JPH0767067A - Optical disk - Google Patents

Abstract

PURPOSE:To attain the special reproduction of only compression-encoded data by gathering the address of-a sector in which the leading/final data of in-frame/ field compression-encoded data are stored into more than several groups, and recording it in the other sector of the same area as the area in which the compression-encoded data are recorded. CONSTITUTION:Each groups A1-An, B1-Bn, and C1-Cn are groups including the compression-encoded data of an in-frame compression-encoded frame, bidirectional inter-predictive frame compression-encoded frame, and forward inter-predictive frame compression-encoded frame. An address Xi of an optical disk 1 in which the leading/final data of the in-frame encoded data of those groups are stored is recorded in sectors (a), (b), and (c). Then, at the time of the special reproduction of only the in-frame encoded data, the (b) sector is reproduced by an optical pickup 2, and only the in-frame compression-encoded data are reproduced through a reproduction processor 3 according to the leading/final address.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk for recording or reproducing, for each sector, data obtained by band compression coding a digitized video signal.

[0002]

2. Description of the Related Art Moving image signals are converted into digital data,
When recording / reproducing on an optical disk, it is very difficult to record / reproduce in real time because the amount of information is very large. For example, when an NTSC composite signal is quantized with a sampling frequency of 4 fsc (fsc is a color subcarrier frequency) of 8 bits, a transfer rate of about 120 Mbps is required.

However, it is technically very difficult to realize a recording / reproducing system that achieves a transfer rate of 120 Mbps, depending on the characteristics between the optical disk and the recording / reproducing head and the operating performance of the electric circuit system. Therefore, when recording / reproducing information at a high transfer rate on an optical disc, the processing speed in one processing system is reduced by using a plurality of recording / reproducing heads and a plurality of electric circuits, so that the entire apparatus can operate in real time. Processing was possible. However, even if the real-time processing is enabled in this way, the recording / reproducing time is constant as long as the total capacity of the optical disc does not change.

Therefore, in a recording or reproducing apparatus for a digitized moving image signal, the moving image signal is compression-encoded and recorded on an optical disc to such an extent that the deterioration of the information of the original signal is not noticeable, and is decoded at the time of reproduction. A method of increasing the length of the recording / reproducing at the same time as the realization of the recording / reproducing is considered. As a method of compression encoding processing, data of several frames (or fields) is grouped into one group, and at least one frame (or field) of data is stored in a frame (or field) with a relatively low compression rate. The compression encoding process is performed in (inside), and the remaining frames (or fields) are subjected to interframe (or interfield) compression encoding process with a relatively high compression rate. By combining the intra-frame and inter-frame (or intra-field and inter-field) compression encoding processing in this way, it is possible to improve the overall compression rate and to suppress image deterioration relatively.

When this compression-encoded data is recorded or reproduced on an optical disk, a single recording / reproduction processing system is used to record the compression-encoded data within a frame (or within a field) and between frames (or between fields). )
The data compression-encoded in (1) are arranged in time series, the compression-encoded data is divided into sectors each having a fixed capacity, and recording / reproduction is performed while recognizing the address of the sector.

[0006]

However, in the above-described conventional recording or reproducing method, for example, when performing special reproduction for reproducing only compression-encoded data within a frame (or within a field) at the time of reproduction, the inside of the frame (or field) is reproduced. (Inside) It is necessary to have a correspondence table that indicates in which sector the compression coded data is recorded. Conventionally, the correspondence table is recorded in a different area from the area on the optical disk where the compression coded data is recorded. It was

Therefore, the compression-encoded data cannot be recorded at the same time and must be recorded in another area on the optical disk after the compression-encoded data has been recorded. There was a problem that the correspondence table could not be created when the power of the recording / reproducing apparatus itself was turned off.

The present invention solves the above-mentioned drawbacks, and creates a correspondence table showing in which sector the intra-frame (or intra-field) compression encoded data is recorded when the recording / reproducing apparatus or the optical disc has a problem. It is an object of the present invention to solve the problem that it cannot be performed, and to provide an optical disk capable of performing special reproduction for reproducing only compression-encoded data within a frame (or within a field).

[0009]

In order to achieve this object, the present invention collects at least several groups of sector addresses in which the first data and the last data of the compression-coded data within a frame (or within a field) are stored. In addition, the compression-encoded data is recorded in another sector existing in the same area as the sector in which the compression-encoded data is recorded.

Alternatively, the sector addresses in which the first data and the final data of the compression-coded data in the frames (or fields) of several groups are collectively stored are further combined with the addresses of the recorded sectors. It is a structure recorded in the sector.

[0011]

According to the present invention, by reproducing the sector thus recorded, it is possible to recognize in which sector the compression-encoded data in the frame (or in the field) exists, and based on the data, in the frame (or This makes it possible to reproduce only the compression coded data (in the field).

[0012]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram showing a format of an optical disc having one sector for recording a sector address in which head data and final data of intra-frame coded data are stored for every n groups in one embodiment of the present invention.

In FIG. 2, six consecutive image frames in one embodiment of the present invention are grouped into one group, and the first frame and the seventh frame of the first frame are intra-frame compression coded frames. 5, 6 (, 8,
9 is a schematic diagram showing that the (9, 11, 12) frame is a bidirectional prediction interframe compression coding frame and the fourth (10) frame is a forward prediction interframe compression coding frame. FIG.

FIG. 3 is a schematic block diagram of a compressed image reproducing apparatus according to an embodiment of the present invention. As shown in Figure 1,
A1, A2, ..., An and B1, B2 ,.
n and C1, C2, ..., Cn are one group including compression-encoded data of the intra-frame compression-encoded frame, the bidirectional prediction inter-frame compression encoded frame, and the forward prediction inter-frame compression encoded frame, respectively. .

The sector addresses in which the first data and the last data of the intra-frame coded data of each group are stored are recorded in the sectors a, b and c. That is, the sector addresses in which the first data and the last data of the intra-frame coded data shown in group B1 are stored are x1 and xm, respectively.

As shown in FIG. 3, the signal reproduced from the optical disk 1 by the optical pickup 2 during reproduction is sent to the reproduction processor 3 to be subjected to processing such as binarization, digital demodulation or error correction. As for the data processed by the reproduction processor 3, only the compression coded data is sent to the reception buffer 4.

For example, let us consider a case in which only the intra-frame coded data of the optical disc 1 of FIG. 3 recorded in the format shown in FIG. 1 is played during the special reproduction for reproducing only the intra-frame compression coded data. The sector on the optical disc 1 of FIG. 3, for example, the sector b of FIG.
Is reproduced, it is possible to know the sector address in which the start data and the end data of the intra-frame encoded data in the groups B1, B2, ..., Bn exist. Therefore, the reproduction is sequentially performed from the x1 sector in the group B1, and the final data of the intra-frame encoded data exists x
When the reproduction is completed up to m sectors, the sector in which the head of the intra-frame coded data of group B2 exists is known in advance, so the optical pickup 2 is moved to that sector.

Thereafter, the groups B3, B4, ..., Bn
By performing the same operation up to, it is possible to continuously reproduce only the intra-frame coded data. When the operation up to the group Bn is completed and the c sector is reproduced next, the group C
It is possible to know the sector address where the first data and the last data of the intra-frame coded data up to 1, C2, ..., Cn exist. If the same operation is continued thereafter, it is possible to continuously reproduce only the intra-frame coded data. The intra-frame coded data is sent from the reception buffer 4 to the compression / decoding processor 5.

The image signal data decoded by the compression decoder 5 based on the transmitted data is the frame memory 6
After that, the Y, U, and V signals are read from the frame memory 6 at a constant transfer rate in synchronization with each other, and are output to the outside as analog image signals through the D / A converters 7, 8, and 9. It The read speed is adjusted to the sampling frequency at the time of A / D conversion during recording, and the Y signal is 13.5 MHz, U,
The V signal is 6.75 MHz. The data read from the frame memory 6 may be directly output as digital data to the outside. It should be noted that the image frame processing may be performed in field units.

Further, the addresses of the sectors a, b, and c which collectively record the sector addresses in which the first data and the last data of the compression-coded data in the frames (or fields) of several groups are stored are set. Further, the data may be collectively recorded in another sector.

[0021]

As described above, according to the present invention, at least several groups of sector addresses in which the start data and the end data of the compression-coded data in the frame (or in the field) are stored are grouped into the compression-coded data. Since it is recorded in another sector of the same area as the area for recording the compressed coded data at any time, it is possible to record the compressed coded data without accessing another area while recording the compressed coded data. It is possible to record the data, and it is not possible to create a correspondence table at all when the power of the recording / reproducing device itself is turned off due to some inconvenience during the recording of data. It is possible to reliably recognize the sector address where the compression encoded data exists, and Only compressed data to the reproduction process, is to reliably achieve a special playback high-speed reproduction or the like.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a format of an optical disc having one sector for recording a sector address in which head data and final data of intra-frame encoded data are stored for every n groups in an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of the present invention, where 6 frames are grouped into 1 group, 1st and 7th frames are intra-frame compression coded frames, 4th and 10th frames are forward prediction interframe compression coded frames, A schematic diagram showing that the second, third, fifth, sixth, and eighth, ninth, eleventh, and twelfth frames are bidirectional prediction interframe compression encoded frames.

FIG. 3 is a schematic block diagram of a playback device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Optical Disc 2 Optical Pickup 3 Playback Processor 4 Reception Buffer 5 Compression Decoder 6 Frame Memory 7, 8, 9 D / A Converter

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Claims (3)

[Claims] 1. A continuous digitized image frame or field signal is grouped into at least two frames or two fields or more, and at least one frame or one field of the grouped image frames or fields is an intraframe or intrafield compression code. An optical disc which records or reproduces, in sector units, an image signal in which a remaining frame or field is band-compressed by an inter-frame or inter-field compression encoding method using time-axis correlation, Of the frames or fields, the addresses of the sectors in which the beginning data of the image signal band-compressed by the intra-frame or intra-field compression coding method are stored are grouped together for at least several groups, and Optical disc compressed image signal is characterized by recording on another sector of the same region and the region to be recorded. 2. An area for recording an image signal which is band-compressed by grouping together the addresses of sectors for storing the first data and the last data of the image signal band-compressed by the intra-frame or intra-field compression coding method. The optical disc according to claim 1, wherein the optical disc is recorded in another sector of the same area as that of. 3. An address of a sector in which the head data and the final data of an image signal band-compressed by an intra-frame or intra-field compression encoding method are stored together for several groups or more are recorded together. The optical disc according to claim 1, wherein the optical disc is formed.