Does --video-params disable default parameters and prevent target quality?

[mqudsi]

I observed that if I run av1an -e svt-av1 --target-quality=xx .... the output includes

Params: --preset 4 --keyint 240 --rc 0 --crf 25

But if I run av1an -e svt-av1 -v '--preset 10' --target-quality=xx ..., the output just says

Params: --preset 10

To me, this implies that the presence of an explicitly specified --video-params is preventing av1an from supplying its own parameters. My reading of the help output led me to assume that --video-params would be in addition to to and not instead of the default per-encoder video parameters av1an used to get its job done.

IMHO, av1an should always pass its video parameters unless the -v includes the same parameter (in which case the manually supplied parameter should win) - this would be for things like --preset, --keyint, etc. But if -v included --crf and --target-quality was used, I would expect av1an to throw an error complaining that --crf and --target-quality cannot be used together.

[clidx]

I agree with both of your points, but would just add that --crf and --target-quality not conflicting is a holdover from before when --crf had to be manually specified in the params so that av1an could change it. Now, not having them conflict adds unnecessary ambiguity about what av1an is actually doing.

[mqudsi]

Aside from fixing this, can you enlighten me as to what av1an is doing in this case? Is it currently possible to use target quality with a different svt-av1 preset?

[FreezyLemon]

When av1an shows you

Params: --preset 4 --keyint 240 --rc 0 --crf 25

it just means that those are the "base" parameters it uses for encoding. Target quality mode decides on a CRF value for every chunk based on your target quality setting, which means your actual encoder parameters will be --preset 4 --keyint 240 --rc 0 --crf x, with x possibly being different for every chunk.

If you use custom --video-params, that just means that your "base" parameters are different. It does not mean that av1an won't be able to change the CRF value. If you use --video-params "--preset 8 --keyint 0 --lookahead 60", then av1an will automatically add the required stuff to make it work: --preset 8 --keyint 0 --lookahead 60 --crf x. Again, x being decided by the target quality algorithm.

Small edit:
Target quality or not, av1an only uses default encoder parameters if you do not use --video-params. Just FYI

[mqudsi]

Thanks for the explanation! I definitely wasn’t able to intuit that from the output.