H.263编码视频流的混合错误掩盖

Mixed error concealment in H.263 video stream

当H.263编码视频流在因特网上传输时,易受错误的影响,错误不但会影响当前帧还会连续扩散到以后的解码帧,从而导致图像质量的严重恶化,目前消除错误影响的常用算法是空域掩盖和时域掩盖算法,但是单纯地使用空域算法会造成图像的钝化,而时域算法则无法处理大运动的图像区域,因此,建议了一种时域和空域混合掩盖算法,同时使用两类算法对发生错误的图像帧进行掩盖。模拟结果显示该算法能够达到可以接受的图像质量,适应于视频会议、远程教育等应用的要求。

When the compressed bitstream generated by a H.263video coder is transmitted over the Inter-net,it is sensitive to packet loss.Due to the coding structure of the H.263video compression algorithm,the pack-et loss can effect not only the current picture frame but also successive frames so that the quality of the video will be degraded seriously.The error concealment can be used to eliminate the effect.However,spatial conceal-ment will cause the blur of image quality and temporal concealment will make obvious artifacts.In this paper,we propose a hybrid temporal/spatial concealment algorithm that exploits both the spatial and the temporal redundan-cy.The result of simulation shows that this algorithm can lead to the good image quality.