KR100223163B1 - Disc format for multiple speed reproduction and method for multiple speed reproduction of mpeg data thereby, and device thereof - Google Patents

Abstract

The disc for double speed reproduction contains position information of the following I-pictures in the recording area of the I-picture. When playing back moving image data at high speed using such a disc, the waiting time set in the timer is set based on the double speed, and the position information of the I-pictures read from the disc is moved to the position of the next I-picture to be played. When the waiting time set in the moved position is reached, the data is played back. Such a disc system realizes double speed reproduction by using more image information within a given time according to each speed, thereby providing an effect of displaying a more natural image.

Description

Disc format for double speed reproduction, and double speed reproduction method of moving image data using the same, and apparatus therefor.

1 (a) is a diagram for explaining a reference relationship with neighboring pictures when each picture is encoded / decoded in a 1GOP layer according to the MPEG standard;

(B) of FIG. 1 is a diagram for explaining the relationship between the order in which the pictures are decoded in the 1GOP layer and the order in which the pictures are displayed;

2 is a block diagram showing a conventional double speed playback apparatus for moving picture data;

3 is a flow chart for explaining the operation of the device of FIG.

4 is a view showing a disc format for double speed playback according to the present invention;

5 is a block diagram showing a double speed reproduction apparatus for moving picture data using a disc according to the present invention;

6 is a flow chart for explaining the operation of the device of FIG.

7 is an exemplary table showing a waiting time before reproducing an I-picture according to the present invention.

* Explanation of symbols for main parts of the drawings

10: transmission unit 12: signal processing unit

14: output unit 18: memory

20: timer 26: control unit

The present invention relates to a system for recording / reproducing moving image data using a disc, and more particularly, to a disc format for double speed reproduction, a double speed reproduction method for moving image data using the same, and an apparatus thereof.

According to the Moving Picture Expert Group (MPEG) standard, a 1 GOP (Group Of Picture) is composed of one I-picture, P-pictures and B-pictures. Among these, an I-picture is encoded using only its own image information. The P-picture (Predicted-coded picture) uses the previous I-picture or P-picture, and the B-picture (Bidirectional-coded picture) uses the previous I-picture or P-picture, B- Bidirectional-coded pictures are encoded using motion prediction techniques using I-pictures or P-pictures before and after. Even when playing back a moving picture, an I-picture is decoded using only its own information, and a P-picture or B-picture is decoded by motion compensation using previously decoded pictures. FIG. 1 (a) shows a reference relationship with neighboring pictures when each picture is encoded / decoded in a 1GOP layer according to MPEG.

Referring to (b) of FIG. 1 which shows the relationship between the decoding order and the display order of each picture, the P-picture is decoded by referring to the decoded I-picture after decoding the I-picture in 1GOP. Decoded with reference to I-picture and P-picture. When the decoded pictures are displayed on the monitor, the B-picture is displayed before the P-picture.

As can be seen from the above description, B-pictures and P-pictures are encoded / decoded depending on other pictures that have been previously encoded / decoded, so that I-pictures can be randomly accessed or reproduced at high speed. Finding is essential. A conventional method of reading an I-picture from a disc for double speed playback will be described with reference to FIGS. 2 and 3 as follows.

2 shows a general apparatus for double-speed playback of moving picture data conforming to the MPEG standard recorded on a disc. The apparatus shown in FIG. 2 includes a transmission unit 10 for picking up and outputting moving image data from a disk (not shown), a signal processing unit 12 for restoring data received from the transmission unit 10, and outputting a restored signal. An output unit 14 is provided. 2, the control part 16 which controls each part mentioned above is provided.

Referring to FIG. 3 showing a flowchart related to the operation of the apparatus, the controller 16 responding to the user's playback key input controls the transmitter 10 to pick up data from a disc (not shown). . The transmission unit 10 responding to the control of the control unit 16 reads out the moving image data from the corresponding data read position on the disc and outputs the moving image data to the signal processing unit 12. The signal processor 12 restores the input data through a predetermined signal processing process (step 100). While the moving image is being restored, the controller 16 determines whether a double speed playback key and a double speed unit or a double speed number indicating the speed of reproduction are input by the user (step 110). If it is determined in step 110 that the double speed playback key and the double speed number are input, the controller 16 determines a position at which the pickup (not shown) of the transmission unit 10 will skip on the disc according to the double speed (step 120). For example, if the input speed is 10 times, the control unit 16 performs a control to move the pickup of the transmission unit 10 to the data recording position 10 seconds or more from the current position. The transmitter 10 reads data from the moved position and outputs the data to the signal processor 12 (step 130). The signal processor 12 waits until the data read from the moved position, i.e., the position skipped at 10x speed, is an I-picture (step 140). If an I-picture is detected in step 140, the signal processor 12 restores the data of the I-picture and outputs the data to the output unit 14 (step 150). The output unit 14 outputs the restored data to a monitor (not shown). The controller 16 repeats the process from step 120 to step 150 while in the double speed playback mode.

In the conventional system, there are I-pictures that are not read from the disc because the disc position is skipped by the interval according to the double speed reproduction and the reproduction operation is repeated for a predetermined time from the position. Therefore, the faster the speed, the greater the number of I-pictures that are skipped.

Therefore, the images displayed at double speed reproduction are more severe in discontinuity than those at normal reproduction, which makes it difficult for viewers to understand the contents.

Furthermore, when the 60-minute video is reproduced at 4 times speed in the apparatus of FIG. 2, the actual playback time is longer than 15 minutes because the video is waited until the I-picture appears. Therefore, the above-mentioned double speed reproducing apparatus could not realize double speed in the exact meaning.

SUMMARY OF THE INVENTION An object of the present invention for solving such problems is to provide a method for realizing double speed playback by using a disc having position information indicating recording positions of subsequent I-pictures in a recording area of an I-picture.

Another object of the present invention is to use a disc having positional information indicating recording positions of the following I-pictures in a recording area of an I-picture, and using more I-pictures within a given time according to each speed from such a disk. The present invention provides a device capable of realizing double speed playback.

The object of the present invention is to provide a method of double-speed playback of moving picture data according to the MPEG standard recorded on a disc, comprising: a start code indicating the start of an I-picture from a recording area of an I-picture on a disc, followed by a current I-picture. (A) reading positional information indicating positions of a predetermined number of consecutive I-pictures recorded in the data, and data of the I-picture; (B) detecting and storing position information of the I-pictures from the data read in the step (a) and reproducing the current I-picture data; And (c) searching for the recording area of the next I-picture to be used for double speed reproduction using the position information stored in step (b).

Another object of the present invention is to provide a disc system for double-speed playback of moving picture data according to the MPEG standard, comprising: a start code indicating the start of an I-picture in a recording area of an I-picture, and recorded after a current I-picture on a disc. A disc on which position information indicating positions of a predetermined number of consecutive I-pictures and data of the I-picture are recorded; And determine the positions of the next I-pictures to be used for double speed playback using the positional information recorded on the disc, and reproduce the I-picture data recorded at the corresponding position on the disc according to the positional information indicating the positions of the next I-pictures determined. Achieved by a disk system comprising means for repeating the act of doing so.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 shows a disc format according to the present invention, showing in detail the recording area of an I-picture. In the recording area of the nth I-picture of the disc according to the present invention, the start code of the I-picture is recorded. After the start code, positional information indicating positions on the disc on which eight consecutive I-pictures are recorded among the I-pictures recorded after the nth I-picture are recorded. Here, the reason for recording up to eight positional information is explained below. After the position information of the I-pictures is recorded, the data of the nth I-picture is recorded.

5 shows a double speed playback apparatus according to the present invention for double-speed playback of moving picture data from a disk having the disk format shown in FIG. In FIG. 5, the constituent blocks corresponding to FIG. 2 are given the same reference numerals.

The apparatus of FIG. 5 further includes a memory 18 for storing positional information of I-pictures read from a disk not shown. In addition, the controller 20 includes a timer 20 that checks the time set by the controller 26 and generates an interrupt signal when the set time is reached.

The operation of the double speed playback apparatus of FIG. 5 having such a configuration will be described in detail with reference to FIG. 6 and FIG.

When the play key is input from the user, the control unit 26 controls the operation of each component block to perform the play operation (step 200). The transmitter 10 reads data from a disk (not shown) having a format as shown in FIG. 4 and outputs the data to the signal processor 12. The signal processor 12 determines whether the start code of the I-picture is included in the data received from the transmitter 10 (step 210). If the start code of the I-picture is detected in step 210, the control unit 26 reads the position information of the next I-picture after the start code of the I-picture and stores it in the memory 18 (step 220). Then, the control section 26 determines whether the double speed playback key is input by the user (step 230). If the speed playing key is input, the control unit 26 sets the waiting time preset in the timer 20 based on the speed speed unit or the number of speeds input together with the speed playing key.

An example table relating to the set waiting time is shown in FIG. The horizontal axis of FIG. 7 shows a selection period of an I-picture capable of double speed reproduction and realization, and the vertical axis represents a double speed. The example table is made on the assumption that the data processing time required for accessing the first one I-picture in the transmitter 10 is 50 ms, and that each time the number of skipped I-pictures exceeds one by one, 10 ms is required. . The data processing time in the transmission unit 10 is shown in parentheses on the horizontal axis in the example table and the unit is ㎳. In the example table, the numbers enclosed in bold solid lines represent the wait times that can best implement the corresponding double speed for the data processing time of the system. Here, the unit of waiting time is seconds. For example, referring to FIG. 7, if one of the I-pictures is played with a waiting time of 0.067 seconds for every two I-pictures when the data is played back at 15 times speed, the I-pictures can be played back as many times as possible. It can be seen that the 15 times speed can be achieved. According to the example table of FIG. 7, since high-speed reproduction at a maximum speed of 30 times can be realized, as shown in FIG. 4, up to eight positional information of the following I-pictures are recorded.

If the apparatus of FIG. 5 reproduces at 10 times the speed and takes 60 ms to process the data in the transmitter 10, the controller 26 sets 0.1 second to the timer 20 according to the example table of FIG. Then, in order to read one I-picture every two from the disc, the + 2nd I-picture positional information, which is the positional information of the I-picture to be restored next, is read from the memory 18. The control unit 26 moves the pickup of the transmitting unit 10 to the position of the I-picture recorded second after the current position according to the information read from the memory 18 (step 240). Then, the position information of the next I-pictures is read from the moved position and stored in the memory 18 again. The controller 26 waits until the interrupt signal is generated in the timer 20 (step 250). When the timer 20 generates an interrupt signal at a time point of 0.1 second, which is the waiting time set by the controller 26, the controller 26 starts an operation to read and restore the I-picture data at the current position of the disc. The transmitter 10 and the signal processor 12 are controlled (steps 260 and 270). The output unit 14 receives the data restored by the signal processor 12 and outputs the data under the control of the controller 26. The controller 26 repeats the process from step 240 to step 270 while in the fast playback mode.

In general, since 1 GOP is composed of 0.5 seconds of data (15 frames in the NTSC method and 12.5 frames in the PAL method), one I-picture existing in each 1 GOP exists at 0.5 second intervals. At this time, if the moving image data is reproduced at the 10 times speed in a conventional manner, a total of 20 I-pictures are lost for 10 seconds. However, in the present invention, one I-picture is reproduced every two I-pictures, so only 10 I-pictures are lost for 10 seconds. In addition, it takes about 1 second to process 10 seconds of data (20 I-pictures) even in the reproduction time, thereby realizing accurate 10 times speed.

As described above, the disc format for double speed reproduction and the double speed reproduction method of the moving picture data using the same and the apparatus thereof realize more double speed reproduction by using more video information within a given time according to each double speed number. It has the effect of displaying a natural image.

Claims (9)

In the method for double-speed playback of moving picture data according to the MPEG standard recorded on the disc, A start code indicating the start of the I-picture from the recording area of the I-picture of the disc, positional information indicating positions of a predetermined number of consecutive I-pictures recorded after the current I-picture, and data of the I-picture Reading (a); (B) detecting and storing position information of the I-pictures from the data read in the step (a) and reproducing the current I-picture data; And And (c) searching for a recording area of the next I-picture to be used for double speed reproduction using the position information stored in the step (b). The method of claim 1, wherein step (b) Detecting a start code of an I-picture from the read data (b1); And And if the start code of the I-picture is detected in step (b1), reading and storing position information of the next I-picture corresponding to the start code (b2). The method of claim 1, wherein the step (c) comprises: setting a waiting time according to the speed of the speed for reproduction of speed; Determining positions of next I-pictures to be used for double speed reproduction based on the double speed number (c2); And And (c3) moving to the position of the next I-picture determined in the step (c2) when the waiting time set in the step (c1) is reached. 4. The method of claim 3, wherein step (c3) includes reading and storing positional information of subsequent I-pictures at the moved position. In a disc system for double-speed playback of moving picture data according to the MPEG standard, In the recording area of the I-picture, a start code indicating the start of an I-picture, position information indicating positions of a predetermined number of consecutive I-pictures recorded after the current I-picture on the disc, and data of the I-picture A recorded disc; And The positions of the next I-pictures to be used for double speed playback are determined by using the positional information recorded on the disc, and the I-picture data recorded at the corresponding position of the disc is determined according to the positional information indicating the positions of the next I-pictures determined. Means for repeating the playing operation. The method of claim 5, wherein the means A disk system including means for moving to the positions of the next I-pictures to be played based on the positions of the next I-pictures determined for a predetermined waiting time, and reproducing the I-picture of the position after the predetermined waiting time has elapsed. . 6. The disk system according to claim 5, wherein said means determines the positions of the next I-pictures to be reproduced in response to a double speed number for double speed reproduction. 8. The method of claim 7, wherein said means is A transmission unit for reading data from the disc; A signal processor for signal-processing and restoring data read from the transmitter; A memory for storing location information of next I-pictures; A timer for checking a set time; And Set a time based on the double speed number in the timer, and move to the position of the next I-picture to be restored using the position information stored in the memory, and when a signal indicating that the time set from the timer is reached occurs, And a control unit for controlling the transmitting unit and the signal processing unit to restore data of an I-picture at a position. 3. The method of claim 2, wherein step (c) comprises determining positions of the following I-pictures for double speed reproduction among the positional information stored in step (b) based on the number of speeds for double speed reproduction. Double speed playback method.