Possible fp16 overflow issues using OmniSR model

[pokepress]

Information:

• Chainner version: 0.24.1
• OS: Windows 10

Description
I'm experiencing intermittent black frames when upscaling using an OmniSR model in fp16 mode. I first presented this to the neosr project:

neosr-project/neosr#96

Basically, every so often a frame in the output will be pure black. It seems to be specific to the content of the picture, and the frames that turn out black vary depending on the iteration of the model. After some testing, we were able to determine that it appears to be an fp16 precision issue since using fp32 causes the same frame to upscale correctly. Furthermore, the person behind neosr tried converting to an onnx fp16 model and the image upscaled there without issue, so we think this may be something specific to chaiNNer. You can test things out with these files:

https://www.mediafire.com/file/xxsv5yi6unr01bd/black_frame_omnisr.zip/file

Frame 1262 upscales correctly. 1263 produces a black image.

Logs
I looked at the logs, but it doesn't seem like anything in particular shows up there when this happens. It would be nice to log a warning for each black frame if possible, as the issue is intermittent enough that it's generally faster to re-upscale affected segments using fp32 instead of running the whole video through.

[FNsi]

And I guess, using PyTorch backend is working normal....