A method (and apparatus) for coding an audio signal, the method comprising thesteps of partitioning the audio signal into a sequence of successive frames;calculating oneor more noise thresholds for each of a plurality of frames in the sequence,each noisethreshold for a particular one of the frames corresponding to a differentperceptual codingquality for the particular frame; estimating a bit demand for each of acorresponding oneor more perceptual coding qualities for each frame, wherein each estimated bitdemandcomprises a number of bits which would be used to code a given frame at thecorresponding perceptual coding quality; selecting one of the perceptualcoding qualitiesfor the coding of a particular frame based upon the estimated bit demand forthe perceptualcoding quality for the particular frame, and further based on one or more bitdemandsestimated for one or more other frames; and coding the particular frame basedon the noisethreshold corresponding to the selected perceptual coding quality for theparticular frame.In particular, and in accordance with one illustrative embodiment of thepresent invention,the average bit demand for coding each of a plurality of frames at each of aplurality ofdifferent perceptual coding qualities is advantageously estimated, and basedon theseestimates, each frame is coded so as to maintain a relatively consistentperceptual codingquality from one frame to the next.
展开▼
