Patent ID: 7937271

Claim:
A method of decoding an audio signal, comprising: (a) obtaining a bit stream that includes a plurality of frames, each frame including processing information pertaining to said frame and entropy-encoded quantization indexes representing audio data within said frame, and the processing information including: (i) a plurality of code book indexes, each code book index identifying a code book, (ii) code book application information specifying ranges of entropy-encoded quantization indexes to which the code books are to be applied, and (iii) window information; (b) decoding the entropy-encoded quantization indexes by applying the code books identified by the code book indexes to the ranges of entropy-encoded quantization indexes specified by the code book application information; (c) generating subband samples by dequantizing the decoded quantization indexes; (d) identifying a sequence of plural different window functions that were applied within a single frame of the audio data based on the window information; and (e) obtaining time-domain audio data by inverse-transforming the subband samples and using, within the single frame of the audio data, the plural different window functions indicated by the window information, wherein at least one of the application ranges for at least one of the code books is different than any of the quantization units, a quantization unit being defined by a rectangle of quantization indexes that is bounded by a critical band in a frequency domain and by a transient segment in a time domain.