×

Interface apparatus and method for asynchronous encoding of digital television

  • US 4,479,142 A
  • Filed: 05/17/1982
  • Issued: 10/23/1984
  • Est. Priority Date: 05/17/1982
  • Status: Expired due to Term
First Claim
Patent Images

1. An interface for a video encoder arranged to output asynchronously DPCM encoded NTSC video and supplemental data in a T3 data format and rate for interfacing with encoded video sampled at an integer multiple of fsc where fsc is the color subcarrier frequency comprising:

  • a buffer with DPCM encoded video and video sync inputs, means to write video and video sync into said buffer in response to a sampling clock;

    timing circuit control means responsive to a T3 rate clock for producing a data read clock at a submultiple of said T3 rate clock;

    coupling means for coupling the data clock to said buffer for reading out said buffer memory at said data read clock rate to produce a data stream;

    sync detection means responsive to a sync signal read from said buffer for inhibiting said coupling means for a predetermined time;

    supplemental data generator means with an output coupled to a data multiplexing means for generating supplemental data;

    data multiplexing means responsive to video data read from said buffer and to supplemental data from said supplemental data generator means for outputting said video data and supplemental data in time sequence;

    whereby detection of a sync signal inhibits reading of said buffer for said predetermined time allowing insertion of said supplemental data.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×