[HELP] How to convert video to higher bit depth before running certain filter

[Selur]

- '# colorformat <YUV444P16>'

should be just:

# colorformat YUV44416

and since you configured SvtAv1Model for YUV420P10 output, Hybrid would add

# adjusting output color from YUV444P16 to YUV420P10 for SvtAv1Model
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10, dither_type="error_diffusion")

Another question, would it be better to ONLY convert to high bit depth, without applying any other filter, before begin to encode? and how to do that in hybrid?

No clue, why you would do that (makes no sense to me).
But, ... you could do it by adding a custom section with - assuming you want to use YUV444P16:

# requires colorformat YUV444P16

(nothing more, is needed)
Hybrid would then create something like:

...
# defining beforeDeCross-function - START
def beforeDeCross(clip):
  return [clip]
# defining beforeDeCross-function - END
...
[clip] = beforeDeCross(clip)
# clip current meta; color space: YUV444P16, bit depth: 16, resolution: 640x352, fps: 25, color matrix: 470bg, yuv luminance scale: limited, scanorder: progressive, full height: true
# adjusting output color from YUV444P16 to YUV420P10 for NVEncModel
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10)

side note: Hybrid will use the dither_type configured under "Filtering->Vapoursynth->Misc->Script->Dither durin color change", when converting from a lower to a higher
clip = core.resize.Bicubic(clip=clip, format=vs.YUV420P10, dither_type="error_diffusion")

Behind each custom section Hybrid will add a comment, which reports the characteristics it assumes.

Hybrid will adjust the output of the script to whatever color format is configured in the encoder.

Cu Selur

Ps.: I think there is a bug somewhere, Hybrid should only set the dithering when going from a higher to lower bit depth. => uploaded a new dev which fixes that.