Patent ID: 7831421

Claim:
A computer-implemented method comprising: processing a bit stream for an audio signal, including, when one or more missing frames is encountered while processing the bit stream, based at least in part on one or more factors, at a computer processor, selecting a concealment technique from among multiple available signal-dependent concealment techniques, wherein the one or more factors comprise a classification of an available prior frame from an earlier point in the audio signal than the one or more missing frames and a classification of an available following frame from a later point in the audio signal than the one or more missing frames, a count of the one or more missing frames, the count indicating how many consecutive frames are missing, and wherein the classification of the available prior frame is one of a set of possible classifications comprising voiced and unvoiced; determining whether the classification of the available prior frame is voiced or unvoiced and determining whether the classification of the available following frame is voiced or unvoiced, wherein: if the classification of the available prior frame and the classification of the available following frame are both voiced, and the count of the one or more missing frames is less than a threshold value, then the selected concealment technique comprises bi-directional concealment; and if the classification of the available prior frame is voiced, and the count of the one or more missing frames is more than a threshold value, then the selected concealment technique comprises unidirectional concealment; performing the selected concealment technique; and outputting a result.