[HELP] how to encode sup and ass subtitles into videos using Hybrid?

[Selur]

if i want the filesize best quality, "Fast 1st pass" to check or not?

no, disable "Fast 1st pass" then.

Is it accurate that the value i set? According to the original file info, it shows filesize is 9.39GB, so i set 9390.0 into Hybrid Target size, is that right?

GiB usually stands for Gibibyte = 1024^3 byte, see: https://en.wikipedia.org/wiki/Byte so, I would say: No.
9.39GB *1014 ~= 9615 MB (depending on how correct the file size size is indicated, better check the file size in your normal file manager)



Cu Selur