摘要 |
An error recovery method may be engaged by an encoder to recover from misalignment between reference picture caches at the encoder and decoder. When a communication error is detected between a coder and a decoder, a number of non-acknowledged reference frames present in the decoder's reference picture cache may be estimated. Thereafter, frames may be coded as reference frames in a number greater or equal to the number of non-acknowledged reference frames that are estimated to be present in the decoder's reference picture cache. Thereafter, ordinary coding operations may resume. Typically, a final reference frame that is coded in the error recovery mode will be coded as a synchronization frame that has high coding quality. The coded reference frames that precede it may be coded at low quality (or may be coded as SKIP-coded frames). On reception and decoding, the preceding frames may cause the decoder to flush from its reference picture cache any non-acknowledged reference frames that otherwise might collide with the new synchronization frame. In this manner, alignment between the encoder and decoder may be restored. |