摘要:
A method for entropy coding data using parallel entropy coders to encode an input sequence as a plurality of encoded subsequences, which are then combined to form an output bitstream. The input sequence is separated into subsequences on the basis of a context model. A method for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from the bitstream and entropy decoding the encoded subsequences in parallel to generate a plurality of decoded subsequences, which are then interleaved based on a context model to produce a reconstructed sequence.
摘要:
A method for entropy coding data using parallel entropy coders to encode an input sequence as a plurality of encoded subsequences, which are then combined to form an output bitstream. The input sequence is separated into subsequences on the basis of a context model. A method for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from the bitstream and entropy decoding the encoded subsequences in parallel to generate a plurality of decoded subsequences, which are then interleaved based on a context model to produce a reconstructed sequence.
摘要:
Devices and methods for entropy decoding a bitstream of encoded data by extracting a plurality of encoded subsequences from a payload field of the bitstream for parallel decoding on a set of parallel entropy decoders. The method includes dividing the payload of concatenated encoded subsequences into segments using a distribution function and distributing the segments amongst the set of parallel entropy decoders to balance the computational load among the parallel entropy decoders. The received bitstream includes auxiliary information inserted by the encoder to enable the decoder to entropy decode segments that begin with a portion of an encoded subsequence.
摘要:
Methods and encoders/decoders for applying in-loop deblocking to intra-coded images/frames. In a decoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block prior to decoding the subsequent block in the decoding sequence. In an encoding context, a deblocking filter is applied to reconstructed pixels of an intra-coded block in an inter-coding loop before encoding a subsequent block in the coding order for the image.
摘要:
A method and encoder for entropy encoding image data using a dynamically determined coding order, and a method and decoder for entropy decoding encoded data encoded using a dynamically determined coding order. The coding order for encoding quantized transform domain coefficients is dynamically determined for the image based on at least one characteristic of the quantized transform domain coefficients. The characteristic may be quantization step size if non-uniform quantization is employed for blocks of data.
摘要:
Encoding and decoding methods that perform quantization using adaptive reconstruction levels are presented. The reconstruction levels for a given partitioning of the data space may be selected based upon the distribution of data points within each sub-part defined by the partitioning. In some cases, the adaptive reconstruction levels may be based upon an average of the data points within each sub-part. In some cases, the adaptive reconstruction levels may be selected using a rate-distortion analysis including the quantization distortion associated with the levels versus the data points and the rate associated with transmitting the encoded adaptive reconstruction levels. The methods relate to data compression in a range of applications including audio, images and video.
摘要:
An encoder for encoding a video by performing motion estimation using predicted residuals in the rate-distortion cost expression. The predicted residuals are determined by finding a predicted motion vector with respect to the original reference frame and calculating the corresponding residual values. The actual motion vector is then selected based on minimization of the rate-distortion cost expression with respect to the reconstructed reference frame, where the rate-distortion cost expression includes the predicted residuals. In particular, the cost expression includes reconstructed predicted residuals within the distortion term.
摘要:
Methods and encoders and decoders for adaptively quantizing transform domain coefficients in image and/or video encoding/decoding. For an image having a number of blocks, each block having N coefficients, the quantization step size for each coefficient is selected dynamically, thus resulting in a quantizer that may apply different step sizes to different coefficients. The selected step sizes for each coefficient are used for those coefficients within all blocks in the image/frame. In one aspect, the step sizes are selected on the basis of balancing pixel domain distortion when the image/frame is decoded.
摘要:
A method of encoding a video using constrained soft-decision quantization. The soft-decision quantization includes first performing hard-decision quantization to obtain hard quantized coefficients and, then, obtaining a soft quantized coefficient using a rate-distortion calculation over a search range of quantization levels for a transform domain coefficient, wherein the search range of quantization levels for that transform domain coefficient is constrained within a number of quantization levels of a corresponding hard quantized coefficient. The search range may be based upon a fixed threshold, the coefficient position, the hard quantized coefficient magnitude, a threshold value less accumulated distortion, or other factors, including combinations of these factors. The accumulated distortion may be measured by an L1 norm.
摘要:
An encoder for encoding a video by performing motion estimation using predicted residuals in the rate-distortion cost expression. The predicted residuals are determined by finding a predicted motion vector with respect to the original reference frame and calculating the corresponding residual values. The actual motion vector is then selected based on minimization of the rate-distortion cost expression with respect to the reconstructed reference frame, where the rate-distortion cost expression includes the predicted residuals. In particular, the cost expression includes reconstructed predicted residuals within the distortion term.