding the first VBV occupation value, the virtual value is set before the first frame. Assuming that there is a frame in, the information value regarding the VBV occupation value at the end of encoding of the virtual frame is calculated as an initial value. The calculation uses the first picture code amount as the first VBV
By adding to the information value related to the occupied value, from the added value, from the slope according to the encoding rate, (1 / picture rate)
By subtracting the value of how much the code transmission amount is calculated by the time, the initial value of the black circle part of FIG. 16 (1) is obtained. 16 (2) is a conceptual diagram when the value of the coding start point is included in the list. In this case, since there is no information value related to the last VBV occupation value, a virtual image exists after the last frame. If there is a frame, the information value regarding the VBV occupancy value at the start of encoding of the virtual frame is calculated as the final value. The calculation subtracts the final picture code amount from the information value regarding the final VBV occupation value,
From the subtracted value, from the slope according to the coding rate, (1 /
The final value of the black circle portion in FIG. 16 (2) is obtained by adding the values obtained by calculating how much the code transmission amount is based on only the picture rate).

Next, the configuration of an embodiment of the recording / reproducing apparatus to which the present invention is applied is shown in FIG. 4, and the operation of creating VBV buffer information while encoding image data by the MPEG encoding method will be described.

When there is no encoded data in the recording medium 31, that is, when the encoding is performed for the first time, the data reading unit 32 from the recording medium 31 does not have the data, and therefore, the information that there is no data is displayed. It transmits to the VBV buffer information detector 33. Since there is no data even in the VBV buffer information detector 33, the initial value set in advance in the parameter setter 34, that is, the VBV value is set to 80% of the maximum value of VBV defined by MPEG, The time stamp information is 0. These initial setting values are transmitted to the image encoder 35.

In the image encoder 35, the encoding is started from the initial setting value. The image encoder 35 encodes the generated code amount, the PTM value, and the VBV value at the end of picture encoding one frame before the I picture of the bitstream and one frame before the P picture, each time. VB
It is transmitted to the V buffer information generator 36. At the same time, the encoded data is transmitted to the data writing unit 37. Further, the image encoder 35 is configured to detect the generated code amount and PTM at the time when the user temporarily stops or finishes the image compression recording.
The value and the VBV value are transmitted to the VBV buffer information creator 36.

The VBV buffer information generator 36 has the structure shown in FIG. 1 from the input generated code amount value, PTM value and VBV value.
Create VBV buffer information data. Alternatively, the data necessary for creating the data structure is stored in a memory in a predetermined format. The information created by the VBV buffer information creator 36 may be simultaneously written in bursts when the data writing unit 37 writes the encoded data (MPEG image data) in the recording medium 31. Further, the information created by the VBV buffer information creator 36 is recorded and held in a predetermined format when the encoded data (MPEG image data) has been written, that is, after the user temporarily stops or finishes the image compression recording. The written data may be converted into the structure shown in FIG. 1 and written by the data writing unit 37.

Next, the first data recorded on the recording medium 31 is recorded.
A description will be given with reference to FIG. 8 of the case of re-encoding the portion of the section A for enabling the continuous reproduction from a predetermined position with respect to the second two MPEG image data.

First, from the user interface (not shown), the first and second MPs already recorded are recorded.
Ask the user to specify from which point in the EG image data to connect and play.

The recording medium 31 has already recorded the first and second two MPEG image data (compression-coded streams) and the VBV buffer information generated by the recording / reproducing apparatus shown in FIG. Therefore, the data reading unit 32 shown in FIG. 4 reads the VBV buffer information, and the connection point b
The VBV value, the PTM value, and the relative address of the position a in FIG.

When the connection reproduction position is specified from the user interface, for example, when the specification method is position information of the relative address of the data, the relative address information in the EPn information of the VBV buffer information structure is most Use VBV and PTM values linked to data of similar values. If the designation method is the time from the start time of the data or the time stamp information of the point to be connected and reproduced, the EPn of the structure of the VBV buffer information is similarly set.
Using the PTM value in the information, if this value is recorded with a clock of 90 KHz, you can obtain the time in seconds by multiplying that value by the value of 1/90000 seconds, and the position for connecting and reproducing. (Relative address), VBV value, and PTM value can be obtained.

These values are input to the parameter setting unit 34, and the image encoder 35 starts encoding from the set values. On the other hand, the encoded data search unit 38 searches the head position of the section A to be re-encoded in the already recorded bit stream. The search uses the relative address of the data and sets the pointer at a position from the beginning of the bitstream file.

In the image encoder 35, the first MPEG image data corresponding to the section A is decoded, and using the decoded image, the transition of the VBV buffer occupancy value is VBV at the position a.
The rate control is performed so that it starts from the V value and ends up to the VBV value at the position of d, and re-encoding is performed by the MPEG encoding method. The re-encoding may use the completely decoded image as described above, but may use the code amount control technique on the bit stream as disclosed in Japanese Patent Laid-Open No. 11-234677.

Here, if the section A to be re-encoded is VB
If it is longer than the minimum unit of the V buffer information, while re-encoding, the generated code amount, PTM value, and VBV value at the end of picture encoding of the I picture of the bit stream and the P picture one frame before are It is transmitted to the VBV buffer information generator 36. At the same time, the re-encoded data is transmitted to the data writing unit 37.

The VBV buffer information creator 36 creates data having the structure shown in FIG. 1 from the input generated code amount value, PTM value and VBV value. Alternatively, the data necessary for creating the data structure is stored in a memory in a predetermined format. The information in the VBV buffer information generator 36 may be written in bursts at the same time when the encoded data is being written, or when the encoded data has been written, that is, when the user compresses the image. Data recorded and held in a predetermined format when recording is temporarily stopped or ended may be converted into the structure shown in FIG. 1 for writing.

The re-encoded image data of the section A (connection section A re-encoded data) is recorded as a separate file separated from the first and second MPEG image data. Alternatively, the second MPEG image data to be recorded is linked and recorded at the beginning.

The first MPEG image data, the second MPEG image data, the information about the VBV buffer occupation value and its data address information, the re-encoded image data of the section A (or the re-encoding of the section B) The image data or the re-encoded image data of the section A + B) is recorded on different recording media, whether recorded on the same recording medium or a plurality of recording media in any combination. It doesn't matter. When recorded separately on multiple recording media, it indicates the same information group so that each recording media can be operated by linking them (each data and information are linked). Information, such as an ID, may be recorded in each recording medium. The first MPEG image data and the second
When the MPEG image data and the re-encoded image data of the section A (or the re-encoded image data of the section B or the re-encoded image data of the section A + B) are recorded on the same recording medium. In addition, one recording medium can control connection reproduction on the reproduction device side.

When the information regarding the VBV buffer occupancy value for obtaining the connecting section re-encoded image data is obtained by calculation instead of reading from the side information recorded on the medium, the information regarding the VBV buffer occupancy value is calculated. It is not necessary to record the information and its data address information.

In the above embodiments, the recording medium has been described as a recording medium in the recording / reproducing apparatus, but a recording medium detachable from the recording / reproducing apparatus or a recording medium (database) via a network may be used.

Further, in the above-mentioned embodiment, an example in which image data is connected by paying attention to a single MPEG image data has been described.
This may be applied when connecting the MPEG image data in the MPEG transport stream which is the EG multiplexed data.

[0100] The transport stream has variable length coded MPEG image data and fixed length coded.
In many cases, MPEG1 layer 2 audio or AC3 is multiplexed. Therefore, when connecting MPEG image data, which is one of the element-encoded data in the multiplexed data, the ST specified by MPEG at the point of connection.
As a connection method considering the consistency of the D buffer (VBV buffer in video), the method of the above-described embodiment may be applied.

For example, the first and second MPs to be connected from within the first and second MPEG transport streams, respectively.
EG image data is taken out and connected in the same manner as in the above-mentioned embodiment. The rejoined segment re-encoded data (re-encoded image data of the section A, re-encoded image data of the section B, re-encoded image data of the section A + B) used for the joint reproduction is packet-multiplexed by the MPEG method. It may be generated and recorded as the generated MPEG multiplexed data.

The state of FIG. 14 (1) shows the state of packet-multiplexed data of the MPEG transport stream. Packets marked with V are video packets, packets marked with A are audio packets, and packets marked with S are information packets such as PAT and PMT used in the system. Each MPEG2
It is recorded according to the system rules. Video packets are colored in light gray. The state showing all of these is shown in FIG. The state in which only these video packets are collected is shown in FIG. As shown in (4) in the figure, the typical contents of this video packet are an I picture, two B pictures, then one P picture, and so on. is there.

The code amount is adjusted by re-encoding one or more of these pictures. For example, the state in which the code amount is reduced is shown in (5) of FIG. The code amount of each picture is small. The packetization in that state is shown in FIG. The reduced part is colored black. This packet reduces the overall amount of video. Then rebuild the TS. This state is represented in its entirety in FIG. 7 (7). FIG. 8 is an enlarged view of FIG. 7 (7). As a result, a part of the V packet is reduced, and the other element data packets are multiplexed as they are.

According to the MPEG system regulations, PCR clock information must be recorded once every 100 msec.
Also, since the data length has been changed, the PCR clock information described in each element packet is changed as necessary. Also, in the video packet, PTS and DTS are described in the packet in which the leading PES header of the access unit (picture unit of frame or field) exists. In the audio packet, one or more audio frames are packed by PES, and the first P
PTS is described in the packet with ES header. These time stamp information need not be changed unless the number of pictures in the image is increased or decreased, and the audio need not be changed unless the reproduction time length is increased or decreased, but in other cases, Add and modify appropriate PTS and DTS.

Furthermore, when simply re-encoding, the GOP unit from the I picture, which is the reset timing of predictive encoding, is easy to handle, but when the GOPs are not independent, that is, the B picture at the boundary is If it is predicted across both GOPs (when GOP closed gop = 0), the last reference picture of the previous GOP is decoded and stored in an image re-encoding memory (not shown). It may be necessary to keep it.

First MPEG multiplexed data (first MPEG transport stream), second MPEG image data (second MPEG transport stream), information on VBV buffer occupancy value and its data address information. , The re-encoded image data of the section A (or the re-encoded image data of the section B, or the re-encoded image data of the section A + B) is included as element encoded data, and is packet-multiplexed by the MPEG method to be generated. The connected section MPEG multiplexed data may be recorded on the same recording medium, may be recorded on a plurality of recording media in an arbitrary combination, or may be recorded on different recording media. When recorded separately on multiple recording media, it indicates the same information group so that each recording media can be operated by linking them (each data and information are linked). Information, such as an ID, may be recorded in each recording medium. First
MPEG-multiplexed image data, second MPEG-multiplexed image data, re-encoded image data of the section A (or re-encoded image data of the section B, or re-encoded image data of the section A + B) In the case where the MPEG multiplexed data of the connection section is recorded on the same recording medium, the connection reproduction on the reproducing device side can be controlled by one recording medium.

[0107]

As described above, according to the present invention, the first and second MPEG image data (or the first MPEG image data) can be obtained.
Packet-multiplexed first MPEG multiplexed data including image data as element encoded data, and packet-multiplexed second MPEG multiplexed data including second MPEG image data as element encoded data ), When the first MPEG image data is connected to the second MPEG image data to be reproduced at each specified connection position (from the first MPEG multiplexed data to the second MPEG multiplexed data). (When connecting to the encrypted data and playing), there is no inconsistency of overflow or underflow in the connection of the VBV buffer,
Seamless and high-quality reproduction can be realized.

Further, in the present invention, since the re-encoded data of the set connecting section is the only image data to be newly generated / recorded in order to realize seamless high-quality reproduction, re-coding of the connecting section is performed. The recording medium for recording the encoded data can be efficiently used.

[Brief description of drawings]

FIG. 1 is a diagram showing a VBV buffer information structure based on an embodiment of a recording / reproducing apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a relationship between MPEG image data and a relative address according to an embodiment.

FIG. 3 is an explanatory diagram illustrating a VBV value according to an embodiment.

FIG. 4 is a block diagram showing an embodiment of a recording / reproducing apparatus to which the present invention is applied.

FIG. 5 is a diagram showing an example of a conventional MPEG encoder.

FIG. 6 is a diagram showing an example of a conventional MPEG decoder.

FIG. 7 is a diagram for explaining the concept of a VBV buffer in MPEG.

FIG. 8 is a diagram for explaining the concept of connection reproduction that can be realized by the present invention.

FIG. 9 is a diagram for explaining the concept of connection reproduction that can be realized by the present invention.

FIG. 10 is a diagram for explaining the concept of connection reproduction that can be realized by the present invention.

FIG. 11 is an explanatory diagram showing a conventional MPEG multiplexing system.

FIG. 12 is an explanatory diagram showing the relationship between MPEGTS and PS and PES.

FIG. 13 is an explanatory diagram showing a usage example of PSI of MPEG TS.

FIG. 14 is an explanatory diagram showing an arrangement of MPEG TS packets.

FIG. 15 is a diagram for explaining the concept of connection reproduction that can be realized by the present invention.

FIG. 16 is a diagram for explaining an information value related to a VBV buffer occupancy value in one embodiment.

FIG. 17 is a diagram showing a relationship between a VBV buffer occupation value and a VBV delay value.

[Explanation of symbols]

31 recording medium 32 data reader 33 VBV buffer information detector 34 Parameter setter 35 image encoder 36 VBV buffer information generator 37 Data writing section 38 Coded data searcher

Continued front page    (72) Inventor Wataru Inaba             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa             Local Victor Company of Japan, Ltd. (72) Inventor Kenjiro Ueda             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa             Local Victor Company of Japan, Ltd. (72) Inventor Seiji Higurashi             3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa             Local Victor Company of Japan, Ltd. F-term (reference) 5C053 GA11 GB05 GB21 GB22 GB38                 5C059 KK35 KK39 MA00 MA05 MA14                       MA23 MC11 MC38 ME02 NN01                       NN21 PP05 PP06 PP07 PP08                       RC11 SS12 TA46 TB01 TB04                       TC16 TC31 UA02 UA05 UA32                       UA38                 5D044 AB07 EF03 GK08 GK10 HL14

Claims (2)

[Claims] 1. The first and second MPEG image data, which are image data encoded by the MPEG encoding method, are assigned to the first MPEG at a designated connection designation position in each of the MPEG image data. The MP data is used as data for connecting the image data to the second MPEG image data for reproduction.
An MPEG data recording device provided with recording means for generating and recording second connection section re-encoded data encoded by the EG encoding method, wherein the recording means is a part of the second MPEG image data. A section in which the connection designated position is a start position and a position after a second predetermined time from the connection designated position in the second MPEG image data is an end position is a second connection section,
The second connection section decoded image data, which is image data obtained by decoding the second MPEG image data in the second connection section, is re-encoded by the MPEG encoding method to obtain the second connection section. A re-encoding means for generating re-encoded data,
The second connection segment re-encoded data is recorded on a recording medium, and the re-encoding unit changes the information value relating to the VBV buffer occupation value at the time of the re-encoding.
A position corresponding to the end position of the second connection section, starting from the information value relating to the VBV buffer occupation value at the time of encoding the first MPEG image data at the position corresponding to the connection specification position in the image data The second MPEG in
An MPEG data recording device, characterized in that a code amount is controlled and re-encoding is performed so as to end up to an information value regarding a VBV buffer occupation value at the time of encoding image data. 2. The MPEG data recording apparatus according to claim 1, wherein the recording unit includes the second connection section re-encoded data as element encoded data and packet-multiplexes the MPEG method to generate the encoded data. MP for recording second multiplexed MPEG multiplexed data on a recording medium
EG data recorder.