[Bug]: Wrong color matrix coeff is written in AV1 sequence header

[seungha-yang]

Describe the bug When AMF_VIDEO_CONVERTER_COLOR_PROFILE_601 is set, sequence header contains MC_IDENTITY which is broken stream. It should be MC_BT_601

To Reproduce Steps to reproduce the behavior: With the latest (main branch) gstreamer, run command

gst-launch-1.0.exe d3d11testsrc ! "video/x-raw(memory:D3D11Memory),format=NV12" ! amfav1enc ! queue ! av1parse ! d3d11av1dec ! queue ! d3d11videosink

Setup (please complete the following information):

• OS: Windows 11
• Driver Version: 31.0.14043.7000
• GPU: RX 7900 XT
• AV1 encoder

See also https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4370