基于可伸缩视频编码的率失真优化编码算法

Adaptive RD-optimal coding algorithm for scalable video coding

可伸缩视频编码(SVC)可实现视频流空间、时间和信噪比的完全伸缩,但在差错信道上传输容易引起误差扩散,为此提出一种基于SVC的率失真优化编码算法。该算法在分析了差错信道下传输可伸缩视频流误差扩散失真的基础上,在率失真优化模型中引入时间和信噪比分级的误差分级参数,并根据信道状态自适应地确定宏块编码模式。该算法能够有效地抑制误码在各分层的扩散,提高了可伸缩视频流的鲁棒性。仿真结果表明,算法与以往的算法相比具有更好的抗误码性能,适合视频数据在差错信道上的传输。

The SVC provided a full scalability including spatial, temporal and signal-to-noise ratio （SNR） scalability with fine granularity, but each of which might result in error propagation over error channels. This paper addressed a novel rate-dis- tortion optimized （ RDO ） coding algorithm for SVC. After estimated and stored error propagated distortion values for each frame, added a parameter used for indicating error propagation of temporal and SNR layers into the RDO model. Based on these encoding parameters, carried out an optimal maeroblock mode decision scheme. The proposed algorithm can effectively prevent error propagation and enhance error-resilient performance. Simulation results show that the proposed scheme is robust to pack loss and suitable for video transmission over error channels.