Package: ffmpeg
Version: 7:4.1.3-1
Severity: normal

Dear Maintainer,

When trying to convert a video using h264_vaapi codec there is two way
to define the quality of the videos:
- With the 'qp' parameters (works like crf setting of libx264)
- with bitrate control (using -b:v xk).

Only the bitrate control setting works, the qp parameters is not
working (it seem to be encoding as 'lossless' setting with bitrate more
than 30000kbits/s - some test produce bitrate at 60Mbits/s), using the
same 'qp' parameters on Debian Stretch (ffmpeg 3.3.9) works as expected.
Tested on two computers just upgraded to Debian Buster where ffmpeg and
vaapi was working fine.

To reproduce take any video as input and encode with:

$ ffmpeg -vaapi_device /dev/dri/renderD128 -i foo.mp4 \
-vf 'format=nv12,hwupload' -c:V h264_vaapi -qp 23 -an bar.mp4

Change the value of -qp to anything within the range 0 to 51.

You can check the -qp setting of h264_vaapi codec using:
$ ffmpeg -h encoder=h264_vaapi

Unfortunatly I can't try with static build from ffmpeg because of bug
#68 (
Neither with version from snapcraft as vaapi doesn't work either.

This issue is probably more on libavcodec side than on ffmpeg.


-- System Information:
Debian Release: 10.0
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-5-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8),
LANGUAGE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages ffmpeg depends on:
ii libavcodec58 7:4.1.3-1
ii libavdevice58 7:4.1.3-1
ii libavfilter7 7:4.1.3-1
ii libavformat58 7:4.1.3-1
ii libavresample4 7:4.1.3-1
ii libavutil56 7:4.1.3-1
ii libc6 2.28-10
ii libpostproc55 7:4.1.3-1
ii libsdl2-2.0-0 2.0.9+dfsg1-1
ii libswresample3 7:4.1.3-1
ii libswscale5 7:4.1.3-1

ffmpeg recommends no packages.

Versions of packages ffmpeg suggests:
pn ffmpeg-doc <none>

-- no debconf information

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