Patent ID: 8780980
Filing Date: 2014-07-15
Classification: H03M,H04N

Abstract:
1. A video image encoding device comprising: a transformation and quantization unit generating quantized transform coefficients which have been subjected to orthogonal transformation and quantization with respect to video image data on a region basis, a variable length encoding unit performing variable length encoding on the quantized transform coefficients, wherein the variable length encoding unit has a plurality of encoding modes including a modified CAVLC (Context Adaptive Variable Length Coding) mode to perform modified CAVLC encoding on each level of the quantized transform coefficients, a level_prefix of each level being encoded into one of variable-length codes and fixed-length codes, wherein, in the modified CAVLC mode, the variable length encoding unit encodes a level_prefix equal to or greater than a threshold value into one of the fixed-length codes which are distinguishable from each other, wherein, in the modified CAVLC mode, a level_prefix smaller than the threshold value is encoded into one of the variable-length codes, and wherein each of the variable-length codes of the level_prefixes has a bit string formed by placing, in front of ‘1’, one or more ‘0’s the number of which is obtained by adding 1 to a value of the corresponding level_prefix, and each of the fixed-length codes of the level_prefixes consists of a bit string starting with ‘1’ and having a fixed length.