Patents by Inventor Junchen Du

Junchen Du 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: 7895250
    Abstract: The disclosure describes a method for performing a fixed point calculation of a floating point operation (A // B) in a coding device, wherein A // B represents integer division of A divided by B rounded to a nearest integer. The method may comprise selecting an entry from a lookup table (LUT) having entries generated as an inverse function of an index B, wherein B defines a range of values that includes every DC scalar value and every quantization parameter associated with a coding standard, and calculating A // B for coding according to the coding standard based on values A, B1 and B2, wherein B1 and B2 comprise high and low portions of the selected entry of the LUT. The techniques may simplify digital signal processor (DSP) implementations of video coders, and are specifically useful for MPEG-4 coders and possibly others.
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: February 22, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Shu Xiao, Junchen Du, Tao Shen
  • Publication number: 20100086057
    Abstract: Techniques for reducing bus traffic during texture decoding of a video bitstream are provided. In one configuration, a wireless communication device (e.g., cellular phone, etc.) comprises a processor configured to execute instructions operative to decode and separate in a bitstream macroblock (MB) information and residual packet data. The residual packet data is used to generate codec-independent non-zero MB-packets having a universal order that is codec independent. The codec-independent non-zero MB-packets and MB information are then used for reconstructing pixels of a respective frame of the video bitstream.
    Type: Application
    Filed: October 8, 2008
    Publication date: April 8, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Shu Xiao, Junchen Du
  • Publication number: 20060282237
    Abstract: The disclosure describes a method for performing a fixed point calculation of a floating point operation (A // B) in a coding device, wherein A // B represents integer division of A divided by B rounded to a nearest integer. The method may comprise selecting an entry from a lookup table (LUT) having entries generated as an inverse function of an index B, wherein B defines a range of values that includes every DC scalar value and every quantization parameter associated with a coding standard, and calculating A // B for coding according to the coding standard based on values A, B1 and B2, wherein B1 and B2 comprise high and low portions of the selected entry of the LUT. The techniques may simplify digital signal processor (DSP) implementations of video coders, and are specifically useful for MPEG-4 coders and possibly others.
    Type: Application
    Filed: May 25, 2005
    Publication date: December 14, 2006
    Inventors: Shu Xiao, Junchen Du, Tao Shen
  • Patent number: 6845135
    Abstract: An improved cascaded biquad infinite impulse response (IIR) filter structure is provided. The IIR filter of the invention may be implemented in a digital signal processor (DSP) such as a very long instruction word (VLIW) type DSP, as well as other processing circuitry, e.g., an integrated circuit. The new filter structure, among other advantages, overcomes the bottleneck condition known to occur in the updating operation of the w2(n?1) state of a conventional cascaded biquad IIR filter. In one illustrative implementation of the invention, this is accomplished by adding a single 32-bit intermediate state thus providing a cascaded biquad IIR filter structure such that the w2(n?1) state may be updated one clock cycle earlier. Thus, in a StarCore SC140 DSP example where a corresponding conventional cascaded biquad IIR filter structure executes at seven cycles per input sample, the improved cascaded biquad IIR filter structure of the present invention executes at six cycles per input sample.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: January 18, 2005
    Assignee: Agere Systems Inc.
    Inventor: Junchen Du
  • Publication number: 20020126750
    Abstract: An improved cascaded biquad infinite impulse response (IIR) filter structure is provided. The IIR filter ofthe invention may be implemented in a digital signal processor (DSP) such as a very long instruction word (VLIW) type DSP, as well as other processing circuitry, e.g., an integrated circuit. The new filter structure, among other advantages, overcomes the bottleneck condition known to occur in the updating operation of the w2(n-1) state of a conventional cascaded biquad IIR filter. In one illustrative implementation of the invention, this is accomplished by adding a single 32-bit intermediate state thus providing a cascaded biquad IIR filter structure such that the w2(n-1) state may be updated one clock cycle earlier. Thus, in a StarCore SC 140 DSP example where a corresponding conventional cascaded biquad IIR filter structure executes at seven cycles per input sample, the improved cascaded biquad IIR filter structure of the present invention executes at six cycles per input sample.
    Type: Application
    Filed: January 22, 2001
    Publication date: September 12, 2002
    Inventor: Junchen Du