A Fast Intra/Inter Mode Decision Algorithm of H.264/AVC for Real-time Applications

A novel fast Intra/Inter mode decision algorithm for H.264/AVC is proposed in this paper. By reducing the calculations incurred in both intra- and inter-prediction in video encoding, the computational complexity is significantly decreased, which is an essential requirement for real-time video communications applications. The motion vectors of previously encoded macroblocks are exploited to detect the motion speed according to the pre-defined threshold, and the degradation of encoding efficiency can be minimized by adaptive adjustment scheme based on motion speed. The experimental results showed that the proposed fast mode decision algorithm is able to reduce 51.29% total encoding time on the average with a negligible PSNR loss less than 0.1 dB and a bitrate increase under 2%