摘要:
A 2D transform and its inverse have an implementation as a sequence of lifting steps arranged for reduced computational complexity (i.e., reducing a number of non-trivial operations). This transform pair has energy compaction properties similar to the discrete cosine transform (DCT), and is also lossless and scale-free. As compared to a separable DCT transform implemented as 1D DCT transforms applied separably to rows and columns of a 2D data block, the transforms operations are re-arranged into a cascade of elementary transforms, including the 2x2 Hadamard transform, and 2x2 transforms incorporating lifting rotations. These elementary transforms have implementations as a sequence of lifting operations.
摘要:
Various techniques and tools for encoding and decoding (e.g., in a video encoder/decoder) binary information (e.g., skipped macroblock information) are described. In some embodiments, the binary information is arranged in a bit plane, and the bit plane is coded at the picture/frame layer. The encoder and decoder process the binary information and, in some embodiments, switch coding modes. For example, the encoder and decoder use normal, row-skip, column-skip, or differential modes, or other and/or additional modes. In some embodiments, the encoder and decoder define a skipped macroblock as a predicted macroblock whose motion is equal to its causally predicted motion and which has zero residual error. In some embodiments, the encoder and decoder use a raw coding mode to allow for low-latency applications.