ffmpeg screengrabber

ffmpeg-screengrab.sh

#!/bin/sh
usage() {
	cat << EOF
ffmpeg screengrabber wrapper. End recording by pressing 'q'.

Usage: $0 [options] [name]

Parameters:

  name                  optional string to include in the file name

  -h, --help            Show this help screen
  -w, --window          Choose window to set recording area
                        (default: record whole screen)
EOF
}

# Parameter parsing
# ----------------
opt_title=
opt_window=
while [ -n "$1" ]; do
	case "$1" in
		-w|--window)	opt_window=1;;
		-h|--help)	usage "$0"; exit;;
		*)		opt_title="${opt_title}${1}"
	esac
        shift
done

# Variable setup
# --------------

if [ -z "$DISPLAY" ]; then
        echo "Error: Empty \$DISPLAY variable. Are you sure you're running an X session?"
        exit 1
fi

tmpfile=$(mktemp --tmpdir ffmpeg-screengrab.XXXXXXXX)
trap "rm $tmpfile" EXIT

# Output file name
if [ -n "$opt_title" ]; then
	opt_title="-${opt_title}"
fi
outputfile="screengrab${opt_title}-$(date +%Y%m%d-%H%M%S).mkv"

# Recording area
if [ -z "$opt_window" ]; then
        opt_window="-root"
else
        opt_window=""
        echo "Please select the window you want to record by clicking the mouse in that window..."
fi
xwininfo $opt_window > "$tmpfile"

#awk '/-geometry / { print ' | 
winname=$(awk '/Window id:/ { $1=""; print }' "$tmpfile")
winx=$(awk '/Absolute upper-left X:/ { print $4 }' "$tmpfile")
winy=$(awk '/Absolute upper-left Y:/ { print $4 }' "$tmpfile")
winw=$(awk '/Width:/  { print $2 }' "$tmpfile")
winh=$(awk '/Height:/ { print $2 }' "$tmpfile")
if 
        [ -z "$winx" ] ||
        [ -z "$winy" ] ||
        [ -z "$winh" ] ||
        [ -z "$winw" ]; then
        echo "Error: could not detect geometry from xwininfo :("
        exit 2
fi
winarea="${winw}x${winh}"
winpos="+${winx},${winy}"

# Recording
# ---------
printf "Recording %s\n" "$winname"
printf "Recording size %s, offset %s\n" "$winarea" "$winpos"
printf "Writing to %s\n" "$outputfile"
printf "Press q (in this terminal) to stop recording.\n\n"
sleep 3

ffmpeg -f x11grab \
	-video_size "${winarea}" \
        -i ${DISPLAY}${winpos} \
	-framerate 10 \
	-c:v h264 -preset ultrafast -q:v 2 \
	"${outputfile}"

printf "Recording written to %s\n" "$outputfile"