#!/bin/sh

# gst-screencast - screencasting of a window using GStreamer
#
# Copyright (C) 2015  Antonio Ospite <ao2@ao2.it>
#
# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.

set -e
set -x

[ "x" = "x$1" ] && { echo "usage: $(basename $0) <output_file> [<ximagesrc_options>]" 1>&2; exit 1; }

[ -f "$1" ] && { echo "ERROR: file already exists!" 1>&2; exit 2; }

FILENAME="$1"

if [ "x" = "x$2" ];
then
  # uncomment to capure the whole frame with window manager border and decorations
  XWININFO_OPTIONS="-frame"

  WIN_INFO="$(xwininfo $XWININFO_OPTIONS)"

  #XID=$(echo "$WIN_INFO" | grep "Window id" | cut -d ' ' -f 4)
  #XIMAGESRC_ARGS="xid=$XID"

  X=$(echo "$WIN_INFO" | sed -n -e "/^[[:space:]]*Absolute upper-left X:[[:space:]]*/s///p")
  Y=$(echo "$WIN_INFO" | sed -n -e "/^[[:space:]]*Absolute upper-left Y:[[:space:]]*/s///p")
  WIDTH=$(echo "$WIN_INFO" | sed -n -e "/^[[:space:]]*Width:[[:space:]]*/s///p")
  HEIGHT=$(echo "$WIN_INFO" | sed -n -e "/^[[:space:]]*Height:[[:space:]]*/s///p")

  BORDER_SIZE=27
  XIMAGESRC_ARGS="startx=$(($X - $BORDER_SIZE)) starty=$(($Y - $BORDER_SIZE)) endx=$(($X + $WIDTH + $BORDER_SIZE)) endy=$(($Y + $HEIGHT + $BORDER_SIZE))"

  XIMAGESRC_ARGS="startx=$(($X - $BORDER_SIZE - 1)) starty=$(($Y - $BORDER_SIZE - 7)) endx=$(($X + $WIDTH + $BORDER_SIZE)) endy=$(($Y + $HEIGHT + $BORDER_SIZE + 7))"
else
  XIMAGESRC_ARGS="$2"
fi

VIDEO_CODEC="video/x-raw,format=I420 ! jpegenc quality=90"
#VIDEO_CODEC="openjpegenc"

gst-launch-1.0 -v \
  ximagesrc use-damage=0 show-pointer=0 $XIMAGESRC_ARGS ! video/x-raw,framerate=25/1 ! \
  videoconvert ! videorate ! $VIDEO_CODEC ! queue ! mux. \
  matroskamux name=mux ! filesink location="$FILENAME"
  #pulsesrc ! audioconvert ! 'audio/x-raw,rate=44100,channels=2' ! queue ! mux. \