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JVET-O0191 3 i (m48299)

15th Meeting: Gothenburg, SE, July 2019 2019-07-10 11:22

CE1-related: Simplified CABAC initialization method

Authors: Frank Bossen Sharp

Abstract

Several CABAC initialization methods are studied in CE1. An alternative is proposed, which is asserted to have lower complexity. Indeed 25% faster code can be realized in software compared to the fastest CE1 method. From a coding efficiency point of view, the proposed method is as good if not better than the methods studied in CE1 under the conditions defined in CE1: considering averages, in the worst case, it is 0.01% worse than the best CE1 result (RA: -0.01% vs -0.02%); in the best case it is 0.11% better than the best CE1 result (RA, high QP: 0.11% vs 0.22%).

Meeting Notes

JVET-O0191 CE1-related: Simplified CABAC initialization method [F. Bossen (Sharp)]

This contribution was discussed Friday 5 July at 1700 (chaired by GJS).

Several CABAC initialization methods have been studied in CE1. An alternative is proposed, which is asserted to have lower complexity. It is asserted that 25% faster code can be realized in software compared to the fastest CE1 method. From a coding efficiency point of view, the proposed method is asserted to be as good if not better than the methods studied in CE1 under the conditions defined in CE1: considering averages, in the worst case, it is reportedly 0.01% worse than the best CE1 result (RA: −0.01% vs −0.02%); in the best case it is 0.11% better than the best CE1 result (RA, high QP: 0.11% vs 0.22%).

JVET-O0946 was written in response to this, and is thus closely related.

It was commented that at the high QP range there are only 8 valid probabilities that can be used, and in this region there would not be enough bins coded to sufficiently adapt the probabilitites to refine them. The proponent said that extremely high QPs may not be so important to optimize for.