Abstract
H.26L is a new, emerging video coding standard. It is aimed at very low bit rate, real-time, low end-to-end, and mobile application. H.26L intended to replace the previous H.263 and MPEG4 standards by targeting far beyond in compression performance and advanced features like error resilience. From the report [20] we know that the H.26L standard derives most of its performance gains from improved motion estimation. On the other hand, motion estimation is the most computation-intensive routine.We adopt fast-full search algorithm SEA, PNSA and PPNM and make use of overlaps of search range of the seven different block size for motion estimation. Before encoding one frame, we calculate and save 1x4 partial norm in advance to consist of seven different block sizes used in PPNM algorithm. Operation can be reduced while reusing 1x4 partial norm in PPNM algorithm, especially when the search range increases. According to our experimental results, the PPNM with PNS algorithm is faster about 3.3 times than full search within search range.Finally, we port H.26L encoder from PC to TI TMS3206701 DSP platform. And we use techniques in parallel assembly code for integer transform and Hadamard transform to enhance encoding process. For Sub-QCIF format image, TI TMS320C6701 running on 100MHz can encode about 0.21 frame per second.