JVET-AC0106 EE1-1.10: Complexity Reduction on Neural-Network Loop Filter [J. N. Shingala, A. Shyam, A. Suneia, S. P. Badya (Ittiam), T. Shao, A. Arora, P. Yin, S. McCarthy (Dolby)]
This contribution reports the experimental results of EE1-1.10. The models for complexity reduction in this EE test are originally proposed in JVET-AA0080 and JVET-AB0136, with the introduction of parallel fusion of deblocked samples and NNLF outputs for further improvement. In EE1-1.10.1, the model with CP decomposition plus fusing adjacent 1x1 convolution is tested. In EE1-1.10.2, the model with CP decomposition, fusing adjacent 1x1 convolution and split architecture for luma and chroma components is tested. The models are implemented on top of NNVC common software NNVC-3.0. They are also implemented with fixed point using SADL. BD-Rate results are reported compared to NNVC-3.0 anchor. While the JVET-X0140 low complexity model achieves about 5.16% luma gain for AI and 4.98% for RA with worse case block level complexity of 33.6 KMAC/Pixel, the proposed models can achieve better trade-off with lower complexity. The AI and RA results of {Y, Cb, Cr} BD-Rate gain are as follows:
EE1-1.10.1: CP-decomposition with fusing, worst case block level complexity of 16.2 KMAC/Pixel
- LibTensorflow, fp32: AI {-4.65%, -5.66%, -5.03%}, RA {-5.05%, -6.29%, -4.46%}
- SADL, fp32: AI {-4.64%, -5.62%, -4.97%}, RA {-5.02%, -6.36%, -4.38%}
- SADL, int32: AI {-4.62%, -5.62%, -4.96%}, RA {-5.01%, -6.24%, -4.32%}
EE1-1.10.2: CP-decomposition with fusing and split luma chroma (24L, 8C), worst case block level complexity of 17.7 KMAC/Pixel
- LibTensorflow, fp32: AI {-4.94%, -7.76%, -7.69%}, RA {-5.43%, -7.79%, -6.57%}
- SADL, fp32: AI {-4.91%, -7.21%, -6.97%}, RA {-5.37%, -7.61%, -6.31%}
- SADL, int32: AI {-4.88%, -7.24%, -6.99%}, RA {-5.34%, -7.64%, -6.34%}
This was presented in session 12.
The method uses 4 models, each of size about 57K parameters, 17.7 kMAC/Pix
It was agreed to study this in a next EE, including:
- Training crosscheck
- Int16 implementation
- If possible, SIMD implementation in SADL
The possibility of further reduction of number of computations should be considered.