#!/bin/bash

# any2avi: converts any video file to avi file compatible with most devices

# compile ffmpeg with LAME, X264, FAAC, and XVID enabled:
#
# FAAC=yes XVID=yes ./ffmpeg.SlackBuild

#
# CONFIGURATION SECTION BEGINS HERE
#

accepted_width="720"            # highest accepted width
accepted_height="576"           # highest accepted height

accepted_video="mpeg4 msmpeg4 mpeg2video mpeg1video"    # all accepted video codecs
accepted_audio="mp3 ac3 mp2 wmav2 pcm_s16le"            # all accepted audio codecs

#accepted_video="(ms)?mpeg4 mpeg[12]video"      # all accepted video codecs
#accepted_audio="mp[23] ac3 wmav2 pcm_s16le"    # all accepted audio codecs

#
# CONFIGURATION SECTION ENDS HERE
#

infile="$1"

if [ "$infile" == "" ]
then
cat <<EOF
any2avi: converts any video file to avi file compatible with most devices

any2avi file

EOF
    exit
fi

tempfile="/tmp/.ffmpeg.tmp"

accepted_scale=${accepted_width}x${accepted_height}

ffmpeg -i "$infile" 2> $tempfile

if [ ! -e $tempfile ]
then
cat <<EOF
any2avi: cannot create $tempfile file

EOF
    exit
fi

video_string=$(grep 'Video: ' $tempfile)
audio_string=$(grep 'Audio: ' $tempfile)

rm $tempfile

orig_vcodec=$(echo $video_string | awk '{print $4}')
orig_vcodec=${orig_vcodec/,/}
orig_acodec=$(echo $audio_string | awk '{print $4}')
orig_acodec=${orig_acodec/,/}
orig_scale=`echo $video_string | sed -E "s/.* ([0-9]+x[0-9]+)[ ,].*/\1/"`

orig_width=$orig_scale
orig_width=${orig_width/x*/}
orig_height=$orig_scale
orig_height=${orig_height/*x/}

orig_aspect=$(echo "scale=2 ; $orig_width/$orig_height" | bc)

if [ $orig_width -le $accepted_width ] && [ $orig_height -le $accepted_height ]
then
    video="rejected"
    for video_format in $accepted_video
    do
        if [ "$(echo $orig_vcodec | egrep -w $video_format)" != "" ]
        then
            video="accepted"
        fi
    done
    audio="rejected"
    for audio_format in $accepted_audio
    do
        if [ "$(echo $orig_acodec | egrep -w $audio_format)" != "" ]
        then
            audio="accepted"
        fi
    done
    if [ "$video" == "accepted" ] && [ "$audio" == "accepted" ]
    then
cat <<EOF
any2avi: no conversion required

#   scale = $orig_scale
#  aspect = $orig_aspect
#  vcodec = $orig_vcodec
#  acodec = $orig_acodec

EOF
        exit
    fi
fi

function count_scale() {
    if [ $orig_width -gt $accepted_width ]
    then
        factor=$(echo "scale=2 ; $orig_width/$accepted_width" | bc)
        width=$accepted_width
        height=$(echo "$orig_height/$factor" | bc)
        height=$(($height/2))
        height=$(($height*2))
    else
        width=$orig_width
        height=$orig_height
    fi
    if [ $height -gt $accepted_height ]
    then
        factor=$(echo "scale=2 ; $height/$accepted_height" | bc)
        height=$accepted_height
        width=$(echo "$width/$factor" | bc)
        width=$(($width/2))
        width=$(($width*2))
    fi
    scale=${width}x${height}
}

count_scale

aspect=$(echo "scale=2 ; $width/$height" | bc)
bitrate=$(($width*$height*50*25/256/1000))k

function run() {
cat <<EOF
# accepted:
#   scale = $accepted_scale
#  vcodec = $accepted_video
#  acodec = $accepted_audio

# original:
#   scale = $orig_scale
#  aspect = $orig_aspect
#  vcodec = $orig_vcodec
#  acodec = $orig_acodec

# used:
#   scale = $scale
#  aspect = $aspect
# bitrate = $bitrate
#  vcodec = mpeg4 (libxvid)
#  acodec = mp3   (libmp3lame)

$command

EOF
    eval $command
}

command="ffmpeg -i \"$infile\" -codec:v libxvid -b:v $bitrate -aspect $aspect -s $scale -codec:a libmp3lame -b:a 160k -ar 48000 \"$infile.avi\""
run