The present invention provides a mechanism for preventing quality degradation of decoded data during the decoding of encoded data. In one embodiment, error propagation is detected and corresponding data is flagged. An error recovery process is then applied to the flagged data. In an alternate embodiment, scores for hypotheses are calculated for lost/damaged data. A score distribution is used for detection of the false hypotheses. The data are flagged if their score distribution is within a range defined by a threshold and an error recovery process is applied to recover those data having associated error flags set.