#!/bin/sh
DTCBIN=/usr/local/bin/ffplay
DTCARG="-an -vn -nodisp -stats"
ENCBIN=/usr/local/bin/ffmpeg
AWK=/usr/bin/awk
GREP=/usr/bin/grep
OUTDIR=.

usage() {
  echo "usage: `basename $0` [options] <filename>"
  echo
  echo "options:"
  echo "-o <dir> : Output directory. default: $OUTDIR"
  echo "-h       : Print this message."
}

if [ -z "$1" ]; then
  usage
  exit
fi

while [ $# -ne 0 ]; do
  case "$1" in
  -o)
    shift
    if [ -n "$1" -a -d "$1" ]; then
      OUTDIR=$1
    else
      echo "Invalid Output directory path: $1" >&2
      exit 1
    fi
    ;;
  -h)
    usage
    exit
    ;;
  *)
    break
    ;;
  esac
  shift
done

if [ -z "$1" ]; then
  echo "Input filename is not given." >&2
  exit 1
fi

while [ $# -ne 0 ]; do
  if [ ! -f "$1" ]; then
    echo "given Input filename doesn't exist: $1" >&2
    shift
    continue
  fi

  VINFO=`$DTCBIN $DTCARG "$1" 2>&1 | \
    $AWK ' \
      / Video: / {
        videomode = "";
        split(substr($5, 1, length($5)-1), vid, "x");
        if( int(vid[1] / 160) == int(vid[2] / 90) ) videomode = "C";
        if( int(vid[1] /  40) == int(vid[2] / 30) ) videomode = "N";
        if( videomode == "" ) videomode = "x";
        } 
      / Audio: / {
        audiofreq = $5
        }
      END { print videomode, audiofreq }
    ' `
  VMODE=`echo $VINFO | $AWK '{ print $1 }'`
  AFREQ=`echo $VINFO | $AWK '{ print $2 }'`

  if [ ! -n "`echo $AFREQ | $GREP "[[:digit:]]\{1,\}$"`" ]; then
    echo "Invalid audio sampling freq. Skipping: $1" >&2
    shift
    continue
  fi

  case "$VMODE" in
  C)
    $ENCBIN -y -i "$1" -bitexact -vcodec mpeg4 -qns -nr -mbd 2 -4mv -trell \
      -s 240x136 -padtop 20 -padbottom 20 \
      -r ntsc -qscale 4 -acodec aac -ac 2 -ar $AFREQ -ab 24 \
      "${OUTDIR}/${1}.mp4"
    ;;
  N)
    $ENCBIN -y -i "$1" -bitexact -vcodec mpeg4 -qns -nr -mbd 2 -4mv -trell \
      -s 240x176 \
      -r ntsc -qscale 4 -acodec aac -ac 2 -ar $AFREQ -ab 24 \
      "${OUTDIR}/${1}.mp4"
    ;;
  *)
    echo "Invalid video mode detecting [${VMODE}] . Skipping: $1" >&2
    ;;
  esac

  shift
done