#!/bin/bash
#
# Calin-Andrei Burloiu, 2010, calin.burloiu@gmail.com
#
# This script transcodes all input videos with a specified extension to a new
# format with a given resolutin and video bitrate. The audio bitrate is hard
# coded to 192 kb/s. The output_path parameter is optional. If not given it
# puts all output files in the same folder as the corresponding input.
#

if test $# -lt 4; then
    echo "Usage: $0 input-path input-extension output-format resolution video-bitrate [output-suffix] [output_path]"
    exit 1
fi

in_path="$1"
in_ext="$2"
out_format="$3"
resolution="$4"
bitrate="$5"
if [ ! -z "$6" ]; then
    out_suffix="$6"
else
    out_suffix=""
fi
if [ ! -z "$7" ]; then
    out_path="$7"
fi

FFMPEG=/usr/bin/ffmpeg
ABITRATE=192k

(
IFS=$'\n'
for filename in $(find "$in_path" -name "*.$in_ext"); do
    if [ ! -z "$out_path" ]; then
        new_filename="${out_path}"$(basename "$filename" ."$in_ext")"$out_suffix"."$out_format"
    else
        new_filename=$(dirname "$filename")/$(basename "$filename" ."$in_ext")"$out_suffix"."$out_format"
    fi

    if [ -e $new_filename ]; then
        echo "$0: $new_filename already exists" >&2
        continue
    fi

    case "$out_format" in
        "avi" )
            $FFMPEG -i "$filename" -f avi -acodec libmp3lame -ab $ABITRATE -ar 44100 -ac 2 -vcodec libx264 -vpre normal -b "$bitrate" -r 25 -s $resolution -threads 0 "$new_filename"
            ;;
        "flv" )
            $FFMPEG -i "$filename" -f flv -acodec libmp3lame -ab $ABITRATE -ar 44100 -ac 2 -vcodec libx264 -vpre normal -b "$bitrate" -r 25 -s $resolution -threads 0 "$new_filename"
            ;;
        "mp4" )
            $FFMPEG -i "$filename" -f mp4 -acodec libmp3lame -ab $ABITRATE -ar 44100 -ac 2 -vcodec libx264 -vpre normal -b "$bitrate" -r 25 -s "$resolution" -threads 0 "$new_filename"
            ;;
        "ogg" )
            $FFMPEG -i "$filename" -f ogg -acodec libvorbis -ab $ABITRATE -ar 44100 -ac 2 -vcodec libtheora -b "$bitrate" -r 25 -s $resolution -threads 0 "$new_filename"
            ;;
        "webm" )
            $FFMPEG -i "$filename" -f webm -acodec libvorbis -ab $ABITRATE -ar 44100 -ac 2 -vcodec libvpx -b "$bitrate" -r 25 -s $resolution -threads 0 "$new_filename"
            ;;
        "ts" )
            $FFMPEG -i "$filename" -f mpegts -acodec libmp3lame -ab $ABITRATE -ar 44100 -ac 2 -vcodec libx264 -vpre normal -b "$bitrate" -r 25 -s $resolution -threads 0 "$new_filename"
            ;;

        * )
            echo "Format $out_format is not implemented!" 1>&2
            exit 1
            ;;
    esac

done
)