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Gamma problem with 2vuy compressor / ICM session

Hi list,
I am having trouble compressing ARGB CVPixelBuffers with the 2vuy compressor through an ICM compression session.

The resulting video is showing a considerable gamma shift. I believe the 2vuy compressor is assuming that the ARGB buffers have a gamma value of 2.2 whereas they actually have a gamma of 1.8.

This does not happen with the yuv2 compressor, here everything looks fine.

Question:
0) am I doing something wrong?
1) how can I manually convert the gamma from 1.8 to 2.2 before sending my buffers to the ICM
2) or force the ICM to do the conversion for me
3) or is this a bug with the 2vuy compressor... shall I file a bug report?

Note: I compared the ImageDescriptions that are being generated from the ICM for 2vuy and yuv2.
The yuv2 compressor generates no image description extensions.
The 2vuy compressor gerenates both a 'colr' and 'gama' image description extensions. ‘colr‘ is filled with type:nclc, primaries:6, function:2 (means unknown), matrix:2, ‘gama‘ is filled with 2.2

Thanks n advance
Mark





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