摘要:
A bit rate control mechanism for a digital image or video compression system estimates a complexity parameter for a current picture, or block of samples, of a video signal as a function of parameters for a prior picture of the video signal, which parameters include a bit rate. From the complexity parameter a quality factor for the current picture is determined and applied to a quantizer to compress the current picture. A complexity pre-processor may also be used to detect scene changes in the video signal prior to estimating the complexity parameter. If there is a scene change detected, then the rate control mechanism is reset prior to estimating the complexity parameter for the first picture in the new scene. Also a video buffer verifier is controlled so that the buffer occupancy at the end of a specified image sequence is at a target value so that looping and editing applications are facilitated.
摘要:
A bit rate control mechanism for a digital image or video compression system estimates a complexity parameter for a current picture, or block of samples, of a video signal as a function of parameters for a prior picture of the video signal, which parameters include a bit rate. From the complexity parameter a quality factor for the current picture is determined and applied to a quantizer to compress the current picture. A complexity pre-processor may also be used to detect scene changes in the video signal prior to estimating the complexity parameter. If there is a scene change detected, then the rate control mechanism is reset prior to estimating the complexity parameter for the first picture in the new scene.
摘要:
A method and apparatus for determining timing information from an MPEG-2 stream carrying Advanced Video Coding (AVC) content is disclosed. The method includes receiving an initial access unit from the MPEG-2 stream, and determining whether the MPEG-2 stream contains a temporal picture order count (POC) parameter. If the temporal POC parameter is contained in the MPEG-2 stream, the temporal POC parameter is used to compute a presentation time stamp (pts) for a next presentation unit (m).
摘要:
A real-time encoder, e.g., a real-time H.264 compliant encoder or a real-time AVC compliant encoder is disclosed. For example, the encoder comprises a first digital signal processor (DSP) for processing a first panel of an input image and a second digital signal processor (DSP) for processing a second panel of the input image. Finally, the encoder comprises a field programmable gate array (FPGA) for supporting both the first DSP and the second DSP.
摘要:
A method, protocol and apparatus for transporting Advanced Video Coding (AVC) content, e.g., using MPEG-2 systems is disclosed. Specifically, the present method is related to the carriage of various flavors of AVC streams in a uniform fashion over MPEG-2 systems (e.g., both transport and program streams). The method includes generating the AVC content from an input stream, and thereafter transporting the AVC content in a transport stream or a program stream over MPEG-2. The AVC content is generated in accordance with at least one constraint that is associated with the transport stream or the program stream.
摘要:
Method and apparatus for motion estimation in a video encoder is described. In one example, a motion estimator includes registers, first-in-first out (FIFO) logic, costing logic, and processing logic. The registers are configured to store an even field and an odd field of a current macroblock pair in a current frame in a video stream. The FIFO logic is configured to store a reference window of a reference frame in the video stream. The costing logic is configured to produce cost data. The processing logic is coupled to the registers, the FIFO logic, and the costing logic. The processing logic is configured to generate common sums of absolute differences (SADs) for the current macroblock pair, generate SADs for partitions of the current macroblock pair from combinations of the common SADs, and cost and minimize the SADs for the partitions.
摘要:
A system for coding of digital video images such as bi-directionally predicted video object planes (B-VOPs), in particular, where the B-VOP and/or a reference image used to code the B-VOP is interlaced coded. For a B-VOP macroblock which is co-sited with a field predicted macroblock of a future anchor picture, direct mode prediction is made by calculating four field motion vectors, then generating the prediction macroblock. The four field motion vectors and their reference fields are determined from (1) an offset term of the current macroblock's coding vector, (2) the two future anchor picture field motion vectors, (3) the reference field used by the two field motion vectors of the co-sited future anchor macroblock, and (4) the temporal spacing, in field periods, between the current B-VOP fields and the anchor fields. Additionally, a coding mode decision process for the current MB selects a forward, backward, or average field coding mode according to a minimum sum of absolute differences (SAD) error which is obtained over the top and bottom fields of the current MB.
摘要:
The present invention discloses a system and method for performing motion estimation associated with an encoder, e.g., a H.264/MPEG-4 AVC compliant encoder. For example, the method selects a motion vector centering for a current block in a search area of at least one reference picture. The method calculates a matching cost for each of a plurality of candidate motion vectors derived from the search area, and outputs at least one of the plurality of candidate motion vectors based on the matching cost associated with each of the plurality of candidate motion vectors to a main coding loop.
摘要:
A method and apparatus for selecting a coding mode for a block of a current picture are disclosed. For example, the method selects a coding mode in accordance with a cost function, for coding the block, wherein the cost function comprises a coding distortion parameter and a number of coding bits parameter, wherein said coding distortion parameter is measured in accordance with at least one of: between a prediction residual and a reconstructed prediction residual, or between a transformed prediction residual and a dequantized transformed prediction residual, wherein the number of coding bits parameter is computed in accordance with at least one of: from a true number of compressed bits resulting from coding said block, directly from a plurality of bins, or directly from a plurality of quantized transform coefficients.
摘要:
A method and apparatus for selecting a coding mode for a block of a current picture are disclosed. For example, the method selects a coding mode in accordance with a cost function, for coding the block, wherein the cost function comprises a coding distortion parameter and a number of coding bits parameter, wherein said coding distortion parameter is measured in accordance with at least one of: between a prediction residual and a reconstructed prediction residual, or between a transformed prediction residual and a dequantized transformed prediction residual, wherein the number of coding bits parameter is computed in accordance with at least one of: from a true number of compressed bits resulting from coding said block, directly from a plurality of bins, or directly from a plurality of quantized transform coefficients.