Hardware oriented re-design and matrix approximation analysis for transform in High Efficiency Video Coding (HEVC)

In this paper, we propose an adaptive truncate k-bit re-configurable approximation (aTra) method which can achieve similar video coding efficiency as the original transform but substitute all low efficient multiplication by conformed shifting and addition operations, lifting the utilization of the hardware implementation and making simple hardware implementation and high efficiency pipeline design possible. Also, we may be the first to propose three mathematical constraints for the hardware matrix approximation to make the final performance controllable. The proposed method can achieve regular data flow and massive operation reduction balancing the rate distortion (RD) performance and data throughput. Particularly for the current secondary transform, rotational transform (ROT), we obtain the hardware friendly ROT through our proposed method based on one of the constraints. The simulation results implemented in the HEVC reference software HM1.0 present the validity of our method. Our method achieves similar performance when compared with the original one but it is much better than the simple hardware implementation.