Patents by Inventor Vincent Liu

Vincent Liu 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: 7418007
    Abstract: A statistical multiplexer for coding and multiplexing multiple channels of digital television data, or multiple panels of HDTV digital television data. A bit rate need parameter is determined for each encoder in a stat mux group, and an encoding bit rate is allocated to each channel based on its need parameter. A transmission bit rate is allocated to each channel as a time-lagged version of its need parameter to minimize a rate mismatch between the output and the input of a decoder buffer. A packet processor checks for impending decoder buffer overflow or underflow events to set minimum and maximum limits on the transmission bit rate. Moreover, these limits are set based on whether a new transmission bit rate can be implemented before the decoding time stamp (DTS) of the current or next frame.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: August 26, 2008
    Assignee: General Instrument Corporation
    Inventors: Vincent Liu, Siu-Wai Wu, Michael Casteloes, Robert J. Stone, Rebecca Lam
  • Patent number: 7251275
    Abstract: Methods and apparatus for statistical multiplexing in a dual pass encoding scheme are provided. A first pass encoder encodes alternate slices of anchor frames as I-slices and P-slices respectively in order to generate statistics for both I and P frame encoding for the same anchor frame. A second pass encoder determines the encoding complexity estimates for a plurality of frames in a look-ahead pipeline and sums the encoding complexity estimates of selective frames in the look-ahead pipeline to determine the initial need parameter for a current frame to be encoded. The second pass encoder computes a need parameter for encoding the current frame based on the initial need parameter. The need parameter is used by a statmux processor to determine the encoding bit rate for second pass encoding of the current frame.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: July 31, 2007
    Assignee: General Instrument Corporation
    Inventors: Siu-Wai Wu, Vincent Liu, Yong He
  • Publication number: 20060171878
    Abstract: The invention relates to a method for extracting hydrogen from a gas containing methane, especially natural gas. Hydrocarbons contained in the gas are catalytically broken down in a reformer (4) by steam in order to form hydrogen, carbon monoxide and carbon dioxide. Catalytic conversion of the obtained carbon monoxide with steam occurs in a downstream conversion step in order to form carbon monoxide and water. Carbon dioxide is removed from the converted gas flow (8) by gas washing (7), and the washed hydrogen-rich gas flow (10) is subsequently divided in a pressure-swing adsorption system (11) into a product gas flow (12) made of hydrogen and a waste gas flow (13). The waste gas flow (13) is introduced with hydrogen (14), which is separated from the gas flow (10) after gas washing, into a reformer (4) which is essentially a carbon-free combustible gas, and is combusted there. The invention also relates to a system for carrying out the method.
    Type: Application
    Filed: July 24, 2004
    Publication date: August 3, 2006
    Inventors: Michael Blumenfeld, Vincent Liu, Bernd Mielke, Marcus Michel
  • Patent number: 7068719
    Abstract: A mechanism for splicing advertisements, local programming and the like into a digital video transport stream is provided. In order to achieve proper splicing, an appropriate number of frames is inserted between bitstreams to properly close a GOP of the first bitstream into which a second bitstream carrying the spliced content is inserted. Program clock references (PCRs) of the bitstreams are adjusted as necessary in order to force continuity between the bitstreams. For inserting advertisements, the PCR of the program stream and ad stream can be tracked, and the PCR of the program stream can be used both before and after splicing. For local program insertion (which are typically substantially longer than advertisements), the PCR of the local program can be used, after adjustment thereof with an offset to maintain continuity at the splice point. The PTS and/or DTS of the inserted bitstream can be modified to keep them continuous at the splice point for both video and audio streams.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: June 27, 2006
    Assignee: General Instrument Corporation
    Inventors: Vincent Liu, Robert S. Nemiroff, Siu-Wai Wu
  • Patent number: 6989047
    Abstract: The invention relates to a process for the absorptive separation of NH3 and CH4 from a gas under high pressure, which at least contains NH3, H2, N2 and CH4, using a high-boiling, physically acting and regenerable solvent which contains homologues of alkylene glycol-alkyl-ether and which also may contain water, the absorbed components NH3, H2, N2 and CH4 being separated from the laden solvent in at least two further process steps at different pressure rates, thereby withdrawing at least one NH3-rich and at least one CH4-rich gas fraction from the solvent. This process is particularly suitable to be incorporated as unit in an ammonia production plant.
    Type: Grant
    Filed: April 5, 2002
    Date of Patent: January 24, 2006
    Assignee: Uhde GmbH
    Inventors: Michael Wyschofsky, Vincent Liu
  • Publication number: 20060007960
    Abstract: Method and apparatus for processing transport stream packets received from a network for distribution to user terminals is described. In one embodiment, a pair of clock reference packets in the transport stream packets is identified. The pair of clock reference packets includes a first clock reference packet having an output time stamp and a second clock reference packet. A difference between a time value of the second clock reference packet and a time value of the first clock reference packet is computed. An output time stamp for the second clock reference packet is calculated in response to the output time stamp of the first clock reference packet and the difference.
    Type: Application
    Filed: July 12, 2004
    Publication date: January 12, 2006
    Inventors: Vincent Liu, Robert Nemiroff, Guofei Wu
  • Patent number: 6961376
    Abstract: Methods and apparatus for rate control in a dual pass encoding scheme are provided. A first pass encoder encodes alternate slices of anchor frames as I-slices and P-slices respectively in order to generate statistics for both I and P frame encoding for the same anchor frame. An initial complexity estimate for encoding a current frame is determined by the first pass encoder based on statistics from first pass encoding of the current frame and from first pass encoding of a prior encoded frame. A second pass encoder estimates an encoding complexity for the current frame based on the initial complexity and statistics from second pass encoding of the prior encoded frame. The second pass encoder then determines a bit budget for second pass encoding of the current frame based on the encoding complexity.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: November 1, 2005
    Assignee: General Instrument Corporation
    Inventors: Siu-Wai Wu, Vincent Liu, Yong He
  • Publication number: 20050226276
    Abstract: A method and apparatus for switching a source of an audiovisual program configured for distribution among a plurality of user terminals is described. In one example, a first real-time digital bitstream and a second real-time digital bitstream are received. The source is mapped to the first real-time digital bitstream. A request is received from a remote controller. The request is operative to switch the source of the audiovisual program. The source of the audiovisual program is switched to the second real-time digital bitstream in response to the request. Time stamp data in the second real-time digital bitstream is adjusted to provide a continuous time base for the audiovisual program.
    Type: Application
    Filed: April 8, 2004
    Publication date: October 13, 2005
    Inventors: John Sanders, Guofei Wu, Yuan-Yuan Young, Vincent Liu
  • Patent number: 6904094
    Abstract: An efficient processing system, such as for transcoding video data. In an embodiment that is suitable for single or multiple processor embodiments, a processing mode is set for each input video frame, e.g., as a full transcode mode, which uses motion compensation, a requantization mode, which avoids motion compensation, or a bypass mode. The processing mode selection is based on a number of processing cycles that are available to process a frame, and an expected processing requirement of the frame. The bypass or requantization modes are selected to avoid a buffer overflow of the processor.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: June 7, 2005
    Assignee: General Instrument Corporation
    Inventors: Vincent Liu, Robert S. Nemiroff, Siu-Wai Wu, Ajay Luthra, Limin Wang
  • Publication number: 20050041689
    Abstract: An efficient statistical remultiplexer for processing a number of channels that include video data. In one aspect, transcoding of the video data is delayed while statistical information is obtained from the data. Bit rate need parameters for the data are determined based on the statistical information, and the video data is transcoded based on the respective bit rate need parameters following the delay. In another aspect, a transcoding bit rate for video frames is updated a plurality of times at successive intervals to allow a closer monitoring of the bit rate. Minimum and maximum bounds for the transcoding bit rate, e.g., for buffer overflow and underflow protection, are also updated in each interval.
    Type: Application
    Filed: September 20, 2004
    Publication date: February 24, 2005
    Applicant: General Instrument Corporation
    Inventors: Siu-Wai Wu, Robert Nemiroff, Vincent Liu, Ajay Luthra
  • Patent number: 6847656
    Abstract: An efficient statistical remultiplexer for processing a number of channels that include video data. In one aspect, transcoding of the video data is delayed while statistical information is obtained from the data. Bit rate need parameters for the data are determined based on the statistical information, and the video data is transcoded based on the respective bit rate need parameters following the delay. In another aspect, a transcoding bit rate for video frames is updated a plurality of times at successive intervals to allow a closer monitoring of the bit rate. Minimum and maximum bounds for the transcoding bit rate, e.g., for buffer overflow and underflow protection, are also updated in each interval. In another aspect, the pre-transcoding quantization scales of the macroblocks in a frame are scaled to provide corresponding new quantization scales for transcoding based on a ratio of a pre-transcoding amount of data in the frame and a target, post-transcoding amount of data for the frame.
    Type: Grant
    Filed: September 25, 2000
    Date of Patent: January 25, 2005
    Assignee: General Instrument Corporation
    Inventors: Siu-Wai Wu, Robert S. Nemiroff, Vincent Liu, Ajay Luthra
  • Patent number: 6804301
    Abstract: The invention relates to an improved system and method for encoding digital images within frames for digital television transmission. Every anchor frame in a first pass encoder is encoded as a P-frame. Groups of macroblocks, such as slices in the P-frame, are alternately encoded as I-slices and P-slices. This allows both I and P encoding complexity to be computed in a single pass, without having to encode the same frame twice. Accordingly, the I-frame decision can be made at a second pass encoder instead of at the first pass encoder, thus taking advantage of a look-ahead pipeline architecture to more effectively align the I-frames with scene changes.
    Type: Grant
    Filed: August 15, 2001
    Date of Patent: October 12, 2004
    Assignee: General Instrument Corporation
    Inventors: Siu-Wai Wu, Vincent Liu
  • Publication number: 20040139856
    Abstract: The invention relates to a process for the absorptive separation of NH3 and CH4 from a gas under high pressure, which at least contains NH3, H2, N2 and CH4, using a high-boiling, physically acting and regenerable solvent which contains homologues of alkylene glycol-alkyl-ether and which also may contain water, the absorbed components NH3, H2, N2 and CH4 being separated from the laden solvent in at least two further process steps at different pressure rates, thereby withdrawing at least one NH3-rich and at least one CH4-rich gas fraction from the solvent. This process is particularly suitable to be incorporated as unit in an ammonia production plant.
    Type: Application
    Filed: March 11, 2004
    Publication date: July 22, 2004
    Inventors: Michael Wyschofsky, Vincent Liu
  • Patent number: 6740258
    Abstract: Process and plant for the production of synthesis gas, hydrogen and/or reducing gas by means of a primary reformer heated on the shell side, used in conjunction with a pressure swing adsorption unit for purifying the product gas, the purpose of which is to find a solution to the problem of utilising the work potential of the fuel gas from the pressure swing adsorption unit, which is used to fire the primary gas reformer. This is achieved by supplying the waste desorption gas from the pressure swing adsorption unit to the inlet side of an ejector, which is driven by a part stream of the fuel gas for the primary reformer, the waste desorption gas being admixed to a main fuel gas stream and/or a regulating gas stream, depending on the particular mode of operation.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: May 25, 2004
    Assignee: Krupp Uhde GmbH
    Inventors: Michael Wyschofsky, Vincent Liu
  • Patent number: 6731685
    Abstract: A statistical multiplexer for coding and multiplexing multiple channels of digital television data, or multiple panels of HDTV digital television data. A bit rate need parameter is determined for each encoder in a stat mux group by scaling the complexities of previous pictures of the same and different picture types. Scaling factors based on an activity level, motion estimation score, and number of pictures of a certain type in a GOP, may be used. Moreover, the scaling factors may be bounded based on a linear or non-linear operator to prevent large variations in the factors. An encoding bit rate is allocated to each channel based on its need parameter.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: May 4, 2004
    Assignee: General Instrument Corporation
    Inventors: Vincent Liu, Siu-Wai Wu, Hanson On, Robert S. Nemiroff, Michael Casteloes, Jing Yang Chen, Rebecca Lam
  • Patent number: 6724825
    Abstract: A system for providing an accurate time reference for multiple input and output digital video signals of a transcoder that is particularly suited for use with MPEG data. The multiple streams are synchronized with a single master system time clock at the transcoder. Timing data from the master clock is compared to timing data from packets that are input to the transcoder to determine an offset. In particular, timing data, such as a program clock reference (PCR) field, is recovered from packets of different channels that are input to the transcoder. For each channel, timing data is then provided for packets that are output from the transcoder based on the offset and timing data of the master clock at the respective output times. In particular, the adjusted timing data is determined as a sum of the offset and an associated hardware error, less a delay (PcrSysDly) associated with the transcoder, which includes a lookahead delay and a buffer delay.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: April 20, 2004
    Assignee: General Instrument Corporation
    Inventors: Robert S. Nemiroff, Vincent Liu, Siu-Wai Wu
  • Patent number: 6694060
    Abstract: A controller allocates a bit size for a current frame in a group of pictures of a first compression-encoded digital video signal that is to be spliced following transmission of the group of pictures with a second compression-encoded digital video signal. The signals are spliced after a predetermined switching time. The spliced signals are buffered by a decoder buffer and then decoded by a decoder. When the second signal has a variable bit-encoding rate and the current frame is not decoded until after the predetermined switching time, the maximum bit size is determined in accordance with an estimate of the decoder buffer fullness at the predetermined switching time. When the second signal has a predetermined maximum variable bit-encoding rate and the current frame is not decoded until after the predetermined switching time, the minimum bit size is determined in accordance with the predetermined maximum bit-encoding rate of the second signal.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: February 17, 2004
    Assignee: General Instrument Corporation
    Inventors: Vincent Liu, Jingyang Chen, Siu-Wai Wu
  • Publication number: 20030235220
    Abstract: Methods and apparatus for statistical multiplexing in a dual pass encoding scheme are provided. A first pass encoder encodes alternate slices of anchor frames as I-slices and P-slices respectively in order to generate statistics for both I and P frame encoding for the same anchor frame. A second pass encoder determines the encoding complexity estimates for a plurality of frames in a look-ahead pipeline and sums the encoding complexity estimates of selective frames in the look-ahead pipeline to determine the initial need parameter for a current frame to be encoded. The second pass encoder computes a need parameter for encoding the current frame based on the initial need parameter. The need parameter is used by a statmux processor to determine the encoding bit rate for second pass encoding of the current frame.
    Type: Application
    Filed: June 25, 2002
    Publication date: December 25, 2003
    Applicant: General Instrument Corporation
    Inventors: Siu-Wai Wu, Vincent Liu, Yong He
  • Publication number: 20030235247
    Abstract: Methods and apparatus for rate control in a dual pass encoding scheme are provided. A first pass encoder encodes alternate slices of anchor frames as I-slices and P-slices respectively in order to generate statistics for both I and P frame encoding for the same anchor frame. An initial complexity estimate for encoding a current frame is determined by the first pass encoder based on statistics from first pass encoding of the current frame and from first pass encoding of a prior encoded frame. A second pass encoder estimates an encoding complexity for the current frame based on the initial complexity and statistics from second pass encoding of the prior encoded frame. The second pass encoder then determines a bit budget for second pass encoding of the current frame based on the encoding complexity.
    Type: Application
    Filed: June 25, 2002
    Publication date: December 25, 2003
    Applicant: General Instrument Corporation
    Inventors: Siu-Wai Wu, Vincent Liu, Yong He
  • Publication number: 20030081631
    Abstract: Methods and apparatus are provided for allocating bandwidth among members of two statistical multiplexing groups having overlapping members. At least two groups of such services having overlapping members are defined. The members of a first one of the groups consume a first bandwidth and the members of a second one of the groups consume a second bandwidth. A total bandwidth of all the members of the groups together is restricted to be no more than a total available bandwidth. In order to accomplish this, the members of the first and second groups are statistically multiplexed based on bandwidth requirements of members common to both said first and second groups.
    Type: Application
    Filed: October 4, 2002
    Publication date: May 1, 2003
    Applicant: General Instrument Corporation
    Inventors: Vincent Liu, Siu-Wai Wu, Ly Tran, Craig Cuttner