Internal processing in 32 bit depth?

[Selur]

My mistake, Flash3kDB is listed as 16 bit http://vsdb.top/plugins/f3kdb but i decide that it is 8 bit because if i turn off threshold and grain strength (dithering) it start to look like 8-bit. Maybe some mistake in Hybrid input?

I don't think so.
Looking at the documentation:

input_mode

Not available in Vapoursynth, since this can be inferred from clip properties

Specify source video type.

0: Regular 8 bit video
1: 9 ~ 16 bit high bit-depth video, stacked format
2: 9 ~ 16 bit high bit-depth video, interleaved format

Default: 0 (input_depth = 8 or not specified) / 1 (input_depth > 8)

input_depth

Not available in Vapoursynth, since this can be inferred from clip properties

Specify bit-depth of source video.

Range: 8 ~ 16

Default: 8 (input_mode = 0 or not specified) / 16 (input_mode = 1 or 2)

output_mode

Not available in Vapoursynth, f3kdb will only output high bitdepth clip in native format

Specify output video type. Meaning of values are the same as input_mode.

When output_mode = 2, frames will be 2x wider and look garbled on preview, it will return to normal after correctly encoded by high bit-depth x264)

Default: 0 (output_depth = 8 or not specified) / 1 (output_depth > 8)

output_depth

Specify output bit-depth.

If output_depth = 16, dither algorithm specified by dither_algo won’t be applied.

Range: 8 ~ 16

Default: 8 (output_mode = 0 or not specified) / 16 (output_mode = 1 or 2)

source: https://f3kdb.readthedocs.io/en/latest/u...parameters
especially the:

Vapoursynth, f3kdb will only output high bitdepth clip in native format

I assumed that f3kdb would always output 16bit,...

Let's see the script that you used and it should be apparent if there's a bug in the script generator.

Cu Selur