JPH10112841A - Digital moving picture disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital moving picture disk which does not need a special circuit on a digital moving picture disk reproducing device and also facilitates special reproduction other than positive direction normal reproduction at the time of reproducing a moving picture. SOLUTION: This digital moving picture disk which digitally converts a video signal of a moving picture, compresses the video signal and records it has two data recording layers, encodes a digitally converted video signal so as to have twice as many frames as the frame numbers n (n is an integer) of a reproduced moving picture for one second, compresses an encoded video signal so as to have twice frame numbers when the encoded video signal is undergone predictive encoding, records predictive coding data of compressed odd frames on a data recording layer 51 and records predictive coding data of compressed even frames on a data recording layer 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital moving picture disk, and more particularly, to a digital moving picture disc which facilitates special reproduction other than normal forward reproduction when reproducing moving pictures.

[0002]

2. Description of the Related Art When performing slow playback with a conventional digital moving picture disc playback apparatus, each recorded frame is played back at a fixed time interval longer than the time interval between frames during normal playback, so that a slow playback image is obtained. Slow playback is performed using what appears to be moving.

[0003]

However, in the above-described conventional slow reproduction, since the number of frames does not change, there is a problem that the movement becomes jerky if the time interval between frames during reproduction is increased. Was.

[0004] For this reason, if the number of frames is increased, smooth slow motion reproduction can be performed. However, in order to generate a new frame by performing motion prediction or the like, an increase in the amount of required memory or motion prediction is required. However, there is a problem that it cannot be easily realized, such as the necessity of adding a dedicated circuit for performing the operation.

In the case where data compression (hereinafter, also simply referred to as compression by MPEG) is performed by using compression by the MPEG system or the like, once reproduction is performed in the normal direction in order to perform reproduction at the normal reproduction speed in the reverse direction. It is necessary to store the result in a memory and rearrange it in the reverse direction. For this purpose, the storage capacity of the memory is several times that of the forward reproduction. As a result, a special circuit has to be added for a normal reproduction speed in the reverse direction, which is rarely used, and there is a problem that the circuit becomes expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital moving picture disk in which special reproduction other than normal normal reproduction in moving picture reproduction is facilitated without adding a special circuit to the digital moving picture disc reproducing apparatus.

[0007]

A digital moving picture disc according to the present invention is a digital moving picture disc for converting a moving picture video signal into a digital signal and compressing and recording the video signal, wherein the data recording layer has two layers. , One of the videos played
Encode the digitally converted video signal so that the number of frames per second is n times (n is an integer),
At the time of predictive encoding of the encoded video signal, the encoded video signal is compressed so that the number of frames is doubled, and the compressed predicted encoded data of the odd frame is stored in one data recording layer. Recording, and recording the compressed prediction encoded data of the even frame on the other data recording layer.

According to the digital moving picture disk of the present invention, a normal moving picture can be viewed by reading and reproducing only the data of one data recording layer. At the time of slow reproduction, in addition to the data of one data recording layer, the data recorded on the other data recording layer are alternately read out and reproduced for each frame, so that the slow reproduction is performed by the data of only one data recording layer. Smooth slow motion video can be obtained more smoothly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital moving picture disk according to the present invention will be described below with reference to an embodiment. FIG. 1 is a cross-sectional view illustrating a configuration of a digital moving image disk according to an embodiment of the present invention. FIG. 2 is a schematic surface view of the digital moving image disk according to the embodiment of the present invention. The case of two layers is illustrated.

In a digital moving picture disk 50 according to an embodiment of the present invention, a first data recording layer 51 is formed on a surface of a substrate 53, and video data and audio data are multiplexed on the data recording layer 51. The recorded data is engraved in the form of pits, a second data recording layer 52 is formed on the back surface of the substrate 54, and data obtained by multiplexing video data and audio data is recorded on the data recording layer 52. And is integrally formed with the front surface of the substrate 53 and the back surface of the substrate 54 facing each other.

As shown in FIG. 2, a center hole 56 is provided in a center portion of the digital moving picture disk 50, and pits 55 are formed in a spiral shape. It is recorded toward the outer circumference.

Next, data recorded on the digital moving picture disk 50 will be described. The number of frames per second of the digital moving image disc to be played is n (n = integer).

For convenience of explanation, the case of a conventional digital moving picture disc will be described first. In FIGS. 3 and 4, numerals indicate frame numbers. As shown in FIG. 3A, in a conventional digital moving image disc, in the case of compression by the MPEG method, data of a first frame to an intra-frame coded image (also referred to as an I-picture), a bidirectional predictive coded image ( The data of the B-picture and the data of the inter-frame forward prediction coded image (also referred to as the P-picture) are rearranged as shown in FIG. 3B and recorded on the disk.

Next, the case of the digital moving picture disk 50 will be described with reference to FIG. When digitally encoding a moving image, the moving image is encoded so as to be, for example, 2n frames per second. Then, when performing predictive encoding, FIG.
As shown in 1), compression is performed by the MPEG method so that an I-picture or a P-picture is obtained every six frames. This compressed data is divided into odd frames and even frames. With this separation, the odd-numbered frame includes the I-picture, the P-picture, and the B-picture as shown in FIG. 4 (a-2), but the even-numbered frame includes the I-picture, the P-picture and the B-picture. As shown in FIG. 7, the data is only for B-picture.

In the above description, the method of compressing so that an I-picture and a P-picture come every six frames can be arbitrarily selected in the compression method according to the way of setting the period M of the I-picture and the P-picture. . In addition, M-pictures are usually set to be I-pictures and P-pictures every three frames.
In order to make all even-numbered frames become B-pictures as a result of the compression in the PEG compression, in the present embodiment, 6 (=
(3 × 2) The number of frames is set to 6 so that an I or P-picture is obtained every frame. B-
If the number of pictures is increased too much, the correlation between before and after cannot be obtained. Therefore, in this example, six frames are used.

When the moving picture data compressed by the MPEG system as described above is recorded on the digital moving picture disk 50, the data on the odd frame side is rearranged as shown in FIG. Is recorded on the data recording layer 51. This rearrangement of odd frames is similar to the rearrangement shown in FIGS. 3 (a) and 3 (b). The data on the even-numbered frame side is recorded on the second data recording layer 52 as shown in FIG. Rearrangement is not performed on the data on the even frame side.

On the digital video disk 50, data on the odd-numbered frame side is taken out from the digital code encoded when the digital video disk is created and recorded on the first data recording layer 51, and the data on the even-numbered frame side is taken out. Recording is performed on the second data recording layer.

When recording is performed in this manner, the even frame side has only a B-picture, so the data amount is small. For this reason,
At the time of mastering the digital moving image disk 50, the temporal position on the moving image based on the data recorded on the first data recording layer 51 and the temporal position on the moving image based on the data recorded on the second data recording layer 52 are different. It is created by adding padding data to the even-numbered frame side so as to be in the vicinity and performing adjustment.

When the digital moving picture disk 50 constructed as described above is normally reproduced, a normal moving picture can be viewed by reading out and reproducing only the data of the first data recording layer 51. At the time of slow reproduction, in addition to the data of the first data recording layer 51, the second data recording layer 5
The data recorded in the first data recording layer 51 is also read and used alternately for each frame.
Smooth slow-motion playback video can be obtained by performing slow playback with only data.

FIG. 5 is a block diagram of the entire reproducing apparatus for reproducing the digital moving picture disk 50. Digital moving image data in which video data and audio data are multiplexed is recorded on the digital moving image disk 50. A pickup 61 that can read recorded data from the first data recording layer 51 or the second data recording layer 52 as necessary.
The data read out by the pickup 61 is reproduced, supplied to the video data / audio data (AV) separation section 67 through the RF amplifier 64, and separated into video data and audio data. The separated video data is supplied to a video decoding / decompression processing unit 7.
0, the video output processing unit 69
, And output as a decoded and expanded analog video signal.

The audio data separated by the video / audio data (AV) separation section 67 is decoded by the audio decoding / decompression processing section 72, decompressed, and processed and decoded by the audio output processing section 71. The analog audio signal is output as a compressed and expanded analog audio signal.

The servo processor 65 moves the pickup 61 to an address portion to be reproduced and adjusts the rotation speed of the spindle motor 62. The overall control based on the instruction output from the key switch group 74 is performed by the CPU 66. In this case, when a normal reproduction instruction is issued from the key switch group 74, only the data recorded on the first data recording layer 51 is read and reproduced, an image based on the video data is displayed on the monitor, and the audio signal is displayed. Is output from the speaker. When a slow reproduction instruction is issued from the key switch group 74, data recorded in the first and second data recording layers 52 are alternately read and reproduced for each frame, and a slow image based on video data is monitored. And the sound based on the audio signal is output from the speaker.

Next, in the case of performing reproduction in the reverse direction, in the case of compression by the MPEG system having a predicted frame in the time axis direction, the reproduction in the reverse direction is performed by decoding the data decoded in the forward direction once. You need to sort in the opposite direction. For this reason, the memory needs to be added more than usual due to the configuration of the device, and the device needs to be added. In view of this, digitally coded data prepared in advance from the end contrary to normal reproduction is prepared.

Therefore, the first digital moving disk 50
In the data recording layer 51, moving image data digitally encoded in the forward direction is recorded, and in the second data recording layer 52, moving image data digitally encoded in the reverse direction is recorded in the spiral direction of the first data recording layer 51. The recording is performed in the opposite direction and from the outer peripheral side.

When the digital moving picture disk 50 on which data is recorded is reproduced in the forward direction (including slow and fast forward), the data is read from the first data recording layer 51 and reproduced in the reverse direction (slow and fast forward). (Including return), the reading from the second data recording layer 52 is switched. At this time, the data recorded on the second data recording layer 52 has the spiral direction opposite to that of the data recorded on the first data recording layer 51 and is recorded in the opposite direction. There is no need to change the rotation direction, and the data should be in the vicinity, so even if the data read layer is switched, the movement amount of the pickup is very small, and only the reproduction is performed in the order of data at the time of decoding, and the moving image in the opposite direction Can be obtained instantaneously.

[0026]

As described above, according to the digital moving picture disk of the present invention, special reproduction other than normal normal reproduction in moving picture reproduction can be performed without adding a special circuit to the digital moving picture disc reproducing apparatus. Can be easily done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a digital moving image disk according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a digital moving image disk according to one embodiment of the present invention.

FIG. 3 is a schematic explanatory diagram for explaining recorded data of a conventional digital moving image disk.

FIG. 4 is a schematic explanatory diagram for explaining recording data of a digital moving image disk according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a digital video disc player for a digital video disc according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 50 Digital moving image discs 51 and 52 First and second data recording layers 53 and 54 Substrate 55 Pit 56 Center hole II picture BB picture PP picture

Claims (1)

[Claims] 1. A digital moving picture disc for converting a moving picture video signal into a digital signal and compressing and recording the video signal, wherein the data recording layer has two layers and the number of frames per second of the moving picture to be reproduced is n ( (n is an integer), encodes a video signal that has been digitally converted into a frame twice as large as the number of frames, and encodes the video signal so that the number of frames is doubled during predictive encoding of the encoded video signal. Compressing the signal, recording the compressed odd-frame predicted coded data on one data recording layer, and recording the compressed even-frame predicted coded data on the other data recording layer. Digital video disc to do.