公开(公告)号：NO912273D0

公开(公告)日：1991-06-13

申请号：NO912273

申请日：1991-06-13

Applicant: GEN INSTRUMENT CORP

Inventor： KRAUSE EDWARD A ,  PAIK WOO H ,  LIU VINCENT ,  ESSERMAN JIM

IPC: H03M7/30 ,  G06T9/00 ,  H04N7/26 ,  H04N7/32 ,  H04N7/36 ,  H04N7/50 ,  H04N

Abstract: A method and apparatus are provided for processing digital video signals for transmission in a compressed form. A set of pixel data is compressed without motion compensation to provide a first compressed video signal. The pixel data is compressed using motion compensation to provide a second compressed video signal. The data in the first and second compressed video signals is quantified. A comparison is made to determine which of the signals contains the least data. Successive sets of pixel data are sequentially compressed and quantified and the compressed video signal having the least data for each particular set is selected. The selected signals are encoded to identify them as motion compensated or non-motion compensated signals, and combined to provide a compressed video signal data stream for transmission. Apparatus for receiving and decoding the signals is also disclosed.

公开(公告)号：CA2421794C

公开(公告)日：2013-06-25

申请号：CA2421794

申请日：2001-09-04

Applicant: GEN INSTRUMENT CORP

Inventor： WU SIU-WAI ,  NEMIROFF ROBERT S ,  LIU VINCENT ,  LUTHRA AJAY

IPC: H04N21/2365 ,  H04N7/26 ,  H04N7/50 ,  H04N21/236

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 (110, 112, 200, 300) 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 of the macroblocks in a frame are scaled to provide corresponding new quantization scales for transcoding based on a ratio of pre-transcoding amount of data in the frame and a target, post-transcoding amount of data for the frame. The quantization scales are adjusted for different poritons of the frame as transcoding progresses to ensure that a minimum amount of transcoding bandwidth is allocated to each macroblock.

公开(公告)号：CA2365365C

公开(公告)日：2013-01-29

申请号：CA2365365

申请日：2001-12-18

Applicant: GEN INSTRUMENT CORP

Inventor： LIU VINCENT ,  CHEN JINGYANG ,  WU SIU-WAI

IPC: H04N7/26 ,  H04N7/50 ,  H04N21/44

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 buyer 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.

公开(公告)号：CA2396308C

公开(公告)日：2013-01-22

申请号：CA2396308

申请日：2002-07-29

Applicant: GEN INSTRUMENT CORP

Inventor： WU SIU-WAI ,  LIU VINCENT ,  HE YOUNG

IPC: H04N7/50 ,  H04J3/04 ,  H04N7/24 ,  H04N7/26 ,  H04N7/58

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 fox 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 fi~ame 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.

公开(公告)号：DE60131993D1

公开(公告)日：2008-01-31

申请号：DE60131993

申请日：2001-08-31

Applicant: GEN INSTRUMENT CORP

Inventor： LIU VINCENT ,  WU SIU-WAI ,  CASTELOES MICHAEL ,  STONE ROBERT J ,  LAM REBECCA

IPC: H04N7/26 ,  H04N21/234 ,  H04N21/2365 ,  H04N21/434 ,  H04N21/44

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.

公开(公告)号：CA2449124A1

公开(公告)日：2002-12-12

申请号：CA2449124

申请日：2002-05-14

Applicant: GEN INSTRUMENT CORP

Inventor： NEMIROFF ROBERT S ,  LIU VINCENT ,  WU SIU-WAI

IPC: H04N21/234 ,  H04N21/236 ,  H04N21/81 ,  H04N7/24 ,  H04N7/52

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 bitstream to properly close a GOP of the first bistream 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 betwee n the bistreams. For inserting advertisements, the PCR of the program stream a nd 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 an/or DTS of the inserted bistream can be modified to keep them continuous at the splice point for both video and audio streams. T he spliced bitstream is transcoded to maintain a desired output bit rate, and t o provide overflow/underflow protection of the video buffers.

公开(公告)号：CA2421794A1

公开(公告)日：2002-04-04

申请号：CA2421794

申请日：2001-09-04

Applicant: GEN INSTRUMENT CORP

Inventor： LUTHRA AJAY ,  LIU VINCENT ,  NEMIROFF ROBERT S ,  WU SIU-WAI

IPC: H04N7/26 ,  H04N7/50 ,  H04N21/236 ,  H04N21/2365 ,  H04N7/58 ,  H04N7/24

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 ne ed parameters for the data are determined based on the statistical information, and the video data is transcoded (110, 112, 200, 300) based on the respectiv e bit rate need parameters following the delay. In another aspect, a transcodi ng 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 of the macroblocks in a frame are scaled to provide corresponding new quantization scales for transcoding based on a ratio of pre-transcoding amount of data in the frame and a target , post-transcoding amount of data for the frame. The quantization scales are adjusted for different poritons of the frame as transcoding progresses to ensure that a minimum amount of transcoding bandwidth is allocated to each macroblock.

公开(公告)号：DE69422654T2

公开(公告)日：2000-08-17

申请号：DE69422654

申请日：1994-03-23

Applicant: GEN INSTRUMENT CORP

Inventor： DEROVANESSIAN HENRY ,  LIU VINCENT

IPC: H03M7/40 ,  H04B1/66 ,  H04N7/26

Abstract: A variable length codeword packer (Fig. 3) communicates codeword data in successive m-bit bytes. A binary sum is accumulated (86) indicative of a total number of codeword bits received over time. A byte pointer (90) is derived from at least one most significant bit of the binary sum. A bit pointer (92) is derived from a plurality of least significant bits of the binary sum. A first data storage array (20) has a plurality of m-bit first storage bytes and is responsive to the byte pointer for storing received codeword data in the first storage bytes. A second data storage array (22) has a plurality of m-bit second storage bytes and is responsive to the byte and bit pointers for filling the second storage bytes with codeword data from the first data storage array (20). m-bit bytes of codeword data (25) are output from each filled second storage byte to provide successive m-bit bytes of codeword data. The use of a multistage approach in packing variable length codewords substantially reduces the complexity as compared to single stage designs.

公开(公告)号：ES2133274T3

公开(公告)日：1999-09-16

申请号：ES91108087

申请日：1991-05-18

Applicant: GEN INSTRUMENT CORP

Inventor： KRAUSE EDWARD A ,  PAIK WOO H ,  LIU VINCENT ,  ESSERMAN JIM

IPC: H03M7/30 ,  G06T9/00 ,  H04N7/26 ,  H04N7/32 ,  H04N7/36 ,  H04N7/50

Abstract: A method and apparatus are provided for processing digital video signals for transmission in a compressed form. A set of pixel data is compressed without motion compensation to provide a first compressed video signal. The pixel data is compressed using motion compensation to provide a second compressed video signal. The data in the first and second compressed video signals is quantified. A comparison is made to determine which of the signals contains the least data. Successive sets of pixel data are sequentially compressed and quantified and the compressed video signal having the least data for each particular set is selected. The selected signals are encoded to identify them as motion compensated or non-motion compensated signals, and combined to provide a compressed video signal data stream for transmission. Apparatus for receiving and decoding the signals is also disclosed.

公开(公告)号：HK1013758A1

公开(公告)日：1999-09-03

申请号：HK98115012

申请日：1998-12-23

Applicant: GEN INSTRUMENT CORP

Inventor： PAIK WOO H ,  KRAUSE EDWARD A ,  LIU VINCENT ,  SHEN PAUL ,  DEROVANESSIAN HENRY

IPC: H04N1/41 ,  G06T9/00 ,  H04N7/08 ,  H04N7/081 ,  H04N7/58 ,  H04N19/00 ,  H04N21/2365 ,  H04N21/434 ,  H04N

Abstract: A multichannel image compression system uses a plurality of encoders (10, 12 ... 14) to compress image data. A coding level command is provided to each of the encoders to specify a level of quality to be provided by each encoder. Encoded image data, provided by the encoders in response to the coding level command, is multiplexed (26) into a combined signal for transmission. The coding level command is adjusted in response to an accumulated amount of data from the combined signal, to maintain the accumulated data within a throughput capability of a communication channel (48). Although the coding level command may specify a global coding level that is the same for all of the encoders, the encoders can derive local coding levels from the global coding level to provide different encoding qualities. Decoder apparatus (30-46) is provided to recover an image from the compressed image data.