Fast mode decision algorithm for spatial and SNR scalable video coding

Scalable video coding (SVC) has found more and more applications in a variety of the adaptive network streaming and the terminal. In the current SVC, an exhaustive search technique is employed to select the best coding mode for each macro block. This technique achieves the optimal trade-off between the bit-rate and distortion, but it results in extremely large encoding time which obstructs it from practical use. In this paper, we propose a fast mode decision algorithm for inter frame coding for spatial and coarse grain signal to noise ratio (SNR) scalability. In the proposed method, we predict the enhancement layer mode using both collocated macro block and its neighboring block mode in the base layer. The proposed method can achieve the time saving up to 78 percent in spatial scalability and 35 percent in coarse grain quality scalability (CGS) with the negligible loss of quality and increment in bit rate.