Abstract: Packetized video data with a base-layer and at least one enhancement-layer organized in a GOP structure may contain packet loss errors. A method for detecting such errors includes the steps of reading header information relating to a layer, generating a scheme or selecting a predefined scheme according to the header information. The scheme can be made up of a display order number, and/or a number of reference frames and temporal level for the frames of the respective layer. The method can then extract from received video data frames the display order number, and/or the number of reference frames and temporal level parameters, and detect that one or more frames or packets are missing. The received parameters are compared with the parameters of expected frames according to the scheme and a missing packet or frame is determined by a mismatch between received and expected parameters.

Abstract: An inverse wavelet transformer causes a level-graded buffer to store one of two lines of coefficient data generated through a synthesis filtering operation. In order to adjust an output timing of image data, the inverse wavelet transformer causes an output buffer to store temporarily the other line of the two lines of coefficient data in a period throughout which the output buffer stores no baseband image data and then causes the level-graded buffer to store the other line of the two lines of coefficient data. In this way, the level-graded buffer stores coefficients generated through the synthesis filtering operation on a line-by-line basis.

Abstract: This invention is a method of video encoding. The number N macroblocks stored in a temporary buffer depends upon an estimated number of motion vectors. N macroblocks of current and prior frame data is transferred to the temporary buffer. The invention determines for each macroblock whether to be inter frame predicted or intra frame predicted. The inter and intra macroblocks are separately encoded based upon this determination and stored in an output buffer. Output macroblocks are output from the output buffer in raster scan order. This technique permits the process to loop over differing number of macroblocks in differing parts of the encoding process. Entropy encoding complexity from separating inter and intra macroblock encoding is avoided by separating a symbol generation phase from an encoding phase.

Abstract: Optimised bit allocation is important in video compression to increase the coding efficiency, i.e. to make optimum use of the available data rate. In view of the human visual system, a human usually pays more attention to some part of a picture rather than to other parts of that picture. Therefore the bit allocation should be optimised for different-attention picture areas (GOBi). The inventive distortion-driven bit allocation scheme allocates the coding/decoding error distortion to picture areas consistently with the human visual system, and satisfies the constraint of bit rate as well. The invention uses a distortion/bitrate/rhoquantization parameter histogram analysis. Based on corresponding tables (DGOBi[QPn], RGOBi[QPn] and ?GOBi[QPn]), the relationships between quantization parameter, rate, distortion and percentage of non-zero coefficients for the different-attention areas are determined (PREALUTI, DISALL, RALL).

Abstract: A method for reducing computational complexity of video compression standard is provided, and it includes an intra 4×4 macroblock (I4MB) search algorithm, an intra 16×16 macroblock (I16MB) search algorithm and a chroma search algorithm. The I4MB search algorithm and I16MB search algorithm accelerate the prediction process of the luma macroblock, and the chroma search algorithm accelerates the prediction process of chroma macroblock. The above algorithms can greatly reduce the computation of prediction mode of video compression standard.