Patents by Inventor Thomas Lookabaugh

Thomas Lookabaugh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5828414
    Abstract: A method and apparatus for reducing program clock reference (PCR) jitter in transport packets of a transport stream compliant with MPEG-2 or another suitable audio-video encoding standard. The PCRs from a given single program transport stream (SPTS) of a multi-program transport stream are processed in a phase-locked loop (PLL) to generate dejittered PCRs for that SPTS. The PLL for a given SPTS receives as inputs the PCRs from that SPTS and a cycle count for each PCR indicative of the number of asynchronous clock cycles counted since the previous PCR. The PLL generates a given dejittered PCR as a function of the previous dejittered PCR, the cycle count for the given PCR, and a clock frequency mismatch estimate for the given program clock. The clock frequency mismatch estimate is generated by filtering a sequence of jitter estimates, each corresponding to the difference between a previous PCR and its corresponding dejittered PCR.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: October 27, 1998
    Assignee: Divicom, Inc.
    Inventors: Michael G. Perkins, Thomas Lookabaugh