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Drivers & Software

Journeyman III

bad quality of h264_vaapi encoder in AMD Ryzen™ 5 PRO 4650G

Hello. I'm testing the AMD h/w h264 encoder quality on "AMD Ryzen™ 5 PRO 4650G" with Ubuntu20.04LTS.

The following ffmpeg command generates output.mp4. But the quality of video is poor compared to libx264.
(ffmpeg was complied with option "--enable-vaapi --enable-hwaccel=h264_vaapi ...")


./ffmpeg -hwaccel vaapi -f v4l2 -i /dev/video3 -vaapi_device /dev/dri/renderD128 -vcodec h264_vaapi -tune film -b:v 1M -vf format='nv12|vaapi,hwupload' output.mp4 -y

I analyze the output bitstream (output.mp4) in more. The bitstream has only Intra blocks for all P frames.

How to enable Inter blocks of H264 encoder ? 

Additionally, I tested the same command on "AMD Ryzen 5 3400G". The output bitstream has Inter blocks for P frames, which is obviously better quality.

As I know, the difference is the CPU. 

Can anyone tell me more about this issue?


Thanks for your response.

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