时空域结合的Ⅰ帧综合差错隐藏方案

Temporal and Spatial Combined Ⅰ Frame Error Concealment Scheme

为提高视频压缩码流在Internet网络丢包信道中传输的抗误码性能,提出了一种在解码端基于场景判断时域空域相结合的Ⅰ帧综合差错隐藏方案。采用了H.264中灵活宏块顺序模式组织宏块打包数据,在场景判断的基础上利用了帧间信息对Ⅰ帧进行时域差错隐藏,并通过对匹配块的可靠性检测抑制了误码扩散效应;同时改进了传统Ⅰ帧空域隐藏算法,根据丢失块边缘上的梯度预测丢失块的纹理状况,分为平滑、单纹理和多纹理区域进行掩盖。仿真结果表明,对于一般性运动视频,时域空域结合的隐藏算法比空域算法掩盖质量提高2 dB以上。

A temporal and spatial combined Ⅰframe error concealment scheme is proposed under packet-loss channel. This scheme is based on FMO （ Flexible Macroblock Ordering） mode in H. 264, introduces temporal information between frames for Ⅰ frame concealment after scene change detection, and prevents error propagation by block reliability checking. In spatial concealment part, the the gradients on the block edge, and then spatial interpolation simulation results show that this temporal and spatial combined texture of the lost block is estimated according to is performed based on the texture direction. The concealment scheme achieves significant improvement on Ⅰ frame＇s error robustness.