ImageMagick: support converting videos

[amannucci (Anthony Mannucci)]

The convert program is broken. It is configured to use the delegate avconv which does not exist, and is not available via Macports. The dependency used to be on ffmpeg, which does exist. This is to convert video such as mpeg.

[mf2k (Frank Schima)]

In the future, please fill in the Port field and Cc the port maintainers (port info --maintainers ImageMagick).

[ryandesign (Ryan Carsten Schmidt)]

The ImageMagick Portfile makes no mention of ffmpeg or supporting converting from video files, but I'm happy to look into adding this feature.

[amannucci (Anthony Mannucci)]

I fixed the problem by modifying the delegates.xml, using the file included in the binary OS X distribution on the ImageMagick site. The delegates.xml in MacPorts should be changed.

[ryandesign (Ryan Carsten Schmidt)]

So far, I have not figured out how to tell ImageMagick to use ffmpeg. The delegates.xml file is created at build time, and the placeholder "@MPEGDecodeDelegate@" is replaced with the mpeg decode delegate program name. I don't know how to tell ImageMagick's configure script what program name it should use there.

[petrrr]

Cc Me!

[petrrr]

I today ran into the same issue, actually there may be even to different issued.

(1) Trying to get an AVI video output resulted in only the first frame being present in the resulting file (2) MPEG output tries to call avconv, this seems to be part of a library called libav

I understood, that only (2) delegates conversion to ffmpeg (or maybe libav as an alternative). While (2) should be built-in, so this maybe a different problem.