Bug#1076478: ffmpeg hevc_vaapi and h264_vaapi stuck at q=-0.0

[Terrance Hendrik]

Package: ffmpeg
Version: 7:7.0.1-2

Actually begins at least  Version: 7:6.1.1-4+b4

using any arguments for hevc_vaapi, encoding q stuck at 0, resulting in
extremely high bitrate and huge files.

example command

```
q=32
ffmpeg -i ${v} -vaapi_device /dev/dri/renderD128  -vf
'scale=1920:1080,pad=1920:1088:0:4,format=nv12,hwupload' -c:v hevc_vaapi
-b_depth 2 -async_depth 8 -compression_level 13 -qp ${q} -y
${v%.*}.vaapi.qp${q}.bd2.mp4
```

output

```
...
frame=26500 fps=204 q=-0.0 Lsize=20448421KiB time=00:18:23.47
bitrate=151805.4kbits/s dup=16 drop=5 speed= 8.5x

```

**vainfo**
```
libva info: VA-API version 1.22.0
libva info: Trying to open
/usr/lib/x86_64-linux-gnu/dri/radeonsi_drv_video.so
libva info: Found init function __vaDriverInit_1_22
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.22 (libva 2.12.0)
vainfo: Driver version: Mesa Gallium driver 24.1.3-2 for AMD Radeon 780M
(radeonsi, gfx1103_r1, LLVM 17.0.6, DRM 3.57, 6.9.8-amd64)
vainfo: Supported profile and entrypoints
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
      VAProfileH264Main               : VAEntrypointVLD
      VAProfileH264Main               : VAEntrypointEncSlice
      VAProfileH264High               : VAEntrypointVLD
      VAProfileH264High               : VAEntrypointEncSlice
      VAProfileHEVCMain               : VAEntrypointVLD
      VAProfileHEVCMain               : VAEntrypointEncSlice
      VAProfileHEVCMain10             : VAEntrypointVLD
      VAProfileHEVCMain10             : VAEntrypointEncSlice
      VAProfileJPEGBaseline           : VAEntrypointVLD
      VAProfileVP9Profile0            : VAEntrypointVLD
      VAProfileVP9Profile2            : VAEntrypointVLD
      VAProfileAV1Profile0            : VAEntrypointVLD
      VAProfileAV1Profile0            : VAEntrypointEncSlice
      VAProfileNone                   : VAEntrypointVideoProc
```