Fast Intra Mode Decision Algorithm for H264/AVC HD Baseline Profile Encoder

The high performance of H.264/AVC video encoder is accompanied with a wide computation complexity especially for high definition (HD) video sequences. One of the major H.264/AVC features to be optimized is the mode decision for both inter and intra prediction. Thus, based on high correlation observed between selected inter prediction mode and intra mode decision, a fast intra mode decision algorithm based on the best inter prediction mode for H264 high definition (HD) baseline profile encoder is proposed. The evaluation of the proposed approach was based on the rate distortion and PSNR variation, execution time and percentage of skipping intra4x4 and intra16x16. The proposed scheme is performed on 720p (1280x720) and 1080p (1920x1088) HD video sequences. Experimental results show that the proposed algorithm can save up to 60% of intra prediction computation time, 16% of skipping intra16x16 and up to 83% for intra4x4 without inducing PSNR degradation and bit-rate increase. General Terms Video compression techniques and signal processing