* Add AV1 transcoding support
- AV1 encoding on CPU via SVT-AV1 (libsvtav1 in ffmpeg)
- Supports CRF and optionally capped CRF (max bitrate)
- Tested playback successfully in Chrome Win+Android, Firefox Win+Linux, Android app
* AV1: Add support for encoding threads option
* Revert previous commit; specifying params multiple times is bad
We need to specify all svtav1-params at once, so putting the thread option into getThreadOptions is not possible.
* AV1: Override VAAPI getSupportedCodecs as it does not yet support AV1 unlike nvenc, qsv, amf
* Change BaseHWConfig supported codecs to only H264/HEVC
Configs that support VP9 and/or AV1 need to override getSupportedCodecs()
* Set SVT-AV1 threads with svtav1-params, remove duplicate block in NVENCConfig
* AV1Config: Fix empty svtav1-params array being added to options
* add tests
* update api
* allow crf-based two-pass mode
* formatting
* suggest 35
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Co-authored-by: mertalev <101130780+mertalev@users.noreply.github.com>
