I get this Error:
Error: Permission denied - /usr/local/lib/libswscale.dylib
What is this dylib for ? I upgraded and broke my installation by that (i assume) and tried to uninstall and unlinked. Unlink worked. uninstall gave me the error.
What is the correct procedere ? sudo brew uninstall ffmpeg ?
Why did I upgrade ? It worked fine before ...
libswscale is the software picture scaler of ffmpeg.
Normally brew uninstall ... should work. In all likelihood you installed ffmpeg manually at some point (sudo make install) or forced brew to install with sudo (which brew normally refuses).
In general you should avoid sudo with brew, but in this case it would be OK to fix the broken stuff:
sudo brew uninstall ffmpeg
Alternatively sudo rm the files brew complains about.