Not sure what section this belongs to so i decided on here. I've been exporting photo slideshows in iphoto to quicktime. I've noticed that the song doesn't transfer over when uploaded to youtube etc. The quicktime movie plays great but once uploaded the sounds goes away...unless it's an mp3. I haven't enough experiments to know for sure so I'm asking here.

Why would a quicktime movie have sound on it if the original source was mp3 and not when the original source is AAC, only once uploaded to the web?

I have 50% of my songs on iTunes as AAC default the other as mp3 192. Only the mp3 192's seem to be able to be read by websites when embedded into a movie. Anybody have experience with this?