GIF support in Windows ?

[probine]

I have a program that shows images. Some of those images are ".GIF". So far, I have been able to show ".JPG" and ".PGN" images in different labels, but as soon as I want to show a ".GIF" image... it doesn't work.

The .gif image is not shown.

How can I tell Qt to show this type of images ?

[jpn]

Have you built Qt with GIF support? If not, run configure -help for details. GIF support is disabled by default because of some copyright/patent/whatever issues.

[probine]

I did not built Qt. I just downloaded the free version from the website. Qt 4.2.2.

I am using it in Windows.

I guess there should be a plug-in or something like that, so I don't have to compile Qt my self.

[ChristianEhrlicher]

You have to recompile it by yourself because TT does not ship a binary package with enabled gif support due to licensing issues. Why not use png?

[probine]

No problem, then I will just use JPG and PNG.

I want it to use GIF, because some users may have their images in GIF format.

[Eldritch]

You have to recompile it by yourself because TT does not ship a binary package with enabled gif support due to licensing issues. Why not use png?

...so after you run configure with -qt-gif you also need to recompile Qt? Dang. I was hoping it just turned on some stuff in the headers. *sigh*

I thought the licensing issues had to do with the generation of GIF images rather than the display of them.

[wysota]

...so after you run configure with -qt-gif you also need to recompile Qt?
Correct. Trolltech GIF support can't be compiled as a plugin (don't ask me why, there is simply no option to do that). You can always implement your own GIF plugin though.


I thought the licensing issues had to do with the generation of GIF images rather than the display of them.
No, you need a licence to use the LZW compression algorithm (the patent has not been lifted everywhere in the world yet). As you need to decompress the image to display it, it may require a licence...