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Dynamic Dataclasses

Since (vs-)muxtools 0.2.0 all video and audio encoders use pydantic dataclasses.
These allow users to pass kwargs to them.

These kwargs are used to pass custom params to the encoder processes.
Have a look at part of the CLIKwargs class docstring here: 

test = Encoder(clip, colorspace="BT709")
print(test.get_custom_args())
# returns ['--colorspace', 'BT709']

# if it starts with an _ it will be a single - argument
# empty values will be stripped
test = Encoder(clip, _vbr="")
print(test.get_custom_args())
# returns ['-vbr']

# if it ends with an _ it will preserve underscores
test = Encoder(clip, _color_range_="limited")
print(test.get_custom_args())
# returns ['-color_range', 'limited']

Yes, append is still supported

... and now also almost everywhere and better!

test = Encoder(clip, append="-vbr --bitrate 192")
test = Encoder(clip, append=["-vbr", "--bitrate", "192"])
test = Encoder(clip, append={"-vbr": "", "--bitrate": "192"})
# all of them return ['-vbr', '--bitrate', '192']

Practical Uses

In terms of video encoders I mostly implemented this to serve SVTAV1 and the FFMPEG encoders.

You can for example do something like 

SVTAV1(qp_clip=src, sharpness=3, film_grain=3, tune=3, variance_boost_strength=3, variance_octile=5, frame_luma_bias=20)
and you will find that most of these params are not actually defined in the SVTAV1 class constructor.
They will however still get passed to it as --sharpness 3 --film-grain 3 --variance-boost-strength 3 --variance-octile 5 --frame-luma-bias 20.

This will also work for x264/5 but considering the settings there are just a string to begin with, I don't see much of a point.

Affinity

This only1 applies to the video encoders but you can now pass an affinity kwarg to the classes.

Just like the vs-tools set_affinity function, this will lock the process (of the encoder, instead of vapoursynth) to the cores you request.

A fun and interesting tidbit that inspired me to write this is that SVTAV1 seems to always inherit the affinity of the parent that started it.
Which means that it would be locked to the same affinity you set for your filtering when using it through muxtools.
muxtools simply overwrites it to use all cores now if nothing custom was passed.

  1. Make an issue if you want to see that for audio stuff. Can't think of a usecase tho. ↩