ImageMagick depends on libav, libav not provided

[mexon (Matthew Exon)]

I'm trying to put together a timelapse video from individual frames, like:

convert *.jpg output.mp4

This produces:

convert: delegate failed `'avconv' -nostdin -v -1 -i '%M%%d.jpg' '%u.%m' 2> '%u'' @ error/delegate.c/InvokeDelegate/1919.

The issue is that it wants avconv, but avconv is not available with MacPorts. See here:

​https://superuser.com/questions/568464/how-to-install-libav-avconv-on-osx

As you can see from the answers, installing avconv is possible if you use MacPorts, but is very inconvenient. Whereas with brew it's trivial.

There has been an attempt to bring avconv into MacPorts here. It was rejected because "it appears that ffmpeg provides all this provides". It seems not. The current situation leaves ImageMagick in a broken state.

[ryandesign (Ryan Carsten Schmidt)]

​According to the ImageMagick forum, it looks like ImageMagick used to require ffmpeg for reading video files, but as of late 2013 it will use either ffmpeg or libav/avconv, whichever is installed.

It looks like ImageMagick does not declare a dependency on ffmpeg. Do you have it installed? If not, try sudo port install ffmpeg.

I don't recall why ImageMagick doesn't declare a dependency on ffmpeg, but it might be because I would guess that most people use ImageMagick only to manipulate images; I didn't even know it could produce a video from a set of images. Adding a heavy dependency like ffmpeg would add overhead that most people probably wouldn't need. But maybe we should add a variant to the port for this.

#42299 might be related or the same issue.

If you would like MacPorts to offer libav/avconv, please re-open #50039 and discuss there.

[mf2k (Frank Schima)]

+1 on at least adding a ffmpeg variant to ImageMagick. Although I think the dependency and support should just be added always.