#!/bin/sh

# Encode a movie as divx/mp3 to fit on a CD

[ -z "$1" ] && echo "example: `basename $0` all dvd:// -dvd-device <dvbackupdir>" && exit 1

trap 'echo "encoding interrupted" ; exit 1' SIGINT


COMMAND=$1
shift

# includes input options
OPTS=$@


# We're using 3 phase encoding. The first pass will do only audio,
# which enables a good estimate of the necessary bitrate to fit on a
# CD. The output of mencoder is saved to the file 'recommended'.

AUDIO_OPTS="-oac mp3lame -lameopts vbr=3"

audio () {
    rm -f frameno.avi
    mencoder \
	-ovc frameno \
	$AUDIO_OPTS \
	-o frameno.avi \
	-quiet \
	$OPTS >recommended
}

# The 'recommended' file generated in the first pass is grepped for
# the bitrate to use. The result is written to the file 'bitrate'.

bitrate () {
    cat recommended \
	| grep '^Recommended video bitrate for 700MB' \
	| awk '{print $7}' >bitrate
}

# Perform multipass video encoding using the bitrate determined from
# the first (audio) pass. This is no longer using the audio stream
# from frameno.avi, since that seems to be deprecated (gives sync problems)

_video () {
    mencoder \
	$AUDIO_OPTS \
	-ovc lavc \
	-mc 0 \
	-lavcopts vcodec=mpeg4:$1:aspect=16/9:vbitrate=`cat bitrate` \
	-quiet \
	-o movie.avi \
	$OPTS
}

# The first pass writes the statistics file. See man page for vpass.


video1 () { 
    _video vpass=1:turbo
}

# The second pass reads it.

video2 () {
    _video vpass=2
}

# Perform all passes.

all () {
    audio
    bitrate
    video1
    video2
}

$COMMAND