[FFmpeg-trac] #10615(undetermined:new): av1_vaapi does not respect qp, despite implementing qp as a viable rc_mode

[FFmpeg]

#10615: av1_vaapi does not respect qp, despite implementing qp as a viable rc_mode
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             Reporter:  tjhexf        |                     Type:  defect
               Status:  new           |                 Priority:  normal
            Component:  undetermined  |                  Version:  5.1.3
             Keywords:                |               Blocked By:
             Blocking:                |  Reproduced by developer:  0
Analyzed by developer:  0             |
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 Summary of the bug:
 How to reproduce:

 {{{
 ffmpeg -i input.mkv -vaapi_device /dev/dri/renderD128 -vf
 format='nv12,hwupload' -c:v av1_vaapi -qp:v 40 output.mkv
 }}}

 ffmpeg will fail to use qp, writing:

 [out#0/matroska @ 0x3c25140] Codec AVOption qp (Constant QP (for P-frames;
 scaled by qfactor/qoffset for I/B)) has not been used for any stream. The
 most likely reason is either wrong type (e.g. a video option with no video
 streams) or that it is a private option of some encoder which was not
 actually used for any stream.

 Logs imply it's using qp 25, despite not allowing for overriding this.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10615>
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