A CU-Level Rate and Distortion Estimation Scheme for RDO of Hardware-Friendly HEVC Encoders Using Low-Complexity Integer DCTs

Abstract of MAT LAB System On DCT for Rate-Distortion Optimization

MAT LAB System on DCT for Rate-Distortion Optimization

These methods decide particular coding modes in earlier stages or skip them by analyzing the characteristics of the predicted residuals.

However, computational powers for non-skipped modes are still necessary to obtain the RD costs by performing DCT and entropy coding.

As another approach, many studies on rate and distortion estimation were carried out for H.264/AVC  and some recent works have been reported for HEVC .

Since HEVC adopts quadtree structures of coding blocks with hierarchical coding depths, it becomes more difficult to estimate accurate rate and distortion values without actually performing transform, quantization, inverse transform, de-quantization, and entropy coding.

Furthermore, DCT for rate-distortion optimization (RDO) is computationally high, because it requires a number of multiplication and addition operations for various transform block sizes of 4-, 8-, 16-, and 32-orders and requires recursive computations to decide the optimal depths of CU or transform unit.

Conclusion

A CU-level Rate and Distortion Estimation Scheme for RDO of Hardware-friendly HEVC Encoders Using Low-Complexity Integer DCTs,Integer DCT plays an important role in RDO-based HEVC coding performance. However, it requires a large computational complexity, which is a burden for HEVC-friendly hardware encoders.