https://bugs.freedesktop.org/show_bug.cgi?id=99029
--- Comment #6 from Andy Furniss adf.lists@gmail.com --- (In reply to Martin Bednar from comment #4)
The file is the OSS Elephant's dream movie : https://orange.blender.org/ Purposely tested with this for easy sharing. Contained streams (ffmpeg -i ): Stream #0:0: Video: msmpeg4v2 (MP42 / 0x3234504D), yuv420p, 1920x1080, 10002 kb/s, 24 fps, 24 tbr, 24 tbn, 24 tbc Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, 5.1(side), fltp, 448 kb/s
I think ffmpeg will silently fall back to s/w decode with this file as it's not normal h264.
If you don't specify a bitrate it seems ffmpeg will use cqp = 20 (which will come out quite high bitrate on some content).
-profile:v 77 : I tested values and in the end found one in ffmpeg sources. Are these values documented anywhere?
Not sure about ffmpeg, but they are standard numbers in the world of h264
B-Frames : so basically VCE is useless in its B-Frame-less state?
I wouldn't go that far, for realtime encoding it is useful and libx264 with realtime settings wouldn't use b-frames either (well depends on how much CPU you have available in practice). For example my card can do 2160p60 realtime in an artificial test - though in practice for say, game/screen recording I would need hardware CSC which Windows may have, but linux doesn't.
I was hoping to create a tvheadend streaming server with live hw-accelerated transcoding, is this at all possible with AMD VCE cards?
If the input is progressive h.264 maybe - VCE doesn't encode interlaced which could be an issue depending on what your local broadcasters use.
TV tends to be quite low bitrate anyway - if you are not reducing size then re-encoding may not be the best way to go.
gstreamer can, for my dual instance VCE card, be faster than ffmpeg, on your APU I don't know whether it would be.
gstreamer can use vaapi (I don't think a current mesa regression affects transcoding). OMX can be used, but it's cqp only, with vaapi you can target bitrates.