#!/bin/bash
#
# Author:       Twily                                                                                            2016
# Description:  Record anything on your desktop, -trim, crop, scale or speed up the video and convert to webm or gif.
# Requires:     ffmpeg, xwininfo, slop, mpv, libnotify, keybind (C-A-x) in your WM to "pkill -f 'x11grab'"
# Usage:        $ sh ./screencast2 -h|--help
# Tip:          Use CRF 10 for WEBM and 0 for GIF
#

DIR='/home/guest/'      # Directory to store files
FILE='out'              # Output filename(.*)
TEMP='edit'             # Edit filename(.*)

RECORD='screen'         # 'screen' 'window' 'region'
MARGIN=$(( 24 + 0 ))    # Margin in window mode (px) (+ 0 for border)
TITLEBAR=0              # Titlebar height in window mode (px)
SLOPWIDTH=2             # Slop border width (px)

PRESET='ultrafast'      # Default 'ultrafast' (x264 --help for preset list)
FPS=30                  # Frames per second [12-60]
CRF=10                  # Constant rate factor [0-51] (Lower is better quality)
QMAX=10                 # Maximum Quantization [1-31] (Lower is better quality)

DELAY=2                 # Seconds before recoring

DISPLAY=':0.0'          # Set monitor to record (:0.0 or :0.1)

SOUND=false             # Record with sound (Requires ALSA Loopback device); see http://pastebin.com/qXWFS81k
LOOPBACK='1,1'          # Loopback device

HELP=false
EDIT=false

OPTS=`getopt -o hwrsf:c:q:d:e: --long help,window,region,sound,fps:,crf:,qmax:,delay:edit: -- "$@"`
eval set -- "$OPTS"

while :; do
    case "$1" in
        -h|--help)    HELP=true;              shift 1 ;;
        -w|--window)  RECORD='window';        shift 1 ;;
        -r|--region)  RECORD='region';        shift 1 ;;
        -s|--sound)   SOUND=true;             shift 1 ;;
        -f|--fps)     FPS="$2";               shift 2 ;;
        -c|--crf)     CRF="$2";               shift 2 ;;
        -q|--qmax)    QMAX="$2";              shift 2 ;;
        -d|--delay)   DELAY="$2";             shift 2 ;;
        -e|--edit)    FILE="$2" && EDIT=true; shift 2 ;;
        --) shift; break ;;
        *) echo "Internal error!"; exit 1
    esac
done

if $HELP; then
    echo -e "Screencast help: \n\n" \
        "-w | --window          Select record mode 'window'\n" \
        "-r | --region          Select record mode 'region'\n" \
        "-s | --sound           Record with sound from loopback\n" \
        "-f | --fps 30          Frames per second [12-60]\n" \
        "-c | --crf 10          Constant rate factor [0-51] (Lower is better quality)\n" \
        "-q | --qmax 10         Maximum Quantization [1-31] (Lower is better quality)\n" \
        "-d | --delay 2         Seconds before recording\n" \
        "-e | --edit out        Edit out(.mkv) in '$DIR' (No recording)\n"
    exit 0
fi

getgeometry() {
    unset x y w h
    eval $($1 | 
        sed -n -e "s/^ \+Absolute upper-left X: \+\([0-9]\+\).*/x=\1/p" \
               -e "s/^ \+Absolute upper-left Y: \+\([0-9]\+\).*/y=\1/p" \
               -e "s/^ \+Width: \+\([0-9]\+\).*/w=\1/p" \
               -e "s/^ \+Height: \+\([0-9]\+\).*/h=\1/p" )
}
appendmargins() {
	x=$(( x-$MARGIN ))
	y=$(( y-$MARGIN-$TITLEBAR ))
	w=$(( w+($MARGIN*2) ))
	h=$(( h+($MARGIN*2)+$TITLEBAR ))
}

drawrectangle() {
    unset x y w h
	region=$(slop -t 0 -b $SLOPWIDTH -c 1,1,1,1 -f "%x %y %w %h" --nokeyboard) || exit 1
	IFS=' ' read -r x y w h <<< "$region"
}
appendrectangle() {
	x=$(( x-$SLOPWIDTH ))
	y=$(( y-$SLOPWIDTH ))
	w=$(( w+($SLOPWIDTH*2) ))
	h=$(( h+($SLOPWIDTH*2) ))
}

recordmkv() {
    notify-send "Desktop is now being recorded.\nStop by pressing Ctrl+Alt+X."

    if $SOUND; then
        ffmpeg -f alsa -ac 2 -i hw:$LOOPBACK \
            -f x11grab -s $w'x'$h -r $FPS -i $DISPLAY'+'$x','$y \
            -c:v libx264 -preset $PRESET -crf $CRF -y "$DIR$FILE.mkv"
    else
        ffmpeg -f x11grab -s $w'x'$h -r $FPS -i $DISPLAY'+'$x','$y \
            -c:v libx264 -preset $PRESET -crf $CRF -y "$DIR$FILE.mkv"
    fi

    notify-send "Screencast has stopped recording."
    echo -e "\nRecording saved to '\033[1;32m$DIR$FILE.mkv\033[0m'.\n"
}

if ! $EDIT; then
    case "$RECORD" in
        'window')
            getgeometry 'xwininfo'
            appendmargins
            ;;
        'region')
            drawrectangle
            appendrectangle
            ;;
        *)
            getgeometry 'xwininfo -root'
            ;;
    esac

    echo -n "Recording begins in "
    while [ "$DELAY" -gt 0 ]; do
        echo -n $DELAY".."
        DELAY=$(( DELAY-1 ))
        sleep 1
    done

    recordmkv
else
    if [ -f "$DIR$FILE.mkv" ]; then
        echo -e "\nLoaded file '\033[1;32m$DIR$FILE.mkv\033[0m'."
    else
        echo -e "\n\033[1;31mError: \033[0mFile '$DIR$FILE.mkv' does not exist..."
        exit 0
    fi
fi

convertwebm() {
    read -r -p $'\nChange QMAX for Webm? ['$QMAX']: ' wQMAX
    wQMAX=${wQMAX:-$QMAX}

    if $SOUND; then
        diff='0.6' # Cut off X seconds from the end of the webm (Workaround to recording w/ sound)
        duration=$(ffprobe -loglevel quiet -of compact=p=0:nk=1 -show_entries format=duration -i "$DIR$FILE.mkv")
        durationDiff=$(echo "$duration-$diff"|bc -l)

        ffmpeg -i "$DIR$FILE.mkv" -t $durationDiff \
            -c:v libvpx -qmin 1 -qmax $wQMAX -preset $PRESET \
            -c:a libvorbis "$DIR$FILE.webm"
    else
        ffmpeg -i "$DIR$FILE.mkv" \
            -c:v libvpx -qmin 1 -qmax $wQMAX -preset $PRESET \
            -c:a libvorbis "$DIR$FILE.webm"
    fi

    echo -e "\nWebm conversion saved to '\033[1;32m$DIR$FILE.webm\033[0m'.\n"
}

convertgif() {
    read -r -p $'\nChange FPS for Gif? ['$FPS']: ' gFPS
    gFPS=${gFPS:-$FPS}

    PALETTE="$DIR"'palette.png'

    ffmpeg -i "$DIR$FILE.mkv" -vf palettegen=stats_mode=diff -y "$PALETTE"
    ffmpeg -i "$DIR$FILE.mkv" -i "$PALETTE" -lavfi paletteuse=dither=none -r $gFPS "$DIR$FILE.gif"

    rm "$PALETTE"

    echo -e "\nGif conversion saved to '\033[1;32m$DIR$FILE.gif\033[0m'.\n"
}

editmkv() {
    rm -f "$DIR$TEMP.mkv"

    while :; do
        read -n1 -r -p $'\nPress key to select \033[1;33m{edit}\033[0m action: \033[0;32m[o]riginal\033[0m \033[0;32m[p]review\033[0m \033[0;36m[t]rim\033[0m \033[0;36m[c]rop\033[0m \033[0;36m[s]cale\033[0m \033[0;36m[f]rames\033[0m \033[0;31mover[w]rite\033[0m \033[0;33m[b]ack\033[0m \n' key

        case "$key" in
            'o') mpv "$DIR$FILE.mkv" --loop=inf ;;
            'p') mpv "$DIR$TEMP.mkv" --loop=inf ;;
            't')
                read -r -p $'\nEnter video start time (hr:min:sec.ms): \n' stime
                read -r -p $'\nEnter video end time (hr:min:sec.ms): \n' etime
                ffmpeg -i "$DIR$FILE.mkv" -ss "$stime" -to "$etime" "$DIR$TEMP.mkv"
                ;;
            'c')
                read -r -p $'\nEnter geometry to crop (width:height:x:y): \n' vcrop
                ffmpeg -i "$DIR$FILE.mkv" -filter:v "crop=$vcrop" "$DIR$TEMP.mkv"
                ;;
            's')
                read -r -p $'\nEnter dimension to scale (width:height or iw/2:ih/2): \n' vscale
                ffmpeg -i "$DIR$FILE.mkv" -vf scale="$vscale" "$DIR$TEMP.mkv"
                ;;
            'f')
                rm -f "/tmp/output-"*.png
                read -r -p $'\nSpeed up video by reducing frames to (<'$FPS$') fps: \n' vfps
                ffmpeg -i "$DIR$FILE.mkv" -r $vfps -f image2 "/tmp/output-%06d.png"
                ffmpeg -r $FPS -i "/tmp/output-%06d.png" -c:v libx264 -preset $PRESET -crf 0 "$DIR$TEMP.mkv"
                ;;
            'w')
                echo -e "\nOverwriting original '\033[1;32m$DIR$FILE.mkv'."
                mv "$DIR$TEMP.mkv" "$DIR$FILE.mkv"
                break
                ;;
            'b') break ;;
        esac
    done
}

while :; do
    read -n1 -r -p $'\nPress key to select \033[1;33m{main}\033[0m action: \033[0;32m[p]review\033[0m \033[0;34m[w]ebm\033[0m \033[0;35m[g]if\033[0m \033[0;36m[e]dit\033[0m \033[0;31me[x]it\033[0m \n' key
    
    case "$key" in
        'p')
            mpv "$DIR$FILE.mkv" --loop=inf
            ;;
        'w') convertwebm ;;
        'g') convertgif  ;;
        'e') editmkv     ;;
        'x')
            exit 0
            ;;
        *)
            echo
            ;;
    esac
done

exit 0