KR100189893B1 - Variable bit rate reproduction system for double speed reproduction - Google Patents

Abstract

The present invention relates to a variable bit rate disc reproduction system for double speed reproduction, comprising: an RF reproduction unit for demodulating an RF signal reproduced at a predetermined track on a disc; A CD / SD reproducing unit for reproducing the data demodulated by the RF reproducing unit according to a corresponding format and outputting a data preparation signal when a data block corresponding to a predetermined size is prepared; After checking the status of the last block played back and the VBR buffer, the size of the block to be input from the CD / SD playback unit is recognized, and the command for the start address and block size of the recognized block is applied to the CD / SD playback unit. A variable transmission unit for switching at a speed corresponding to double speed playback or normal playback in accordance with the amount of data stored in the VBR buffer when the data demand amount during the double speed playback is larger than that of the CD / SD playback unit; An AV playback unit for outputting a data request signal to the variable transmission unit according to the screen reproduction speed, and decoding and outputting the video or audio signal output from the variable transmission unit according to the data request signal; And a servo unit for controlling the pickup to move to the track containing the block recognized by the variable transfer unit on the disc. Therefore, if the amount of data required by the AV playback unit is higher than the amount of data that can be supplied from the CD / SD playback unit, the still image that can be detected by the viewer during double speed playback is divided into small screens that the viewer cannot detect. By inserting it into the screen, the playback speed of the double speed playback screen can be dramatically improved.

Description

Disc variable transfer playback system for double speed playback

1 is a block diagram showing a disc variable transfer playback system for double speed playback according to the present invention.

2 is a diagram showing a buffer state and a surface state during normal reproduction and conventional double speed reproduction when V _SD ? V _AV .

3 is a diagram showing a buffer state and a screen state in the conventional double speed playback in the case of V _SD V _AV .

4 is a diagram showing a buffer state and a screen state in the improved double speed reproduction according to the present invention when V _SD V _AV .

The present invention relates to a disc reproducing system, and more particularly to a disc variable transfer reproducing system for double speed reproduction.

Generally, in a variable bit rate (hereinafter referred to as VBR) reproducing system, the data transmission rate (V _AV ) in the audio / video (AV) reproducing unit (40 in Fig. 1) is CD / SD during double speed reproduction. Since it is larger than the data transfer rate (V _SD ) that can be output from the reproducing unit (20 in FIG. 1), the data is reproduced as much as the data stored in the VBR buffer (33 in FIG. 1) until the VBR buffer is filled again. The AV playback section freezes the screen. Therefore, as shown in FIG. 3, since the double speed playback screens A, B, C, and D and the still pictures a, b, c, and d are repeatedly repeated at regular intervals, the quality of the double speed playback screen is degraded. There is.

Accordingly, an object of the present invention is to supply the AV playback unit by repeatedly performing double speed playback with high transmission speed and normal playback with low transmission speed according to the amount of data stored in the VBR buffer in order to solve the above-mentioned problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a disc variable transfer playback system for double speed playback for controlling data amount.

Disc variable transmission playback system for double speed playback according to the present invention to achieve the above object is an RF playback unit for demodulating the RF signal to be reproduced on a predetermined track on the disk;

A CD / SD reproducing unit for reproducing the data demodulated by the RF reproducing unit according to a corresponding format and outputting a data preparation signal when a data block corresponding to a predetermined size is prepared;

After recognizing the size of the block to be input from the CD / SD reproducing unit by checking the state of the last block and the VBR buffer that was played just before, the CD / SD reproducing command for the start address and the block size of the recognized block A variable transmission unit which is applied to a negative speed, and converts the data into a speed corresponding to double speed playback or normal playback in accordance with the amount of data stored in the VBR buffer when the data demand amount is larger than the data supply amount of the CD / SD playback unit;

An AV reproducing unit for outputting a data request signal to the variable transmission unit according to a screen reproduction speed, and decoding the video or audio signal output from the variable transmission unit according to the data request signal and outputting the decoded image to an external device; And

And a servo unit for controlling the pickup to move to the track containing the block recognized by the variable transfer unit on the disk.

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

1 is a block diagram showing a variable-variable transmission and playback system for double speed playback according to the present invention, which is demodulated by an RF playback section 10 and an RF playback section 10 that demodulate an RF signal played back from a corresponding block of a disk. CD / SD playback unit 20 for reproducing data from the RF signal in CD or SD format, respectively, and variable transmission unit for controlling the AV bitstream according to the variable bit rate of data reproduced in the CD / SD playback unit 20. 30, the tracks of the disc are held or moved according to the target tracks recognized by the AV playback unit 40 and the variable transmission unit 30 for receiving data from the variable transmission unit 30 and playing the video and audio. The servo part 50 is comprised. Here, the RF regeneration unit 10 includes a front end amplifier 11, an equalizer 12, a detector 13, and a phase locked loop (PLL) 14, and the CD / SD regeneration unit 20 includes a demodulator 21. ) And the error corrector 22, the variable transfer unit 30 is composed of a CPU 31, a DAMC (Direct Access Memory Controller) 32 and a VBR buffer 33, the AV playback unit 40 is a video It consists of a playback section 41 and an audio playback section 42.

Looking at the operation according to the configuration of Figure 1 as follows.

First, since the amount of data constituting the unit screen is variable, the speed of reading data from the disk must also be variable. However, since the mechanism of the disk has a limit in response speed, an electronic circuit is required to cancel it, and this is the VBR buffer 33 in the variable transmission unit 30.

That is, since the amount of data constituting the unit screen compressed and stored on the disk is variable according to the complexity of the screen information in order to extend the playback time, the spiral of the VBR buffer 33 and the servo unit 50 is controlled by controlling the data expansion. spiral) Use the on / off function to vary the speed of the data being played back from the disc.

At this time, the data transfer rate control from the disc to the VBR buffer 33 is implemented using the servo unit 50, and the data transfer rate control from the VBR buffer 33 to the AV playback unit 40 is reproduced. This is realized by the request signal of the AV playback section 40 operating in accordance with the speed.

In normal playback, since the amount of data required by the AV playback section 40 is equal to or smaller than the amount of data played on the disk, the data amount of the margin is stored in the VBR buffer 33 as shown in FIG. If the amount of data required by the AV playback section 40 is larger than the amount of data stored in the VBR buffer 33, the data to be played back from the disk by driving or stopping the disk using the spiral on / off function of the servo section 50 is used. Adjust the amount. In the case of double speed playback, when the amount of data required by the AV playback unit 40 is equal to or smaller than the amount of data played on the disc, the same as in normal playback as shown in FIG. 2, and in the case of a large amount, the CD / SD playback unit 20 The AV playback section 40 is applied according to the amount of data stored in the VBR buffer 33 by applying a high speed playback command, a double speed playback command and a low transmission rate command, to the VBR buffer 33 so as to depend on the amount of data to be supplied. Control the speed of the data so that it is output. At this time, when normal playback or V _SD ≥ V _AV , A, B, C, and D are repeatedly repeated as shown in FIG.

On the other hand, when the variable playback speed of the AV playback unit 40 during normal playback is defined as the fixed playback speed from the V _AV disc as V _SD , there is the following relationship.

Normal playback:

V _MIN ≤V _AV ≤ V _MAX

V _SD 〓 V _MAX

When playing at double speed:

N × V _MIN ≤V _AV ≤N × V _MAX

V _SD 《N × V _MAX (N is any number greater than 1)

On the other hand, in the case of V _SD 1V _AV V _MAX, the data flow of the entire system is performed by repeatedly executing the high speed command, the normal speed play command, which is a high speed command, and the normal play command, which is a command of the low speed, according to the amount of data stored in the VBR buffer 33. The flow of V _AV of the playback unit 40 is controlled. Accordingly, the AV playback unit 40 sets the unit buffer lower limit (N, N + 1, ...) and the unit buffer upper limit (M, M + 1, ...) in the VBR buffer 33 during the double speed playback command. When the outputted data reaches the unit buffer lower limit N according to the data request signal of the signal, it switches to the normal playback command for a predetermined time to cover the data of the consumed VBR buffer 33. Accordingly, when the data to be supplemented reaches the buffer upper limit M of the stage, the data is switched back to the double speed replay command to output the data up to the unit buffer lower limit N. If the data is not supplemented up to the buffer upper limit M of the stage, the buffer lower limit of the data stage consumed by the double speed playback command display is set to N + 1. On the other hand, when V _MIN ? V _AV ? V _MAX, the data flow of the entire system is controlled by the data request signal of the AV playback section 40 as in normal playback. That is, the flow of V _SD of the CD / SD playback unit 20 is controlled by using the spiral on / off functions of the VBR buffer 33 and the servo unit 50 according to the V _AV of the AV playback unit 40.

Herein, the operation of the present invention will be described for each component as follows.

First, the RF reproducing unit 10 demodulates the RF signal reproduced from the target track on the disc through the front end amplifier 11, the equalizer 12, the detector 13, and the phase synchronization loop (PLL) 14 to perform CD / Output to the SD reproducing section 20.

The CD / SD reproducing unit 20 detects the header portion of the start block and reproduces data in accordance with the corresponding format, but outputs only the block length determined by the variable transmission unit 30. When the data block to be output is prepared, the CD / SD reproducing unit 20 requests a data ready signal from the variable transfer unit 30.

In the variable transfer section 30, the CPU 31 checks the state of the buffer 33 through the DAMC 32 and the last block that was played just before, and the size of the block to be input from the CD / SD playback section 20. Recognize. Then, a command for the start address and size of the recognized block is applied to the CD / SD reproducing unit 20. At the same time, the variable transfer unit 30 instructs the servo unit 50 to move the pickup to the physical track containing the target block on the disc. At this time, the correct target track is -1 track of the track containing the block. In addition, the variable transmission unit 30 instructs the servo unit 50 to follow the track in the target track (spira1 on). On the other hand, the variable transfer unit 30 receives the data preparation signal from the CD / SD playback unit 20, and then inputs the data to the VBR buffer 33 through the DAMC (32). The variable transmission unit 30 analyzes the header portion of the input data to determine whether it is a video block or an audio block, and outputs the data to the video reproducing unit 41 or the audio reproducing unit 42 according to the determination result.

The AV reproducing unit 40 outputs a data request signal to the variable transmission unit 30 according to the screen reproduction speed. Accordingly, the AV reproducing unit 40 decodes the video or audio signal output from the variable transmission unit 30 to monitor (not shown) or Output to a speaker (not shown).

At this time, the variable transmission section 30 is output to the AV playback section 40 when the data request signal of the AV playback section 40 is larger than the data supply capability of the CD / SD playback section 20 as shown in FIG. The data flow switches the double speed playback command with a high data transfer rate and the normal playback command with a low data transfer rate to supply data to the AV playback section 40 in accordance with the current VBR buffer 33, and the AV playback section ( When the data request signal of 40 is less than or equal to the data supply capability of the CD / SD playback section 20, the data flow output to the AV playback section 40 is supplied by the data request signal of the AV playback section 40. Therefore, in the case of double speed playback with V _SD V _AN , still pictures a, b, c, and d are inserted into the double speed pictures A, B, C, and D as shown in FIG. _C , D + d The screen is displayed continuously.

As described above, in the variable bit rate disc reproducing system for double speed reproduction according to the present invention, a viewer generated during double speed reproduction when the amount of data required by the AV reproducing unit is greater than the amount of data that can be supplied by the CD / SD reproducing unit during double speed reproduction. By dividing the detectable still picture into a small picture that cannot be detected by the viewer, it is advantageous to significantly improve the quality of the double speed play screen by inserting it into the double speed play screen.

Claims (2)

An RF reproducing unit for demodulating the RF signal reproduced in a predetermined track on a disc, and reproducing the data demodulated in the RF reproducing unit according to a corresponding format, and outputting a data preparation signal when a data block corresponding to a predetermined size is prepared. The size of the block to be input from the CD / SD playback unit by checking the state of the CD / SD playback unit, the last block played just before, and the VBR buffer, and then the start address and block size of the recognized block. Command to the CD / SD playback unit, and if the data demand amount during the double speed playback is larger than the data supply amount of the CD / SD playback unit, the speed is switched to the speed corresponding to the double speed playback or normal playback according to the amount of data stored in the VBR buffer. A variable transmission unit for outputting a data request signal to the variable transmission unit according to the screen reproduction speed, and according to the data request signal. An AV reproducing unit for decoding the video or audio signal output from the variable transmission unit and outputting the decoded image; And a servo unit for controlling pickup to move on a disc to a track containing a block recognized by the variable transfer unit. The apparatus of claim 1, wherein the variable transfer unit sets a unit buffer lower limit and a unit buffer upper limit in the VBR buffer, executes a double speed playback command, and consumes when data output according to the data request signal of the AV playback unit reaches a unit buffer lower limit. After switching to the normal playback command for a predetermined time to cover the data of the VBR buffer, and if the supplementary data reaches the unit buffer upper line again, it switches back to the double speed playback command and outputs data up to the unit buffer lower limit line. Disc variable transfer playback system for double speed playback.