Abstract: A block of a frame of a video stream can be encoded using lossless coding that generates a transform domain residual block and a spatial domain difference block. The compression ratio of the coding may be improved by selecting an optimal quantization value on a per-block basis. The optimal quantization value can be selected by quantizing a residual block resulting from prediction of the block using a plurality of candidate quantization values and selecting the candidate quantization value that results in the fewest number of bits for the quantized residual block.

Abstract: A method for encoding a frame having a plurality of blocks in a video stream using transform-domain intra prediction is disclosed. The method includes generating, using a two-dimensional transform, a set of transform coefficients for a current block; generating, using a one-dimensional transform, a set of transform coefficients for previously coded pixel values in the frame; determining, using the set of transform coefficients for the previously coded pixel values, a set of transform coefficients for a prediction block; determining a residual based on the difference between the set of transform coefficients for the current block and the set of coefficients for the prediction block; and encoding the residual.

Abstract: Encoding and decoding a video image having a plurality of frames using a two-step quantization and coding process are disclosed. A block of a frame are encoded by identifying pixels having certain spatial characteristics, forming a second block from the block while replacing the identified pixels with a single pixel value, such as an average of the remaining original pixels. The second block is encoded, such as by transformation and quantization, and placed into a bitstream. The second block is decoded and subtracted from the original block to generate a difference block. The difference block is encoded, such as by quantization, and is placed in the bitstream. At a decoder, both blocks are decoded and combined to reconstruct the original block.

Abstract: Encoding and decoding is accomplished herein using a multi-reference picture buffer. Reference frames are assigned to reference picture buffers when used for encoding and are identified with picture IDs unique relative to other picture IDs currently associated with the reference picture buffers. The maximum picture number used as the picture ID can be based on a number of reference picture buffers available to encode and decode the frames plus a value based on an expected error rate. The picture IDs can be assigned based on a least recently used policy. When a reference frame is no longer needed for encoding and decoding, a picture ID number associated with the reference frame can be released for re-assignment to a new reference frame.

Abstract: A method for decreasing end-to-end delay in a video conferencing context is disclosed. At video conferencing system startup, a processor is initialized to receive either a top field or a bottom field of video frame data. If the first line of a new field arriving after initialization does not match a field state that the processor is initialized to, the present invention senses the state mismatch and adjusts a display buffer by one display line, and the field is stored in the display buffer. The display buffer is adjusted in order to preserve a vertical spatial relationship between the top and bottom fields.

Abstract: There is provided herein a system for video encoding and decoding that uses short-term and long-term buffers. Reconstruction of each block within an image may be performed with reference to one of the buffers, so that different portions of an image, or different images in a sequence, may be reconstructed using different buffers. There is also provided herein systems for signaling, between an encoder and a decoder, the use of the above buffers and related address information. The encoder may, for example, transmit information identifying video data as corresponding to a particular one of the buffers, and the decoder may transmit information relating to the size of the short-term and the long-term buffer. The buffer sizes may be changed during transmission of video data by including buffer allocation information in the video data. Also disclosed herein are methods and apparatuses according to the above.

Abstract: A method for decreasing end-to-end delay in a video conferencing context is disclosed. At video conferencing system startup, a processor is initialized to receive either a top field or a bottom field of video frame data. If the first line of a new field arriving after initialization does not match a field state that the processor is initialized to, the present invention senses the state mismatch and adjusts a display buffer by one display line, and the field is stored in the display buffer. The display buffer is adjusted in order to preserve a vertical spatial relationship between the top and bottom fields.

Abstract: A method for decreasing end-to-end delay in a video conferencing context is disclosed. At video conferencing system startup, a processor is initialized to receive either a top field or a bottom field of video frame data. If the first line of a new field arriving after initialization does not match a field state that the processor is initialized to, the present invention senses the state mismatch and adjusts a display buffer by one display line, and the field is stored in the display buffer. The display buffer is adjusted in order to preserve a vertical spatial relationship between the top and bottom fields.

Abstract: A method for decreasing end-to-end delay in a video conferencing context is disclosed. At video conferencing system startup, a processor is initialized to receive either a top field or a bottom field of video frame data. If the first line of a new field arriving after initialization does not match a field state that the processor is initialized to, the present invention senses the state mismatch and adjusts a display buffer by one display line, and the field is stored in the display buffer. The display buffer is adjusted in order to preserve a vertical spatial relationship between the top and bottom fields.

Abstract: There is provided herein a system for reducing artifacts associated with multi-threaded video coding. The system generates a virtual thread from the multi-threaded data. The virtual thread combines the multi-thread data with estimates of virtual thread data in a manner that variably weights the combination according to motion information decoded from the multi-thread. A post-processing system is described that generates a single, virtual thread of video data, based upon image and motion data from a plurality of different threads in a multi-threaded video stream. The system estimates motion vectors for the virtual thread, generates frames of estimated video data, and applies the estimated frames to a filter. The filter generates an output that combines each new estimated frame with the current reference frame on a pixel-by-pixel basis.

Abstract: A system and method for providing video quality improvement are afforded. A video stream is monitored. A quality of at least one data field associated with the video stream is determined. A command is generated in response to the determined quality of the at least one data field. A video frame is then displayed according to the command.

Abstract: A system and method for providing video quality improvement are afforded. A video stream is monitored. A quality of at least one data field associated with the video stream is determined. A command is generated in response to the determined quality of the at least one data field. A video frame is then displayed according to the command.

Abstract: A method for decreasing end-to-end delay in a video conferencing context is disclosed. At video conferencing system startup, a processor is initialized to receive either a top field or a bottom field of video frame data. If the first line of a new field arriving after initialization does not match a field state that the processor is initialized to, the present invention senses the state mismatch and adjusts a display buffer by one display line, and the field is stored in the display buffer. The display buffer is adjusted in order to preserve a vertical spatial relationship between the top and bottom fields.

Abstract: Transmitting and receiving video data includes an encoder storing macroblocks in a plurality of reference buffers, the encoder transmitting macroblocks encoded relative to each of the reference buffers, a decoder receiving the macroblocks, and, in response to the decoder indicating an error with respect to a particular macroblock corresponding to a first one of the buffers, the encoder using a second one of the buffers for error recovery if there is no error associated with the second buffer. In response to the decoder indicating an error with respect to a particular macroblock and all of the buffers having errors associated therewith, the encoder may transmit at least one macroblock that is encoded independent of any other macroblocks.

Abstract: A method and system is provided for encoding a digital video stream, which requires less computation overhead as compared to conventional systems. Specifically, the encoded digital video stream includes direct mode predicted frames in place of some of the standard predicted frames. The direct mode predicted frames are formed without computing motion vectors for each macro-block of the direct mode predicted frame. During decoding, motion vectors from a co-located macro-block of a preceding predicted frame is copied and applied to each macro-block of the direct mode predicted frame. Because computing motion vectors is generally the most computing intensive task of encoding digital video streams, the use of direct mode predicted frames can greatly reduce the computation requirements for encoding digital video streams.

Abstract: There is provided herein a system for video encoding and decoding that uses short-term and long-term buffers. Reconstruction of each block within an image may be performed with reference to one of the buffers, so that different portions of an image, or different images in a sequence, may be reconstructed using different buffers. There is also provided herein systems for signaling, between an encoder and a decoder, the use of the above buffers and related address information. The encoder may, for example, transmit information identifying video data as corresponding to a particular one of the buffers, and the decoder may transmit information relating to the size of the short-term and the long-term buffer. The buffer sizes may be changed during transmission of video data by including buffer allocation information in the video data. Also disclosed herein are methods and apparatuses according to the above.

Abstract: There is provided herein a system for reducing artifacts associated with multi-threaded video coding. The system generates a virtual thread from the multi-threaded data. The virtual thread combines the multi-thread data with estimates of virtual thread data in a manner that variably weights the combination according to motion information decoded from the multi-thread. A post-processing system is described that generates a single, virtual thread of video data, based upon image and motion data from a plurality of different threads in a multi-threaded video stream. The system estimates motion vectors for the virtual thread, generates frames of estimated video data, and applies the estimated frames to a filter. The filter generates an output that combines each new estimated frame with the current reference frame on a pixel-by-pixel basis.