v4l2_stateful_decoder: Add software Q08C support

Add a software converter for Q08C frames to the v4l2_stateful_decoder.
This allows us to MD5 sum and dump Q08C frames to better test the video
decoding path used in production.

Note that this CL adds Q08C support, but prioritizes it lower than NV12
when v4l2_stateful_decoder is selecting a CAPTURE format. This is
intentional so that we don't enable Q08C conversion for all of our
tests.

The Q08C specification changes for frames larger than 1920x1080 in a way
that the software decoder does not fully support. Software Q08C
conversion is also fairly expensive, so widely enabling it for our
PlatformDecoding tests will blow up our testing run time. So, as a
compromise, a follow up CL will enable software Q08C conversion for a
representative subset of our test vectors.

BUG=b:318862905
TEST=Tested by running
"v4l2_stateful_decoder -f crowd_run.ivf -a -c Q08C -d"
on a trogdor device.

Change-Id: I4df104fd60e5b222a1d787e6b0d2bff35de95543
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/drm-tests/+/5170792
Reviewed-by: Fritz Koenig <frkoenig@chromium.org>
Tested-by: Justin Green <greenjustin@google.com>
Commit-Queue: Justin Green <greenjustin@google.com>
6 files changed