JVET-P0730 AHG15: default quantization matrix [P. de Lagrange, E. François (InterDigital)] [late]

It is proposed to replace the all-16 default quantization matrix with an 8..64 linear ramp along the diagonal. Combined with JVET-P0110, this is said to reduce the coding cost of custom QM by allowing first-order approximation through scale and offset, and provide a reasonable default as-is.

Not evident that default matrices are needed, as it is unknown and highly application dependent what would be the best default. From this point of view, it might even be dangerous to define a default, as it might be misleading.

Saving the bits in APS might not be a big advantage.

No action was taken on this.