Example for drawing a custom spinner into MPV's window.

issue.md

mpv-player/mpv#11630

mpv_spinner_demo.sh

#!/bin/bash
# -*- coding: utf-8, tab-width: 2 -*-
#
#  mpv_spinner_demo - Example for drawing a custom spinner into MPV's window.
#  Copyright (C) 2023  Marcel Krause <mk+copyleft@pimpmybyte.de>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License along
#  with this program; if not, write to the Free Software Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


set -o pipefail -o errexit

BGCOLOR='black'   # <-- any ImageMagick color names/syntax

SPINNER_FRAMES=(
  # Using the spinner from NetworkManager
  /usr/share/icons/Humanity/apps/24/nm-stage02-connecting*.svg
  )
[ -f "${SPINNER_FRAMES[0]}" ] || exit 4$(local -p >&2
  echo "E: First spinner image frame is not a file." >&2)

mpv --force-window=immediate <(sleep 10m) & MPV_PID=$!

SECONDS=0
while [ "$SECONDS" -lt 3 ]; do
  WIN_ID="$(wmctrl -xpl | sed -nre 's!^(0x\S+) *\S+ *'"$MPV_PID"' .*$!\1!p')"
  [ -z "$WIN_ID" ] || break
  # Window not yet open, let's retry soon:
  sleep 0.1s
done

[ -n "$WIN_ID" ] || exit 4$(
  echo "E: Failed to find window ID for pid $MPV_PID" >&2)

function mpv_alive () { kill -0 "$MPV_PID" 2>/dev/null; }

while mpv_alive; do
  for SPIN in "${SPINNER_FRAMES[@]}"; do
    mpv_alive || break
    # echo "Drawing $SPIN into window $WIN_ID"
    convert "$SPIN" -background "$BGCOLOR" -flatten png24:- \
      | display -window "$WIN_ID" -resample 500% -backdrop - \
      || true # <-- no idea why "display" exits with return value 1.
    sleep 0.1s
  done
done