为了在3G网络上传输H.264实时视频流,提出了一种鲁棒性容错编码策略.该系统首先将视频序列分成两个子序列分别进行编码,并在不同路径中传输,以降低因信道突发错误而造成连续丢包的概率,对丢失的数据则采用高精度的双向加权运动补偿进行预测.为了使出错子流快速恢复正常解码状态,采用多参考帧策略,使用正确解码子流的参考帧作为出错子流的参考帧来进行预测编码,以消除误差扩散.实验结果表明,该方法在无线网络环境中不仅能有效地抵抗误码和丢包对传输图像质量的影响,而且能保证视频流的正常播放和改善图像质量.与相关方法比较,该方法提高重建图像质量超过0.6dB.

To deliver H.264 real-time video streaming over 3G networks,an error resilient coding scheme is presented in this paper.The system first divides original sequence into two sub-sequences to encode separately and then transmits the resulting two bitstreams over different channels so that the effect of burst channel error on image quality can be decreased.The frames which are not correctly decoded are predicted by bidirectional weighted interpolation of the frames from the other sub-stream.In order to restore the decoding process of the sub-stream suffering transmission error,the reference picture of the other sub-streams correctly decoded is selected as reference for the error sub-stream so that the error propagation can be eliminated.The simulation results show that the proposed method can efficiently combat bit error and packet loss in wireless channels and improve the image quality.The performance of the proposed method gains more than 0.6dB compared with the related approaches.