Packet Loss Concealment for Critically-Sampled Filter Bank-Based Codecs Using Multi-Sinusoidal Detection

摘要

Systems and methods are described for concealing packet loss in a received audio stream. Candidate frequency lines may be identified within one or two previous frames of the audio stream. For two-frame concealment, gains may be calculated for each candidate frequency line between a first frame and a second frame, and candidate frequency lines may be selected based on the calculated gains. Different techniques may be used to select the candidate frequency lines, including a full-search method and a hybrid method based on selecting peaks from a pseudospectrum. Sub-band predictors may be selected from a database of predictor candidates based on the selected candidate frequency lines. Each predictor may be a function of frequency, and the selected predictors may be arranged as a matrix. The sub-band predictors may then be applied to corresponding blocks of the second frame to obtain sub-band coefficients used to reconstruct the lost frame.