Patents by Inventor John T. Dowdal

John T. Dowdal 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: 7924704
    Abstract: A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. A voice playout unit in the receiver shares its nominal delay buffer with a history buffer of a packet loss concealment algorithm up to a maximum limit described in a standard. This reduces or eliminates need to allocate memory for the history buffer. A history buffer can also be extended to retain an original portion of voice signal packets received prior to a packet loss as well as generated voice signals as they are generated. A scratch buffer is used as a working buffer and replaces the function of a pitch buffer.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: April 12, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: John T. Dowdal, Sachin Adlakha, Dunling Li
  • Publication number: 20090310603
    Abstract: A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. A voice playout unit in the receiver shares its nominal delay buffer with a history buffer of a packet loss concealment algorithm up to a maximum limit described in a standard. This reduces or eliminates need to allocate memory for the history buffer. A history buffer can also be extended to retain an original portion of voice signal packets received prior to a packet loss as well as generated voice signals as they are generated. A scratch buffer is used as a working buffer and replaces the function of a pitch buffer.
    Type: Application
    Filed: August 24, 2009
    Publication date: December 17, 2009
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: John T. Dowdal, Sachin Adlakha, Dunling Li
  • Patent number: 7590047
    Abstract: A method to reduce memory requirements for a packet loss concealment algorithm in the event of packet loss in a receiver of pulse code modulated voice signals. A voice playout unit in the receiver shares its nominal delay buffer with a history buffer of a packet loss concealment algorithm up to a maximum limit described in a standard. This reduces or eliminates need to allocate memory for the history buffer. A history buffer can also be extended to retain an original portion of voice signal packets received prior to a packet loss as well as generated voice signals as they are generated. A scratch buffer is used as a working buffer and replaces the function of a pitch buffer.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: September 15, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: John T. Dowdal, Sachin Adlakha, Dunling Li
  • Patent number: 7386447
    Abstract: An overflow problem of LSF quantization in G.729 Annex B speech encoding which may lead to non-assignment of a codebook index. Preferred embodiments fix the problem with default or limited random variable assignments or flagging the overflow and adjusting the frame encoding such as by limiting spectral components or changing quantization targets.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: June 10, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Dunling Li, Gokhan Sisli, John T. Dowdal, Zoran Mladenovic
  • Publication number: 20030135363
    Abstract: An overflow problem of LSF quantization in G.729 Annex B speech encoding. Preferred embodiments fix the problem with default or limited random variable assignments or flagging the overflow and adjusting the frame encoding such as by limiting spectral components or changing quantization targets.
    Type: Application
    Filed: November 4, 2002
    Publication date: July 17, 2003
    Inventors: Dunling Li, Gokhan Sisli, John T. Dowdal, Zoran Mladenovic