摘要:
Methods of encoding and decoding for video data are described for encoding or decoding coefficients for a transform unit. In particular, the sign bits for the non-zero coefficients are encoded using sign bit hiding. Two or more sets of coefficients are defined for the transform unit and a sign bit may be hidden for each set, subject to satisfaction of a threshold test. The sets may correspond to coefficient groups that are otherwise used in multi-level significance map encoding and decoding.
摘要:
A method for decoding compressed data that has been encoded using a context model, each context having a context state corresponding to a probability estimate. Each bin of the data has been encoded using the probability estimate corresponding to the context state for the context associated with that bin. At the decoder, for decoding a series of bins associated with a given context, an initial probability estimate is determined using an initial context state for the given context and the series of bins are decoded and reconstructed using that initial probability estimate. After the series is decoded, the context state is updated based on the reconstructed bins for the series to produce an updated context state for that context to be used in decoding a subsequence portion of the bitstream.
摘要:
Methods and devices are described for entropy coding data using an entropy coder to encode quantized transform domain coefficient data. Last significant coefficient information is signaled in the bitstream using two-dimensional coordinates for the last significant coefficient. The context for bins of one of the coordinates is based, in part, upon the value of the other of the coordinates. In one case, instead of signaling last significant coefficient information, the number of non-zero coefficients is binarized and entropy encoded.
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:
Encoders and methods of encoding that incorporate deblocking into the encoding process. An encoder performs a two-cycle encoding process. First, an original block is processed and then reconstructed and deblocked. The reconstruction and the deblocked reconstruction are compared to the original and an intermediate block is created that contains the portions of the reconstruction or the deblocked reconstruction that are more similar to the original. In the second cycle, the intermediate block serves to generate a modified original block, which is then used in a prediction process to create a new prediction block. The new prediction block as compared to the original gives new residuals. The new prediction and new residuals are entropy coded to generate the encoded video data. The new prediction block and new residuals incorporate the deblocking elements selectively identified during the first cycle, thereby eliminating the need for deblocking at the decoder. The prediction operation may be motion prediction or spatial prediction.
摘要:
Methods, and corresponding codec-containing devices are provided that have source coding schemes for encoding a component of an excitation. In some cases, the source coding scheme is an enumerative source coding scheme, while in other cases the source coding scheme is an arithmetic source coding scheme. In some cases, the source coding schemes are applied to encode a fixed codebook component of the excitation for a codec employing codebook excited linear prediction, for example an AMR-WB (Adaptive Multi-Rate-Wideband) speech codec.