| 摘要 |
<p>A variable-length encoding process for video data, wherein the compression rate at the time of video image encoding is increased by improving the level encoding method in particular. A CAVLC encoding unit (22) acquires transformation and quantization coefficients which have been obtained by orthogonally transforming and quantizing video image data in each block unit, determines whether variable-length encoding is to be conducted in the encoding mode of table (A41), table (B42), or a mixture of table (A41) and table (B42) at a level encoding mode controller (39), and outputs the decision result to a level_prefix unit (40). In the table (B42), a fixed-length bit string is allocated to a level_prefix which is of at least a prescribed value. The level_prefix unit (40) performs a level_prefix encoding operation in an encoding mode in accordance with the decision result and outputs to an output controller (26).</p> |
