Research And Application Of Fast Intra Prediction Algorithm In H.264

With the rapid development of consumer electronics, video application has become popular, so video compression technology needs to be more effective and efficient. H.264 is one of the most widely used coding standards which has good compression ratio. But on the other hand, its encoding process is highly complex and quite difficult to achieve real-time software encoding. To improve the encoding speed, a variety of fast algorithms and hardware acceleration modules has been developed.In this paper, an in-depth study on H.264 fast intra prediction technology was performed. The research focused on two types of fast intra prediction algorithm: statistic-based algorithm and directional-based algorithm. For the first type of algorithm, the reason for quality degeneration was analyzed. To solve the problem, a fast intra prediction algorithm based on content adaptive threshold was proposed. The algorithm makes use of content adaptive threshold to control the number of mode searched, so a lot of computation is reduced. For the second type of algorithm, a fast intra mode decision algorithm in the transform domain was presented. The intermediate transform coefficients in the prediction process are used to extract the direction information, and then this direction information is used to guide prediction. Experimental results show that this algorithm can significantly reduce the complexity of intra prediction with only negligible coding efficiency loss. Finally, a hardware architecture for this algorithm was presented. This hardware architecture has simple structure and easy to be implemented.