gstreamer_play/subclass/
play_video_renderer.rs

1// Take a look at the license at the top of the repository in the LICENSE file.
2
3use glib::{prelude::*, subclass::prelude::*, translate::*};
4
5use crate::{ffi, Play, PlayVideoRenderer};
6
7pub trait PlayVideoRendererImpl: ObjectImpl + ObjectSubclass<Type: IsA<PlayVideoRenderer>> {
8    fn create_video_sink(&self, play: &Play) -> gst::Element;
9}
10
11unsafe impl<T: PlayVideoRendererImpl> IsImplementable<T> for PlayVideoRenderer {
12    fn interface_init(iface: &mut glib::Interface<Self>) {
13        let iface = iface.as_mut();
14
15        iface.create_video_sink = Some(video_renderer_create_video_sink::<T>);
16    }
17}
18
19pub trait PlayVideoRendererImplExt: PlayVideoRendererImpl {
20    fn parent_create_video_sink(&self, play: &Play) -> gst::Element {
21        unsafe {
22            let type_data = Self::type_data();
23            let parent_iface = type_data.as_ref().parent_interface::<PlayVideoRenderer>()
24                as *const ffi::GstPlayVideoRendererInterface;
25
26            let func = (*parent_iface)
27                .create_video_sink
28                .expect("no parent \"create_video_sink\" implementation");
29            let ret = func(
30                self.obj()
31                    .unsafe_cast_ref::<PlayVideoRenderer>()
32                    .to_glib_none()
33                    .0,
34                play.to_glib_none().0,
35            );
36            from_glib_none(ret)
37        }
38    }
39}
40
41impl<T: PlayVideoRendererImpl> PlayVideoRendererImplExt for T {}
42
43unsafe extern "C" fn video_renderer_create_video_sink<T: PlayVideoRendererImpl>(
44    video_renderer: *mut ffi::GstPlayVideoRenderer,
45    play: *mut ffi::GstPlay,
46) -> *mut gst::ffi::GstElement {
47    static VIDEO_SINK_QUARK: std::sync::OnceLock<glib::Quark> = std::sync::OnceLock::new();
48
49    let video_sink_quark =
50        VIDEO_SINK_QUARK.get_or_init(|| glib::Quark::from_str("gstreamer-rs-play-video-sink"));
51
52    let instance = &*(video_renderer as *mut T::Instance);
53    let imp = instance.imp();
54
55    let sink = imp.create_video_sink(&Play::from_glib_borrow(play));
56
57    let sink_ptr: *mut gst::ffi::GstElement = sink.to_glib_none().0;
58
59    let old_sink_ptr = glib::gobject_ffi::g_object_get_qdata(
60        video_renderer as *mut _,
61        video_sink_quark.into_glib(),
62    ) as *mut gst::ffi::GstElement;
63    if !old_sink_ptr.is_null() && old_sink_ptr != sink_ptr {
64        panic!("Video sink must not change");
65    }
66
67    unsafe extern "C" fn unref(ptr: glib::ffi::gpointer) {
68        glib::gobject_ffi::g_object_unref(ptr as *mut _);
69    }
70
71    glib::gobject_ffi::g_object_set_qdata_full(
72        video_renderer as *mut _,
73        video_sink_quark.into_glib(),
74        glib::gobject_ffi::g_object_ref(sink_ptr as *mut _) as *mut _,
75        Some(unref),
76    );
77
78    sink_ptr
79}