I was experimenting with my HF200 footage today.

I uploaded a MTS (shot in AVCHD) file straight into youtube and was able to get full frame HD with it: YouTube - Test Ben raw AVCHD file (http://www.youtube.com/watch?v=oHi4DiMngdU&feature=channel_page)

Can someone explain why youtube doubled the length (thus slowing down the video) of the video, yet kept the audio?

Just to make sure, I put up a second native AVCHD clip and this time even the sound was messed up.

YouTube - Test Skytrain native AVCHD MTS file (http://www.youtube.com/watch?v=R0V2LFCBaes)

I'm even surprised it came out as it did - AVCHD is NOT a supported format for Youtube upload.

See their recommendations here: Learn More : Optimizing your video uploads - YouTube Help (http://www.google.com/support/youtube/bin/answer.py?hl=en&answer=132460)

One solution that works very well is described in this thread: http://www.dvinfo.net/conf/flash-web-video/139496-i-reached-top-video-quality-youtube.html

I hope this helps.