Patent ID: 6871106

Claim:
An audio signal coding apparatus receiving an audio signal which has been time-to-frequency transformed, and outputting a coded audio signal, said apparatus comprising: a first-stage encoder operable to quantize the time-to-frequency transformed audio signal; second-and-subsequent-stages of encoders each operable to quantize a quantization error output from a previous-stage encoder; a characteristic decision unit operable to judge a characteristic of the time-to-frequency transformed audio signal, and decide a frequency band of the audio signal to be quantized by each of the encoders; and a coding band control unit operable to receive the frequency band decided by the characteristic decision unit and the time-to-frequency transformed audio signal, decide a connecting order of the respective encoders in each of the multiple stages, and transform the quantization bands of the respective encoders and the connecting order of the encoders to code sequences.