ffmpeg-dump

#! /usr/bin/env ksh93
# A full screen or individual window screenshot tool using ffmpeg's x11grab.
# usage:
# -f: screenshot of entire screen
# -b: include borders of selected window (default: no decorations)
# Get more details on usage from running the program with '-h' or '--help'.

# Requires `xwininfo`, `xprop`, `ffmpeg`, `sed`, `cut`, and `grep`.
# `xdotool` is an optional dependency, but recommended.
# The first two are installed in the 'x11-utils' package on Debian and similar.
# I think it should work with bash as well as to ksh93 (which I wrote it for);
# to try it, replace the '#! /usr/bin/env ksh93' at the top with '#! /bin/bash'
# for instance. I think for POSIX shell (/bin/sh) to work I'd have to rewrite
# the $(( )) math operations to use 'expr' or 'bc' instead.

# It can optionally use `xdotool` to try to give focus screenshotted window;
# presently, this is just done automatically if xdotool is detected on the
# system, but if it bothers anyone I'd be happy to make it a configuration
# option or run-time flag.

help_text() {
       echo "$0"
       echo "A full screen or individual-window screenshot tool using ffmpeg/x11grab."
       echo "Usage:"
       echo "$(basename "$0")"' [OPTIONS] OUTPUT-DIR [FILENAME]'
       echo "If FILENAME is not specified, then the screenshot will be saved in"
       echo 'OUTPUT-DIR and given a name in the format:'
       echo '"Screenshot at YYYY-MM-DD HH-MM-DD.png".'
       echo "Unless otherwise requested, default behavior is to allow the user to click"
       echo "the window to be screenshotted. Other modes of operation are described below."
       echo ""
       echo "OPTIONS:"
       echo "-b, --borders     Include window borders (decorations) in a window screenshot"
       echo "                    (can be used alongside -w or on its own)."
       echo "                    Default: don't include window borders/decorations."
       echo "-d, --decorations Synonyms for -b."
       echo "-f, --fullscreen  Take screenshot of the entire screen instead of one window."
       echo "-h, --help        Show this message and exit."
       echo "-m, --show-cursor Show mouse pointer in screenshot (default: hide pointer)."
       echo "-t, --timer [int] Wait [int] seconds before capturing."
       echo "-w, --window      Take a screenshot of only one window selected by integer"
       echo "                  window ID."
}

wininfoattr()
{
  # $1 is window id
  # $2 is attribute to get
  xwininfo -id "$1" | grep "$2" | sed 's/.*\: *//'
}

unalias grep 2>/dev/null
unalias ffmpeg 2>/dev/null
unalias xwininfo 2>/dev/null

FULL_SCR=0
WIN_ID=0
WIDTH=0
HEIGHT=0
RESOLUTION=""
INCLUDE_BORDERS=0
DELAY_TIME=0
PARSING=1
SHOW_CURSOR=0

if [ "$#" -eq 0 ]; then
  1>&2 echo "Error: no arguments given."
  1>&2 help_text
  exit 1
fi

while [[ $PARSING -eq 1 ]]; do
  case "$1" in
    '-b' | '--borders' | '-d' | '--decorations')
      INCLUDE_BORDERS=1
      shift
      ;;
    '-t' | '--timer' | '--delay' )
      if [[ "$#" -gt 1 ]]; then
        DELAY_TIME="$2"
        shift 2
      else
        # bug: actually check if a number was passed, since this error message
        # will NOT be generated if timer is not the last argument and
        # no delay will be used.
        1>&2 echo "Error: No time was specified for timer. Exiting."
        exit 1
      fi
      ;;
    '-f' | '--full' | '--fullscreen' )
      FULL_SCR=1
      if [ "$DELAY_TIME" -eq 0 ]; then
        DELAY_TIME=1
      fi
      shift
      ;;
    '-m' | '--show-cursor')
      SHOW_CURSOR=1
      shift
      ;;
    '-w' | '--window')
      shift
      WIN_ID="$1"
      shift
      ;;
    '-h' | '--help')
      help_text
      exit 0
      ;;
    *)
      PARSING=0
      ;;
  esac
done
if [[ "$FULL_SCR" -eq 1 ]]; then
  WIN_ID=`xwininfo -root -int|grep Window\ id|sed 's/.*Window id\: //;s/ .*//'`
  RESOLUTION=`xwininfo -id "$WIN_ID" | grep geometry | sed 's/^.*geometry *//;s/+.*//;s/-.*//'`
  X_CORNER=0
  Y_CORNER=0
else
  # click to select window
  # geometry is unreliable for e.g. terminal windows, so use width and height
  # instead, which are guaranteed pixels i think.

  #  WIN_ID=`xdotool getwindowfocus`
  # xwininfo comes in x11-utils, so the xdotool dependency can be avoided if
  # we use it instead.
  if [[ "$WIN_ID" -eq 0 ]]; then # can be set by -w at run-time
    WIN_ID=`xwininfo -int|grep Window\ id|sed 's/.*Window id\: //;s/ .*//'`
  fi

  if [[ "$INCLUDE_BORDERS" -ne 1 ]]; then
    WIDTH=`wininfoattr "$WIN_ID" 'Width'`
    HEIGHT=`wininfoattr "$WIN_ID" 'Height'`
    
    X_CORNER=`wininfoattr "$WIN_ID" 'Absolute upper-left X'`
    Y_CORNER=`wininfoattr "$WIN_ID" 'Absolute upper-left Y'`
    BORDER_WIDTH_LEFT=0
    BORDER_WIDTH_RIGHT=0
    BORDER_HEIGHT_TOP=0
    BORDER_HEIGHT_BOTTOM=0
  else
    # check if we have xdotool for a little bonus feature (in my opinion)
    2>/dev/null type xdotool > /dev/null
    if [[ "$?" -eq 0 ]]; then
      # If we have xdotool, we can use it to set the active window focus.
      # if we don't have xdotool, don't worry about it; it's not too important.
      # Basically, though, since the GUI wrapper tool I wrote for this script
      # will steal the input focus, we can just do this in order to try to
      # return it to the window we were using afterwards without requiring any
      # further user actions.
      # Note that this might not pop the window to the topmost level; it just
      # returns keyboard focus and stuff.
      xdotool windowfocus "$WIN_ID"
    fi

    # Factor in window decorations.
    # Thanks to stack overflow for the xprop command, I wasn't able to find
    # out any other ways to get decoration info. (X protocol limitations, yay)
    EXTENTS="$(xprop _NET_FRAME_EXTENTS -id "$WIN_ID")"
    # BORDER_WIDTH_LEFT="$(echo $EXTENTS | sed 's/.* = //;s/,.*//')"
    # BORDER_WIDTH_RIGHT="$()"
    BORDER_WIDTH_LEFT="$(echo $EXTENTS | cut -d ',' -f 1 | sed 's/.*= *//')" # width of left border
    BORDER_WIDTH_RIGHT="$(echo $EXTENTS | cut -d ',' -f 2 | sed 's/ *//')" # width of right border
    BORDER_HEIGHT_TOP="$(echo $EXTENTS | cut -d ',' -f 3 | sed 's/ *//')"  # height of title bar
    BORDER_HEIGHT_BOTTOM="$(echo $EXTENTS | cut -d ',' -f 4 | sed 's/ *//')" # height of bottom border

    WIDTH=$((`wininfoattr "$WIN_ID" 'Width'`+"$BORDER_WIDTH_RIGHT"+"$BORDER_WIDTH_LEFT"))
    X_CORNER=$((`wininfoattr "$WIN_ID" 'Absolute upper-left X'`-"$BORDER_WIDTH_LEFT"))
    HEIGHT=$((`wininfoattr "$WIN_ID" 'Height'`+"$BORDER_HEIGHT_BOTTOM"+"$BORDER_HEIGHT_TOP"))
    Y_CORNER=$((`wininfoattr "$WIN_ID" 'Absolute upper-left Y'`-"$BORDER_HEIGHT_TOP"))
  fi
  SCREEN_HEIGHT=`xwininfo -root -int | grep Height | sed 's/.*\: *//'`
  SCREEN_WIDTH=`xwininfo -root -int | grep Width | sed 's/.*\: *//'`
  # catch things that would make x11grab fail, like off-screen window corners.
  # to correct anything off the top or the left, adjust CORNER variables.
  # to correct anything off the bottom or the right, adjust WIDTH or HEIGHT.
  # window goes off left side of screen
  if [[ "$X_CORNER" -lt 0 ]]; then
    WIDTH=$(("$WIDTH"+"$X_CORNER")) # subtract unseen area from total width.
    X_CORNER=0
  fi
  # window goes off top of screen
  if [[ "$Y_CORNER" -lt 0 ]]; then
    HEIGHT=$(("$HEIGHT"+"$Y_CORNER")) # subtract unseen area from total height.
    Y_CORNER=0
  fi
  # window goes off right of screen
  if [[ $(("$WIDTH"+"$X_CORNER")) -gt "$SCREEN_WIDTH" ]]; then
    WIDTH=$(("$SCREEN_WIDTH"-"$X_CORNER"))
  fi
  # window goes off bottom of screen
  if [[ $(("$HEIGHT"+"$Y_CORNER")) -gt "$SCREEN_HEIGHT" ]]; then
    HEIGHT=$(("$SCREEN_HEIGHT"-"$Y_CORNER"))
  fi

  RESOLUTION="$WIDTH"'x'"$HEIGHT"
fi
dograb()
{
  # args: [destination-dir] [filename]
  # ffmpeg command dissected
  # -loglevel warning		Don't print anything except warnings/errors.
  # -video_size			Tell ffmpeg x11grab the size of the area to grab.
  # -f x11grab			Use x11grab for video capture
  # -draw_mouse 0			Prevent x11grab from drawing the cursor over the
  #						screenshot
  # -i 					Input (X11 display and corner information)
  # -frames:v 1			Only write a single frame (since this isn't a video).
  # -s					Set output frame size
  # -f image2				Force 'image2' output format. IIRC, 'image' is a
  #						long-obsolete format.
  # -y					Overwrite (assume 'yes' to questions).
  # $1					Pass output file name argument
  if [[ "$#" -ge 2 ]]; then
    FILENAME="$1""/""$2"
  else
    FILENAME="$1""/""$(date +'Screenshot at %Y-%m-%d %H-%M-%S')"".png"
  fi
  echo PARAMS: "$@"
  #  ffmpeg -loglevel warning -video_size "$RESOLUTION" -f x11grab $MOUSEPARAM_A $MOUSEPARAM_B -i "$DISPLAY"'+'"$X_CORNER"','"$Y_CORNER" -frames:v 1 -s "$RESOLUTION" -f image2 -y "$FILENAME"
  # imagemagick convert seems to give better compression. we output uncompressed png from ffmpeg using -compression_level 0 and then let imagemagick do all the heavy lifting.
  ffmpeg -loglevel warning -video_size "$RESOLUTION" -f x11grab -draw_mouse "$SHOW_CURSOR" -i "$DISPLAY"'+'"$X_CORNER"','"$Y_CORNER" -frames:v 1 -s "$RESOLUTION" -f image2 -compression_level 0 -vcodec png - | convert png:- "$FILENAME"
  echo 'Image saved as '"$FILENAME"'.'
  exit
}
if [[ "$DELAY_TIME" -gt 0 ]]; then
  # not necessary to have behind the 'if' gate, necessarily, but this might
  # actually improve speed by avoiding fetching a program from the disk.
  sleep "$DELAY_TIME"
fi
dograb "$@"