Case

#!/bin/sh
 
if [ "`snmpget -v 1 -c public des IF-MIB::ifAdminStatus.12 | grep up`" ]
then
        echo "disabling port 12.."
        snmpset -v 1 -c private des IF-MIB::ifAdminStatus.12 i 2 > /dev/null
else
        echo "enabling port 12.."
        snmpset -v 1 -c private des IF-MIB::ifAdminStatus.12 i 1 > /dev/null
fi

mkvextract tracks input.mkv 1:video.h264 2:audio.ac3
mp4creator -create=video.h264 -rate=29.970 output.mp4
mp4creator -hint=1 output.mp4
ffmpeg -y -i audio.ac3 -vn -acodec libfaac -ac 2 -ab 384kbits audio.aac
mp4creator -c audio.aac -interleave -optimize output.mp4
rm audio.aac audio.ac3 video.mp4

#!/bin/sh
 
if ! [ -f "$1" ]
then
        echo "usage: $0 filename"
        exit
fi
 
vt=1
at=2
fps=23.976
fps=29.970
audio=ac3
 
filename=$1
 
size=`stat "$filename" | awk '{print $8}'`
if  [ 4314967296 -lt "$size" ]
then
        mkvmerge -o "`echo $filename|sed -e 's/mkv/Part.mkv/'`" --split 4G "$filename"
        mask="`echo $filename|sed -e 's/mkv/Part-*.mkv/'`"
        files=`ls $mask`
else
        files=$filename
fi
 
for i in $files
do
        mkvextract tracks "$i" $vt:video.h264 $at:audio.$audio
        mp4creator -create=video.h264 -rate=$fps output.mp4
        mp4creator -hint=1 output.mp4
        if [ "$audio" = "dts" ]
        then
                mplayer -vo null -ao pcm audio.dts
                ffmpeg -y -i audiodump.wav -vn -acodec libfaac -ac 2 -ab 384kbits audio.aac
                rm audiodump.wav
        else
                ffmpeg -y -i audio.ac3 -vn -acodec libfaac -ac 2 -ab 384kbits audio.aac
        fi
        mp4creator -c audio.aac -interleave -optimize output.mp4
        rm audio.aac audio.$audio video.h264
        outfile=`echo $i|sed -e 's/mkv/mp4/'`
        mv output.mp4 "$outfile"
        mp4creator -list $outfile
done

#!/bin/sh
 
if ! [ -f "$1" ]
then
        echo "usage: $0 filename"
        exit
fi
 
vt=`mp4creator --list $1|grep video|awk '{print $1}'`
at=`mp4creator --list $1|grep audio|awk '{print $1}'`
fps=`mp4creator --list $1|grep video|awk '{print $11}'`
 
mp4creator --extract=$vt $1
mv $1.t$vt video.h264
mp4creator --extract=$at $1
mv $1.t$at audio.aac
 
echo -n "demuxed? [yes/no]: "
while read x
do
        if [ "$x" = "yes" ]
        then
                break
        else
                echo -n "demuxed? [yes/no]: "
        fi
done
 
mp4creator -create=video.h264 -rate=$fps output.mp4
mp4creator -hint=1 output.mp4
mp4creator -c audio.aac -interleave -optimize output.mp4
mv output.mp4 $1
rm audio.aac video.h264