ARM64 encoding issues

[robmikh]

The encoder behaves strangely on ARM64 devices (tested with a first gen Surface Pro X):

Ignoring the strange colors in the initial frame (which would be fixed by a better default palette #4), subsequent frames are encoded as mostly white for some reason. I'm not sure if this is a bug in giffun or in the Qualcomm GPU driver...

This is where I really wish PIX would be able to resolve the shader symbols ☹️

[robmikh]

It's somehow related to how the texture diff compute shader interacts with the LUT lookup pixel shader. When I disable the texture differ, the gif looks correct. I tried using different texture registers, but it didn't seem to make a difference.