Converting AVCHD files to mp4 I have recently recorded some college lectures using my Canon handycam.

The files I seem to have are in AVCHD format.

I'd like to know if there is a relatively fast method to convert them into .mp4 format.

I bought iMovie but with dismay I have been totally defeated by its interface. 

I was thinking of using ffmpeg but thought I'd ask the question here first.

Thanks.
Handbrake should be able to handle AVCHD files. It relies on some codec library files from VLC player, so it may help to have that installed as well. Handbrake uses ffmpeg underneath the hood.

Alternatively, AVIdemux may also be useful. It's a bit more of an editor than just an encoder, but if it can read the source files, it should be able to output the desired encoding.

Commercially, SmartConverterPro has worked okay for me.