Fast all zero block detection algorithm for versatile video coding

The new generation versatile video coding (VVC) standard brings extremely high compression efficiency. Meanwhile, the complexity of the encoder is also greatly increased. In view of this, this paper proposes a fast algorithm for all zero block detection to speed up the quantization process, thereby reducing the complexity of the encoder. The method proposed in this paper consists of three parts. Firstly, genuine all zero blocks are detected based on a fixed threshold which is derived by hard decision quantization formula. Secondly, parts of pseudo all zero blocks are detected based on an adaptive threshold which is derived by analyzing the positions of transform coefficients under a certain condition. Finally, for the remaining pseudo all zero blocks, machine learning is introduced and the decision is made through the fully connected neural network. Experimental results show that the proposed fast algorithm achieves up to 7.505% and 7.049% coding time saving under Low Delay B and Random Access configurations with only 0.470% and 0.578% performance loss on average, respectively.