libsvt_hevc no encoder options or documentation

[Marty]

Summary of the bug:
libsvt_hevc has been added to ffmpeg, but there are a few issues:
1) There is no documentation on ffmpeg.org
2) There does not seem to be a *-params option for libsvt_hevc to specify encoder options in the ffmpeg cli. I have tried -svthevc-params, -svt-hevc-params, -svt_hevc-params, -svt-params.
3) The embedded help ffmpeg -h encoder=libsvt_hevc lists a -tune parameter. This parameter is accepted by the cli, but it shows as deprecated and ignored.
4) libsvt_hevc has an encoder option to disable loop filters -dlf 1, but that is not accepted, nor is a -deblock encoder option

How to reproduce:
Compiled with ffmpeg windows build helper script. Cross compiled on linux kubuntu 22.04 lts.

ffmpeg version N-109920-gac6eec1fc2-ffmpeg-windows-build-helpers Copyright (c) 2000-2023 the FFmpeg developers built with gcc 10.2.0
compile command is 
cross_compile_ffmpeg.sh --disable-nonfree=n --build-svt=y --compiler-flavors=win64

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Gyan]

libsvt_hevc has been added to ffmpeg

No. libsvthevc and libsvtvp9 are not part of ffmpeg. Intel makes available libavcodec encoder wrappers for these two encoders and some build scripts integrate them. The repos have links to documentation[1][2].

[1]: ​https://github.com/OpenVisualCloud/SVT-HEVC/blob/master/Docs/svt-hevc_encoder_user_guide.md
[2]: ​https://github.com/OpenVisualCloud/SVT-VP9/blob/master/Docs/svt-vp9_encoder_user_guide.md