[FFmpeg-user] Questions about h264_amf encoder

Chao Liu yijinliu at gmail.com
Sat Mar 24 14:05:58 EET 2018

I am trying to see how good h264_amf encoder is. I use ffmpeg to encode a
1080 video on Windows 10 running Ryzen 5 2500U. Two observations:

- The encoded video quality is pretty poor, much worse than x264 with a
smaller bitrate.

- I got about 70fps with ~70% GPU usage. I was expecting to get better
numbers though.
  As a comparison, on a much slower intel CPU Celeron n3450, using
h264_vaapi to encode the same file, I got 30 fps with less than 20% GPU

The command I use is:
ffmpeg -i transcode-test.mkv -pix_fmt nv12 -c:v h264_amf -profile:v
constrained_baseline -rc cqp -qp_i 0 -qp_p 0 -qp_b 0 h264_amf.mkv

(looks like the qp parameters don't change anything..)

Did I do sth. wrong?

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