| 摘要 |
A coding rate conversion device can easily avoid the possibility of a violation of the standard taking place when all of the coded blocks included in a macroblock are to be deleted, with a high degree of efficiency in rate conversion performed when an MPEG-2 coding rate is converted through requantization. The coding rate conversion device performs a rate conversion on first coded data by inversely quantizing the first coded data having been quantized with a first quantization step and requantizing the first coded data with a second quantization step larger in step size than the first quantization step. The coding rate conversion device includes: a block specifying unit which specifies an object block having a nonzero coefficient, out of a plurality of blocks included in the first coded data; and a non-zeroing unit which performs non-zeroing processing by which a first nonzero coefficient of the specified object block become a nonzero coefficient even after the rate conversion is performed using the second quantization step, when the rate conversion is performed on the specified object block.
|
