Error resilient macroblock rate control for H.264/AVC video coding
In this paper, an error resilient rate control scheme for the H.264/AVC standard is proposed. This scheme differs from traditional rate control schemes in that macroblock mode decisions are not made only to minimize their rate-distortion cost, but also take into account that the bitstream will have to be transmitted through an error-prone network. Since channel errors will probably occur, error propagation due to predictive coding should be mitigated by adequate Intra coding refreshes. The proposed scheme works by comparing the rate-distortion cost of coding a macroblock in Intra and Inter modes: if the cost of Intra coding is only slightly larger than the cost of Inter coding, the coding mode is changed to Intra, thus reducing error propagation. Additionally, cyclic Intra refresh is also applied to guarantee that all macroblocks are eventually refreshed. The proposed scheme outperforms the H.264/AVC reference software, for typical test sequences, for error-free transmission and several packet loss rates.