<amir.rouhi at ...> writes: > BTW i am using FFMPEG on windows with win xp platform. > does it make any causes for such errors? > ffmpeg -i D:\test\1.mpg -vf "select=eq(pict_type\,I)" I know this will not really help you, but both above line and your original single quotes work fine on a Linux shell. Perhaps try MSys? Carl Eugen