Thanks to a Urkki, I've found out that mencoder-SVN nowadays supports AVCHD transcoding pretty well now. So I'll publish my current (quite easy) script for converting AVCHD into 720p Mpeg4.
First get a current svn version of mplayer and compile and install it:
svn checkout svn://svn.mplayerhq.hu/mplayer/trunk mplayer
CFLAGS= ./configure && make && sudo make install
Then you can use this command:
mencoder 00001.MTS -o 1.avi -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=10000:threads=2:ilme:ildct -lavdopts threads=2 -vf scale=1280:720:1 -fps 50
- I need fps 50 because mplayer doesn't yet detect the fps automatically in my files.
- I've used two threads to speed things up on multi-core systems: threads= should be the number of cores your cpu has.
- I have interlaced content and preserve the interlacing: scale=...:1, ilme:ildct.