better codecs and extensions handling

[jessy]

Hallo all, i want to buy a sansa clip zip, and maybe install rockbox, i found here a nice simulator, so i can see how it will be.
I have many music file, some have probably the wrong extension, and some are in flv and mpeg (yes they are video but i only want to listen the music in it)
In my test, that kind of file doesn't play, and i can't see them if the extension is not known, but it works if i change the extension with the correct audio codec.
It doesn't work "as is" because as i can see in the dos window, the player see the extension, for example mp3, and it use the mp3 codec, if it doesn't work, it skip the file...
My idea is to change that so, i can see every file regardless it's extension, and if a file doesn't work with the default codec, it tries all the others codec before skipping, and maybe add an option to add the correct extension to the filename, so for example filename.xxx became filename.xxx.mp3.

[saratoga]

There is no feasible way to correctly decode a file with a completely random extension on a mobile device. However if there are extensions that are used but we do not support that is easy to fix.

Flv support could be done but i am not interested in working on it. It would be more efficient to just extract the aac stream and put it into mp4.