Abstract: One aspect of the invention relates to a messaging communication scheme for controlling, configuring, monitoring and communicating with a signal processor within a Voice Over Packet (VoP) subsystem without knowledge of the specific architecture of the signal processor. The messaging communication scheme may feature the transmission of control messages between a signal processor and a host processor. Each control message comprises a message header portion and a control header portion. The control header portion includes at least a catalog parameter that indicates a selected grouping of control messages and a code parameter that indicates a selected operation of the selected grouping.

Abstract: Apparatus and methods are provided for encoding video data in a manner which significantly reduces the computation performed by the video encoder and the video decoder without suffering any degradation in the perceived quality of the compressed video data. In particular, apparatus and methods are provided for determining which blocks might be zeroed out after quantization. This determination is performed after motion estimation, the classification of the frame as either an I frame, P frame, or a B frame, and the determination of a quantization step size (QP) for the block, but before DCT. If a given block is determined to be a “zero” quantized block, then the DCT, quantization, zig-zag scan and variable length coding steps are omitted, and a variable length code output is provided indicating that the block B is a “zero” quantized block.

Abstract: A compression system and process employs a group of quantizers (or sets of predefined quantized values) and involes the selection of the quantizers for each video frame or frame portion. For each frame portion, a selection of the most appropriate quantizer is made. The selection of which quantizer from the selection group is most appropriate for coding of a video frame or frame portion is based on a formula which takes into account both the distortion (accuracy) and bit rate characteristics of each quantizer. The quantizer that exhibits the best combined distortion and bit rate characteristics is selected for coding the frame or frame portion. A similar formula, based on both distortion and bit rate characteristics, is used to select the particular quantization value within the quantizer set for each video signal value being coded.

Abstract: A compression system and process include adaptive quantization for selection of one quantizer, for each video frame or frame portion, from a group of quantizers, where each quantizer is a set of predefined quantizer values, and coding of the quantized values using a common entropy coding table for all quantizers, or a separate entropy coding table for each quantizer. The entropy coding tables are obtained during a training procedure. The selection of the quantizer is based on a formula which takes into account the distortion and bit rate characteristics of each quantizer. A similar formula, based on the distortion and bit rate characteristics, is used to select the particular quantizer value within the chosen quantizer for each video signal value being coded.

Abstract: A compression system and process include adaptive quantization for selection of one quantizer, for each video frame or frame portion, from a group of quantizers, where each quantizer is a set of predefined quantizer values, and coding of the quantized values using a common entropy coding table for all quantizers, or a separate entropy coding table for each quantizer. The entropy coding tables are obtained during a training procedure. The selection of the quantizer is based on a formula which takes into account the distortion and bit rate characteristics of each quantizer. A similar formula, based on the distortion and bit rate characteristics, is used to select the particular quantizer value within the chosen quantizer for each video signal value being coded.

Abstract: A compression system and process include adaptive quantization for selection of one quantizer, for each video frame or frame portion, from a group of quantizers, where each quantizer is a set of predefined quantizer values, and coding of the quantized values using a common entropy coding table for all quantizers, or a separate entropy coding table for each quantizer. The entropy coding tables are obtained during a training procedure. The selection of the quantizer is based on a formula which takes into account the distortion and bit rate characteristics of each quantizer. A similar formula, based on the distortion and bit rate characteristics, is used to select the particular quantizer value within the chosen quantizer for each video signal value being coded.

Abstract: A method and apparatus for compressing and transmitting variable amounts of video data in real time over a channel having a fixed bandwidth. A trellis having a plurality of nodes is provided. Each of the plurality of nodes has an associated quantization parameter and bit number. The bit number associated with each node corresponds to a quantity of bits consumed in reaching that node. For each of the plurality of blocks, a minimum path through the trellis is selected. A quantization parameter associated with the selected minimum path is selected. A number of bits is assigned to each of the plurality of blocks in accordance with the selected quantization parameter. A substantially fixed number of bits is distributed among the plurality of blocks which make up each of the plurality of frames in accordance with the selected quantization parameter.

Abstract: A technique for coding color components of video signals wherein a color component of an image signal sequence is filtered into a plurality of subband image signals. One or more pixels of a first subband image signal are coded using one or more bits of a first quantity of bits. The first subband image signal reflects an image structure of a color component of the image signal sequence. The first subband includes low spatial and temporal frequencies of the color component. A second quantity of bits is used for coding one or more pixels of a second subband image signal. This second quantity of bits comprises one or more bits of the first quantity of bits not used in coding pixels of the first subband image signal. One or more pixels of the second subband image signal are coded using one or more of the second quantity of bits. The second subband image signal reflects image object motion information of the color component of the image signal sequence.