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GTK sink

gtksink is a GStreamer video sink that exposes the video output as a GTK widget. This is useful when a Python GTK application needs to embed video inside its own window instead of opening a separate video window.

The important part is the sink widget property:

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video_widget = sink.props.widget

You can then add that widget to a GTK layout, connect GTK events to it, and run the normal GTK main loop.

Install

On Ubuntu or Debian:

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sudo apt install python3-gi gir1.2-gtk-3.0 gir1.2-gstreamer-1.0 gstreamer1.0-gtk3 gstreamer1.0-plugins-base

Check that the element is available:

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gst-inspect-1.0 gtksink

Simple usage

The example creates a videotestsrc pipeline, gets the GTK widget from gtksink, adds it to a Gtk.Window, and prints mouse-click coordinates on the video widget.

Simple gtksink example 
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import gi # type: ignore

gi.require_version("Gtk", "3.0")
gi.require_version("Gst", "1.0")

from gi.repository import Gtk, Gst  # type: ignore # noqa: E402

Gst.init(None)

pipeline = Gst.parse_launch(
    "videotestsrc ! videoconvert ! gtksink name=sink"
)

sink = pipeline.get_by_name("sink")

# Get the GTK widget from gtksink
video_widget = sink.props.widget


def on_button_press(widget, event):
    print(
        f"Mouse click: "
        f"x={event.x:.1f}, "
        f"y={event.y:.1f}, "
        f"button={event.button}"
    )


video_widget.add_events(
    1 << 8   # GDK_BUTTON_PRESS_MASK
)

video_widget.connect(
    "button-press-event",
    on_button_press
)

window = Gtk.Window()
window.set_default_size(800, 600)
window.add(video_widget)

window.connect("destroy", Gtk.main_quit)

window.show_all()

pipeline.set_state(Gst.State.PLAYING)

Gtk.main()

pipeline.set_state(Gst.State.NULL)

Demo

  • Mouse click event
  • Keyboard press event
Simple gtksink example 
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import gi # type: ignore

gi.require_version("Gtk", "3.0")
gi.require_version("Gst", "1.0")
gi.require_version("Gdk", "3.0")

from gi.repository import Gtk, Gst, Gdk # type: ignore # noqa: E402

Gst.init(None)

pipeline = Gst.parse_launch(
    "videotestsrc ! videoconvert ! gtksink name=sink"
)

sink = pipeline.get_by_name("sink")

# Get the GTK widget from gtksink
video_widget = sink.props.widget


def on_button_press(widget, event):
    print(
        f"Mouse click: "
        f"x={event.x:.1f}, "
        f"y={event.y:.1f}, "
        f"button={event.button}"
    )


def on_key_press(widget, event):
    key_name = Gdk.keyval_name(event.keyval)
    print(f"Key press: {key_name}")

    if event.keyval == Gdk.KEY_Escape:
        Gtk.main_quit()
        return True

    return False

video_widget.add_events(
    1 << 8   # GDK_BUTTON_PRESS_MASK
)

video_widget.connect(
    "button-press-event",
    on_button_press
)



window = Gtk.Window()
window.set_default_size(800, 600)
window.add(video_widget)

window.connect("destroy", Gtk.main_quit)
window.connect("key-press-event", on_key_press)

window.show_all()

pipeline.set_state(Gst.State.PLAYING)

Gtk.main()

pipeline.set_state(Gst.State.NULL)