V4L2 and DRM choose different, incompatible ways to represent
tiled/compressed etc. formats. While the later uses combinations of
format fourccs and opaque, vendor/hardware specific modifiers, for the
later every such combination is a distinct new format.
Traditionally Gst implemented each of the V4L2 formats if needed.
Given the large number of tiling and compression modes, this is
quite work intensive - and often actually not needed.
In many situations Gst just needs to pass buffers from V4L2 to DRM in
the form of EGL, VK, Wayland or KMS.
Thus implement a direct translation for some V4L2 formats to DRM ones,
limited to the DMA_DRM API, allowing much quicker enablement of formats
while requiring peers to use external implementations (usually Mesa or
KMS) for tiling etc.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7355>
