How to ensure minimal audio quality loss when exporting from iMovie?

You could export your audio-video movie using the Best Quality (pro res) setting, that would give you an uncompressed LPCM audio file. The file size would be large, maybe 4x or so larger than the AAC file. But, you would have your single image song-cover preserved. I think that that's the way I would try. You Tube will do whatever it is going to do, but might as well upload the highest quality possible and see what happens.

Good luck with your project.

-- Rich

Hi,

I have not worked with audio enough to answer your question.

As a matter of information, when you export from iMovie using the Audio Only setting you will be given the options to export at WAV or AIFF formats, that are both lossless (uncompressed).

With either format you will get a 48000Hz audio.

If you export at the High Quality setting you will get an AAC file that is lossy and compressed, although still 48000Hz. As you can see from the screen shot below, the AAC Data Size is considerably smaller than WAV.

-- Rich