Fine grain scalability of bitrate using AVC/H.264 bitstream truncation

Firstly the paper reports experimental results proving that Cascaded Pixel Domain Transcoder (CPDT) is extremely inefficient when used for AVC/H.264 bitstream transcoding aimed at bitrate reduction not exceeding 30% of primary bitrate. In the paper, proposed is a transcoder that exploits structured truncation of bitsream and an algorithm for such truncation is described. The experimental results are described that show that the proposed transcoder provides bitrate reduction with very small or negligible loss of quality for bitrate reductions not exceeding about 30%. The transcoder complexity is much smaller than that of CPDT.