The processing time was around 4m20s on a MacBook Pro with 3GB RAM.
Is this good or bad? One possible speedup I could use is to compress more than one image at a time, although the progress indicator would probably have to become asynchronous.
Just curious about PNGOUT - did you get permission to bundle it with your app? Their license http://www.advsys.net/ken/utils.htm#pngoutkziplicense seems pretty restrictive: "Redistributing, repackaging, or reusing the PNGOUT or KZIP executable is prohibited without the express consent of Ardfry Imaging, LLC, and a formal business agreement.
No I didn't, thanks for pointing this out. I'll remove it for now; didn't realize their license had that restriction. That's pretty lame :\.
Could you not take the ffmpegX route and have the people download the pngout on their own? If they do not download it you can still make the program work without pngout but for the people that want the smallest filesize they can take the additional steps to download it and put it in the correct location.
Also, I think that having it finish quicker is >> correctly indicated timeline.
Alternately, just pop up a confirmation dialog stating "I hereby confirm that I am requesting of my own volition to download PNGOUT to aid the functionality of this program," and then download it automatically.
The license clearly specifies that "reusing" is itself not allowed without permission, so that doesn't change anything...his program still uses pngout without permission, and it's his (the programmmer's) use that is at issue here, not the end user.
A similar tool is ImageOptim http://pornel.net/imageoptim/en , an open souce GUI for the following PNG / JPG optimizers: AdvPNG, OptiPNG, PngCrush, JpegOptim, jpegtran, and optionally PNGOUT.
Just curious about PNGOUT - did you get permission to bundle it with your app? Their license http://www.advsys.net/ken/utils.htm#pngoutkziplicense seems pretty restrictive: "Redistributing, repackaging, or reusing the PNGOUT or KZIP executable is prohibited without the express consent of Ardfry Imaging, LLC, and a formal business agreement."