Supported file protocols:
I.. = Input  supported
.O. = Output supported
..S = Seek   supported
FLAGS NAME
----- 
I..   applehttp
I.S   concat
IOS   file
IO.   gopher
IOS   http
I..   mmsh
I..   mmst
.O.   md5
IO.   pipe
IO.   rtmp
IO.   rtp
IO.   tcp
IO.   udp
