H.264/AVC是新的视频编码标准,其高效的编码效率和良好的网络适配性,使它在多媒体通信中得到广泛应用,然而由于Internet网络是一种不保证QOS的“尽力”网络,基于Internet网络的视频业务将不呵避免地受到数据分组丢失的影响,因此文中基于H.264编码算法的特点提出多种新颖的视频抗分组丢失方法,包括Tornado码的不等保护,利用SEI域自适应改变纠错能力和交互式防误码扩散等.综合使用该文提出的多种抗分组丢失方法,在高丢包率环境下,与使用简单误码掩盖算法相比,恢复图像的平均PSNR可以提高8~15dB,且算法与H.264标准兼容,没有过多增加信道负担和运算复杂度,具有实用价值.
H. 264/AVC, the result of the collaboration of the ISO/IEC Moving Picture Experts Group and the ITU-T Video Coding Experts Group, is the newest standard for video coding. H. 264/AVC can be widely used in many areas because of its higher coding efficiency and the net work-friendly video representation. However, Internet is a bestLeffort network without ensuring QoS especially in real-time service(e, g. video communication), the packets lost will occur in video communication and the quality of the reconstructed image is reduced and even unaccepted. So error resilience techniques are necessary for video communication over Internet. This paper provides some error resilience methods based on H. 264/AVC, which include using a forward error correction Tornado code with packet unequal-protection according to different essentiality of video bit-stream, using SEI(Supplemental Enhancement Information)domain to change error corrected ability of Tornado code dynamically to adapt to the environment of the network, and a method of interactive error-propagation prevention, i.e. refreshing intra macroblocks in independent slice between encoder and decoder based SEI domain. Compared with simply using error concealment, the proposed techniques can improve the video quality about 8~15dB over variable and error prone channel. Furthermore, these methods are compatible with H. 264/AVC without any in creasing channel burden and arithmetic complexity, and can be used in practice.