Compile ffmpeg for iOS

[alemio]

Here are the instructions for compiling ffmpeg for macOS.

https://sourceforge.net/projects/qtav/

What I have to set to compile for iOS?

If I link the libraries with your instructions I have this error
building for 'iOS', but linking in object file (/usr/local/ffmpeg/arm64/lib/libavcodec.a2) built for 'macOS'

[jsulm]

@alemio Build instructions are here: https://github.com/wang-bin/QtAV/wiki/Build-QtAV
Simply use qmake from your Qt for iOS installation.