JP2617772B2 - Information signal recording disk and information signal recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information signal recording disk and an information signal recording / reproducing apparatus, and in particular, the data amount constantly changes with time like a video signal which has been subjected to compression processing. The present invention relates to an information signal recording disk for recording such a signal at a high density for a long time and an information signal recording / reproducing apparatus therefor.

(Prior art and its problems) Conventionally, when a video signal is compressed and recorded on a recording medium, when recording the information signal recording disk (disk) as a recording medium while keeping the rotation angular velocity or linear velocity constant, The limitations of the recording density of the disc,
The rotational angular velocity or linear velocity of the disk is determined by the compression rate of the compressed video signal being the lowest, that is, by the restriction from the part having the largest data amount.

For example, when recording a video signal of a moving image, the compression ratio does not increase at a change of a scene (scene), but in other portions, the correlation between frames is strong, and the compression ratio can be increased. In such a case, the difference in the recordable time is very large depending on the state of the signal to be recorded, such as a further increase in the compression ratio.

Therefore, although the compression ratio is increased in most portions of the video signal of the moving image, the recording specification is determined in accordance with the less frequent and low compression ratio portions, so that the compression effect cannot be sufficiently obtained. Recording could not be performed for a long time.

In the data compression method described above, encoding is performed by controlling the quantization step width so that the amount of code transmitted per unit time is substantially constant.

On the other hand, variable length compression in which the amount of code transmitted per unit time is variable, that is, data is compressed by performing encoding at a variable transfer rate is conceivable.

This method of compressing data at a variable transfer rate is simply referred to as variable length compression in the following description.

In the variable-length compression, the transmission code amount per unit time is changed as necessary, so that, for example, when compressed image data is recorded on an information signal recording disk having a predetermined recording capacity, the recording time is reduced. If the resolution is fixed, a reproduced image with higher definition is obtained, and if the definition of the reproduced image is fixed, recording for a longer time can be performed.

However, in a reproducing apparatus for reproducing an information signal recording disk on which a variable-length compressed signal is recorded, access to a search request destination (search request destination address) on the information signal recording disk (hereinafter also referred to as random access). However, there is a problem in that a complicated device is required to perform the above, and a long time is required for the random access, and it is difficult to perform a special reproduction such as a fast forward reproduction in which the reproduction is performed at a speed several times faster than the real time. .

Accordingly, it is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an information signal recording disk and an information signal recording / reproducing apparatus capable of recording at high density for a long time.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a concentric or spiral signal recording track, and a temporally continuous information signal is divided into predetermined blocks. The main data obtained by subjecting the signals divided into blocks to variable-length compression are allocated to an integer number of sectors individually determined for each block, and are continuously recorded from near the head of the sector. The margin of the last sector
Information filled with data other than the main data (sub-data) or blank data for adjusting the data amount, and the code of the temporally continuous information signal is sequentially and continuously recorded without any gap in the signal recording track direction. A signal recording disk is provided. Further, in a recording apparatus for an information signal recording disk, a block dividing means for dividing a continuous signal into blocks having a predetermined length or less, and a variable length for compressing a signal divided into the blocks into a variable length. Compression means for allocating the main data for each block obtained by the variable length compression to an integer number of sectors, and for adjusting the data amount of the main data and other data (sub data) for each block; The blank data is time-division multiplexed with the main data substantially at the beginning, and the data amount of each block and the data of an assigned number of sectors are allocated. A continuous data generating means for continuously generating data for each block whose data amount substantially coincides, and an information signal recording having concentric or spiral signal recording tracks on the continuous data generated by the continuous data generating means. An information signal recording device provided with a recording means for recording on a disk.

Further, in the reproducing apparatus for reproducing the information signal recording disk, the time required to read the data portion having the lowest compression rate of the main data recorded on the information signal recording disk is the time occupied by the original signal. Reading means having a constant reading speed so as to be substantially the same; decoding decoding means for demodulating a signal from the reading means; storage means for storing decoded data decoded (demodulated) by the decoding means; Data separation means for separating decoded data stored in the storage means into main data and other sub-data in accordance with a format; decompression means for decompressing (decoding) the main data separated by the data separation means;
Reproduction control means for controlling the reading means so as to repeatedly read information on the same track of the information signal recording disk when the sufficiency of the storage means is equal to or more than a predetermined value; Information signal for performing a search for the main data for each block based on the physical address to be recorded, the program elapsed time in the original signal, and the recording position comparison data indicating the correspondence between the elapsed time and the recording position. A playback device is provided.

FIG. 1 shows an information signal recording disk (disc) according to the present invention.
FIG. 4 is a diagram showing an example of the recording specification of the embodiment.

In the figure, the original signal is a temporally continuous video signal such as a moving image. First, the original signal is divided into blocks each for one frame (two fields) [first.
A in FIG. At this time, the audio signal is also divided into blocks each corresponding to one frame in accordance with the video signal.

Next, the signals (data) divided into blocks
Is subjected to variable length compression to obtain compressed data. In this case, the variable length compression is performed by making use of the correlation with the previous block as needed. By performing the variable length compression, the compression ratio can be increased. Further, the compressed data [main data] and sub-data such as address data are allocated to an integer number of sectors, and the main data for each block is recorded from near the head of the sector.

The address data is given in units of sectors or blocks as needed.

Although the recording capacity of each sector is fixed as is well known, the number of sectors to be allocated varies depending on the compression ratio.

Then, the blank portion of the sector is filled with sub-data other than the above-mentioned compressed data [main data], address data and the like, and blank data indicating no signal [b in FIG. 1].

The sub-data is, for example, data indicating the size of a blank portion generated in the last sector of the allocated sector, or an elapsed time rotation speed indicating a correspondence between a program elapsed time and a disk rotation speed at that time. This is control data, or recording position control data indicating the relationship between the program elapsed time and the track number of the position where the program is recorded at that time.

In this way, the continuous data is filled with no gaps in the time axis direction [c in FIG. 1]. Then, the continuous data is recorded on the disk such that the start point of the main data and the head of the sector substantially coincide with each other.

FIG. 3 is a diagram showing an example of a recording form on a disc on which data is recorded according to the above-mentioned recording specifications.

This has a concentric or spiral signal recording track, which is divided into sectors having a predetermined recording capacity.

Here, as an example, a recording pattern of an outer peripheral portion of a disk [FIG. 3 (a)] having signal recording tracks recorded from the outer periphery to the inner periphery at a constant linear velocity (hereinafter abbreviated as CLV) is shown in an enlarged manner. [FIG. 3 (b)].

The numbers in FIG. 3 (b) indicate the order of the sectors,
Here, data for about 3.5 sectors is recorded during one rotation.

In the blank portion of the sector, address data such as the program elapsed time (elapsed time from the start of the program in the original signal) and the like and sub-data such as the recording position comparison data and the elapsed time rotation number comparison data are recorded. .

Next, a recording apparatus for recording data on a disc according to the above recording specifications will be described.

FIG. 2 is a block diagram showing the configuration of an embodiment of the information signal recording device according to the present invention.

In the figure, image data and audio data [main data] are temporarily stored in storage circuits 1 and 2, respectively. Further, the image data is also supplied to the block division control signal generation circuit 3.

[Data A] such as the address data, the data indicating the start and end of the block, and the data indicating the compression method are also temporarily stored in the storage circuit 4.

Each data stored in the storage circuits 1, 2 and 4 is divided into blocks of one frame (two fields) by a block division control signal generated by the block division control signal generation circuit 3 based on image data. Can be

Further, the image data and audio data divided into these blocks are supplied to compression circuits 5 and 6, respectively, and are subjected to variable length compression. In this case, the audio data is subjected to variable length compression as needed.

The above-mentioned variable-length-compressed image data and audio data are supplied to an adding circuit 7, where the data A (address data, data indicating the start and end of a block, and the compression method are stored in a storage circuit 4). Data, etc.).

When the image data is a moving image, the compression rate is greatly increased by obtaining the correlation in the time axis direction. In addition, there is not much merit in the time axis direction at the transition of a scene, but a great result is obtained when the same scene continues.

Next, the data added by the adding circuit 7 is supplied to the sector designating circuit 8 to time-division multiplex the data B described later and the data amount adjusting blank data, and these data are integers which are individually determined for each block. Divided into sectors.

As described above, the sector designating circuit 8 stores data other than the main data and the data A, for example, data (numerical value) indicating the size of the margin of the sector, recording position control data, elapsed time rotation number control data, etc. [Data B And the data B or the blank data for adjusting the data amount is filled in a blank portion of the last sector, and continuous data is generated without gaps in the time axis direction.

The continuous data generating means is mainly composed of the adder 7 and the sector designating circuit 8. In this case, the main data for each block, the other sub data, and the blank data for data amount adjustment are an integer number. Time-division multiplexing is performed with a data amount substantially equal to the recording capacity of the sector, and data for each block is continuously generated.

The continuous data thus obtained is supplied to a signal recording / reproducing device 9 such as a VTR, where a cutting master tape is created.

Further, a reproduced signal obtained by reproducing the cutting master tape is supplied to a cutting format encoding circuit 10, where encoding (modulation) is performed in accordance with the cutting format, and recorded on a disk (or a master disk) 11 by a cutting machine. Cutting). In this case, the data is recorded such that the start point of the main data substantially coincides with the head of the sector.

It should be noted that the recording method on the disk may be of various recording forms such as an optical type, a magnetic type, and a capacitance type.

Next, a reproducing apparatus for reproducing a disc recorded by the above recording apparatus will be described.

FIG. 4 is a block diagram showing a configuration of an embodiment of an information signal reproducing device according to the present invention.

In the figure, a signal (reproduced data) [d in FIG. 1] read from a disk 11 by a reading means is supplied to a decoding circuit 12, where it is decoded (demodulated).

The decoded data (bit string) demodulated by the decoding circuit 12 is supplied to the storage circuit 13 and temporarily stored in sector units. [E in FIG. 1] The storage circuit 13 has a storage capacity of, for example, four sectors. Therefore, data of just over one rotation of the disk shown in FIG. 3 can be stored.

The decoded data once stored in the storage circuit 13 is supplied to an image data separation circuit 14, an audio data separation circuit 15, a data A separation circuit 16 and a data B separation circuit 17, respectively.
Data A and data B are separated.

The separated image data (variable-length compressed image data) and audio data (variable-length compressed audio data) are supplied to decompression circuits 18 and 19, respectively, where the compressed data is decompressed (decoded) to obtain the original image. Data and audio data are obtained [f in FIG. 1].

Also, when playing back a disk, the amount of data output from the storage circuit 13 per unit time changes depending on the signal compression ratio. In addition, the reading speed when reproducing the disc is constant, and the time required to read the data portion having the lowest compression ratio of the data recorded on the disc is substantially the same as the time occupied by the original signal. read.

When the storage circuit 13 becomes full, the reproducing element (pickup) of the disc repeatedly reproduces the same location (the same track) and waits at one location.

The change from d1, d2, d3, d4 in FIG. 1d indicates that the reproducing element (pickup) has returned (kicked back) to the track one track before. FIG. 3B shows the position.

These controls at the time of reproduction are performed by the reproduction control circuit 20 shown in FIG.
In this case, it is linked to the state of the storage circuit 13 (such as the degree of sufficiency in the storage state).

The search (random access) of image data or audio data at the time of reproduction is performed by the random access control circuit 21.
The search is performed by searching the next search request destination (search request destination address) based on the address data and the recording position comparison data obtained from the data A separation circuit 16 and the data B separation circuit 17, respectively.

For example, from the elapsed time rotation speed comparison data indicating the correspondence between the elapsed time of the program and the disk rotation speed, the disk rotation speed at the search request destination (search request destination address) is known, and the disk rotation speed is calculated by the value. And the reproducing element feed control circuit 22 to the position to be reproduced at the rotation speed.
The playback element (pickup) is sent under the control of
A detailed search is performed using the address data read at that position.

Alternatively, the search may be performed using the track number and the sector number obtained from the recording position comparison data.

Alternatively, it is possible to perform a search more easily by using both searches together.

In the present invention, the information signal recording device shown in FIG. 2 and the information signal reproducing device shown in FIG. 4 may be configured independently, or may be configured as a system combining both.

(Effects of the Invention) As described above, according to the information signal recording disk and the information signal recording / reproducing apparatus of the present invention, since the effect of compression is sufficiently exhibited, a long-time signal can be efficiently recorded at high density. Can,
Another feature is that data retrieval and trick play can be performed at high speed without being affected by variable length compression.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a recording specification of an information signal recording disk (disk) according to the present invention. FIG. 2 is a block diagram showing a configuration of an embodiment of an information signal recording device according to the present invention. FIG. 3 is a diagram showing an example of a recording form on a disk according to the present invention and a trace pattern at the time of reproduction, and FIG. 4 is a block diagram showing a configuration of an embodiment of an information signal reproducing device according to the present invention. 1,2,4,13 ... memory circuit, 3 ... block division control signal generation circuit, 5,6 ... compression circuit, 7 ... addition circuit, 8 ... sector designation circuit, 9 ... signal recording / reproducing device , 10 ... cutting format encoding circuit,
11 disk, 12 decoding circuit, 14 image data separation circuit, 15 audio data separation circuit, 16 data A separation circuit, 17 data B separation circuit, 18, 19 decompression circuit , 20: a reproduction control circuit, 21: a random access control circuit, 22: a reproduction element feed control circuit.

Claims (3)

(57) [Claims] In an information signal recording disk having concentric or spiral signal recording tracks divided into sectors of a fixed data amount, a temporally continuous information signal is divided into blocks, and the code amount for each block is divided. The main data for each block obtained by performing data compression (variable length compression) by encoding with variable is continuously recorded from near the beginning of one sector,
The information signal characterized in that sub-data other than the main data for each block is recorded in a blank portion of the last sector where the recording is performed, and codes of the temporally continuous information signal are sequentially recorded. Recording disk. 2. An information signal recording apparatus for recording on an information signal recording disk having concentric or spiral signal recording tracks divided into sectors of a fixed data amount, a block for dividing a temporally continuous signal into blocks. A variable-length compression unit that performs data compression (variable-length compression) on the output of the block division unit by encoding with a variable code amount for each block to obtain main data for each block; Time-division multiplexing of main data for each block, sub data other than the main data for each block, and blank data for data amount adjustment so that the main data is substantially at the beginning,
Continuous data generating means for continuously generating data for each block in which the data amount substantially matches the recording capacity of an integer number of sectors, and the output of the continuous data generating means is a concentric or spiral signal. An information signal recording device characterized by recording on a recording track. 3. The main data of each block obtained by dividing a temporally continuous signal into blocks and performing data compression (variable length compression) by coding with a variable code amount for each block is concentric. Alternatively, there is provided an information signal reproducing apparatus for reproducing an information signal recording disk recorded by allocating to an integer number of sectors of a spiral signal recording track, wherein a compression rate of main data recorded on the information signal recording disk is the lowest. Reading means having a constant reading speed such that the time required to read the data portion is substantially the same as the time occupied by the original signal; decoding means for demodulating a signal from the reading means; Storage means for storing the output of the storage means and outputting the degree of sufficiency; and data separation means for separating the output of the storage means into main data and other sub-data for each block. Decompression means for decoding and decompressing the main data of each block separated by the data separation means, and when the sufficiency of the storage means is equal to or more than a predetermined value, information of the same track of the information signal recording disk is repeated. Reproduction control means for controlling the reading means so as to read, physical addresses separated and output by the data separation means, the program elapsed time in the original signal, and the correspondence between the elapsed time and the recording position. An information signal reproducing apparatus characterized in that the main data for each block is searched for based on the indicated recording position comparison data.