Record a window ('s size) with ffmpeg

recordWindow.sh

#!/bin/sh

# do we have the necessary software?
FFMPEG=`which ffmpeg`
XWININFO=`which xwininfo`
XDGOPEN=`which xdg-open`

if [ -z "$FFMPEG" ]; then
	echo "ffmpeg not available"
	exit 1
fi

if [ -z "$XWININFO" ]; then
	echo "xwininfo not found."
	exit 1
fi

OUTPUT="$1"

echo "Please click the window you wish to record. Press q to quit recording."

data=`$XWININFO`

XPOS=`echo "$data" | grep "Absolute upper-left X:" | cut -d ':' -f2 | sed 's/^ *//'`
YPOS=`echo "$data" | grep "Absolute upper-left Y:" | cut -d ':' -f2 | sed 's/^ *//'`
WIDTH=`echo "$data" | grep "Width:" | cut -d ':' -f2 | sed 's/^ *//'`
HEIGHT=`echo "$data" | grep "Height:" | cut -d ':' -f2 | sed 's/^ *//'`

# let's get the window borders too, they are 1px in each direction
#let XPOS-=1
#let YPOS-=1
#let HEIGHT+=2
#let WIDTH+=2

echo "Will record size ${WIDTH}x${HEIGHT} at position ${XPOS}x${YPOS}."

$FFMPEG -f alsa -ac 2 -i pulse -f x11grab -r 30 -s ${WIDTH}x${HEIGHT} -i :0.0+${XPOS},${YPOS} -acodec pcm_s16le -vcodec libx264 -threads 0 $OUTPUT

if [ $? -eq 0 ]; then
	printf "\n\n\nFile created:\n"
	ls -l $OUTPUT
	printf  "\nSuccess! File [$OUTPUT] created."

	if [ -n "$XDGOPEN" ]; then
		printf "Open now? [Y/N] "
		read response

		if [ "$response" == "y" ] || [ "$response" == "Y" ]; then
			echo "Opening..."
			xdg-open $OUTPUT
		fi
	fi
else
	echo "Something went wrong :("
fi