JP3241364B2 - Data recording method, data reproducing method, recording / reproducing device, reproducing device, and disk medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for recording and reproducing digital data on a recording medium such as a magnetic disk and an optical disk, and particularly to a data recording method and a reproducing method suitable for high-speed search reproduction. , A recording / reproducing device, a reproducing device, and a disk medium.

[Prior Art] As a digital data, for example, a digital moving image data recording / reproducing method is disclosed in
A method of reproducing a compressed recording image described in Japanese Patent Application Laid-Open No. 310293 is known.

FIGS. 15 and 16 are block diagrams of a moving picture coding apparatus and a moving picture coding apparatus using the digital moving picture data recording / reproducing method according to the prior art.

Here, FIG. 15 shows a moving picture coding apparatus for compressing a moving picture and recording the obtained coded data on an optical disc, and FIG. 16 shows a data decompression of the coded data read from the optical disc. Thus, a moving picture decoding apparatus for reproducing moving pictures is shown.

In FIG. 15, 1 is an input terminal for an input video signal, 2 is a moving picture coding device, and 3 is an optical disk.

In the moving picture coding apparatus 2, 4 is an A / D conversion circuit, 5 is a frame memory, 6 is a picture coding circuit, 7 is a buffer memory, and 8 is a coding mode control circuit.

The input video signal is input from the terminal 1 to the video encoding device 2, and is converted from an analog video signal into digital video data by the A / D conversion circuit 4, and is stored and held in the frame memory 5. .

The moving image data is sequentially read from the frame memory 5 and is subjected to data compression by the high-efficiency encoding in the image encoding circuit 6 to generate encoded data.

An encoding mode instruction signal for each frame of the moving image is generated by the encoding mode control circuit 8 from the moving image data, and the image encoding circuit 6 performs data compression in accordance with the encoding mode.

The encoded data after data compression is temporarily stored in the buffer memory 7 and then recorded on the optical disk 3 according to a predetermined data format.

In addition, there are two types of encoding modes, an inter-frame encoding mode that reduces the redundancy in the time axis direction by using the correlation between frames, and a first frame immediately after a scene change or a high-speed search reproduction. This is an intra-frame encoding mode used for frames to be extracted and used.

The frame number and coding mode are multiplexed and recorded in the coded data of each compressed data frame,
After encoding and recording of all frames are completed, information on the recording position of the intra-coded frame on the optical disc is recorded in a specific area on the optical disc.

In FIG. 16, 3 is an optical disk, 9 is a moving picture decoding device, 10 is an output terminal of an output video signal, and 11 is an input terminal of a high-speed search instruction signal.

In the video decoding device 9, 12 is a buffer memory, 13 is an image decoding circuit, 14 is a frame memory, 15
Is a D / A conversion circuit, and 16 is a high-speed search control circuit.

The video decoding device 9 has a function of performing normal reproduction when the high-speed search instruction signal input from the input terminal 11 is “0” and performing high-speed search reproduction when the high-speed search instruction signal is “1”.

First, in the case of normal reproduction in which the high-speed search instruction signal input from the input terminal 11 is “0”, encoded data is read from the optical disc 3 in the order of frames by the operation of the high-speed search control circuit 16.

Then, the read encoded data is temporarily stored in the buffer memory 12 and then decompressed by decoding in the image decoding circuit 13 to generate moving image data.
The generated moving image data is stored and held in the frame memory 14, converted into an analog video signal by the D / A conversion circuit 15, and then output from the output terminal 10 as an output video signal.

Thereby, the reproduction of the moving image in the frame order, that is, the normal reproduction is realized.

In the case of high-speed search reproduction in which the high-speed search instruction signal input from the input terminal 11 is “1”, a specific frame, that is, intra-frame encoding, is skipped from the optical disc 3 by the operation of the high-speed search control circuit 16. The encoded data of the frame is read.

Then, as in the case of the normal reproduction, the read encoded data is temporarily stored in the buffer memory 12 and then decompressed by decoding in the image decoding circuit 13 to generate moving image data. You.

The generated moving image data is stored and held in the frame memory 14, converted into an analog video signal by the D / A conversion circuit 15, and then output from the output terminal 10 as an output video signal.

As a result, the reproduction of a specific frame that is intermittent, that is, high-speed search reproduction is realized.

Note that the high-speed search control circuit 16 reads the information of the recording position of the intra-coded frame on the optical disk from a specific area of the optical disk in advance, thereby determining the recording position of the specific frame to be read next. It is checked and its reading is executed.

The high-efficiency image coding method used in the above-described conventional data recording / reproducing method will be described below.

High-efficiency image coding methods for realizing data compression of moving images include two methods: an intra-frame coding method and an inter-frame coding method.
It is roughly divided into two.

The intra-frame coding method is used for moving image data.
In this method, complete encoding is performed for each frame to reduce redundancy in space.

Further, the inter-frame coding method is a method of performing coding using information of a coded previous frame to reduce redundancy not only in a space but also in a time axis direction.

As the intra-frame encoding method, the current pixel value is predicted from the value of the encoded previous pixel, and a prediction encoding method of encoding a prediction error which is a difference value, or a block is divided into blocks of a predetermined block size. There is known a transform coding method in which each block is orthogonally transformed and a transform coefficient is quantized. The orthogonal transform performs the same frequency analysis as the Fourier transform, and includes Hadamard transform and discrete cosine transform.

As an inter-frame encoding method, there is a method of encoding a frame difference between an encoded previous frame and a current frame in the same manner as the above-described intra-frame encoding method. In particular, the motion from the previous frame is detected in block units, and the block is shifted by the motion vector.
2. Description of the Related Art A motion-compensated inter-frame predictive coding method that takes a frame difference is known.

Also, there is a change area coding method that codes only the area that has changed with respect to the previous frame.

In general, the data compression rate is higher in the inter-frame coding method having a higher redundancy reduction capability than in the intra-frame coding method. However, in the case of a scene chain in which the image content greatly changes, there is no correlation between frames, and conversely, the intra-frame encoding method may have a higher data compression rate.

In the intra-frame coding method, it is possible to extract and decode only the coded data of a specific frame. However, in the inter-frame coding method, when decoding the coded data, the information of the previous frame is used. Therefore, it is not possible to extract and decode only the encoded data of a specific frame.

For this reason, a method is used in which frames extracted at the time of high-speed search reproduction are encoded by an intra-frame encoding method, and other frames are encoded by an inter-frame encoding method.

Specifically, the first frame after a scene change, the first frame of a frame group including a predetermined number of frames, and the like are intra-coded.

FIG. 17 is a conceptual diagram showing a state where encoded data is recorded on an optical disc.

For example, in a CD (Compact Disc), as shown in this figure, spiral tracks exist from the inner circumference to the outer circumference, and data is recorded in order from the inner circumference on the track. However, the data recording density on the track is constant, and the data amount for one round is larger on the outer circumference than on the inner circumference.

When reading data, the rotation speed changes between the inner circumference and the outer circumference so that the linear velocity becomes constant.

The encoded data of the moving image is recorded from the inner circumference side of the track in the order of the frame. Here, frames extracted at the time of high-speed search reproduction are encoded by an intra-frame encoding method, and the other frames are encoded by an inter-frame encoding method.

Hereinafter, the intra-coded frame is referred to as a refresh frame, and the inter-coded frame is referred to as a normal frame.

FIG. 17 shows an example in which the first frame is a refresh frame, such as a first frame, a ninth frame, and a seventeenth frame. In addition,
Normally, the refresh frame indicated by the bold line has a larger amount of encoded data than the normal frame.

In the case of normal reproduction, the encoded data of each frame is sequentially read from the inner circumference side of the track, and after being decompressed by the moving picture decoding device 9, is output as an output video signal.

On the other hand, in the case of high-speed search reproduction, only the encoded data of the refresh frame indicated by the thick line is sequentially read from the inner circumference side of the track, and
After the data is decompressed in step (1), it is output as an output video signal.

However, in order to realize practical high-speed search reproduction, it is necessary to skip coded data of a normal frame that is not used at high speed.

In order to reduce the frame skip time, for example, a track shampoo that shamps the track from the inner side to the outer side is used.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, no consideration is given to a method of reducing the frame skip time in high-speed search reproduction, and there is a problem in realizing practical high-speed search reproduction. Was.

Some frames including frames extracted during high-speed search playback are intra-coded, and other frames are inter-coded, and the encoded data of such a moving image is simply in the order of the frames. Data is recorded on the track of the optical disk.

Therefore, the encoded data of the refresh frame extracted at the time of the high-speed search reproduction is not relatively regularly arranged on the track of the optical disc.

Therefore, after the reading of the encoded data of the specific refresh frame is completed, the frame skip time required to skip to the start position of the encoded data of the next refresh frame to be read is the encoded data of those refresh frames. Greatly varies depending on the recording position on the track.

In the example shown in FIG. 17, when the coded data of the ninth frame is to be read next to the coded data of the first frame, the track jump of one round is used to obtain the ninth frame.
Since the track jump comes in the middle of the encoded data of the frame, the track jump cannot be used after all, and there is no choice but to wait for rotation until the encoded data of the ninth frame is reached.

When the encoded data of the 17th frame is to be read next to the encoded data of the first frame, after performing a track jump for one round, it also waits for rotation for about one round. There is a need.

In this way, simply when the first frame of a frame group consisting of a predetermined number of frames is intra-coded, or when the first frame immediately after a scene change is intra-coded, the track of the refresh frame on the optical disc is Since there is no regularity in the above recording positions, a frame skip time between refresh frames may be long when performing high-speed search reproduction, and practical high-speed search reproduction cannot be realized.

The present invention is to solve the above problems,
In order to realize high-speed search reproduction, a data skip time between selected data such as a refresh frame is shortened, so that high-speed and practical high-speed search reproduction can be realized.

[Means for Solving the Problems] In order to achieve the above object, in a data recording / reproducing method for recording / reproducing data on a disk medium, a read head determines the position of data to be selectively read at the time of reproduction. After the read operation is completed, the read head changes the track position for reading the next data, and then the read head is set to a position after the first readable position.

[Operation] According to the present invention, in the case of high-speed search reproduction, if the track jump is executed immediately after reading the selected data, the next selected data is read with almost no rotation waiting. As a result, the data skip time is short, and practical high-speed search reproduction can be realized.

Examples Examples of the present invention will be described below in detail with reference to the drawings.

As a first embodiment of the present invention, a case where data rearrangement is performed in order to realize high-speed search reproduction will be described.
This will be described with reference to FIGS.

FIG. 1 is a first example of a moving picture encoding apparatus which performs data processing for recording among recording / reproducing apparatuses in which a data recording / reproducing method according to the present invention is applied to a digital moving image data recording / reproducing method. It is a block diagram of an example.

FIG. 2 is a block diagram of a moving picture decoding apparatus constituting a recording / reproducing apparatus together with the moving picture coding apparatus shown in FIG.

The moving picture decoding apparatus performs data processing for reproduction.

In FIG. 1, reference numeral 2a denotes a moving picture coding apparatus. After input video signals are input from an input terminal 1 and data processing is performed by the apparatus, the data is written to an optical disk 3 by a head 101 as a writing means.

In the moving picture coding apparatus 2a, 4 is an A / D conversion circuit, 5 is a frame memory, 6 is a picture coding circuit, 17
Is a frame reordering circuit which is a determining means for determining a data recording position and which replaces data, 7 is a buffer memory, and 8 is an encoding mode control circuit.

In FIG. 2, reference numeral 9a denotes a moving picture decoding device, which is used to read data from an optical disk 3 by a head 10 serving as reading means.
After processing the data read in step 2, output terminal 10
Output as an output video signal.

Then, in the video decoding device 9a, 18 is a frame order normalization circuit which is a normalization unit for making data into a normal order, 12 is a buffer memory, 13 is an image decoding circuit, 14 is a frame memory, and 15 is a frame memory. The D / A conversion circuit 16 is a high-speed search control circuit which is a designating means for designating data to be selected.

 Next, the operation will be described.

In the moving picture coding apparatus 2a, an input video signal input from the input terminal 1 is converted into moving picture data by an A / D conversion circuit 4, and once stored and held in a frame memory 5, the image coding circuit In step 6, data is compressed by high-efficiency coding.

The encoding mode control circuit 8 switches the encoding mode between intra-frame encoding and inter-frame encoding in accordance with the presence or absence of a scene change and a predetermined number of frames in a frame group.

However, unlike the conventional video encoding apparatus 2 shown in FIG. 15, the intra-frame coded frame located at the head of the frame group consisting of a predetermined number of frames by the frame reordering circuit 17, that is, the refresh frame (The data that is selectively read at the time of reproduction) is output after being delayed, whereby the frame order in the frame group is changed.

Then, the encoded data whose frame order has been exchanged is once stored in the buffer memory 7 and then recorded on the optical disc 3.

In the video decoding device 9a, in the case of normal reproduction in which the high-speed search instruction signal input from the input terminal 11 is '0',
By the operation of the high-speed search control circuit 16, the encoded data is read from the optical disc 3 in the recorded order.

The encoded data read from the optical disc 3 is
Unlike the conventional moving picture decoding device 9 shown in the figure, the frame order normalizing circuit 18 returns the position of the refresh frame whose position is shifted in each frame group to normal.

Then, the encoded data is temporarily stored in the buffer memory 12 and then decompressed by the image decoding circuit 13.

The generated moving image data is once stored and held in the frame memory 14, then converted into an output video signal by the D / A conversion circuit 15, and output from the output terminal 10.

In the case of high-speed search reproduction in which the high-speed search instruction signal input from the input terminal 11 is “1”, only the encoded data of the refresh frame is read out from the optical disc 3 by the operation of the high-speed search control circuit 16. .

At this time, the normal frame order circuit 18 outputs the read coded data of the refresh frame in that order without any particular function.

Then, as in the case of the normal reproduction, the encoded data is temporarily stored in the buffer memory 12 and then decompressed by the image decoding circuit 13.

The generated moving image data is once stored and held in the frame memory 14, then converted into an output video signal by the D / A conversion circuit 15, and output from the output terminal 10.

In the moving picture coding apparatus 2a, the frame number and coding mode are multiplexed and recorded in the coded data of each compressed data frame, and the coding and recording of all frames are completed. Later, information on the recording position of the refresh frame on the optical disk is recorded in a predetermined specific area on the optical disk.

In the moving picture decoding device 9a, the refresh frame recording position information recorded in a specific area of the optical disc in advance is read, and at the time of high-speed search reproduction, the position of the next refresh frame to be read is checked based on the information. Perform a read.

Here, instead of recording the refresh frame recording position information in a specific area on the optical disc, a method of multiplexing and recording the recording position information of the next or previous refresh frame on the encoded data of each refresh frame is also available. is there.

In this method, when it is desired to reproduce from an intermediate frame, in order to reach the frame position, it is necessary to sequentially follow the refresh frames.

FIG. 3 shows a conceptual diagram of the frame structure of the encoded data whose frame order has been changed.

FIG. 4 is a conceptual diagram showing a state in which encoded data is recorded on an optical disk, and FIG. 5 is a conceptual diagram for explaining how to read encoded data of a refresh frame during high-speed search reproduction. is there.

This is an example in which a frame group is composed of eight frames, and the first frame, the ninth frame, the seventeenth frame, and the like, which are the first frames of each frame group, are refresh frames to be intra-coded. However, in order to shorten the frame skip time from the refresh frame to the next refresh frame, as shown in FIG. 3, the order of the frames in each frame group is changed, and the position of the refresh frame is shifted.

In order to reduce the rotation waiting time after a track jump, the data amount of a normal frame existing between refresh frames exceeds threshold values th1 and th9 determined from the recordable data amount for one round in this example. Up to this point, the ninth frame, which is the refresh frame,
Move the position of 17 frames, etc. to the back.

The threshold values th1, th9, etc. are increased from the inner circumference to the outer circumference so that the values increase according to the track position.
In addition, the determination is made in consideration of the amount of data that goes excessively during the track jump.

As a result, as shown in FIG. 4, the encoded data of each frame is recorded on the optical disk. However, the refresh frame is indicated by a thick line.

At the time of high-speed search reproduction, the first frame, the ninth frame, the seventeenth frame, and the like, which are refresh frames, are read out as shown in FIG.

First, the encoded data of the first frame is read from position 1S to position 1E.

Next, a track jump is performed outward by one turn, and after reaching the position 1J, a rotation wait is performed to a position 9S, which is the start of the next ninth frame.

Similarly, reading of the coded data of the ninth frame, skipping of frames up to the seventeenth frame, reading of the coded data of the seventeenth frame, and the like are sequentially performed.

The approximate interval at which a refresh frame is inserted by intra-frame encoding may be different depending on the content of a moving image recorded on an optical disc and the purpose of use.

Therefore, the number of track jumps used for performing high-speed search reproduction is not limited to one round, but becomes N rounds (N is a natural number).

This value of N is recorded in a predetermined specific area on the optical disk, similarly to the recording position information of the refresh frame.
At the time of reproduction, it is read in advance.

It should be noted that there is a method of multiplexing and recording the value of N with the encoded data of the refresh frame, and in this case, it is possible to easily cope with a case where the value of N is changed halfway.

FIG. 6 is a detailed block diagram of the frame order permutation circuit 17 in the moving picture encoding device 2a.
It is a timing chart showing the operation.

By the operation of the frame reordering circuit 17, the position of the refresh frame in each frame group is shifted and recorded on the optical disk as described above.

In FIG. 6, 19 is a data output switching circuit, 20 is a refresh frame buffer memory, 21 is a normal frame buffer memory, 22 is a data input switching circuit, 23 is a refresh frame detection circuit, and 24 is a frame reordering control circuit.

The timings of the signals indicated by (a) to (h) in FIG. 6 are described in corresponding (a) to (h) in FIG.

First, encoded data of a moving image subjected to data compression is input as input data (a) in frame order.

The refresh frame detection circuit 23 detects whether a refresh frame is intra-frame encoded or a normal frame is inter-frame encoded, based on the frame number and encoding mode added to the encoded data. The detection signal (b) is output.

As shown in FIG. 7, the frame type detection signal (b)
Is '0' for a refresh frame and '1' for a normal frame.

When the frame type detection signal (b) input from the refresh frame detection circuit 23 is “0”, the data output switching circuit 19 transfers the encoded data (a) to the refresh frame buffer memory 20 through the path (c). Write.

When the frame type detection signal (b) is "1", the encoded data (a) is written to the normal frame buffer memory 21 through the path (d).

The frame reordering control circuit 24 first outputs “0” indicating a refresh frame as the frame type instruction signal (e), and gives it to the data input switching circuit 22.

Then, the data input switching circuit 22 reads the encoded data stored in the refresh frame buffer memory 20 through the path (f) and outputs the encoded data as encoded data (h).

Next, the frame reordering control circuit 24 switches the frame type indication signal (e) to “1” indicating a normal frame, and supplies the signal to the data input switching circuit 22.

Then, the data input switching circuit 22 switches the input of the encoded data to the normal frame buffer memory 21 side,
Output as encoded data (h) through the path (g).

The frame reordering control circuit 24 integrates the data amount of the coded data of the normal frame output as the coded data (h), and again when the integrated data amount exceeds the predetermined threshold value th1 or th9. The frame type indication signal (e) is switched to '0' indicating a refresh frame.

The threshold values th1 and th9 are determined from the recordable data amount for one round of the track position where the encoded data is recorded, and the data amount that is excessive during a track jump.

By the above operation, the frame order of the encoded data (a) is switched so as to be suitable for high-speed search reproduction, and the encoded data (h) is recorded on the optical disc as shown in FIG.

Note that, even if the leading refresh frame of the frame group is shifted to its last position, if the integrated data amount of the encoded data of the normal frame up to that position does not exceed a predetermined threshold value, the refresh frame is It is placed at the last position of the frame group.

In this case, the refresh frame is skipped and not used in the high-speed search reproduction.

Next, FIG. 8 is a detailed block diagram of the frame order normalizing circuit 18 in the video decoding device 9a, and FIG. 9 is a timing chart showing the operation.

In FIG. 8, 25 is a data output switching circuit, 26 is a refresh frame buffer memory, 27 is a normal frame buffer memory, 28 is a data input switching circuit, 29 is a refresh frame detection circuit, and 30 is a frame order normalization control circuit. . The timings of the signals indicated by (a) to (h) in FIG. 8 are described in corresponding (a) to (h) in FIG.

First, encoded data of a moving image read from an optical disk is input as encoded data (a) in a state where the frame order is changed. The refresh frame detecting circuit 29 detects whether each frame of the encoded data (a) is a refresh frame or a normal frame, and outputs a frame type detection signal (b) as '0' or '1'.

When the frame type detection signal (b) is “0” indicating a refresh frame, the data output switching circuit 25 encodes the signal on the path (c). And outputs the converted data (a).

Thereby, the refresh frame buffer memory 26
Each frame of the encoded data (a) is distributed and written to the normal frame buffer memory 27 according to the frame type.

The frame order normalization control circuit 30 first outputs a frame type indicating signal (e) indicating a refresh frame, and the data input switching circuit 28 selects the refresh frame buffer memory 26.

Until the refresh frame buffer memory 26 becomes empty, after the encoded data is output as the encoded data (h) through the path (f), the frame order normalization control circuit 30 indicates a normal frame. A frame type indication signal (e) is output.

Then, the data input switching circuit 28 selects the normal frame buffer memory 27 and outputs the encoded data of the ordinary frame as encoded data (h) through the path (g).

The frame order normalization control circuit 30 controls the encoded data (h) by the number of normal frames originally encoded during the refresh frame, that is, by the number of seven frames.
After the encoded data of the normal frame is output as
The frame type indicating signal (e) is switched so as to indicate the refresh frame again.

By the above operation, in the case of the normal reproduction, the frame order of the encoded data (a) is returned to normal, and the encoded data (h) is decoded and the moving image is reproduced.

In the case of the high-speed search reproduction, the input encoded data (a) is only the encoded data of the refresh frame, and all the encoded data is written in the refresh frame buffer memory 26.

Then, the frame order normalization control circuit 30 outputs '0' as the frame type instruction signal until the refresh frame buffer memory 26 becomes empty, so that the encoded data read from the refresh frame buffer memory 26 remains unchanged. Output as encoded data (h).

Further, in the moving picture decoding apparatus 9a, when shifting from normal playback to high speed search playback, if the frame being read at that time is a refresh frame, the process immediately shifts to high speed search playback. If the frame being read is a normal frame, the process shifts to high-speed search reproduction from the time when a subsequent refresh frame is reached.

If the frame being read at that time is a normal frame, there is a method of performing a track jump to the position of the next refresh frame and shifting to high-speed search reproduction, but there are cases where the track jump cannot be executed conveniently. .

Therefore, during the transition time, the image of the last frame before the transition may be held and displayed in order to reduce the psychological burden on the user.

In addition, when the moving picture decoding apparatus 9a shifts from the high-speed search playback to the normal playback, even if an attempt is made to shift from the refresh frame currently being read to the normal playback, there is a normal frame that has already been read. It is sufficient to start reading from the first normal frame of the next frame group and shift to normal reproduction.

There is also a method of returning to the position of the first normal frame of the frame group to which the refresh frame being read at that time belongs, starting reading of the normal frame, and shifting to normal reproduction. This can take some time.

Therefore, during the transition time, in order to reduce the psychological burden on the user, it is desirable to hold and display the image of the last frame before the transition.

Also, regarding the display at the time of high-speed search, generally, the encoded data amount of the refresh frame is larger than the encoded data amount of the normal frame, so that it is necessary to read the encoded data of each refresh frame from the optical disc. This time is longer than one frame display time.

Therefore, in the case of high-speed search reproduction, it is desirable to display the image of the current refresh frame for a time corresponding to several frames and then to display the next refresh frame.

As a second embodiment of the present invention, in order to realize a high-speed search, an embodiment in which data when a data amount between selected data becomes a predetermined data amount is a target of the high-speed search, This will be described with reference to FIGS. 10, 11, and 12.

FIG. 10 is a block diagram showing a second embodiment of a moving picture encoding apparatus for performing data processing for recording among recording / reproducing apparatuses using the digital moving picture data recording / reproducing method according to the present invention. It is.

FIG. 11 is a block diagram of a moving picture decoding apparatus constituting a recording / reproducing apparatus together with the moving picture coding apparatus shown in FIG.

The video decoding device performs data processing for reproduction.

In FIG. 10, reference numeral 2b denotes a moving picture coding apparatus. After input video signals are input from the input terminal 1 and data processing is performed by this apparatus, the data is written to the optical disk 3 by the head 101 as a writing means.

In the moving picture coding apparatus 2b, 4 is an A / D conversion circuit, 5 is a frame memory, 6 is a picture coding circuit, 7 is a buffer memory, and 8a is a code which is a determining means for determining a data recording position. It is a conversion mode control circuit.

In FIG. 11, reference numeral 9b denotes a moving picture decoding apparatus, and the head
After processing the data read in step 2, output terminal 1
Output from 0 as an output video signal.

In the video decoding device 9b, 12 is a buffer memory, 13 is an image decoding circuit, 14 is a frame memory, 15
Is a D / A conversion circuit, and 16 is a high-speed search control circuit which is designating means for designating data to be selected.

 Next, the operation will be described.

In the moving picture coding apparatus 2b, an input video signal input from the input terminal 1 is converted into moving picture data by an A / D conversion circuit 4 and is temporarily recorded and held in a frame memory 5; Is compressed by high-efficiency coding.

The encoding mode control circuit 8a switches the intra-frame encoding mode and the inter-frame encoding mode as needed while monitoring the encoded data output from the image encoding circuit 6.
The image encoding circuit 6 is instructed by the encoding mode instruction signal.

Then, the encoded data that has been compressed is temporarily stored in the buffer memory 7 and then recorded on the optical disc 3.

Unlike the conventional image encoding device 2 shown in FIG. 15, switching of the encoding mode instruction signal in the encoding mode control circuit 8a is performed as follows.

First, an encoding mode instruction signal indicating the intra-frame encoding mode is output, and the image encoding circuit 6 generates encoded data of one refresh frame for one frame.

From the next frame, an encoding mode instruction signal indicating the inter-frame encoding mode is output, and the encoded data of the normal frame is generated by the image encoding circuit 6.

Then, the data amount of the encoded data of the normal frame is integrated, and when the integrated data amount exceeds a predetermined threshold value, the mode is switched to an encoding mode instruction signal indicating the intra-frame encoding mode.

In the video decoding device 9b, when the high-speed search instruction signal input from the input terminal 11 is "0" for normal reproduction, the encoded data of all frames is sequentially transmitted to the optical disk 3
And normal reproduction is realized.

Further, in the case of high-speed search reproduction in which the high-speed search instruction signal is "1", only the encoded data of the refresh frame is read out from the optical disc 3 in an intermittent manner, and high-speed search reproduction is realized.

FIG. 12 is a conceptual diagram showing a state where encoded data is recorded on an optical disc.

As in the case of the first embodiment shown in FIG. 4, in order to reduce the frame skip time between refresh frames in the case of high-speed search reproduction, a refresh frame is placed at a position where the rotation waiting time after a track jump is reduced. Has been arranged.

In this example, the first frame, the eleventh frame, the twenty-third frame, and the like are intra-frame coded refresh frames.

The manner of reading the encoded data of the refresh frame during the high-speed search reproduction is the same as in the case of the first embodiment shown in FIG.

According to the first and second embodiments described above, by optimizing the arrangement of the refresh frames to be recorded on the optical disk, the execution time of the frame skip using the track jump for N rounds is short, and the execution time is high. Practical high-speed search reproduction can be realized.

In the second embodiment, at the time of reproduction, the recording position of the data to be selected and read out on the medium is changed to the track for reading the next selected data after the read head finishes reading the selected data. After changing the position, it was set as the first readable position, but the position of the selected data is
It may be a position after the first readable position and a position which is 1/2 or less from the readable position.

Also in this case, a high-speed and practical high-speed search can be realized.

By the way, in the above two embodiments, the high-speed search reproduction in the forward direction is considered to be fast and practical, but the high-speed search reproduction in the reverse direction as well as the forward direction is necessary. In such a case, the recording / reproducing method according to the present invention, in which the arrangement of the refresh frames is similarly regular, is effective.

That is, in this case, (N + 1/2) circumferences or N
What is necessary is just to arrange a refresh frame for every circumference.

In this case, the frame skip times between the refresh frames in the forward direction and the reverse direction are equalized.

Of course, in this case, the moving picture decoding apparatus requires not only a high-speed search instruction signal but also an input terminal for a forward / reverse direction instruction signal.

 This will be described with reference to FIGS. 13 and 14.

FIG. 13 and FIG. 14 are conceptual diagrams of a state where encoded data is recorded on an optical disc.

FIG. 13 shows a case where refresh frames are arranged every 1.5 turns, and FIG. 14 shows an example where refresh frames are arranged every two turns.

In each case, similarly to the above-described first embodiment, a refresh frame of intra-frame encoding is generated every eight frames, and the recording position of the refresh frame is adjusted by changing the frame order in each frame group. It was done.

Note that a method similar to that of the above-described second embodiment may be used.

In the above-described embodiment in which only the high-speed search reproduction in the forward direction is considered, the encoded data amount of the next normal frame of the refresh frame is integrated, and the integrated data amount is N.
The next refresh frame is arranged at a position larger than the sum of the recordable data amount for the circumference and the data amount that is excessive during the track jump.

On the other hand, in the present embodiment that considers both forward and reverse high-speed search reproduction, not only the amount of encoded data of the normal frame but also the amount of encoded data of the refresh frame and the next normal frame is reduced. At the position where the integrated data amount becomes larger than the sum of the recordable data amount for (N + 1/2) or N or more rounds and the data amount that is excessive during the track jump, the next A refresh frame is placed.

Which of (N + 1/2) or N is selected may be selected from FIGS. 13 and 14, whichever is more desirable, according to the amount of encoded data of the refresh frame.

Note that both methods may be mixed in one disk or in one recording unit in one disk.

According to the present embodiment, by arranging refresh frames to be recorded on the optical disc regularly, the frame skipping using the track jump can be performed in both the forward high-speed search reproduction and the reverse high-speed search reproduction. The execution time is equalized, and practical high-speed search reproduction with good usability can be realized.

In addition, the amount of data that can be recorded between data that is selectively read during reproduction is equal to or greater than the amount of data that can be recorded for N rounds (N is a natural number) of the disk medium, and the amount of data that can be Even when the position of the selected data is determined so that the data amount increases, a high-speed search can be realized.

When recording, the read head changes the track position in order to read the next selected data, in the case of selecting and reading data by the method described above, and in the case of selecting data to be read in the reverse reproduction. After that, the data at the first readable position may be specified.

Although the recording / reproducing apparatus has been described above, according to the reproducing apparatus having a reproducing function among these apparatuses, high-speed and practical high-speed search reproduction can be performed.

The embodiment described so far has been directed to an optical disc such as a CD in which a spiral track exists and data is read by rotation at a constant linear velocity.

However, a plurality of tracks exist concentrically, and data is read out by rotation at a constant angular velocity.
The present invention is similarly applicable to a write-once optical disc and a rewritable optical disc.

Further, the present invention can be similarly applied to not only optical disks but also magnetic disks such as floppy disks and hard disks.

Further, in the above embodiments, the apparatus having both the recording and reproducing functions has been mainly described. However, the method according to the present invention can be applied to a recording apparatus having only a recording function. .

[Effects of the Invention] According to the present invention, when performing high-speed search reproduction, data to be extracted and used are regularly arranged on the tracks of the disk, so that the skip time between data is reduced, and high-speed practical use is achieved. High-speed search reproduction can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a moving picture coding apparatus using a data recording / reproducing method according to the present invention, and FIG. 2 is a data recording apparatus according to the present invention together with the moving picture coding apparatus shown in FIG. FIG. 3 is a block diagram of a moving picture decoding apparatus constituting a reproducing apparatus, FIG. 3 is a conceptual diagram showing a frame structure of encoded data output in the first embodiment, and FIG. 4 is a diagram of encoded data in the first embodiment. FIG. 5 is a conceptual diagram showing a recording state on an optical disk, FIG. 5 is a conceptual diagram showing coded data reading at the time of high-speed search reproduction in the first embodiment, and FIG. FIG. 7 is a timing chart showing the operation of the frame reordering circuit, FIG. 8 is a detailed block diagram of the frame reordering circuit in the first embodiment, and FIG. 9 is a frame reordering circuit. The behavior of FIG. 10 is a block diagram of a moving picture coding apparatus using a data recording / reproducing method according to a second embodiment of the present invention, and FIG. 11 is a block diagram showing data recording together with the moving picture coding apparatus shown in FIG. FIG. 12 is a block diagram of a moving picture decoding apparatus constituting a reproducing apparatus, FIG. 12 is a conceptual diagram showing a recording state of coded data on an optical disc in a second embodiment, and FIGS. 13 and 14 are diagrams of the present invention. A conceptual diagram showing a recording state of encoded data on an optical disc in another embodiment,
FIG. 15 is a block diagram of a moving picture coding apparatus using a conventional data recording / reproducing method, and FIG. 16 is a moving picture decoding apparatus which constitutes a conventional data recording / reproducing apparatus together with the moving picture coding apparatus shown in FIG. FIG. 17 is a conceptual diagram showing a recording state of encoded data according to the prior art on an optical disk. 2,2a, 2b ... moving picture coding device, 3 ... optical disc, 6
…… Image coding circuit, 8,8a …… Coding mode control circuit,
9, 9a, 9b: video decoding device, 13: image decoding circuit, 16: high-speed search control circuit, 17: frame order permutation circuit, 18: frame order normalization circuit.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toyota Honda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Masami Nishida 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa (56) References JP-A-2-72780 (JP, A) JP-A-63-59286 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 20/12 H04N 5/85

Claims (18)

(57) [Claims] 1. A data recording method for recording data including specific data reproduced during high-speed search reproduction on a disk-shaped recording medium, wherein recording of second specific data read after the first specific data. The start position is defined as a position after the first readable position after the read head finishes reading the first specific data and changes the track position, and from the readable position.
Recording the second specific data from the recording start position and writing the information of the recording positions of the first and second specific data to the recording medium; Recording method. 2. A method according to claim 1, wherein, of the specific data reproduced during the high-speed search reproduction, the second specific data read after the first specific data is read by the read head when reading of the first specific data is completed, and A disk in which a position starting from the first readable position after changing the position, and a position not more than a half turn from the readable position is recorded as a recording start position, and information of a recording position of the specific data is recorded. A method for reading out the recording position information from a recording medium having a shape, reading out the specific data based on the information on the recording position, and performing high-speed search reproduction. 3. A recording / reproducing apparatus for recording / reproducing data on / from a disc-shaped recording medium, comprising: reading means for reading data at the time of reproduction; and instruction means for instructing the reading means to read specific data read at the time of high-speed search reproduction. Deciding means for deciding a recording position on a recording medium on which data is recorded at the time of recording; and writing means for writing information on data and recording position based on an instruction of the deciding means, Means that the recording start position of the second specific data to be read after the first specific data is set to the first readable position after the reading means finishes reading the first specific data and changes the track position. A recording / reproducing apparatus thereafter, wherein the position is 1/2 or less of the readable position. 4. A reproduction apparatus for reproducing data including specific data reproduced at the time of high-speed search reproduction and data on a disk-shaped recording medium in which information of a recording position of the specific data is recorded. Reading means for reading the recording position information; and designating means for designating a recording position of the specific data to the reading means based on the recording position information, The recording start position of the second specific data to be read later is a position after the first readable position after the reading means finishes reading the first specific data and changes the track position, and is at or after the readable position. A playback device characterized by designating a position that is less than 1/2 turn from a proper position. 5. A data recording method for recording, on a disk-shaped recording medium, specific data reproduced during high-speed search reproduction and normal data other than the specific data, the data is read subsequent to the first specific data. The recording start position of the second specific data is set to a position after the first readable position after the read head finishes reading the first specific data and changes the track position by N (N is a natural number) circumferences. A data recorded between the specific data and the second specific data is only normal data. 6. A recording / reproducing apparatus for recording / reproducing data on / from a disk-shaped recording medium, comprising: reading means for reading data during reproduction; and instruction means for instructing said reading means to read specific data read during high-speed search reproduction. At the time of recording, determining means for determining a recording position on a recording medium on which data is to be recorded; and writing means for writing data based on an instruction from the determining means, wherein the determining means comprises: The recording start position of the second specific data to be read after the specific data is set to the first position after the reading means finishes reading the first specific data and changes the track position by N (N is a natural number). And the data recorded between the first specific data and the second specific data are only normal data other than the specific data. That recording and reproducing apparatus. 7. The recording / reproducing apparatus according to claim 3, wherein the data on the recording medium is divided into a plurality of frames, and the frames of the specific data are intra-coded. The frame of data other than the specific data is inter-frame coded, and the recording / reproducing apparatus further includes a decoding unit for decoding the intra-frame coded data and the inter-frame coded data. Recording and playback device. 8. A data recording method for recording a data frame including a frame of specific data reproduced at the time of high-speed search reproduction on a disk-shaped recording medium, wherein the second specific data is read after the first specific data. The frame order is different from the frame order of normal reproduction in order to set the data recording start position after the first readable position after the read head finishes reading the first specific data and changes the track position. A data recording method characterized by recording in a different order. 9. A method for reproducing data on a disk-shaped recording medium on which frame data including specific frame data reproduced during high-speed search reproduction is recorded, wherein the recording medium includes a first specific data frame. The recording start position of the second specific data frame read after is the position after the first readable position after the read head finishes reading the first specific data frame and changes the track position, and The recording order of the frames is recorded in a different order from the frame order of the normal reproduction so that the frame data is located at a position less than 1/2 circle from the readable position, and the frame data is recorded from the recording medium in the recording order. A method for reading data and converting it to the normal playback frame order for playback. 10. A recording / reproducing apparatus for recording / reproducing frame data on a disk-shaped recording medium, comprising: reading means for reading frame data during reproduction; and instructing means for instructing said reading means on specific frame data to be read during high-speed search reproduction. The recording start position of the second specific frame data read after the first specific frame data can be read first after the read head finishes reading the first specific frame data and changes the track position. Deciding means for deciding the order of recording each frame data by changing the frame order to a different order from the frame order of normal reproduction so that A recording / reproducing apparatus having a writing unit for writing a group. 11. The recording / reproducing apparatus according to claim 10, wherein the determining means determines that the data amount of the normal frame data which is not the specific frame data between the first specific frame data and the second specific frame data is: When the predetermined threshold value is not exceeded, the frame order is switched so that the normal frame data after the second frame data is between the first frame data and the second frame data. Recording and playback device. 12. The recording / reproducing apparatus according to claim 10, wherein, of the data on the recording medium, the specific frame data is intra-frame encoded, and data other than the specific frame data is inter-frame encoded. The recording / reproducing apparatus, further comprising: decoding means for decoding the intra-frame encoded data and the inter-frame encoded data. 13. A reproducing apparatus for reproducing data on a disk-shaped recording medium on which frame data including specific frame data reproduced at the time of high-speed search reproduction is recorded, wherein said recording medium includes a first specific data frame. The recording start position of the second specific data frame read after is the position after the first readable position after the read head finishes reading the first specific data frame and changes the track position, and The recording order of the frames is recorded in a different order from the frame order of the normal reproduction so that the frame data is located at a position less than 1/2 circle from the readable position, and the frame data is recorded from the recording medium in the recording order. And a conversion unit for converting the read frame data into a frame sequence for normal reproduction. 14. A reproducing apparatus according to claim 13, wherein a first buffer for storing the specific frame data read by the reading means, and a second buffer for storing data other than the specific frame data read by the reading means. A reproducing device, wherein the converting means takes out frame data from the first and second buffers so as to be in a normal reproducing frame order. 15. The recording / reproducing apparatus according to claim 3, wherein said instruction means reads out the first data during high-speed search reproduction, and thereafter reads the first data. Recording the second specific data starting from the first readable position after changing the track position and starting from a position less than 1/2 circumference from the readable position. Playback device. 16. A disk-shaped recording medium on which data including specific data reproduced at the time of high-speed search reproduction is recorded, wherein the second specific data read after the first specific data is read by the read head. After the reading of the specific data of 1 has been completed and the track position has been changed, a position after the first readable position and a position less than 1/2 round from the readable position are recorded as a recording start position, A recording medium on which information of a recording position of the specific data is recorded. 17. A disk-shaped recording medium on which frame data including specific frame data reproduced at the time of high-speed search reproduction is recorded, wherein recording of a second specific data frame read after the first specific data frame is performed. The start position is a position after the first readable position after the read head finishes reading the first specific data frame and changes the track position, and
A recording medium in which the recording order of frame data is recorded in a different order from the frame order of normal reproduction so that the recording order is set to a position less than or equal to 1/2 of the readable position. 18. A disk-shaped recording medium on which specific data reproduced during high-speed search reproduction and normal data other than the specific data are recorded, wherein the second specific data read after the first specific data is: When the read head finishes reading the first specific data and changes the track position, a position substantially the same as the first readable position is recorded as the recording start position, and the first specific data and the second specific data are recorded. A recording medium, characterized in that data recorded between the data and the data is only normal data.