Better script for transcoding avchd files to mpeg-4 using mencoder.

By slacy|General|5 Comments

So, you’ve got a shiny new Canon HG10 (or similar) that outputs avchd files, and you’ve got a Linux box, and you want to do something with those movies? Well, I’ve got a script for you. This will transcode an .mts or .m2ts to an .avi, using an excellent 2-pass encoding. All you need in the current top-of-trunk mencoder from subversion (see mplayerhq.hu).

#!/bin/bash
#
# We make a temp directory for each encoder so that we can run more than one
# in parallel (dual core, baby!). Set variables below to change config
# options. Most notably, you’ll need to give the path to your mencoder. To
# transcode to AVCHD, you’ll need the latest mencoder from subversion (see
# http://mplayerhq.hu)
#
ORIGDIR=`pwd`
FILE=$@
MENCODER=~slacy/Desktop/mencoder/mencoder
TMPDIR=/tmp/transcode.$$
LOG=$FILE.mencoder.log
BITRATE=3000

mkdir -p $TMPDIR
cd $TMPDIR

# If you want to encode using x264, you can use the two lines below. I got
# these working, but my computer still isn’t fast enough to play back the
# generated files, so I gave up on x264 encoding. I keep the originals
# around, so its not a huge deal.
#
# $MENCODER $ORIGDIR/$FILE -o $FILE.avi -oac copy -ovc x264 -x264encopts bitrate=$BITRATE:pass=1:subq=1:bframes=1:frameref=1:turbo=2 -fps 120 -ofps 60 -vf yadif=3,scale=1280:720 >> $LOG
# $MENCODER $ORIGDIR/$FILE -o $FILE.avi -oac copy -ovc x264 -x264encopts bitrate=$BITRATE:pass=2:subq=6:partitions=all:8x8dct:me=umh:frameref=5:bframes=1:b_pyramid:weight_b -fps 120 -ofps 60 -vf yadif=3,scale=1280:720 >> $LOG

# Here are the encode lines to generate the mpeg-4 encoding. Note the
# 2-pass, which gives much higher quality.
#
$MENCODER $ORIGDIR/$FILE -o $FILE.avi -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=$BITRATE:vpass=1:mbd=2:trell:v4mv:last_pred=2:dia=-1:vmax_b_frames=2:vb_strategy=1:cmp=3:subcmp=3:precmp=0:vqcomp=0.6:turbo -fps 120 -ofps 60 -vf yadif=3,scale=1280:720 >> $LOG
$MENCODER $ORIGDIR/$FILE -o $FILE.avi -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=$BITRATE:vpass=2:mbd=2:trell:v4mv:last_pred=2:dia=-1:vmax_b_frames=2:vb_strategy=1:cmp=3:subcmp=3:precmp=0:vqcomp=0.6:turbo -fps 120 -ofps 60 -vf yadif=3,scale=1280:720 >> $LOG

# Make sure there isn’t anything in the way…
rm -f $ORIGDIR/$FILE.avi
rm -f $ORIGDIR/$LOG

# And now move the newly generated files back where the original came from.
mv $FILE.avi $ORIGDIR
mv $LOG $ORIGDIR

# And remove our tmpdir to clean up.
rm -fr $TMPDIR