Rate Control and Error Concealment of H.263 Video Codec

• Main Authors: Liao, Chun-Chieh, 廖俊傑
• Other Authors: Chang Pao-Chi
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/36852778558047819717

碩士 === 國立中央大學 === 電機工程學系 === 85 === ABSTRACT H.263 is a very low bit-rate video coding standard which has been used with modem and wireless transmissions. Although the video coding output is naturally variable bitrate (VBR), the channel delivering the video stream is often constant bitrate (CBR). Thus, the rate control which converts the VBR video into CBR streams is necessary. We present an adaptive rate control algorithm which achieves CBR by adjusting the quantization stepsize. Experiment results show that the algorithm can effectively maintain CBR. In addition, The error propagation caused by transmission errors may seriously deteriorate the video quality. We present here an efficient error concealment with macro-block interleaving technique for H.263 video. At the transmitter, macro-blocks of I-pictures and P-pictures are interleaved to preserve adequate information for performing efficient error concealment. At the receiver, de- interleaving and effective error concealment techniques are utilized for reducing error damage. Our simulations reveal satisfactory performance.