A Frame Layer Bit Allocation for H.264 based on Mode Decision

The H.264/AVC video coding standard delivers a significantly better performance compared to previous standards, supporting higher quality video over lower bit rate channels. Rate control plays an important role in realtime video communication applications using H.264/AVC. An important step in many existing rate control algorithms is to determine the target bits for each P frame. This paper aims in improving video distortion by allocating more bits to frames with higher complexity and fewer bits to low complexity frames. In this work, the distribution of macroblock (MB) modes in a frame is considered as a measure of its complexity. The bit budget is then allocated to frames according to their complexity and buffer satus. Simulation results show that the proposed method effectively improves the PSNR average and meets the target bitrate more closely. In addition the proposed technique is less complex than other existing frame layer bit allocation schemes that are based on frame complexity.