record screen with ffmpeg

screen_record.sh

#!/bin/bash

# how to use
#
#              |----------------------- $1 - filename; can be _
#              |    |------------------ $2 - window coordinate x
#              |    | |---------------- $3 - window coordinate y
#              |    | |   |------------ $4 - width
#              |    | |   |    |------- $5 - height
#              |    | |   |    |   |--- $6 - display number
#              |    | |   |    |   |
# screen_video well 0 100 1280 600 0
#
# and after we got file well.flv

if [[ -z $(command -v ffmpeg) ]]; then echo "need istall ffmpeg"; exit 1; fi

if [[ -z "$1" || "$1" == "_" ]]; then
    name="temp_screen_video_$(\
        cat /dev/urandom |\
        tr -dc 'a-zA-Z0-9' |\
        fold -w 4 |\
        head -n 1)"
else
    name="$1"
fi

if [[ -n "$2" ]]; then       x=$2; else       x=0;    fi
if [[ -n "$3" ]]; then       y=$3; else       y=0;    fi
if [[ -n "$4" ]]; then   width=$4; else   width=1280; fi
if [[ -n "$5" ]]; then  height=$5; else  height=800;  fi
if [[ -n "$6" ]]; then display=$6; else display=0;    fi

video_size="${width}x${height}"
position="${x},${y}"

trap ctrl_c INT

ctrl_c() {
    echo "record was stopped: ${name}.flv"
    exit 0
}

echo "run record: ${name}.flv"
ffmpeg -v 0 -y -video_size ${video_size} -framerate 25 -f x11grab -i :${display}.0+${position} -strict -2 -qscale 5 "${name}".flv