JP2003018548A - Mpeg recording/reproducing method, mpeg recording/ reproducing apparatus and mpeg recording/reproducing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously reproduce and output bit streams recorded at a different time without causing a sense of visual incongruity. SOLUTION: When an I-picture or a P-picture is detected from a stream A received at an I/F 3, in a tape drive 4, information I/P about these picture is recorded in a sub-code region on a magnetic tape. Also, when a stream B is received, information SC including the information I/P immediately before recording into the magnetic tape and information about the first picture of the stream B is recorded before the recording region of the stream B. To continuously reproduce the streams A and B, in a video decoding section 6, a copy picture is inserted into the last picture of the stream A and the first picture of the stream B on the basis of a value calculated from recording information of the information SC by a CPU 2, time stamp information added to each picture in the stream B is rewritten so as to have continuity from the stream A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MPEG recording / reproducing method and an MPEG recording / reproducing method for receiving video data of an MPEG bit stream, recording it on a recording medium, and reproducing and outputting it.
The present invention relates to a PEG recording / reproducing device.

[0002]

2. Description of the Related Art Recently, as a compression / expansion method for moving images,
The MPEG (Moving Picture Expert Group) system is known. In particular, the MPEG-2 system which has become widespread in recent years is capable of transmitting a plurality of programs as one stream by using MPEG-TS (Transport Stream). It is used. In addition, such MPEG-
M that receives TS, temporarily records it on a recording medium such as a magnetic tape or HDD (hard disk drive), and then reads and decodes the recorded data, reproduces and outputs it.
A PEG recording / reproducing device is known.

The MPEG-TS is composed of a plurality of fixed length TS packets of 188 bytes, and this TS packet is composed of a fixed length packet header of 4 bytes, a variable length adaptation field and a payload. . The adaptation field is used for transmitting information such as a program clock reference (hereinafter referred to as PCR) and the like, and has a stuffing function for making the TS packet a fixed length. In addition to the picture data, the payload also contains playback output time management information (Presentation
Time Stamp: Hereinafter, such information as PTS) and decoding time management information (Decoding Time Stamp: DTS) are stored.

In the MPEG recording / reproducing apparatus, the reference time intended on the encoder side is reproduced in a synchronizing signal (System Time Clock: hereinafter abbreviated as STC) inside the reference decoder by referring to the value of PCR. Further, PTS and DTS are reproduction output and decoding time management information, respectively, and are MPEG.
In the recording / reproducing apparatus, when the STC value matches the PTS value, the corresponding access unit is reproduced and output, and when the decoding time and the reproducing time of the picture are different, decoding is performed based on the DTS. .

[0005]

In such an MPEG recording / reproducing apparatus, when a stream recorded on a recording medium at a certain time is followed by another stream, the time stamp recorded in each stream is recorded. The value of is not continuous. Therefore, when these streams are to be continuously reproduced, the image immediately before the transition from the previously recorded stream to the next stream or a monochrome image is displayed for a while, and the PC by the next stream is displayed.
The method of reproducing this stream after detecting R is adopted. However, with this method, when reproducing the boundary of the recorded stream, a display freeze always occurs for a relatively long time. Therefore, it is difficult to display a continuous image without a sense of discomfort at the seam of the stream. there were.

The present invention has been made in view of the above problems, and provides a MPEG recording / reproducing method capable of continuously reproducing and outputting bit streams recorded at different times without causing a display discomfort. With the goal.

Another object of the present invention is to provide an MPEG recording / reproducing apparatus capable of continuously reproducing and outputting bit streams recorded at different times without causing a display discomfort.

[0008]

In order to solve the above problems, the present invention provides an MPEG recording / reproducing method for receiving video data by an MPEG bit stream, recording the video data on a recording medium, and reproducing and outputting the video data. When the picture data of either the I-picture or the P-picture is detected from the 1 bit stream, the picture data of the picture is recorded in the recording medium, and
When information about the picture is recorded in a first recording area on the recording medium and a second bit stream is received and recorded on the recording medium after the first bit stream is received, the Information on the first recording area and information on the first picture of the second bitstream are recorded in the second recording area on the recording medium, and the first and second bitstreams are reproduced and output. In this case, based on each information recorded in the second recording area, a copy picture based on a predetermined picture of the first bit stream is provided between each picture of the first and second bit streams. So that the time stamp information attached to each picture in the second bitstream is continuous from the first bitstream. Performs a decoding process instead come, MPEG recording and reproducing method, characterized in that there is provided.

In such an MPEG recording / reproducing method, every time the data of the I-picture and P-picture is detected when the first bit stream is received, the information on each picture is recorded on the recording medium. It is recorded in one recording area. Further, when the second bit stream is received and recorded on the recording medium, each piece of information in the first recording area immediately before recording and information on the first picture of the second bit stream are recorded on the recording medium. It is recorded in the second recording area.

When reproducing and outputting the first and second bit streams, the first and second pictures are formed between the pictures of the first and second bit streams based on the information recorded in the second recording area. A copy picture based on a predetermined picture of the second bit stream is inserted, the time stamp information attached to each picture in the second bit stream is rewritten so as to be continuous from the first bit stream, and decoding processing is performed. . Therefore, at the time of reproduction, after the display of the image by the first bit stream, the copy pictures of a few frames are continuously displayed,
Further, the images of the second bit stream are continuously displayed.

Further, according to the present invention, in an MPEG recording / reproducing apparatus for receiving video data in an MPEG bit stream, recording it on a recording medium, and reproducing and outputting it, an I-picture or P-picture is received from the first bit stream received. When the data of any one of the pictures is detected, the image data of the picture is recorded in the recording medium, and the information regarding the picture is recorded in the first recording area on the recording medium. Information of the first recording area immediately before recording and information on the first picture of the second bitstream when the second bitstream is received and recorded on the recording medium after the reception of the second bitstream. To a second recording area on the recording medium, and recording means for recording the first and second recording areas. A predetermined picture of the first bitstream between the pictures of the first and second bitstreams, based on the information recorded in the second recording area, when reproducing and outputting the streamstream. And a decoding processing unit that inserts a copy picture based on the above and rewrites the time stamp information attached to each picture in the second bit stream so as to be continuous from the first bit stream and performs decoding processing. An MPEG recording / reproducing apparatus characterized by the above is provided.

In such an MPEG recording / reproducing apparatus, when the recording control means detects the picture data of either the I-picture or the P-picture from the received first bit stream, it relates to each of these pictures. Information is recorded in the first recording area on the recording medium, and when the second bit stream is received and recorded on the recording medium after receiving the first bit stream, the information in the first recording area immediately before recording And information about the first picture of the second bitstream, the second information on the recording medium.
Is recorded in the recording area of.

When the decoding processing means reproduces and outputs the first and second bit streams, the first and second bit streams are recorded based on the respective information recorded in the second recording area.
A copy picture based on a predetermined picture of the first bitstream is inserted between each picture of the second bitstream, and the time stamp information attached to each picture in the second bitstream is continued from the first bitstream. And the decryption process is performed. Therefore, at the time of reproduction, the copy picture of a small number of frames is continuously displayed after the display of the image by the first bit stream, and further the images by the second bit stream are continuously displayed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration example of the MPEG recording / reproducing apparatus of the present invention.

The MPEG recording / reproducing apparatus 1 shown in FIG.
A device for receiving PEG-TS, recording it on a magnetic tape as a recording medium, extracting video data, reproducing and outputting the data, and a CPU 2 that controls the entire device and an MPE.
Communication interface for receiving G-TS (hereinafter referred to as I / T
3), a tape drive 4 for recording / reproducing a magnetic tape, and a DRAM (Dynamic Random Access Memory) for temporarily storing data read from the magnetic tape.
5, a video decoding unit 6 for decoding the data read from the DRAM 5 and outputting a video signal, and a display unit 7 for displaying an image by the video signal.

The CPU 2 is connected to the I / F 3, the tape drive 4, the DRAM 5 and the video decoding unit 6 via the system bus 8, reads out necessary data from each of these devices, and controls the operation of each device. To do. I / F3
Is connected to an external device such as a host computer, a network, or the like, receives a TS packet in which an MPEG stream including video data is stored, and supplies the TS packet to the tape drive 4. The tape drive 4 writes the data of the TS packet received by the I / F 3 to the magnetic tape by the helical scan method, and supplies the read data to the DRAM 5. The DRAM 5 temporarily stores the data of the TS packets read from the magnetic tape when reproducing the video data, and sequentially outputs the data to the video decoding unit 6. The video decoding unit 6 extracts the video data from the input TS packet and decompresses it,
A video signal according to the NTSC (National TV Standards Committee) standard is output to the display unit 7. Display 7
Is composed of, for example, a display device or the like, and receives a video signal to display an image.

When the MPEG recording / reproducing apparatus 1 receives and records an MPEG stream containing video data, when a TS packet is received by the I / F 3, the CPU 2 needs to judge the attribute of each packet. A packet of a proper video stream is extracted, output to the tape drive 4, and recorded on a magnetic tape. At this time, as described later, every time the CPU 2 detects an I-picture or a P-picture from each picture included in the video stream, the subcode of the track on the magnetic tape in which the head portion of each detected picture is recorded. To record information such as a time stamp on each picture.

When the video data is reproduced, the tape drive 4 is driven by the control of the CPU 2 so that the TS packets recorded on the magnetic tape are sequentially read and stored in the DRAM 5. In addition, DRAM5
Under the control of the CPU 2, the TS packets are sequentially read and supplied to the video decoding unit 6. At this time, as will be described later, the CPU 2 reads in advance the information recorded in the subcode area of the magnetic tape, and based on this information, D
It controls the reading of TS packets from the RAM 5.

In the video decoding unit 6, a video stream is extracted from the input TS packet, and VBV (Vide) is extracted.
o Buffering Verifier) Data of each picture included in the video stream is stored in the buffer memory on the decoder side called a buffer. Further, PCR is extracted from this video stream, and the value of STC (frequency 27 MHz) is sequentially counted by an STC counter (not shown). Further, this STC decoding is used as a reference clock, and when the value of DTS included in the video stream matches STS, the picture data is read from the VBV buffer and expanded, and the value of PTS is changed to STS. When they match, they are reproduced as a 1-frame video signal and output to the display unit 7.

By the way, the data recorded in the sub-code area on the magnetic tape at the time of receiving the TS-packets is used when continuously reproducing the video streams having different coding times. Here, assuming that the video stream received and recorded first is stream A, and the one recorded immediately thereafter is stream B, when the streams A and B are continuously reproduced, in the above-mentioned MPEG recording / reproducing apparatus 1, the video decoding unit 6, the time stamp attached to the stream B is rewritten so that the decoding and reproduction output timing of the stream B is continuous from the stream A, and the decoding process is performed. Then, the copy picture obtained from the stream A is inserted. The data recorded in the subcode area of the magnetic tape is read by the CPU 2 prior to the decoding process, and is used for calculation of the rewriting value of the time stamp of the stream B and the number of inserted copy pictures.

Next, the operation of the MPEG recording / reproducing apparatus 1 when two video streams having different coding times are received will be described. In Figure 2,
The state of recording of two video streams on a magnetic tape is schematically shown.

FIG. 2 shows a state in which the data of the stream A is first recorded on the magnetic tape, and a new stream B received after this is overwritten from the middle of the recording area of the stream A. There is. In FIG. 2, the received TS packets are recorded in the main data area 41 of each track in order from the lower side in the drawing. Also,
A sub-code area 42 is provided on the upper side of each track in the figure. In the figure, the main data area 41
Shows the image type of the picture included in each TS packet.

In the MPEG recording / reproducing apparatus 1, when the TS packet of the stream A received at the I / F 3 is recorded on the magnetic tape, when an I-picture or a P-picture is detected from the TS packet from the received packet,
In the subcode area 42 of the track in which this TS packet is recorded, the data I such as the time code relating to the picture is recorded.
Record / P. Therefore, as shown in FIG. 2, on the magnetic tape, the data I / P is recorded in the subcode area 42 of the track in which the TS packet including the head portion of the I-picture and P-picture data is recorded. .

When the stream A is received by the I / F 3, the CPU 2 uses the TS packet including the head data of the I-picture and the P-picture to detect DTS and VB.
Information on the accumulated amount of this picture in the V buffer (VBV-De
lay: hereinafter, abbreviated as VD). Also, T
The PCR obtained from the S packet is synchronized with the STC to detect the arrival time of the TS packet including the head data of the picture (hereinafter, referred to as STS). Furthermore, when recording this TS packet on a magnetic tape,
The recorded track number (hereinafter, referred to as Tr. No) and the sync block number (hereinafter, referred to as SB. No) attached to the packets in the track in order are detected. Based on the detection by the CPU 2 described above, each time an I-picture or a P-picture is received on the magnetic tape, the STS and D for the TS-packet including each picture and this head data as the data I / P.
TS, VD, Tr. No and SB. Each value of No is recorded in the subcode area 42.

The STS, DTS and VD are 90
It is recorded as a value based on KHz. Next, when the reception of the stream A ends and the reception of the stream B starts after this, the tape drive 4 firstly records the data I / I recorded immediately before the new data is recorded on the magnetic tape. P is read, and each value of this data I / P is C
It is supplied to PU2. Data I / read at this time
P is the data recorded in the subcode area 42 of the track number "6" shown in FIG.

Here, as will be described later, this data I /
The P-picture corresponding to P is not decoded and reproduced in the case of continuous reproduction, and is the last decoded picture (see FIG. 2).
Since it is a picture next to the (B-picture), each value of the data I / P for this picture is S
TS_Next, DTS_Next, VD_Next,
Tr. No_Next and SB. It will be called No_Next.

Further, the CPU 2 receives the received stream B
When the first I-picture or P-picture is detected from the TS packet of this picture, the DTS of this picture (hereinafter referred to as DT
S_Top) and VD (hereinafter VD_Top)
value), and the STS of this packet
(Hereinafter referred to as STS_Top) is detected. Furthermore, the Tr. On the basis of No., the recording track number of the above-mentioned TS packet (hereinafter, Tr.
No. Top) and a sync block number (hereinafter referred to as SB. No_Top) are detected.

Based on these values, the CPU 2 calculates the following values necessary for continuous reproduction of the streams A and B, and records them in advance on the head portion of the data of the stream B on the magnetic tape. deep. The copy picture to be inserted between each stream A and B is
It becomes a P-picture for displaying the same image as the I-picture or P-picture that is finally decoded and reproduced and output in the stream A.

Therefore, the CPU 2 has the above-mentioned DTS.
When extracting _Next and VD_Next, the data of the last I-picture or P-picture in the stream A can also be extracted to calculate the data amount of the copy picture to be inserted. Here, the transfer time of the copy picture data to the VBV buffer (90 KHz standard)
Is T_Copy, ES based on copy picture data
The number of bytes of (Elementary Stream) is B_Copy, and the number of packets when this data is stored in a TS packet is P_Copy.

The bit rate at the time of decoding recorded in the sequence header of each stream A and B is Bit_R.
Assuming ate, T_Copy is calculated by the following equation (1).

[0031]

## EQU1 ## T_Copy = B_Copy / Bit_Rate * 1800 (1) Since the value of Bit_Rate is described with 400 bit / s as a reference, "1800" in the above formula (1) is for unit conversion. Is the numerical value of "90 *
10 ³ * 8/400 ”.

Further, the difference between the values of VD is VD_TN (= V
D_Top-VD_Next) and the number of copy pictures to be inserted (the number of frames) is N_Copy,
When the value of VD_TN becomes “0” or negative, Tr. Since the first I-picture or P-picture of stream B can be decoded at the P-picture decoding time (DTS_Next) that appears in No. “6”, N_Copy = 0. Also,
When VD_TN is positive, VBV is used when decoding the first picture of stream B in DTS_Next.
Because the buffer overflows, N_Cop
The value of y is expressed by the following equation (2).

[0033]

## EQU00002 ## N_Copy = VD_TN / (3003-T_Copy) (however, rounding up to one decimal place) (2) Also, the value of "3003" in the above equation (2) is NTS.
Frame cycle in C standard (frequency 29.97Hz)
Is a value expressed based on 90 Hz.

Here, when the continuous reproduction of the streams A and B is performed, the TS packet storing the copy picture data between the streams A and B is simulated in the video decoding unit 6 as described later. Continuous reproduction is performed by sequentially decoding the generated TS packets including these. In the TS packet inserted between the streams A and B, a stuffing byte is added to the adaptation field of the TS packet as necessary in order to compensate for the difference in the output time of the inserted TS packet with respect to the data amount of the copy picture. Is inserted. Further, in the data of the stream B after the decoding process is performed by the inserted TS packet, an offset is added to the value of the added time stamp, and the data is rewritten so as to be continuous from the time stamp of the previous TS packet. .

When the time required for inserting the stuffing byte is T_Stuf (90 KHz standard) and the number of bytes is B_Stuf, these values are obtained by the following equations (3) and (4).

[0036]

[Equation 3] T_Stuf = (3003-T_Copy) * N_Copy-VD_TN                                                               …… (3)

[0037]

## EQU00004 ## B_Stuf = T_Stuf * Bit_Rate / 1800 (4) The numerical values calculated by the above calculation are recorded on the magnetic tape when the stream B is recorded. As shown in FIG. 2, when recording the stream B, a new stream B is recorded.
One or a plurality of tracks (two tracks in FIG. 2) at the beginning of the recording area of No. 2 are areas for recording sub-code-only data (hereinafter referred to as SC), and TS packets are recorded from the subsequent tracks. It

As the data SC, STS_Next, DTS_Next, T from the data I / P for the last I-picture or P-picture of the stream A is used.
r. No_Next and SB. No_Next and STS_Top, DTS_T from the data I / P for the first I-picture or P-picture of stream B
op, Tr. No_Top and SB. The value of No_Top is recorded, and the values of N_Copy and B_Stuff are further recorded from the values calculated as described above.

Next, the operation during continuous reproduction of the streams A and B will be described. Fig. 3 shows V during continuous playback
The transition of the accumulated amount in the BV buffer and the state of TS packet insertion are shown.

When continuous reproduction of the streams A and B is performed, when the reading of the recording area of the stream A from the stream A is started in the tape drive 4, the read TS packets are sequentially supplied to the DRAM 5, and Prior to the start of decoding, the CPU 2 obtains the record information of the data SC and calculates the information about the TS packet to be inserted and the rewriting amount of the time stamp about the stream B based on this information.

First, the time difference between the time stamps assigned to the streams A and B, that is, the rewrite amount for the time stamp of the stream B is V_Rstp.
_TN (90 KHz standard), this value is, as shown in FIG. 3, the number of inserted copy pictures (N_Co
It is calculated from the following equation (5) based on py).

[0042]

## EQU00005 ## V_Rstp_TN = DTS_Next-DTS_Top + 3003 * N_Copy ... (5) From this, if the STS interval after rewriting the time stamp is STS_Diff, this value is given by the following equation (6).
Required by.

[0043]

## EQU00006 ## STS_Diff = V_Rstp_TN + STS_Top-STS_Next (6) Further, as shown in FIG.
DTS_ after rewriting from the timing of S_Next
Top timing (ie DTS_Next + V_
It is sufficient that the TS packet including the stuffing byte is generated before the TS packet in which the copy picture is stored is generated. Therefore,
P_S is the number of TS packets including stuffing bytes
tuff, the number of all TS packets inserted is P_
Assuming Ins, these values are given by the following equation (6),
It is obtained by (7) and (8).

[0044]

[Equation 7] P_Stuf = B_Stuf / 184 (however, rounding up to one decimal place)                                                               …… (7)

[0045]

## EQU00008 ## P_Ins = P_Copy * N_Copy + P_Stuf (8) Note that "184" in Expression (7) is the TS packet 1
It is the number of bits excluding the header part from the number of bytes "188" for one.

As described above, after the TS packet including the last picture (B picture in FIGS. 2 and 3) of the stream A is output from the DRAM 5 to the video decoding unit 6, the TS generated inside the video decoding unit 6 is output. The initial value of the STS value of the packet is the value of STS_Next, and in subsequent TS packets, T_Ins is sequentially added. In the first P_Stuf portion of the generated TS packet, the stuffing byte of data “0” is stored by the data amount of B_Stuf, and the data portion of less than 184 bytes in the TS packet is adjusted in the adaptation field.

Next, a TS packet storing the data of the copy pictures for the number of N_Copy is generated.
The initial value of DTS for the copy picture is DTS_Ne.
The initial values of xt and PTS are DTS_Next + 3003, and 3003 for the next copy picture.
It is increased in steps.

When the generation of these insertion packets is completed, the TS packet from the DRAM 5 is read again,
When the DTS of the data of the stream B matches the DTS_Top, the DTS of the picture after the TS packet,
V_Rstp_TN is sequentially added to PTS and PSR, and decoding and reproduction output processing are performed based on these rewritten time stamps.

When a TS packet to be inserted is generated, a cyclic counter value (Continuity Counter: hereinafter, abbreviated as CC) and a display order number value (Temporal Reference: hereinafter, TR) added to a copy picture. (Abbreviated) is described so as to continue from each value given to the stream A. Further, when the time stamp of stream B is rewritten subsequently, the values of CC and TR attached to each picture of stream B are also rewritten so as to be continuous with the inserted copy picture.

By the above operation, the decoding and reproduction output timing of the picture of stream B is adjusted so as to be synchronized with stream A, and the first picture of stream B is read after the decoding timing of the last picture of stream A. The shortest time is until the decoding timing of. A copy picture is inserted between the streams A and B in order to adjust decoding timing and prevent underflow / overflow of the VBV buffer, and stuffing bytes are inserted in order to adjust timing. Therefore, at the time of display transition from the stream A to the stream B on the display unit 7, the display of images by the stream B is continuously started after the copy pictures for a small number of frames are displayed, and the sense of discomfort is extremely small. It becomes possible to view continuous moving images.

Next, FIG. 4 is a flow chart showing the operation of the MPEG recording / reproducing apparatus 1 when receiving two streams. In step S401, the I / F
At 3, the reception of the TS packet including the data of the stream A is started. In step S402, the CPU 2
When the TS packet including the head data of the I-picture and the P-picture is detected from the TS packet received by the I / F 3, the DTS, VD and PCR attached to this picture are acquired. Also, along with this, the CPU 2
The STS of the TS packet including the head data of the picture is detected by synchronizing with the STC by PCR.

In step S403, the CPU 2
Tr. Which records this TS packet on a magnetic tape. No and SB. When No is detected, the tape drive 4 is controlled to record the TS packet in the main data area 41 on the magnetic tape, and in the subcode area 42, a TS including each picture and this head data as data I / P. -STS, DTS, VD, T for packets
r. No and SB. Record each value of No. In step S405, it is determined that the TS packet of the stream A has been received, and if the reception is continued, the process returns to step S402, and if it is finished, the step S406.
Proceed to.

In step S406, the reception of the stream B is started by the I / F3. In step S407, the CPU 2 controls the tape drive 4 to control the data I / O of the subcode area 42 recorded immediately before the area where the stream B is newly recorded on the magnetic tape.
Play the values of P and get these values. In step S408, the CPU 2 receives the T received by the I / F 3.
When the first I-picture or P-picture in stream B is detected from the S packet, the I / P data for this picture, that is, DTS_Top and VD
Get the value of _Top. Also, STS_Top for this TS packet is detected.

In step S409, the CPU 2
Based on each acquired value, the data to be written as the data SC, that is, the values of N_Copy and B_Stuf are calculated. In step S410, the tape drive 4 is controlled to set DTS_Ne as the data SC on the track before the area in which the data of the stream B is written.
xt, STS_Next, Tr. No_Next, S
B. No_Next, DTS_Top, STS_To
p, Tr. No_Top, SB. No_Top, N_C
Record each of the opy and B_Stuf values.

In step S411, the data SC is recorded on the recording track, and then the TS received by the I / F 3 is received.
The packets are sequentially recorded on the magnetic tape, and the data I / P is recorded in the subcode area 42 as necessary, and this recording is continued until the reception of the stream B is completed.

In the above stream receiving operation, the data I / P of the stream A immediately before new recording and the data I / P of the first picture in the stream B are set at the beginning of the recording area of the stream B. By pre-recording as data SC, at the time of continuous reproduction of streams A and B, a value relating to the generation of TS packets to be inserted and a rewriting amount with respect to the time stamp of stream B can be calculated based on this recording information. Is possible.

At the start of reception of stream B, N_
By calculating the values of Copy and B_Stuf in advance and recording them in the data SC, the amount of calculation at the time of continuous reproduction can be suppressed. Note that this N_Copy
The values of B_Stuf and B_Stuf may be calculated based on the data SC read during continuous reproduction, instead of being calculated at the start of reception of the stream B and recorded in the data SC.

Next, FIG. 5 is a flowchart showing the operation of the MPEG recording / reproducing apparatus 1 during continuous reproduction of two streams. In step S501, the CPU
By the control of 2, the reproduction output of the magnetic tape in the tape drive is started, and the reading of the TS packet including the data of the stream A is started. The data read from the magnetic tape is temporarily stored in the DRAM 5.

In step S502, the TS packet is read from the DRAM 5 for each picture and supplied to the video decoding unit 6, and the video decoding unit 6 performs decoding and reproduction output processing. In the video decoding unit 6, the video stream of the stream A is extracted from the input TS packet, and the data of each picture included in this video stream is accumulated in the VBV buffer. In addition, PCR is extracted from this video stream and ST
The value of C is sequentially counted and used as a reference clock, and when the value of DTS included in the video stream matches STS, picture data is read from the VBV buffer and expanded, and the value of PTS is STS. When it coincides with, it is reproduced as a 1-frame video signal and output to the display unit 7.

In step S503, the CPU 2
The reading of the data SC from the magnetic tape is monitored, and if not read, the process returns to step S502 to continue the decoding and reproduction output processing of the stream A, and if read, the process proceeds to step S504. In step S504, the CPU 2 acquires the Tr. No_
Next and SB. DRAM based on No_Next
The reading of the picture from 5 is stopped.

In step S505, the CPU 2 rewrites the time stamp of each picture of the stream B (V_Rst) based on the data obtained from the data SC.
p_TN) is calculated, and information (TS_Diff, P_Stuf, P_I) about the TS packet to be inserted is further calculated.
ns, T_Ins) and each value is calculated by the video decoding unit 6
Supply to. In step S506, the video decoding unit 6 generates a TS packet containing stuffing bytes and a TS packet containing copy picture data based on the respective values supplied from the CPU 2, and STS_
From the timing of Next, the copy picture data is sequentially accumulated in the VBV buffer, and the decoding and reproduction output processing is performed.

In step S507, under the control of the CPU 2, at the timing of STS_Top + V_Rstp_TN, the Tr. No_Top and SB. The reading of the TS packet from the DRAM 5 is restarted based on the value of No_Top, and the TS packet is supplied to the video decoding unit 6. In step S508, the video decoding unit 6 adds V_Rstp_ to the time stamp (DTS, PTS, SCR) for each picture of the stream B stored in the input TS packet.
TN is added to rewrite these values.

In step S509, stream B
Picture data is sequentially accumulated in the VBV buffer,
The stream B is decoded based on the rewritten time stamp. Therefore, in the video decoding unit 6, the data of the first picture of the stream B is read and decoded one frame after the timing of reading and decoding the data of the copy picture accumulated in the VBV buffer. After that, the data of the stream B is sequentially reproduced and output based on the rewritten time stamp.

In the above operation during continuous reproduction of the streams A and B, during the transition of the streams A and B,
By pre-reading the data SC recorded on the magnetic tape, it becomes possible to calculate the information for generating the TS packet to be inserted. Further, by rewriting the time stamp of the picture of the stream B, the decoding and reproduction output timing of the stream B is adjusted so as to be synchronized with the stream A in the shortest time, and the copy picture between the streams A and B is adjusted. By inserting the TS packet in which the stuffing byte is stored, the decoding timing is adjusted and the occurrence of underflow / overflow of the VBV buffer is prevented.
Therefore, when the reproduction shifts from the stream A to the stream B, a continuous reproduced image with less display discomfort is output.

In the embodiment of the present invention described above, the received video stream is recorded on the magnetic tape, but the recording medium is not limited to the magnetic tape, and may be, for example, an HDD (hard disk drive) or a DVD. (Digi
tal Versatile Disc) -a disk type recording medium such as a RAM may be used. In this case, a recording area for recording the data I / P and the data SC on the magnetic tape of the MPEG recording / reproducing apparatus 1 may be provided on the recording medium.

The processing function of the MPEG recording / reproducing apparatus 1 can be realized by a computer. In that case, a program describing the processing contents of the functions that the MPEG recording / reproducing apparatus 1 should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing content can be recorded in a computer-readable recording medium. Computer-readable recording media include magnetic recording devices, optical disks, magneto-optical recording media, semiconductor memories, and the like. The magnetic recording device includes a hard disk device (HDD), a flexible disk (FD), a magnetic tape, and the like. Optical discs include DVD, DVD-RAM, CD (Compac
t Disc) -ROM, CD-R (Recordable) / RW (ReWri
table) etc. Magneto-optical recording media include MO (Magneto
-Optical disk).

When distributing the program, for example, a DVD or a CD-ROM in which the program is recorded.
Portable recording media such as. It is also possible to store the program in the storage device of the server computer and transfer the program from the server computer to another computer via the network.

The computer executing the program stores, for example, the program recorded in the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. In addition, the computer can also sequentially execute processing according to the received program each time the program is transferred from the server computer.

[0069]

As described above, the MPEG of the present invention is used.
In the recording / reproducing method, in the second recording area on the recording medium, each piece of information about the picture of the first bit stream recorded in the first recording area immediately before the recording of the second bit stream, and the second information And information about the first picture of the bitstream of the. Further, when reproducing and outputting the first and second bit streams, the first and second pictures are formed between the pictures of the first and second bit streams based on the respective information recorded in the second recording area.
A copy picture based on a predetermined picture of the second bit stream is inserted, the time stamp information attached to each picture in the second bit stream is rewritten so as to be continuous from the first bit stream, and decoding processing is performed. . As a result, at the time of reproduction, a copy picture of a small number of frames is continuously displayed after the display of the image by the first bit stream, and further the images by the second bit stream are continuously displayed. It is possible to perform continuous reproduction output with less discomfort in display at the joint of two bit streams.

Further, in the MPEG recording / reproducing apparatus of the present invention, under the control of the recording control means, the second recording area on the recording medium is recorded on the first recording area immediately before the recording of the second bit stream. Each information about the picture of the first bitstream and the information about the first picture of the second bitstream are recorded. When reproducing and outputting the first and second bitstreams, the decoding processing means controls the first and second bitstreams based on the respective information recorded in the second recording area. A copy picture based on a predetermined picture of the first bit stream is inserted between the pictures, and the time stamp information attached to each picture in the second bit stream is rewritten so as to be continuous from the first bit stream. , Decryption processing is performed. As a result, at the time of reproduction, a copy picture of a small number of frames is continuously displayed after the display of the image by the first bit stream, and further the images by the second bit stream are continuously displayed. It is possible to perform continuous reproduction output with less discomfort in display at the joint of two bit streams.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration example of an MPEG recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram schematically showing how two video streams are recorded on a magnetic tape.

FIG. 3 is a diagram showing changes in the amount of accumulation in a VBV buffer and TS packet insertion during continuous reproduction.

FIG. 4 is a flowchart showing an operation of the MPEG recording / reproducing apparatus when receiving two streams.

FIG. 5 is a flowchart showing an operation during continuous reproduction of two streams in the MPEG recording / reproducing apparatus.

[Explanation of symbols]

1 ... MPEG recording / reproducing apparatus, 2 ... CPU, 3 ... I
/ F, 4 ... Tape drive, 5 ... DRAM, 6 ...
Video decoding unit, 7 ... Display unit, 8 ... System bus

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5C053 FA21 GA11 GB06 GB37 HA33                       JA22 KA04 KA24 LA06                 5C059 MA00 PP05 PP06 RB04 RC02                       RC04 RC12 RC28 SS02 SS11                       SS13 TA18 TA73 TC20 TC24                       UA05                 5D044 AB07 BC01 CC01 DE24 DE25                       EF05 FG21 FG23 GK08 GK12

Claims (15)

[Claims] 1. An MPEG recording / reproducing method for receiving video data in an MPEG bitstream, recording the video data on a recording medium, and reproducing and outputting the video data, which is either an I-picture or a P-picture from the received first bitstream. When the picture data of the picture is detected, the picture data of the picture is recorded in the recording medium, and the information about the picture is recorded in the first recording area on the recording medium. When the second bit stream is received and recorded on the recording medium after reception, the information of the first recording area immediately before recording and the second information
And information about the first picture of the bit stream are recorded in the second recording area on the recording medium, and are recorded in the second recording area when reproducing and outputting the first and second bit streams. A copy picture based on a predetermined picture of the first bit stream is inserted between each picture of the first and second bit streams based on each of the generated information, and each copy in the second bit stream is inserted. An MPEG recording / reproducing method, characterized in that time stamp information attached to a picture is rewritten so as to be continuous from the first bit stream and decoding processing is performed. 2. The first recording area stores a transport packet including storage amount information (VD) of the picture in the buffer memory on the decoder side and transport data including the head data of the picture as information about the picture. The arrival time information, the recording position information of the transport packet on the recording medium, and the decoding time management information (DTS) of the picture are recorded.
The described MPEG recording / reproducing method. 3. In the second recording area, together with the recording information of the first recording area regarding the I-picture or P-picture immediately before recording of the second bit stream on the recording medium, the second recording area is recorded. As the information about the first picture of the second bit stream, the storage amount information (V
3. The MPEG recording / reproducing method according to claim 2, wherein D), the arrival time information, the recording position information, and the decoding time management information (DTS) are recorded. 4. The reproduction output according to the difference between the values of the accumulated amount information corresponding to the pictures of the first and second bit streams recorded in the second recording area. Underflow does not occur in the buffer memory on the decoder side, and the decoding timing of each picture of the second bitstream is continuous with the decoding timing of each picture of the first bitstream. Decoding processing is performed by inserting a transport packet including stuffing bytes and a transport packet including data of the copy picture between transport packets of the first and second bit streams. The MPEG recording / reproducing method according to claim 3. 5. The number of stuffing bytes and the number of copy pictures stored in the transport packet inserted during the reproduction output are calculated at the time of receiving the second bitstream. The data is recorded in the second recording area.
The described MPEG recording / reproducing method. 6. A buffer memory on the side of the decoder based on each recording position information corresponding to the first and second bitstreams recorded in the second recording area at the time of the reproduction output. 5. The MPEG recording / reproducing method according to claim 4, wherein the data reading to and from the device is controlled. 7. The time stamp information rewritten during the reproduction output is arrival time information of a transport packet including head data of each picture of the second bit stream, reproduction output time management of each picture. 2. The MPEG recording / reproducing method according to claim 1, which is information (PTS) and decoding time management information (DTS) of each picture. 8. The cyclic counter value, display order number value (TR), and program reference time reference value (TR) of each picture in the second bit stream according to the rewriting of the time stamp information during the reproduction output. 2. The MPEG recording / reproducing method according to claim 1, wherein the PCR) is further rewritten. 9. The copy picture inserted during the reproduction output is the same image as the I-picture or P-picture of the first bitstream displayed immediately before the decoding of the second bitstream. The MPEG recording / reproducing method according to claim 1, wherein the MPEG recording / reproducing is a P-picture to be displayed. 10. The MPEG recording / reproducing method according to claim 1, wherein the recording medium is a magnetic tape. 11. The information regarding the picture recorded in the first recording area includes a track number (Tr. No.) on the magnetic tape as recording position information of the transport packet on the recording medium, and each information. 11. The MPEG recording / reproducing method according to claim 10, wherein a sync block number (SB.No) indicating a recording position of the packet on the track is included. 12. The MPEG recording / reproducing method according to claim 10, wherein the first recording area is provided in a subcode area of the magnetic tape. 13. The MPEG recording according to claim 10, wherein the second recording area is provided in one or a plurality of tracks as a whole from a head portion in which the data of the second bit stream is recorded. How to play. 14. An MPEG recording / reproducing apparatus for receiving video data in an MPEG bitstream, recording the video data on a recording medium, and reproducing and outputting the video data, which is either an I-picture or a P-picture from the received first bitstream. When the data of the picture is detected, the image data of the picture is recorded in the recording medium, and the information about the picture is recorded in the first recording area on the recording medium. When the second bit stream is received and recorded on the recording medium after the reception, the information of the first recording area immediately before recording and the information on the first picture of the second bit stream are recorded. Recording control means for recording in a second recording area on a medium, and the first and second bit streams When reproducing and outputting, based on each information recorded in the second recording area, copying based on a predetermined picture of the first bit stream between each picture by the first and second bit streams. A decoding processing unit that inserts a picture and rewrites the time stamp information attached to each picture in the second bit stream so as to be continuous from the first bit stream, and performs decoding processing. An MPEG recording / reproducing apparatus. 15. An MPEG recording / reproducing program for receiving video data of an MPEG bitstream, recording the video data on a recording medium, and reproducing and outputting the video data. When the data of any picture is detected, the image data of the picture is recorded on the recording medium, and the information on the picture is recorded on the first recording area on the recording medium. When receiving a second bit stream after receiving the stream and recording the second bit stream on the recording medium, information on the first recording area immediately before recording and information on the first picture of the second bit stream are recorded. Recording control means for recording in a second recording area on the recording medium, the first and second bits When reproducing and outputting a stream, based on each information recorded in the second recording area, a predetermined picture of the first bit stream is set between each picture of the first and second bit streams. A computer functions as a decoding processing unit that inserts a copy picture based on the above and rewrites the time stamp information attached to each picture in the second bit stream so as to be continuous from the first bit stream and performs decoding processing MP characterized by
EG recording / playback program.