TRANSCODING APPARATUS, TRANSCODING METHOD AND INTEGRATED CIRCUIT

摘要

A transcoding apparatus includes: a decoding unit for decoding a first bit stream; a bit allocation unit for estimating a bit count that can be used during encoding; a quantization parameter calculating unit for calculating a candidate quantization parameter according to the estimated bit count; a quantization parameter adjuster for determining a second quantization parameter according to the value of the candidate quantization parameter and for determining a ratio of the second quantization parameter to a first quantization parameter; and a bit shifting unit for performing bit shifting of decoded data according to the ratio. The quantization parameter adjuster sets a first critical value, the size of which is equal to twice the first quantization parameter. When the candidate quantization parameter is not smaller than the first threshold value, the second quantization parameter is set to be the same as the first critical value. When the candidate quantization parameter is smaller than the first threshold value, the second quantization parameter is set to be the same as the first quantization parameter.