[JeremyS]

Hi I have some large files of radio shows that I record in aiff format then I export them in Quicktime to mp4 after I have cut out the commercials etc.

The problem is one I have cut out the commericals and re-export it using "Pass-through" in quicktime the new mp4 and the old one for that matter do not show up on my ipod after sync.

In iTunes using "Get info" it says it's a quicktime movie file and when I select convert to AAC in iTunes it give me and error when converting half-way through.

The file is 4 hours in length, after I exported in to mp4 using Quicktime the file is only 130mb so size is not the issue.

Basically what is the best process for me to make sure my files work right after I have recorded my file as an aiff?

I usually want to encode to AAC right after so the file is small, then I want to edit out the commercials and re-save it as AAC to be synced to the iPod.

Also why this confusion, iTunes calls it AAC and Quicktime calls it mp4, why don't they just have a export to AAC in quicktime??

[JeremyS]

Well I found that if I changed the file extension from .MP4 to .m4a they now work and will sync to the iPod, why in the world would Quicktime export this way?

[andreas_g4]

For me, it looks like quicktime is not able to export as AAC, it exports only MPEG 4 content. Of course, AAC is the audio component of MPEG 4, so if you export an AIF file as .mp4, you get a MPEG 4 movie file without any visual content but the audio track is an AAC.
iTunes on the other hand exports directly and only to AAC, as you can see due to the extension .m4a

It's bad that if you open a .m4a file in quicktime it can only be saved as .mp4. I think you have to edit your uncompressed files and convert them with iTunes to .m4a afterwards.