Proper 10bit videos support on GPU #776
Description
This issue is about enabling correct support for 10bit videos on GPU. Currently, we error out on such videos. And before #777 was merged, we would sometimes return incorrect values as previously reported in e.g. #585, #598, and #736.
To properly support 10-bits videos on GPU we need two main changes:
- Run the color-conversion step on uint16 temporary buffers, call the proper NPP functions with a custom color conversion matrix, and cast the uint16 into uint8. This is what I'm working on in Support 10 bits videos on CUDA #790.
- Sometimes, NVDEC cannot decode the video, so it actually relies on the CPU to do the decoding. For those videos, all that's left to do is the color-conversion step. We can either rely on our existing CPU implementation for that, or move the decoded frame to the GPU and run the color-conversion there. Support CPU fallback for videos that don't get decoded by nvdec #792 implements the former as it's easier, but we should try to do the second option eventually.