Since we have to re-encode the video files before uploading to meizu, it doesn't really matter anyway. Just two lines of code in avisynth such as:
LoadPlugin("X:\path\to\vsfilter.dll")
TextSub("X:\path\to\subtitle.srt") # for
SRT,
SSA and
ASS
or
VobSub("X:\path\to\subtitle.sub") # for
SUB/IDX
Of course you should have
avisynth and vsfilter available in your system. Maybe
AutoGK handles easier.