Distributed soft video broadcast with variable block size motion estimation

In recent years, video broadcast has become a popular application, but the traditional hierarchical design requires the source to pick a bitrate and video resolution for encoding before transmission, it cannot be efficient to accommodate users with different channel quality. The proposed DCAST scheme can solve this problem. DCAST uses the ME and MC technology to generate a predicted frame which helps current frame to do coset coding. However, in the ME process, DCAST uses fixed block size. In this paper, we use the variable block size motion estimation to replace the fixed block size motion estimation, it can effectively reduce the block effect and improve the quality of the reconstructed frame generated by MC and predicted frame. The DCAST with variable block size motion estimation is 0.5dB better than DCAST with fixed block size motion estimation.