ffmpeg error "Error initializing complex filters" I use ffmpeg like this:

ffmpeg -i MyOwnSwordsman01.avi -filter_complex "drawtext=fontfile=c:/Windows/Fonts/simsun.ttc: text='第01回 %{pts\:gmtime\:0\:%M：%S}/43：20': x=5: y=466: fontsize=16: fontcolor=yellow@0.9: box=1: boxcolor=blue@0.6" -c:a copy -c:v libx264 -map 0 stamped/MyOwnSwordsman01.avi


It went wrong:

[Parsed_drawtext_0 @ 00000000025fae80] Cannot find a valid font for the family Sans
[AVFilterGraph @ 0000000000e3a160] Error initializing filter 'drawtext' with args 'fontfile=c:/Windows/Fonts/simsun.ttc: text=绗?1鍥?%{pts\:gmtime\:0\:%M\\:%S}/43锛?0: x=5: y=466: fontsize=16: fontcolor=yellow@0.9: box=1: boxcolor=blue@0.6'
Error initializing complex filters.
No such file or directory


So what's the matter? I have confirmed there is a simsun.ttc in C\ disk.

Thanks a lot!
Font paths have to be escaped:

fontfile='c\:\\Windows\\Fonts\\simsun.ttc'