JPH03129979A - Video signal recording disk - Google Patents

Abstract

PURPOSE:To attain high density recording to a digital video signal by providing a frame group head information table and recording consecutively plural frame group data over recording sectors. CONSTITUTION:A frame group head information table HD comprising head information groups of plural frame group data GOF, each consisting of in-frame coding data DTX1 and prescribed number of inter-frame coding data DTX2-DTX 6 as address information is provided and plural frame group data GOF1, GOF2,... are recorded continuously over recording sectors SEC. Thus, a digital video signal VD is recorded with high density without loss of random access performance.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Industrial field of application B. Outline of the invention C. Prior art (Fig. 8) D. Problem to be solved by the invention E. Means for solving the problem (Fig. 1) 1. Effect (1st
Figure) Example G (G1) Configuration of video signal recording disk (Figures 1 to 3) (G2) Power of video signal recording device and video signal reproducing device (Figures 4 and 5) (G3) Configuration of image data generation circuit (FIGS. 6 and 7) (G4) Effects of embodiments (FIGS. 1 to 3) (G5) Other embodiments H Effects of the invention A Industrial application field The present invention The present invention relates to a video signal recording disc, and is suitable for use in recording digital video signals after highly efficient encoding on a disc-shaped recording medium such as a compact disc.

B. Summary of the Invention The present invention provides a video signal recording disk on which digital video signals are encoded and recorded with high efficiency, includes a frame group head information table, and continuously records a plurality of frame group data across recording sectors. By recording, digital video signals can be recorded at high density without impairing random accessibility.

C. Prior Art Conventionally, disc-shaped recording media such as compact discs have been proposed in which a video signal consisting of a moving image is highly efficiently encoded and recorded as intra-frame encoded data and inter-frame encoded data.

For example, as shown in FIG. 8, this high-efficiency encoding converts the moving image images PCI%PC2, PO2, etc. at time points t==L+, ts, ts%, etc. When digitally encoding data and recording it, for example, on a compact disc, the overall recording efficiency is improved by compressing the digital data to be recorded by taking advantage of the fact that the video signal has a large autocorrelation characteristic. is being done.

That is, the intraframe encoding process is performed on images PCI, PO
2, PO2, .
t, PO2, PO2, . . . compressed bit number of image data is recorded.

In addition, the interframe encoding process sequentially processes adjacent images Pct and PO2, PO2 and PO2, as shown in FIG. 8(B).
Image data PC12, PO23, . . . , which is the difference in pixel data between 2, .

Thus, images PCI, PC2, PO2,...
Compared to the case where all pixel data is recorded, digital data with a much smaller number of bits is encoded with high efficiency and recorded on a compact disc.

D Problems to be Solved by the Invention Incidentally, disk-shaped recording media that record highly efficiently encoded digital data use so-called sectors (for example, in the case of hard disks, 512 bytes) as the minimum accessible recording unit. Input data is always recorded and reproduced from the beginning of the sector, thereby allowing random access in units of sectors.

However, if you do this, if the length of the input data is arbitrary, most of the input data will end in the middle of the sector,
In the remaining part, meaningless data (so-called fill bits) will be recorded, and in the worst case, it will be about one sector worth (
There was a problem in that the recording area of 512 bytes (=4.096 bits) was wasted every time the input data was separated.

In practice, to record 1 hour worth of video images, 10.
It is necessary to record digital data for 800 (=30 frames x 3.600 seconds) frames, for example,
Assuming that an average of 256 bytes, which is half of one sector, is wasted for each frame, a total of 27 megabytes of recording area is wasted, which is still insufficient for practical use in terms of disk usage efficiency.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a video signal recording disk that can record digital video signals at high density without impairing random accessibility.

E Means for Solving the Problem In order to solve this problem, in the present invention, the digital video signal VD is divided into intra-frame coded data DTXI and a predetermined number of inter-frame coded data DTX2 to DTX6.
In a video signal recording disk l that is converted into high-efficiency encoded data and recorded, intra-frame encoded data DTX1 and a predetermined number of inter-frame encoded data DTX2 are recorded.
A frame group start information table HD consisting of address information TAG is provided in which the start information of a plurality of frame group data GOF consisting of ~DTX6 is recorded, and a plurality of frame group data GOFI, GOF2, . . . are recorded in a recording sector SEC.
It was recorded continuously over the period.

One effect frame group head information table HD is provided, and a plurality of frame group data GOFI, GOF2, . . .
By recording continuously over the recording sector SEC, without impairing random accessibility,
Digital video signal VD can be recorded at high density.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

(G1) Embodiment of video signal recording disc In FIG. 1, l indicates a compact disc to which the video signal recording disc according to the present invention is applied as a whole, and for example, the recording track TR formed in a spiral shape (FIG. 1(A) )) Above,
A CD frame is formed according to the CD standard.

This ICD frame consists of two
CD frame synchronization signal CD consisting of 4 channel bits
,, Nc, control data CDC consisting of 1 byte?
1. 4-byte long error correction code CDECC in each 12-byte long recording data section CDoyt and CDDT□
1 and CDtcct are added.

In addition, in practice, control data CDcyts recording data section CDat+, CDirt and error correction code CD
1ce+ and coicct are EFM (eig
ht to fourteen modulation
) method, one byte (=8 bits) is recorded as one 14-bit symbol, and each symbol including the CD frame synchronization signal CD, , c is
By adding margin bits, the IC
The entire D frame consists of 588 channel bits.

In addition, the recorded data part CD for 96 pieces of this CD frame
ゎ8.CDoA2 is a CD-ROM as shown in Figure 1(C).
-ROM Used as a 1-sector SEC that complies with the XA standard.

This 1 sector SEC includes a sector synchronization signal SEC5vsc consisting of 12 bytes and a sector header SE consisting of 4 bytes.
A subcode SEC□ consists of C, D, and 8 bytes and stores the sector number from the beginning of the recording track TR. , 2
,048 bytes of user data 5ECUDT, 28
It consists of a sector header SECMII, a subcode SECsmc, user data SEC, and error detection and correction auxiliary data 5ECADT for □.

Here, the video signal is processed as high-efficiency encoded data DTIX in which the first frame data is intra-frame encoded every six frames, and the second to sixth frame data are inter-frame encoded by a predetermined method. The processed high-efficiency encoded data DT2X-DT6X are each highly efficiently encoded and recorded on a compact disc l, and the high-efficiency encoded data DTI for one of these 6 frames is
A 17L/-m group GOF is constructed from X and DT2X to DT6X.

In the case of this compact disc 1, as shown in FIG. 1(D), the user data 5ECuoy of each sector SEC is used continuously for all sectors, and the starting position of each frame group GOF is determined from the starting sector SEC. A header section HD having a table indicating in which sector SEC the data is recorded is recorded, followed by a highly efficient encoded video signal recorded in units of the frame group GOF.

As shown in FIG. 2, this header section HD includes header size data H3Z each having a word length of 32 bits per word, total frame number data NFF, GOF frame number data NFC, and C and OF frame number NF, respectively.
GOF encoding mode data PWC with a word length of G
, GOF recording format data RFG, sector number table length data NTA consisting of l words, and sector number table TAG consisting of a word length equal to sector number table length data NTA.

In practice, the header size data H3Z, total frame number data NFF, and GOF frame number data NFC are the data length of the header HD, the number of all recorded frames, and the number of frames in one frame group GOF width (this In the case of the example, it represents the value "6").

In addition, the GOF encoding mode data PWG indicates a high efficiency encoding method for each frame in each frame group GOF in one word, and in this embodiment, for example, intraframe encoding processing is performed using the value "OJ, adaptive prediction". Level 1 including encoding
Interframe encoding processing is represented by a value "1", and level 2 interframe encoding processing is represented by a value "2".

Furthermore, the GOF recording format data RFG indicates the recording order of each frame in each frame group GOF for each word.
”, “1”, “2”, “4”, and “5” are recorded.

Furthermore, the word length of the sector number table TAG is recorded in the sector number table length data NTA, and in the subsequent sector number table TAG, the start position of the frame group GOF is sequentially recorded word by word from the start.
The sector number of C is recorded.

In addition, each frame group GOF following the header part HD is the third
It is recorded in the format shown in the figure.

That is, the beginning of each frame group GOF has a length of 20 bits, for example, roooo 000000000001.
GOF synchronization signal G having a bit pattern of 1111,
High efficiency encoded data DTIX corresponding to the first frame data is recorded following OFsysc and a frame identification number FID having a length of 16 bits and representing the input sequence number for each frame with a remainder of 2''.

Each of them is 20 bits long, for example, ro
ooo Frame synchronization signal FRMs□ with a bit pattern of 0000000000010000J. , frame identification number FID, and high efficiency encoded data DT2X to DT6X corresponding to the second to sixth frame data are sequentially recorded.

(G2) Configuration of video signal recording device and video signal reproducing device The compact disc l of this embodiment is a mask on which image data encoded with high efficiency by the video signal recording device 2 is recorded, as shown in FIG. Copied based on master 3.

That is, in the video signal recording device 2, the video signal VD
is input to the image data generation circuit 4, and as a result, highly efficient encoded data D for every 6 frames is generated.
1 frame group GO consisting of TIX and DT2X to DT6X
The F portion is supplied to the image data recording processing circuit 5.

This image data recording processing circuit 5 blocks input high-efficiency encoded data DTIX and DT2X to DT6X based on the sector format, and detects the sector number in which the beginning of each frame group GOF is recorded. , to form a sector number table TAG for the header HD.

In this way, the image data recording processing circuit 5 sends the head control signal CN T wno for controlling the positioning of the optical head 7 to a predetermined position to the head control circuit 6, and also outputs the header section HD and the above-mentioned high-efficiency encoded data DTIX. and a recording signal S□ including DT2X-DT6X. In this way, the input video signal VD is highly efficiently encoded and recorded on the mask master 3 of the compact disc 1.

In addition, a plurality of compact discs 1 can be duplicated by making a stamper from the mask master 3 thus formed and resin molding using a method such as the 2P method.

Thus, in this compact disc 1, a sector number table TAG of the header HD is provided, and input high-efficiency encoded data DTIX and DT2X-DT6X are provided.
By continuously recording over a plurality of sectors SEC without adding fill bits or the like, the recording area of the recording track can be used with practically 100% efficiency.

On the other hand, the compact disc 1 duplicated as described above can be reproduced by recoating the video signal 220 as shown in FIG.

That is, in the video signal repainting ZIO, first, prior to playing back the compact disc 1, the image data playback processing circuit 1
1 sends head control signals CNT and HD for positioning the optical head 13 to the first sector SEC of the compact disc 1 to the head control circuit 12, and from the reproduction signal 5PII obtained from the optical head 13 as a result, the header section The sector number table TAG included in the HD is reproduced and written into the memory 14 as header data DTH1.

In such a state, for example, when the user specifies a fast-forward playback operation, the image data playback processing circuit 11 first sequentially performs 1 while referring to the sector number table TAG recorded in the memory 14 as header data DT and a. The sector number in which the head position of each frame group GOF is recorded is detected, and a head control signal CNTl1 for positioning the optical head 13 in the sector SEC of the sector number is sent.

Next, the image data reproduction processing circuit 11 reproduces the high-efficiency encoded data DTIX corresponding to the I frame of the frame group GOF0) from the reproduction signal S□ sent out from the optical head 13 as a result, and converts it into an image. The frame group GO is sent to a data decoding circuit (not shown), and the following frames are sent to the data decoding circuit (not shown)
Only the first frame of F is played back, and fast-forward playback is executed in this way.

Further, for example, when the user specifies a reproduction operation for a predetermined frame, the image data reproduction processing circuit 11 first refers to the sector number table TAG recorded in the memory 14 as header data DTH+1, and determines whether the specified predetermined frame is to be reproduced. While detecting the included frame group GOF,
The sector number in which the head position of the frame group GOF is recorded is detected, and a head control signal CNT+u+o is sent to position the optical head 13 in the sector SEC having the sector number.

Next, the image data reproduction processing circuit 11 outputs high-efficiency encoded data DTIX-DT6X from the first frame of the frame group GOF to the specified predetermined frame from the reproduction signal S□ sent out from the optical head 13 as a result. The image data is reproduced and sent to an image data decoding circuit (not shown), and thus a predetermined frame specified by the user is reproduced.

Thus, this compact disc l has a header section HD.
Read the sector number table TAG included in the
By referring to this, random access can be easily performed.

(G3) Configuration of Image Data Generating Circuit In this embodiment, the image data generating circuit 4 in the video signal recording device 2 described above with reference to FIG. 4 is configured as a circuit as shown in FIG. 6.

The image data generation circuit 4 quantizes the video signal VD into high-efficiency encoded data I)va in the video signal encoding circuit section 22 and temporarily stores it in the transmission buffer memory 23, The efficiency encoded data D0 is read out as transmission data I)ta□ at a predetermined transmission speed and transmitted to the image data recording processing circuit 5.

Here, the transmission buffer memory 23 transmits the transmission data D□ at a transmission speed determined by the transmission capacity to the image data recording processing circuit 5.
0. At the same time, a remaining amount data signal D indicating the amount of data remaining in the transmission buffer memory 23 is transmitted to the video signal encoding circuit section 22 via the feedback loop 26.
give feedback.

As a result, the video signal encoding circuit section 22 converts the video signal VD
By controlling the quantization step when digitally encoding the high-efficiency encoded data I)vn supplied to the transmission buffer memory 23, the amount of highly efficient encoded data I) vn that is held in the transmission buffer memory 23 is controlled. data,
Control to prevent overflow or underflow.

Here, as shown in FIG. 7, the video signal encoding circuit section 22 receives the video signal VD in the preprocessing section 31, converts the luminance signal and chroma signal included in the video signal VD into digital data, and then converts the luminance signal and chroma signal included in the video signal VD into digital data. , one-field dropping processing, one-field line thinning processing, etc. are performed to convert it into moving image data, and this is converted into transmission unit block data Sll consisting of data for 16 pixels (horizontal direction) 016547 minutes, and the current frame is It is stored in the memory 32.

In this manner, the frame image data of the frame to be currently transmitted is held in the current frame memory 32, and this is supplied as current frame data S12 to the subtraction circuit 33 as an addition input.

The subtraction circuit 33 has a previous frame memory 34 as a subtraction input.
The previous frame data S13 obtained from the above is given to the output terminal of the subtraction circuit 33, and deviation data S representing the deviation between the transmission unit block data of the image data of the current frame and the transmission unit block data of the image data of the previous frame is supplied to the output terminal of the subtraction circuit 33.
14 is obtained, which is converted into transform encoded data S15 in a transform encoder circuit 35, such as a discrete cosine transform circuit, and then quantized by a quantizer circuit 36.

Thus, the quantized data S obtained from the quantization circuit 36
16 is highly efficiently encoded again in the variable length encoding circuit 37, and the variable length encoded data S17 is sent to the decoding circuit 38.
After being combined with the first and second management information S18 and S19, the data is supplied to the transmission buffer memory 23 as transmission image data S20.

In addition, the quantized data S16 is inversely transformed in an inverse transform circuit 39 including an inverse quantizer circuit and an inverse transform encoder circuit, and is outputted as decoding deviation data S21 to an adder circuit 39.
Thus, the image data of the current frame sent to the transmission buffer memory 23 is stored in the previous frame memory 34 as the previous frame image data.

On the other hand, the current frame data 312 in the current frame memory 32 is supplied to the motion compensation circuit 41 together with the previous frame data S22 in the previous frame memory 34, so that movement has occurred from the image data of the previous frame among the image data of the current frame. For the transmission unit block of the image part, the motion vector data S23 is formatted and supplied to the previous frame memory 34, and the deviation data 5 is supplied to the decoding circuit 38 as the first management information SI8.
The motion vector data S23 is sent to the transmission buffer memory 23 as part of the header information of the data corresponding to 14.

Further, quantization step data S24 representing the quantization step used in the quantization process in the quantization circuit 36 is given to the variable length encoding circuit 37 as a variable length condition signal, and is also composited as second management information S19. conversion circuit 38
This is supplied to the transmission image data 320 as part of the header information added to the deviation data 314.

With this configuration, the time t in FIG. 8(A)
When attempting to transmit the image data PCI in 1 as intra-frame encoded data, the value "0" data (
In other words, the current frame data 512 to be transmitted is supplied directly to the conversion encoding circuit 35 as deviation data S14 through the subtraction circuit 33.

At this time, the transform encoding circuit 35 sends the transform encoded data 515 obtained by intra-frame encoding to the quantization circuit N136, and in this way, the intra-frame encoded data is transferred to the transmission buffer memory 23 as the transmission image data S20. At the same time, the deviation data S14, and therefore the current frame data S12, are decoded as decoded deviation data 321 in the inverse conversion circuit 39 and stored in the previous frame memory 3.
It is accumulated in 4.

Thus, after the image data PCI is transmitted as intra-frame encoded data, at time t2, the image data P
When C2 is supplied to the subtraction circuit 33 as the current frame data S12, the image data PCI is supplied from the previous frame memory 34 to the subtraction circuit 33 as the image data of the previous frame, and as a result, the subtraction circuit 33 Deviation data 514 corresponding to image data PC12 representing the deviation between image data PC2 as frame data S12 and image data Pct as previous frame data 313 is obtained.

This deviation data 314 is sent to the transmission buffer memory 23 as transmission image data 320 through a conversion encoding circuit 35, a quantization circuit 36, a variable length encoding circuit 37 and a decoding circuit 36, and is sent to the transmission buffer memory 23 as transmission image data 320. 39
The data is decoded at , and supplied to the addition circuit 40 as decoded deviation data S21.

At this time, the addition circuit 40 inputs the image data PCI as the image of the previous frame held in the previous frame memory 34.
, the deviation image represented by the decoding deviation data S21 is converted into motion vector data S obtained from the motion compensation circuit 41.
23, and thus predicts the image data of the current frame based on the data of the previous frame and stores it in the previous frame memory 34.

At this time, the motion compensation circuit 41 sends the image data PCI as the previous frame image data held in the previous frame memory 34 and the motion vector data S23 representing the movement of the image data that has arrived as the current frame data S12. , stores the addition result of the decoding deviation data S21 and the previous frame image data at the vector position represented by the motion vector data S23 in the previous frame memory 34, and sends the motion vector data S23 through the decoding circuit 38. It is sent out as transmission image data S20.

Thus, the video signal encoding circuit section 22 has t=11
When transmitting the image data PC2 (FIG. 8(A)), the image data PCI2 representing the deviation between the image data PCI of the previous frame and the image data PC2 of the current frame is used as the interframe encoded data, and the deviation data 314 and motion vector data S23 are highly efficiently encoded and supplied to the transmission buffer memory 23.

Similarly, when new image data arrives as the current frame data 312 at time points L2, L4, etc., the image data of the previous frame held in the previous frame memory 34, that is, the previous frame data S1
3, the current frame data S12 is encoded with high efficiency as interframe encoded data and sent to the transmission buffer memory 23.
It is designed to be sent to

(G4) Effects of the embodiment According to the above configuration, the high efficiency encoded data DTIX and DT2X-DT6X are recorded for each frame group COF.
Among them, a GOF synchronization signal GOFsYHc representing the starting position is added to the beginning where the high-efficiency encoded data DTIX that has been subjected to intra-frame encoding processing is recorded, and the starting position is recorded for each frame group GOF. The header part HD, which contains the sector numbers to be displayed as a table TAG, is recorded from the first sector SEC, and then a plurality of frame groups G
By recording the OF continuously over the recording sector SEC, it is possible to realize a compact disc 1 that can significantly improve the efficiency of recording area use without impairing the random accessibility of the disc.

(G5) Other Embodiments (1) In the above embodiments, a table was provided in which the positions on the compact disk where the beginning of the l-frame group GOF was recorded corresponded to the sector numbers. , instead of this, the starting position of the frame group GOF may be represented by an absolute address on the compact disc.

In this case, the compact disc l, for example, 540
When recording image data on a CD-ROM having a recording capacity of megabytes, the word length of the table needs to be 32 bits for absolute address specification.

(2) In addition, in the above embodiment, a case was described in which a table was provided in which the starting positions of all frame groups GOF were recorded by sector numbers on one table, but this is not limited to this. The entire image data is divided into several areas, and there is a main table that stores the recording position of the first frame group GOF in each area as an absolute address on the disk, and a main table that stores the recording position of the frame group GOF in each area as an area. It is also possible to provide a table with a multilayered hierarchical structure, such as by providing sub-tables that are stored at relative addresses within the table.

In fact, if you do this, calculation processing such as adding the absolute address of the main table and the relative address of the sub-table will be required to calculate the position of the frame group GOF during recording and playback. Since the recording area of the table and sub-table can be shortened, the recording area of the disk as a whole can be used more effectively.

In this case as well, if we consider the case where image data is recorded on a CD-ROM as described above, the word length of the main table needs to be 32 bits because the absolute address is specified.
Since the sub-table specifies sector numbers using relative addresses, the word length changes depending on how many frame groups GOF are included in each divided area.

For example, if each sector of the disk is 512 bytes,
Assuming that image data encoded with high efficiency at around 30 bps per frame is allowed to be randomly accessed every 6 frames, on an actual disk there will be approximately 1 bit per 45 sectors.
Therefore, if the word length of the sub-table is set to 8 bits, five frame groups GOF can be specified in one sub-table, and if the word length is set to 16 bits, one sub-table can be accessed randomly. This means that up to 1456 frame groups GOF can be specified in the table.

(3) Furthermore, in the above embodiment, a case has been described in which the sector number table is recorded from the beginning of the recording track on the compact disc, but the position of the table is not limited to this and can be synchronized on the recording side and the playback side. If you do this,
Effects similar to those of the above-described embodiments can be achieved even at a certain position such as the middle or end of the disk.

(4) Further, in the above-described embodiment, a case was described in which highly efficiently encoded image data is recorded on a compact disc as a video signal recording disc, but the present invention is not limited to this, and the present invention is not limited to this. The present invention is widely applicable and suitable for recording highly efficiently encoded image data on a disc-shaped recording medium.

H Effects of the Invention As described above, according to the present invention, a frame group head information table is provided and a plurality of frame group data are continuously recorded across recording sectors, so that randomization of a disk-shaped recording medium is A video signal recording disk that can record digital video signals at high density without impairing accessibility can be realized.

[Brief explanation of the drawing]

FIG. 1 is a route map showing an embodiment of the video signal recording disk according to the present invention, FIG. 2 is a route map showing the structure of its header section, FIG. 3 is a route map showing the structure of its frame group data, and FIG. FIG. 4 is a block diagram showing the configuration of a video signal recording device for creating a mask master for a video signal recording disk, FIG. 5 is a block diagram showing the configuration of a video signal reproducing device for reproducing the video signal recording disk, and FIG. and FIG. 7 is a block diagram showing the image data generation circuit in the video signal recording device, and FIG.
The figure is a route map for explaining high-efficiency encoding processing. l...compact disc, 2...video signal recording device, 3...master master disc, 4...
. . . Image data generation circuit, 5 . . . Image data recording processing circuit, 6.12 . . . Head control circuit,
7.13...Optical head, 14...Memory.

Claims (1)

[Scope of Claims] A video signal recording disk in which a digital video signal is converted into high-efficiency encoded data consisting of intra-frame encoded data and a predetermined number of inter-frame encoded data and recorded, comprising: the intra-frame encoded data; and a frame group start information table consisting of address information in which the start information of a plurality of frame group data consisting of a predetermined number of the above-mentioned interframe encoded data is recorded, and a frame group start information table consisting of address information in which the start information of a plurality of frame group data consisting of a predetermined number of the above-mentioned interframe encoded data is recorded continuously. A video signal recording disc characterized in that the video signal is recorded on the disc.