Opened 4 years ago

Closed 4 years ago

#886 closed defect (fixed)

Encoder issue with LMCSUpdateCtrl==2

Reported by: ksuehring Owned by:
Priority: minor Milestone: VTM-8.0
Component: VTM Version:
Keywords: Cc: ksuehring, XiangLi, fbossen, jvet@…


We encoded a 10-bit non-CTC sequence with a few black frames in the beginning with low-delay configuration (luma: 121, cb: 514, cr: 514)

Surprisingly the black frames get reconstructed as white (luma: 929, cb: 514, cr: 514), already in the first intra frame. The encoder reports luma PSNR of ~2dB, decoder matches the encoder.

This effect does not happen with RA or AI configurations.

We traced the issue back to the parameter LMCSUpdateCtrl being set equal to 2 in LD config.

I checked different encoder code locations, which have a dependency on the LMCSUpdateCtrl parameter. So far I found that the problem relates to the model parameters being set in EncReshape.cpp around line 850, but not exactly which parameter.

Change history (3)

comment:2 Changed 4 years ago by ksuehring

  • Milestone set to VTM-8.0

The MR is merged.

comment:3 Changed 4 years ago by XiangLi

  • Resolution set to fixed
  • Status changed from new to closed
Note: See TracTickets for help on using tickets.