KR950007415A - Video and Audio Signal Synchronizer of MPEG Decoding System - Google Patents

Abstract

The present invention is an apparatus for synchronizing video and audio signals in an MPEG decoding system.

The present invention as described above receives and decodes a bit stream of video and audio signals in a moving picture expert group (MPEG) system in which the frame order is transmitted, and synchronizes the decoded video and audio signals. A demultiplexer (DMUX) 60 that receives the bit stream and extracts video and audio frames, and extracts time information and frame interval values at which the video and audio are to be displayed, and from the DMUX 60. A buffer means 70 and 80 for temporarily receiving the extracted video and audio frame bit stream for a predetermined time, and a system clock extracted from the DMUX 60 to provide a reference time of the MPEG system. a video performance time for storing a system time clock (STC) 90 initialized by a referennce and a display time value of the video extracted from the DMUX 60; A video presentation time stamp register (VPTSR) 100 and an audio presentation time stamp register APTSR 110 for storing a performance time value of the voice extracted from the DMUX 60; Compare the system time clock value 91 output from the system time clock 90 and the register 100 with the display time value 101 of the image, or output the system time clock 90 and the register 110. Comparing means 120 and 130 for generating a predetermined pulse when the system time clock value 91 is compared with the playing time value 111 of the voice, and the output 121 of the comparing means 120. Is generated when a predetermined pulse generator is generated, and counting is continued from this initial moment to generate a strobe signal by generating a pulse once per frame interval value provided from the DMUX 60. Reminiscent of Im interval occurs (video time interval generator; VTIG) means 140, and is initialized when a predetermined pulse is generated at the output 131 of the comparison means 130, the frame interval value provided from the DMUX 60 by continuously performing the initialized instantaneous coefficient Decodes the video and audio frames passing through the audio time interval generator (ATIG) means 150 and the buffer means 70 and 80. And video and audio decoder means 160 and 170 for outputting video and audio frames by pulses provided by the predetermined frame interval values from the generators 140 and 150. .

Therefore, in the MPEG decoding system, the frame order is changed and the video (screen) transmitted and the audio signal are synchronized so that a higher quality video and audio can be viewed.

Description

Video and Audio Signal Synchronizer of MPEG Decoding System

Since this is an open matter, no full text was included.

1 is a diagram illustrating a display and decoding sequence of a frame in an MPEG system;

2 is a schematic block diagram of a conventional MPEG decoding system;

3 (a) and (b) show video and audio decoding and display procedures of a conventional MPEG decoding system;

4 is a diagram showing an MPEG decoding system according to the present invention;

FIG. 5 is a diagram showing a video and audio decoding order and a display order realized through the preferred embodiment of the present invention of FIG.

Claims (6)

Receives and decodes a bit stream of video and audio signals in a moving picture expert group (MPEG) system in which video frame order is changed, and synchronizes the decoded video and audio signals. A demultiplexer (DMUX) 60 which receives and extracts a video and audio frame, and extracts time information and a frame interval value at which the video and audio are to be displayed; Buffer means (70) and (80) for temporarily accommodating video and audio frames extracted from the DMUX (60) for a predetermined time; A system sound clock (STC) 90 initialized and operated by a system clock reference extracted from the DMUX 60 to provide a reference time of the MPEG system; An audio time interval generator for generating a strobe signal and a video presentation time stamp register (VPTSR) 100 for storing a display time value of an image extracted from the DMUX 60; ATIG) means 150; After decoding the video and audio frames passing through the buffer means 70 and 80, the video and audio are decoded by the pulses provided by the predetermined frame interval values from the generators 140 and 150. And a video and audio decoder means (160) (170) for outputting a voice frame. The MPEG decoding system of claim 1, wherein the DMUX 60 adjusts the system time clock by extracting a system clock reference (SCR) signal, which is reference time information, from the received bit stream. Video and audio signal synchronizer. 2. The apparatus of claim 1, wherein the VTIG (140) and the VTIG means (150) comprise a programmable counter. The apparatus of claim 1, wherein the frame interval value provided from the DMUX (60) is provided to the VTIG (140) and the ATIG means (150) at system startup. The display apparatus of claim 1, wherein the DMUX 60 stores the display time values of the video and audio in the registers 100 and 110 again when a special effect such as a freeze occurs during operation. 140) and ATIG means (150) is re-initialized video and audio signal synchronization device of the MPEG decoding system. The DMUX 60 sends the image display value and the voice generation time value back to the registers 100 and 110 after a predetermined time in order to match the display time and the voice generation time of the image during operation. And a video and audio signal synchronization device of an MPEG decoding system. ※ Note: The disclosure is based on the initial application.