Research Of Interactive Video Error Control Technique

The video stream employing inter-frame prediction is very sensitive to network transmission errors. A little transmission error maybe promotes error propagation in both the spatial and temporal domains and make the image quality intolerable finally. The truth of video error control techniques is to make the hurt of transmission errors least whenever and wherever the transmission errors happened.Interactive video error control technique is proposed to remove transmission errors by transmitter and receiver's working together. Error tracking has been proved a better interactive video error control technique. In this technique, only severely impaired macroblocks by reason of past frames' errors are refreshed in INTRA mode, so this technique can gain a better trade-off between compress efficiency and robustness. In addition, a multi-frames refresh method is proposed to solve the problem of too many intra-refreshed macroblocks. The main drawback of error tracking is that it lack the ability to accurately estimate ,at the encoder, the overall distortion of the decoder frame reconstruction. Further ,it relay on heuristic thresholds to make macroblocks' mode decisions. Therefore in this paper, a technique named rate-distortion optimization with feedback is introduced, which can compute the overall distortion of the decoder frame reconstruction at the encoder by utilizing foregone network packet loss and the decoder's error concealment method. Then the overall distortion of each macroblock of current encoding frame can be computed at pixel level precision. We then incorporate the macroblock's overall distortion within a rate-distortion(R-D) framework to select the best coding mode such that the trade-off between compress efficiency and robustness is optimized. At the end of this paper, we have discussed this technique respectively according to algorithm complexity, and simulative experimental results based new video coding standard H.26L demonstrate that this technique, under lower round trip delay conditions, has similar efficiency to error tracking ,but it is superior to error tracking withhigher round trip delay.