Android FFMPEG doesn't recognize file: protocol -

i'm running android ffmpeg build through runtime.getruntime().exec() command problem when specify input file error:

e/mainactivity(18168): file:/mnt/sdcard/young.flv: protocol not found 

initially specified file name without "file:" prefix , still same error. how can specify input files?

so apparently ffmpeg build didnt have "file" listed when run "ffmpeg -protocols". added --enable-protocol=file configure , rebuilt ffmpeg. can accept file inputs without adding "file:" prefix