A low-complexity hardware-oriented mode decision scheme based on rate-distoration estimation

Video compression plays an important role in mobile applications, because more and more people use video to communicate with each other (like video call etc). However, the resources (energy, memory etc.) on mobile devices are limited, thus how to achieve a high coding performance in these devices becomes a big challenge. The recent standards such as H.264, HEVC and audio video coding standard (AVS) employ Rate distortion optimization (RDO) to select the best coding modes, however it results in extremely high computational complexity. This work presents a hardware friendly mode decision (MD) scheme. First, hardware-oriented RDcost estimation method is proposed by using least squares technique to reduce computational burden of RDO-based MD. Second, reconstructed-original (REC-ORG) united intra prediction scheme is presented to break the data dependency, while maintaining high coding performance. Third, highly efficient MD pipeline architecture is put forward to enhance MD processing capacity. The coding efficiency of our adopted MD scheme far outperforms (0.402 dB PSNR gain in average) the traditional SAD methods and the throughput of our designed pipeline is increased by 29%, 23% and 23% for I, P and B frames, respectively, compared with the existed RDO-based architecture.