| 摘要 |
A block length judging circuit 120 switches block lengths based on a feature quantity obtained from an input signal. A transform circuit 200 executes transform of the signal into frequency components according to the block length. A masking threshold calculating circuit 250 calculates a masking threshold simulating the masking characteristic of psychoacoustical property for each predetermined intra-block section. An inter-block/intra-block bit assignment circuit 300 executes inter-block bit number assignment and/or intra-block bit number assignment to each predetermined intra-block section. A vector quantization circuit 350 vector quantizes transform signal by switching codebooks 3601 to 360N according to the assignment bit number, and also quantizes gain by using a gain codebook 370.
|
