OPi PC FFMPEG transcoding w/vdpau and hw encoder

[Magnets]

I'm experimenting with video transcoding but am getting problems when using vdpau to decode and the hw video encoder.

Using this

https://github.com/stulluk/FFmpeg-Cedrus

and

https://github.com/uboborov/ffmpeg_h264_H3

 

software decode & hw encode = 15-20FPS but high CPU usage. it can do 60FPS encoding rate with 960x540 30fps h264 source

dropping the compression helps a bit too (-qp 24, default is 30)

 

 

hw decode & hw encode of 1080 h264 = 1FPS, using 4k h265 as the source gives 1.5 FPS

ffmpeg -hwaccel vdpau -i 1080p30.mp4 -c:v cedrus264 -c:a copy -pix_fmt nv12 out.mp4

Is the video engine designed to do transcoding?