Metal device is mandatory to handle P010 chroma on mobile/tv devices.
The Metal device API can only be used in ObjC context hence a new ObjC source file had to be created to handle the device detection.
Those functions can be useful in other places.
One useful case will be to attach color properties properly in the cvpx converter's output image buffers in a future fix without duplicating this mapping code.
Deprecate the "videotoolbox" bool variable. This module should be
enabled/disabled by the "dec-dev" variable like any other hw modules.
The vt decoder device is just used to enable/disable hw decoding on Apple and
act like other hw module. Indeed, VideoToolBox doesn't need any context from
the window to initialize.
Maxime Chapelet