https://bugs.freedesktop.org/show_bug.cgi?id=98005
--- Comment #9 from Andy Furniss adf.lists@gmail.com --- The transcoding test above now makes similar size to cbr.
There is a new issue though. The GOP patch (2) is problematic.
It doesn't show on the transcoding test, but after reading the patch comment about gop affecting rate control I tested with gstreamer default (30) and max =
keyframe-period=300
With vbr plus high bitrates this makes a large difference in file size.
This still happens if I disable dual instance in radeon_vce.c.
CBR seems to be unaffected, though dual instance encoding seems to come out a bit lower than single instance.
The vbr test =
gst-launch-1.0 -f filesrc location=/mnt/ramdisk/trees-1440p50.nv12 blocksize=5529600 ! video/x-raw,format=NV12,width=2560,height=1440,framerate=50/1 ! queue ! vaapih264enc rate-control=vbr bitrate=50000 keyframe-period=300 ! video/x-h264, profile=baseline ! filesink location=/mnt/ramdisk/out.264
Result = 9.4M file (source is 500 frames)
above with keyframe-period=30 = 42M which is close to expected result.