Determining scale factor values in encoding audio data with AAC

摘要

Techniques for determining scale factor values when encoding audio data are described. According to one technique, a particular scale factor value (SFV) is estimated using an audio quality estimator function that is non-linear. After a certain point, a decrease in noise results in a smaller increase in audio quality. According to another technique, an initial SFV is estimated for each scale factor band (SFB). When estimating the cost of transitioning from one SFB to another, only a proper subset of possible SFVs are considered. The proper subset is based, at least in part, on the initial SFV.