Error concealment for sub-band coded audio signals

摘要

A decoder and method of decoding a sub-band coded digital audio signal. The decoder comprises: an input, for receiving sub-band coefficients for a plurality of sub-bands of the audio signal; an error detection unit, adapted to analyze the content of a sequence of coefficients in one of the sub-bands, to derive for each coefficient an indication of whether the coefficient has been corrupted by an error of a predefined type; an error masking unit, adapted to generate from the sequence a modified sequence of coefficients for the sub-band, wherein errors of the predefined type are attenuated; a coefficient combination unit, adapted to combine the received coefficients and the modified coefficients, in dependence upon the indication of error; and a signal reconstruction unit, adapted to reconstruct the audio signal using the combined coefficients.

主权项

1. A decoder for a sub-band coded digital audio signal, the decoder comprising:
an input, which receives audio sub-band coefficients for a plurality of sub-bands of the audio signal; an error detection unit, configured to analyze the content of a sequence of the received audio coefficients in one of the sub-bands, to derive for each coefficient an indication of whether the coefficient has been corrupted by an error of a predefined type; an error masking unit, configured to attenuate audio coefficient errors in the sequence and thereby generate a modified sequence of audio coefficients for the sub-band; a coefficient combination unit, configured to combine the received audio coefficients and the modified audio coefficients, in dependence upon the indication of error; and a signal reconstruction unit, configured to reconstruct the audio signal using the combined coefficients, wherein the coefficient combination unit comprises a cross-fader, configured to mix the received audio coefficients and the modified audio coefficients in a weighted combination, wherein the weighting depends on the indication of error.