Abstract: A dual-pass rate control video encoder including a first pass encoder module configured to receive uncompressed input video including a sequence of pictures, the input video including a plurality of contiguous sequences of pictures each referred to as a Group of Pictures (GOP) that, when coded, begin with an I-picture in display order and end with a last picture before a next I-picture, detect scene changes within the input video. The dual-pass rate control video encoder including a second pass encoder module configured to receive the uncompressed input video via a delay unit.

Abstract: A dual-pass rate control video encoder including a first pass encoder module configured to receive uncompressed input video including a sequence of pictures, the input video including a plurality of contiguous sequences of pictures each referred to as a Group of Pictures (GOP) that, when coded, begin with an I-picture in display order and end with a last picture before a next I-picture, detect scene changes within the input video. The dual-pass rate control video encoder including a second pass encoder module configured to receive the uncompressed input video via a delay unit.

Abstract: A method of dual-pass rate control video encoding and an encoder are disclosed. Uncompressed input video is received with a video encoder. First pass encoding is performed, and a second pass encoding is performed with the video encoder at a delay relative to the first pass. The first pass encoding detects scene changes within the input video, assigns macroblocks to a pre-determined number of activity classes, and determines a complexity of each picture within the sequence of pictures. Information from the first pass encoding concerning the scene changes, the activity classes, and the complexity are used for rate control determined in second pass encoding for producing and outputting a bit stream of compressed video. During at least one of the first pass and second pass encoding, boundaries of at least some of the GOPs are adjusted to be aligned with the scene changes.

Abstract: A method of operating a multi-processor video encoder by determining a target size corresponding to a preferred number of bits to be used when creating an encoded version of a picture in a group of sequential pictures making up a video sequence. The method includes the steps of calculating a first degree of fullness of a coded picture buffer at a first time, operating on the first degree of fullness to return an estimated second degree of fullness of the coded picture buffer at a second time, and operating on the second degree of fullness to return an initial target sized for the picture. The first time corresponds to the most recent time an accurate degree of fullness of the coded picture buffer can be calculated and the second time occurs after the first time.

Abstract: A method of dual-pass rate control video encoding and an encoder are disclosed. Uncompressed input video is received with a video encoder. First pass encoding is performed, and a second pass encoding is performed with the video encoder at a delay relative to the first pass. The first pass encoding detects scene changes within the input video, assigns macroblocks to a pre-determined number of activity classes, and determines a complexity of each picture within the sequence of pictures. Information from the first pass encoding concerning the scene changes, the activity classes, and the complexity are used for rate control determined in second pass encoding for producing and outputting a bit stream of compressed video. During at least one of the first pass and second pass encoding, boundaries of at least some of the GOPs are adjusted to be aligned with the scene changes.

Abstract: Information needed to generate an encoded version of a matrix of j transform coefficients c0 . . . cj?1 representing a block of digital video data is determined by forming a numerical signature ? of the matrix and looking up a value for the information needed in an array employing the signature ? as an index to the array.

Abstract: A method of dual-pass rate control video encoding and an encoder are disclosed. Uncompressed input video is received with a video encoder. First pass encoding is performed, and a second pass encoding is performed with the video encoder at a delay relative to the first pass. The first pass encoding detects scene changes within the input video, assigns macroblocks to a pre-determined number of activity classes, and determines a complexity of each picture within the sequence of pictures. Information from the first pass encoding concerning the scene changes, the activity classes, and the complexity are used for rate control determined in second pass encoding for producing and outputting a bit stream of compressed video. During at least one of the first pass and second pass encoding, boundaries of at least some of the GOPs are adjusted to be aligned with the scene changes.

Abstract: A method of dual-pass rate control video encoding and an encoder are disclosed. Uncompressed input video is received with a video encoder. First pass encoding is performed, and a second pass encoding is performed with the video encoder at a delay relative to the first pass. The first pass encoding detects scene changes within the input video, assigns macroblocks to a pre-determined number of activity classes, and determines a complexity of each picture within the sequence of pictures. Information from the first pass encoding concerning the scene changes, the activity classes, and the complexity are used for rate control determined in second pass encoding for producing and outputting a bit stream of compressed video. During at least one of the first pass and second pass encoding, boundaries of at least some of the GOPs are adjusted to be aligned with the scene changes.

Abstract: A method of operating a multi-processor video encoder by determining a target size corresponding to a preferred number of bits to be used when creating an encoded version of a picture in a group of sequential pictures making up a video sequence. The method includes the steps of calculating a first degree of fullness of a coded picture buffer at a first time, operating on the first degree of fullness to return an estimated second degree of fullness of the coded picture buffer at a second time, and operating on the second degree of fullness to return an initial target sized for the picture. The first time corresponds to the most recent time an accurate degree of fullness of the coded picture buffer can be calculated and the second time occurs after the first time.

Abstract: A method of operating a multi-processor video encoder by determining a target size corresponding to a preferred number of bits to be used when creating an encoded version of a picture in a group of sequential pictures making up a video sequence. The method includes the steps of calculating a first degree of fullness of a coded picture buffer at a first time, operating on the first degree of fullness to return an estimated second degree of fullness of the coded picture buffer at a second time, and operating on the second degree of fullness to return an initial target sized for the picture. The first time corresponds to the most recent time an accurate degree of fullness of the coded picture buffer can be calculated and the second time occurs after the first time.

Abstract: Information needed to generate an encoded version of a matrix of j transform coefficients c0 . . . cj?1 representing a block of digital video data is determined by forming a numerical signature ? of the matrix and looking up a value for the information needed in an array employing the signature ? as an index to the array.

Abstract: Information needed to generate an encoded version of a matrix of j transform coefficients c0 . . . cj?1 representing a block of digital video data is determined by forming a numerical signature ? of the matrix and looking up a value for the information needed in an array employing the signature ? as an index to the array.

Abstract: A method of splicing video content from a secondary encoded video stream into a primary encoded video stream, the method including the steps of identifying a splice out-time tout and a splice in-time tin, at least T time after tout, in the primary stream; causing the fullness of primary encoder's virtual buffer to be less than XB, where X is greater than 0 and less than 1, at the first decode times after tout and tin; encoding the secondary stream such that an initial coded picture is transmitted in no more than B/(XR) time, and encoding the second stream such that, at a final coded picture's decode time, the fullness of the secondary encoder's virtual buffer is less than XB; and replacing video content of the primary stream from tout through tout+T, with the video data of the second stream.

Abstract: A switched digital video distribution infrastructure for selectively distributing transport streams each composed of encoded pictures for decoding and presentation employs a source apparatus to output a first program to a requesting destination device as a constrained bit rate transport stream, receive a program change request from the requesting destination device, and in response to the program change request, output a second program both as an unconstrained variable bit rate stream and as a constrained bit rate transport stream. The requesting destination device decodes the unconstrained variable bit rate transport stream, loads the second program's constrained bit rate transport stream into a decoder buffer until the decoder buffer contains sufficient data to allow the pictures of the second program's constrained bit rate transport stream to be decoded without the decoder buffer running dry.

Abstract: A constant bit rate single program encoded transport stream is demultiplexed from a statistically multiplexed MPEG transport stream by separating a variable bit rate program from the multiplexed MPEG transport stream, loading the sequence of pictures that form the variable bit rate program into a smoothing buffer at a rate that does not exceed a desired constant bit rate and transferring the picture from the smoothing buffer at times indicated by decode time stamps associated with the pictures respectively. If a picture of the sequence becomes available no later than a specified amount of time prior to the picture's decode time stamp, then that picture is loaded into the smoothing buffer commencing the specified amount of time prior to the time indicated by the picture's decode time stamp. If a picture of the sequence becomes available later than the specified amount of time prior to the picture's decode time stamp, then that picture is loaded into the smoothing buffer as soon as possible.

Abstract: Variation in delay in transmission of data from a transmitting station to a receiving station is measured by encapsulating a portion of the data and an outgoing time stamp in a packet, the outgoing time stamp substantially representing the degree of progression of a periodic process at the time of including the outgoing time stamp in the packet. The packet is transmitted from the transmitting station and is received at the receiving station. At the receiving station, an incoming time stamp is added to the packet. The incoming time stamp substantially represents the degree of progression of a periodic process at the time of adding the incoming time stamp to the packet. The incoming time stamp is compared to the outgoing time stamp.

Abstract: A rate and delivery time multiplexing for bandwidth optimization algorithm has an allocation portion and a transrating portion. The allocation portion determines how many bits are available for each group of pictures in each program stream that is to be inserted into an outgoing MPEG Transport Stream (MTS). Based upon the allocated bits the transrating portion, when necessary, further compresses the program streams either in the compressed domain when rate reduction is minimal or in the pixel domain when rate reduction is significant. The result is the ability to transmit more video program streams over a given fixed bandwidth pipe for a given level of acceptable picture degradation.

Abstract: Variation in delay in transmission of data from a transmitting station to a receiving station is measured by encapsulating a portion of the data and an outgoing time stamp in a packet, the outgoing time stamp substantially representing the degree of progression of a periodic process at the time of including the outgoing time stamp in the packet. The packet is transmitted from the transmitting station and is received at the receiving station. At the receiving station, an incoming time stamp is added to the packet. The incoming time stamp substantially represents the degree of progression of a periodic process at the time of adding the incoming time stamp to the packet. The incoming time stamp is compared to the outgoing time stamp.

Abstract: A compressed video and audio transport stream multiplexer pre-builds a multiplex pattern in microprocessor local memory using a microprocessor with a DMA controller. The transport stream headers, a null packet, program specific information tables and packetized elementary stream buffers accessed by an assembly buffer that has DMA control blocks, two blocks per transport stream packet. The DMA control blocks are built and loaded into the assembly buffer based upon the number of packets required for the packetized elementary streams and program specific information according to the multiplex pattern. Packetized elementary stream data is received from respective sources and loaded into the packetized elementary stream buffers, and then output according to the DMA control blocks in the assembly buffer to form the transport stream.

Abstract: Time warping for video viewing is achieved by providing a random access dynamic buffer for a video signal from a selected video channel. The video signal is continuously written into the dynamic buffer in a recirculating fashion, and may be read out on a random access basis so that the viewer may control the realtime video viewing in the same manner as controlling a video cassette recorder up to the duration of the video signal stored in the dynamic buffer. In addition the viewer may view the video at various speeds and skip to any point in the stored information. Portions of the video signal in the dynamic buffer may be stored in a static buffer or transferred permanently to a video cassette recorder for subsequent manipulation by the viewer. To expand the capacity of the dynamic buffer a compression circuit may be provided for compressing the video signal before being written into the dynamic buffer.