I am using FFMPEG-Kit for iOS BUT this issue applies to all releases of FFMPEG-Kit... within my command I run [1:v]format=argb,geq=r='r(X,Y)':a='0.5*alpha(X,Y)'[withOpacitySet]
but it does not work, if I run the command without that it runs fine...
Is it the commas? The quotation marks?