Hi everybody,

As I've banged hy head all the week-end with it, trying a lot of stuffs, reading a lot of stuffs too on this forum and in the Qt doc, I will post a little how-to.

With Visual C++, having jpeg working on another fresh computer is not as simple as copying the qtjpeg4.dll in a imageformats subfolder... It is really frustrating to discover that after discovering that jpeg is a plugin and that it should work this way.

It works perfectly with MinGW but not with Visual C++.

The first thing to do to have it working is to definitely forget about a local installation of the Microsoft Visual C++ run-time (so in the same folder than the app). In this way, the jpeg plugin won't work.

So, you will have to install the Visual C++ redist system wide with the installer vcredist_x86.exe that you can found on the Microsoft Website.

It is possible to install it silently : http://blogs.msdn.com/astebner/archi...-packages.aspx

This is the way I do with the NSIS installer (but if someone know how to forbid or warn if the user wants to remove the Visual C++ redist separately, don't hesitate to post on the thread ;o)).

But this is not enough. Don't esperate to have the jpeg plugin working by putting it in the app subfolder.

You should write a qt.conf file in the app folder on the target machine :

Qt Code: 
  1. [Paths]
  2. Plugins = plugins
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If you do like above, you should place the qtjpeg4.dll in the subfolder plugins\imageformats from the app folder.

Then, it will work !

Quite boring to spend lot of hours on that, hope it will help. Don't hesitate to add it in the FAQ