Synchronous compression and reconstruction system

• US 5,508,816 A
• Filed: 10/07/1993
• Issued: 04/16/1996
• Est. Priority Date: 10/07/1992
• Status: Expired due to Term

• Current Assignee: NEC Personal Computers, Ltd. (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Ueda, Hiroaki, Niwa, Yushi, Matsumoto, Hidehiro
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Chevalier, Robert
• Application Number:
  US08/133,219
• Time in Patent Office: 922 Days
• Field of Search: 358/343, 358/341, 358/335, 358/342, 348/515, 348/423, 348/384, 360/19.1
• US Class Current: 386/355
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/4325 by playing back content from the storage medium reproduction of recorded television signals H04N5/76; reproduction of recorded television signals H04N9/79
• CPC Class Codes: H04N 5/781 on disks or drums
• CPC Class Codes: H04N 7/24 Systems for the transmission of television signals using pulse code modulation H04N21/00 takes precedence
• CPC Class Codes: H04N 7/54 the signals being synchronous H04N21/23602, H04N21/23614, H04N21/2365, H04N21/2368, H04N21/4341, H04N21/4342, H04N21/4347, H04N21/4348 take precedence
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

A synchronous compression system for compressing input video data and audio data with establishing synchronization therebetween, comprises video data compressing circuit for compressing each of first to nth blocks where n is an integer greater than or equal to two in order of the first block to the nth block, audio data compressing circuit for compressing input audio data for one frame, interruption control circuit for controlling to interrupt video data compression when video data compression process is delayed with respect to audio data compression process with reference to frame numbers of those currently compressed in the video data compressing circuit and the audio data compressing circuit.

Claims

1. A synchronous reconstruction system for synchronously decoding and reconstructing digitally coded video data and audio data, comprising:

storage means for preliminarily storing the digitally coded video and audio data;

video data reconstructing means for decoding and reconstructing the digitally coded video data per a predetermined data amount;

audio data reconstructing means for decoding and reconstructing the audio data.;

transfer control means for reading out said digitally coded video data and audio data from said storage means and transferring the read out digitally coded video data and audio data to said video data reconstructing means and said audio data reconstructing means, respectively; and

control means responsive to a completion of both of a video reconstruction process of said video data reconstructing means and an audio reconstruction process of said audio data reconstructing means for controlling a modification of an initiation timing of said video data reconstructing means and an image display period after said video reconstruction process,

wherein said control means comprises;

time measuring means in response to completion of one of said video reconstruction process and said audio reconstruction process for initiating measurement of an elapsed time and terminating said measurement of said elapsed time in response to said completion of both of said video reconstruction process and said audio reconstruction process;

means, responsive to termination of said measurement of the elapsed time by said time measuring means, for deriving a process speed difference between said video reconstruction process and said audio reconstruction process with reference to the elapsed time; and

means for controlling said modification of said initiation timing of said video data reconstructing means or said image display period of video data after said video reconstruction process depending upon the processing speed difference.

2. A synchronous reconstruction system as set forth in claim 1, wherein said control means detects a completion of said audio reconstruction process for a given amount of audio data within a predetermined unit period of said audio data reconstructing means and detects a completion of said video reconstruction process for a given video data amount to be reproduced by said video data reconstructing means.

3. A synchronous reconstruction system as set forth in claim 2, wherein said control means controls to expand or shorten the image display period for the video data per data unit following the given video data amount to be reproduced within said unit period when the processing speed difference is smaller than or equal to a given value.

4. A synchronous reconstruction system as set forth in claim 3, wherein said control means controls thinning or holding of the video data per data unit following the given video data amount to be reproduced within said unit period when the processing speed difference is greater than a given value.

5. A synchronous reconstruction system as set forth in claim 2, wherein said control means controls thinning or holding of the video data per data unit following the given video data amount to be reproduced within said unit period when the processing speed difference is greater than a given value.