A: 

I don't have much experience with this, but do you have the ffmpeg libraries installed on your system? I don't believe they're included with OpenCV.

teeks99
Yes, they're installed.
Adam
+2  A: 

Your link line is missing -lavutil -lavcodec.

alex strange
A: 

I installed OpenCV and FFmpeg using homebrew and both work Ok.

karlphillip