A fast 4x4 intra mode decision for inter frame coding in H.264|MPEG-4 Part 10

The H.264\MPEG-4 Part 10 (AVC) standard incorporates an intra prediction into inter frame coding. However, this leads to excessive increase of encoding time. This paper presents a fast intra mode decision and intra prediction algorithm to reduce encoding time. Basically, the proposed algorithm designs the skip condition for candidate modes of 4x4 intra prediction to be dependent of the content types of sequences and the context of pre-encoded adjacent blocks in terms of intra prediction-related probabilities. The content and context adaptive conditional probability table for the most probable modes is generated during an I-frame coding and is exploited for the intra mode decision in the following P frames until the next I-frame. The experimental results show that the total encoding time saving can be achieved up to maximally 43.17% with negligible PSNR drop and bitrate increase compared to the joint model (JM) reference software of AVC