Playing some animated GIFs using GtkImage displays many grainy artifacts
Update: a one line shell reproducer is:
eog https://i.imgur.com/doXKbmj.gif
Playing some animated GIFs using GtkImage displays many grainy artifacts. It affects eog, eom, gthumb and gnome pix and does not affect KDE gwenview, mpv, firefox and chromium. One can reproduce it using this python3 code, and a somewhat NSFW (sexualized and with some skin, but no private parts) GIF - originally from here , which is called doXKbmj.gif
and which I attach here:
#!/usr/bin/env python
# -*- Mode: Python; py-indent-offset: 4 -*-
# vim: tabstop=4 shiftwidth=4 expandtab
#
# Copyright (C) 2010 Red Hat, Inc., John (J5) Palmieri <johnp@redhat.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
# USA
title = "Images"
description = """GtkImage is used to display an image; the image can be in a
number of formats. Typically, you load an image into a GdkPixbuf, then display
the pixbuf. This demo code shows some of the more obscure cases, in the simple
case a call to gtk_image_new_from_file() is all you need.
"""
import os
from os import path
from gi.repository import Gtk, Gdk, GdkPixbuf, GLib, Gio, GObject
class ImagesApp:
def __init__(self):
self.pixbuf_loader = None
self.image_stream = None
self.window = Gtk.Window(title="Images")
self.window.connect('destroy', self.cleanup_cb)
self.window.set_border_width(8)
vbox = Gtk.VBox(spacing=8)
vbox.set_border_width(8)
self.window.add(vbox)
label = Gtk.Label()
label.set_markup('<u>Image loaded from file</u>')
vbox.pack_start(label, False, False, 0)
frame = Gtk.Frame()
frame.set_shadow_type(Gtk.ShadowType.IN)
# The alignment keeps the frame from growing when users resize
# the window
align = Gtk.Alignment(xalign=0.5,
yalign=0.5,
xscale=0,
yscale=0)
align.add(frame)
vbox.pack_start(align, False, False, 0)
self.base_path = os.path.abspath(os.path.dirname(__file__))
self.base_path = os.path.join(self.base_path, 'data')
filename = "./doXKbmj.gif"
pixbuf = GdkPixbuf.Pixbuf.new_from_file(filename)
transparent = pixbuf.add_alpha(True, 0xff, 0xff, 0xff)
image = Gtk.Image.new_from_pixbuf(transparent)
frame.add(image)
# Animation
label = Gtk.Label()
label.set_markup('<u>Animation loaded from file</u>')
vbox.pack_start(label, False, False, 0)
frame = Gtk.Frame()
frame.set_shadow_type(Gtk.ShadowType.IN)
# The alignment keeps the frame from growing when users resize
# the window
align = Gtk.Alignment(xalign=0.5,
yalign=0.5,
xscale=0,
yscale=0)
align.add(frame)
vbox.pack_start(align, False, False, 0)
# img_path = path.join(self.base_path, 'floppybuddy.gif')
img_path = "./doXKbmj.gif"
image = Gtk.Image.new_from_file(img_path)
frame.add(image)
# Symbolic icon
label = Gtk.Label()
label.set_markup('<u>Symbolic themed icon</u>')
vbox.pack_start(label, False, False, 0)
frame = Gtk.Frame()
frame.set_shadow_type(Gtk.ShadowType.IN)
# The alignment keeps the frame from growing when users resize
# the window
align = Gtk.Alignment(xalign=0.5,
yalign=0.5,
xscale=0,
yscale=0)
align.add(frame)
vbox.pack_start(align, False, False, 0)
gicon = Gio.ThemedIcon.new_with_default_fallbacks('battery-caution-charging-symbolic')
image = Gtk.Image.new_from_gicon(gicon, Gtk.IconSize.DIALOG)
frame.add(image)
# progressive
label = Gtk.Label()
label.set_markup('<u>Progressive image loading</u>')
vbox.pack_start(label, False, False, 0)
frame = Gtk.Frame()
frame.set_shadow_type(Gtk.ShadowType.IN)
# The alignment keeps the frame from growing when users resize
# the window
align = Gtk.Alignment(xalign=0.5,
yalign=0.5,
xscale=0,
yscale=0)
align.add(frame)
vbox.pack_start(align, False, False, 0)
image = Gtk.Image.new_from_pixbuf(None)
frame.add(image)
self.start_progressive_loading(image)
# Sensistivity control
button = Gtk.ToggleButton.new_with_mnemonic('_Insensitive')
button.connect('toggled', self.toggle_sensitivity_cb, vbox)
vbox.pack_start(button, False, False, 0)
self.window.show_all()
def toggle_sensitivity_cb(self, button, container):
widget_list = container.get_children()
for w in widget_list:
if w != button:
w.set_sensitive(not button.get_active())
return True
def progressive_timeout(self, image):
# This shows off fully-paranoid error handling, so looks scary.
# You could factor out the error handling code into a nice separate
# function to make things nicer.
if self.image_stream:
try:
buf = self.image_stream.read(256)
except IOError as e:
dialog = Gtk.MessageDialog(self.window,
Gtk.DialogFlags.DESTROY_WITH_PARENT,
Gtk.MessageType.ERROR,
Gtk.ButtonsType.CLOSE,
"Failure reading image file 'alphatest.png': %s" % (str(e), ))
self.image_stream.close()
self.image_stream = None
self.load_timeout = 0
dialog.show()
dialog.connect('response', lambda x, y: dialog.destroy())
return False # uninstall the timeout
try:
self.pixbuf_loader.write(buf)
except GObject.GError as e:
dialog = Gtk.MessageDialog(self.window,
Gtk.DialogFlags.DESTROY_WITH_PARENT,
Gtk.MessageType.ERROR,
Gtk.ButtonsType.CLOSE,
e.message)
self.image_stream.close()
self.image_stream = None
self.load_timeout = 0
dialog.show()
dialog.connect('response', lambda x, y: dialog.destroy())
return False # uninstall the timeout
if len(buf) < 256: # eof
self.image_stream.close()
self.image_stream = None
# Errors can happen on close, e.g. if the image
# file was truncated we'll know on close that
# it was incomplete.
try:
self.pixbuf_loader.close()
except GObject.GError as e:
dialog = Gtk.MessageDialog(self.window,
Gtk.DialogFlags.DESTROY_WITH_PARENT,
Gtk.MessageType.ERROR,
Gtk.ButtonsType.CLOSE,
'Failed to load image: %s' % e.message)
self.load_timeout = 0
dialog.show()
dialog.connect('response', lambda x, y: dialog.destroy())
return False # uninstall the timeout
else:
img_path = path.join(self.base_path, 'alphatest.png')
try:
self.image_stream = open(img_path, 'rb')
except IOError as e:
dialog = Gtk.MessageDialog(self.window,
Gtk.DialogFlags.DESTROY_WITH_PARENT,
Gtk.MessageType.ERROR,
Gtk.ButtonsType.CLOSE,
str(e))
self.load_timeout = 0
dialog.show()
dialog.connect('response', lambda x, y: dialog.destroy())
return False # uninstall the timeout
if self.pixbuf_loader:
try:
self.pixbuf_loader.close()
except GObject.GError:
pass
self.pixbuf_loader = None
self.pixbuf_loader = GdkPixbuf.PixbufLoader()
self.pixbuf_loader.connect('area-prepared',
self.progressive_prepared_callback,
image)
self.pixbuf_loader.connect('area-updated',
self.progressive_updated_callback,
image)
# leave timeout installed
return True
def progressive_prepared_callback(self, loader, image):
pixbuf = loader.get_pixbuf()
# Avoid displaying random memory contents, since the pixbuf
# isn't filled in yet.
pixbuf.fill(0xaaaaaaff)
image.set_from_pixbuf(pixbuf)
def progressive_updated_callback(self, loader, x, y, width, height, image):
# We know the pixbuf inside the GtkImage has changed, but the image
# itself doesn't know this; so queue a redraw. If we wanted to be
# really efficient, we could use a drawing area or something
# instead of a GtkImage, so we could control the exact position of
# the pixbuf on the display, then we could queue a draw for only
# the updated area of the image.
image.queue_draw()
def start_progressive_loading(self, image):
# This is obviously totally contrived (we slow down loading
# on purpose to show how incremental loading works).
# The real purpose of incremental loading is the case where
# you are reading data from a slow source such as the network.
# The timeout simply simulates a slow data source by inserting
# pauses in the reading process.
self.load_timeout = Gdk.threads_add_timeout(150,
GLib.PRIORITY_DEFAULT_IDLE,
self.progressive_timeout,
image)
def cleanup_cb(self, widget):
if self.load_timeout:
GLib.source_remove(self.load_timeout)
if self.pixbuf_loader:
try:
self.pixbuf_loader.close()
except GObject.GError:
pass
if self.image_stream:
self.image_stream.close()
Gtk.main_quit()
def main(demoapp=None):
ImagesApp()
Gtk.main()
if __name__ == '__main__':
main()
Thanks for looking into it and let me know if you need more info.
This bug happens on fedora 32 x86-64 and mageia v8 x86-64 , including in a new user in icewm.
Edited by Shlomi Fish