Abstract: A video system includes an encoder for generating a compressed bit stream in response to a received video signal. The encoder includes a mode decision processor that is arranged to determine whether the mode of a first pixel block in a first row is an “intra-mode” or an “inter-mode.” The encoder also includes a mode estimation processor that is arranged to estimate the mode of a left pixel block in a second row that is received after the first row in response to the determined mode of the first pixel block in the first row. The encoder also includes a pixel block processor that is arranged to process a pixel block in the second row that is to the right of the left pixel block in response to the estimated mode of the left pixel block.

Abstract: Several systems and methods for filtering noise from a picture in a picture sequence associated with video data are disclosed. In an embodiment, the method includes accessing a plurality of pixel blocks associated with the picture and filtering noise from at least one pixel block from among the plurality of pixel blocks. The filtering of noise from a pixel block from among the at least one pixel block includes identifying pixel blocks corresponding to the pixel block in one or more reference pictures associated with the picture sequence. Each identified pixel block is associated with a cost value. One or more pixel blocks are selected from among the identified pixel blocks based on associated cost values. Weights are assigned to the selected one or more pixel blocks and set of filtered pixels for the pixel block is generated based on the weights.

Abstract: Image frames of a video stream are encoded with the aim of reducing flicker in the video stream when displayed. In one embodiment, the quantization parameter used to quantize an image frame is capped to be not greater than a quantization parameter used to quantize an immediately previous image frame. In another embodiment, the quantization step size used to quantize a macro-block of an image frame is computed based on the value of a quantization error of a co-located macro-block in an immediately previous image frame. In yet another embodiment, macro-block transform coefficients corresponding to high-frequency components are quantized using relatively higher quantization parameter values if the image frame is deemed to contain high activity. In yet another embodiment, flicker-prone macro-blocks of a source frame are replaced by corresponding best-match macro-blocks of a previous reconstructed frame, prior to being encoded.

Abstract: Several systems and methods for filtering noise from a picture in a picture sequence associated with video data are disclosed. In an embodiment, the method includes accessing a plurality of pixel blocks associated with the picture and filtering noise from at least one pixel block from among the plurality of pixel blocks. The filtering of noise from a pixel block from among the at least one pixel block includes identifying pixel blocks corresponding to the pixel block in one or more reference pictures associated with the picture sequence. Each identified pixel block is associated with a cost value. One or more pixel blocks are selected from among the identified pixel blocks based on associated cost values. Weights are assigned to the selected one or more pixel blocks and set of filtered pixels for the pixel block is generated based on the weights.

Abstract: This invention is a method of scalable video encoding and decoding. The scalable video encoding codes both a base layer and an enhanced layer having greater resolution and/or refresh rate. Upon decoding some enhanced layer pictures may be dropped to reach a best resolution and refresh rate within a target data rate. Upon encoding a key picture in at least one group of pictures forming the video is a combined base layer/enhanced layer key picture. Such a combined base layer/enhanced layer key picture cannot be dropped on decoding. This technique reduces drift in the decoder.

Abstract: This invention predicts that intra mode prediction is more effective for the macroblocks where motion estimation in inter mode prediction fails. This failure is indicated by a large value of the inter mode SAD. This invention performs intra mode prediction for only macro blocks have larger inter mode SADs. The definition of a large inter mode SAD differs for different content. This invention compares the inter mode SAD of a current macroblock with an adaptive threshold. This adaptive threshold depends on the average and variance of the SADs of the previous predicted frame. An adaptive threshold is calculated for each new predictive frame.

Abstract: A color space scalable video coding and decoding method and an apparatus for the same are disclosed that can adjust color components or color depth according to the performance of a decoder side. The color space scalable video coding method includes generating transform coefficients by removing the temporal redundancy and spatial redundancy of input video frames, quantizing the transform coefficients, generating a bit stream by entropy coding the quantized transform coefficients, and generating a color space scalable bit stream that includes the bit stream and position information of luminance data in the bit stream.

Abstract: A method of assigning a priority for controlling a bit rate of a bitstream having a plurality of quality layers is provided. The method includes composing first quality layers for a reference picture, composing second quality layers for a current picture that is encoded with reference to the reference picture, and assigning a priority each of the first and second quality layers, wherein a low priority is assigned to a quality layer having a small influence on a video quality reduction of the current picture when the quality layer is truncated.

Abstract: The method, system, and apparatus of linear temporal reference scheme having non-reference predictive frames is disclosed. In one embodiment, a method of a temporal reference scheme includes creating a non-reference predictive frame and a reference predictive frame from a reference frame, increasing a quantization factor of the non-reference predictive frame by a threshold value, and decreasing the quantization factor of the reference predictive frame by the threshold value. The method may include toggling between the temporal reference scheme and another temporal reference scheme in which there may be no non-reference predictive frames and only reference predictive frames based on a scenario. The method may also include calculating a target bit rate across a communication channel through a bit rate calculation algorithm that considers a bandwidth capacity across the communication channel.

Abstract: A method of rate control in coding of a video sequence to generate a compressed bit stream is provided that includes computing a sequence base quantization step size for a sequence of pictures in the video sequence, computing a picture base quantization step size for a picture in the sequence of pictures based on the sequence base quantization step size, a type of the picture, and a level of the picture in a rate control hierarchy, and coding the picture using the picture base quantization step size to generate a portion of the compressed bit stream.

Abstract: Image frames of a video stream are encoded with the aim of reducing flicker in the video stream when displayed. In one embodiment, the quantization parameter used to quantize an image frame is capped to be not greater than a quantization parameter used to quantize an immediately previous image frame. In another embodiment, the quantization step size used to quantize a macro-block of an image frame is computed based on the value of a quantization error of a co-located macro-block in an immediately previous image frame. In yet another embodiment, macro-block transform coefficients corresponding to high-frequency components are quantized using relatively higher quantization parameter values if the image frame is deemed to contain high activity. In yet another embodiment, flicker-prone macro-blocks of a source frame are replaced by corresponding best-match macro-blocks of a previous reconstructed frame, prior to being encoded.

Abstract: A video encoder receives a macro-block of an image frame, and determines whether the macro-block contains text. The video encoder computes a quantization parameter for quantizing the macro-block, with the quantization parameter computed to be smaller if the macro-block is determined to contain text. The video encoder encodes the macro-block using the quantization parameter. Text quality in the encoded macro-block is preserved.

Abstract: A client for playing a video stream and a method thereof adaptively control the video play in accordance with variable communication environments and the size of the video stream to be transmitted. The client includes a demultiplexer for generating elementary stream (ES) packets by demultiplexing a video stream; a FIFO buffer for temporarily storing the ES packets; a play timing modification unit for reducing a gap of a play time caused by a burst error by modifying time stamps of the ES packets that exist in the FIFO buffer if it is judged that the burst error occurs; and a video decoder for generating an output video by decoding the ES packets of which the time stamps are modified. The client can relatively improve the quality of the video streaming in multimedia communications through a wireless or wire network.

Abstract: The method, system, and apparatus of linear temporal reference scheme having non-reference predictive frames is disclosed. In one embodiment, a method of a temporal reference scheme includes creating a non-reference predictive frame and a reference predictive frame from a reference frame, increasing a quantization factor of the non- and reference predictive frame by a threshold value, and decreasing the quantization factor of the reference predictive frame by the threshold value. The method may include toggling between the temporal reference scheme and another temporal reference scheme in which there may be no non-reference predictive frames and only reference predictive frames based on a scenario. The method may also include calculating a target bit rate across a communication channel through a bit rate calculation algorithm that considers a bandwidth capacity across the communication channel.

Abstract: A method of assigning a priority for controlling a bit rate of a bitstream having a plurality of quality layers is provided. The method includes composing first quality layers for a reference picture, composing second quality layers for a current picture that is encoded with reference to the reference picture, and assigning a priority each of the first and second quality layers, wherein a low priority is assigned to a quality layer having a small influence on a video quality reduction of the current picture when the quality layer is truncated.

Abstract: A method and apparatus for encoding/decoding a multi-layer interlaced video signal having macroblocks coded in an interlaced manner is provided. The method includes determining whether a pair of macroblocks of a current layer are of a frame type and a corresponding pair of macroblocks of a lower layer are of a field type; and predicting and encoding a macroblock of the current layer by interpolating information of the top or bottom field of a corresponding macroblock of the lower layer, if the pair of the macroblocks of the current layer are of the frame type and the corresponding pair of the macroblocks of the lower layer are of the field type, and the top and bottom fields of the corresponding pair of the macroblocks of the lower layer have been coded in different prediction modes.

Abstract: A scalable video encoding method and apparatus based on a plurality of layers are provided. The video encoding method for encoding a video sequence having a plurality of layers includes coding a residual of a first block existing in a first layer among the plurality of layers; recording the coded residual of the first block on a non-discardable region of a bitstream, if a second block is coded using the first block, the second block existing in a second layer among the plurality of layers and corresponding to the first block; and recording the coded residual of the first block on a discardable region of the bitstream, if a second block is coded without using the first block.

Abstract: A color space scalable video coding and decoding method and an apparatus for the same are disclosed that can adjust color components or color depth according to the performance of a decoder side. The color space scalable video coding method includes generating transform coefficients by removing the temporal redundancy and spatial redundancy of input video frames, quantizing the transform coefficients, generating a bit stream by entropy coding the quantized transform coefficients, and generating a color space scalable bit stream that includes the bit stream and position information of luminance data in the bit stream.

Abstract: A color space scalable video coding and decoding method and an apparatus for the same are disclosed that can adjust color components or color depth according to the performance of a decoder side. The color space scalable video coding method includes generating transform coefficients by removing the temporal redundancy and spatial redundancy of input video frames, quantizing the transform coefficients, generating a bit stream by entropy coding the quantized transform coefficients, and generating a color space scalable bit stream that includes the bit stream and position information of luminance data in the bit stream.

Abstract: A method and apparatus for audio bass enhancement is provided. The method includes band-pass filtering an input signal; generating at least one even and odd harmonics of the band-pass filtered input signal; and synthesizing the harmonics and the band-pass filtered input signal to be output.