Macroblock-based retransmission for error-resilient video streaming
This paper revisits the problem of source-channel coding for error-resilient video streaming. We propose a new method to enable adaptive redundancy in the bitstream: fine-grain retransmission. Redundancy decisions are made per macroblock (MB), which are locally adaptive and of low overhead, as opposed to coarse packet-level redundancy (e.g. forward error correction). In this scheme, the encoder jointly optimizes the coding mode and redundancy per MB. A corresponding algorithm is presented for exploiting this redundancy at the decoder. The proposed method is general in nature, and can be implemented on top of any (hybrid) video codec. An example implementation is provided, which uses the redundant slice mechanism of H.264 (JM 13.2 reference software). Simulation results show significant performance gains over conventional error-resilient coding techniques.