feat(iced-video): added video format to the video frame

gst/src/plugins/app/appsink.rs

@@ -6,9 +6,71 @@ pub use gstreamer_app::AppSinkCallbacks;
 wrap_gst!(AppSink, gstreamer::Element);
 parent_child!(Element, AppSink);
 
+pub struct AppSinkBuilder {
+    inner: AppSink,
+    callbacks: Option<gstreamer_app::app_sink::AppSinkCallbacksBuilder>,
+}
+
+impl AppSinkBuilder {
+    pub fn on_new_sample<F>(mut self, mut f: F) -> Self
+    where
+        F: FnMut(&AppSink) -> Result<(), gstreamer::FlowError> + Send + 'static,
+    {
+        let mut callbacks_builder = self
+            .callbacks
+            .take()
+            .unwrap_or_else(gstreamer_app::app_sink::AppSinkCallbacks::builder);
+        callbacks_builder = callbacks_builder.new_sample(move |appsink| {
+            use glib::object::Cast;
+            let element = appsink.upcast_ref::<gstreamer::Element>();
+            let appsink = AppSink::from_gst_ref(element);
+            std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| f(appsink)))
+                .unwrap_or(Err(gstreamer::FlowError::Error))
+                .map(|_| gstreamer::FlowSuccess::Ok)
+        });
+        self.callbacks = Some(callbacks_builder);
+        self
+    }
+
+    pub fn on_new_preroll<F>(mut self, mut f: F) -> Self
+    where
+        F: FnMut(&AppSink) -> Result<(), gstreamer::FlowError> + Send + 'static,
+    {
+        let mut callbacks_builder = self
+            .callbacks
+            .take()
+            .unwrap_or_else(gstreamer_app::app_sink::AppSinkCallbacks::builder);
+        callbacks_builder = callbacks_builder.new_preroll(move |appsink| {
+            use glib::object::Cast;
+            let element = appsink.upcast_ref::<gstreamer::Element>();
+            let appsink = AppSink::from_gst_ref(element);
+            std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| f(appsink)))
+                .unwrap_or(Err(gstreamer::FlowError::Error))
+                .map(|_| gstreamer::FlowSuccess::Ok)
+        });
+        self.callbacks = Some(callbacks_builder);
+        self
+    }
+
+    pub fn build(self) -> AppSink {
+        let AppSinkBuilder { inner, callbacks } = self;
+        if let Some(callbacks) = callbacks {
+            inner.appsink().set_callbacks(callbacks.build());
+        }
+        inner
+    }
+}
+
 impl Sink for AppSink {}
 
 impl AppSink {
+    pub fn builder(name: impl AsRef<str>) -> AppSinkBuilder {
+        let inner = AppSink::new(name).expect("Failed to create AppSink");
+        AppSinkBuilder {
+            inner,
+            callbacks: None,
+        }
+    }
     fn appsink(&self) -> &gstreamer_app::AppSink {
         self.inner
             .downcast_ref::<gstreamer_app::AppSink>()
@@ -54,7 +116,7 @@ impl AppSink {
         self
     }
 
-    pub fn on_new_frame<F>(&mut self, mut f: F) -> &mut Self
+    pub fn on_new_sample<F>(&mut self, mut f: F) -> &mut Self
     where
         F: FnMut(&AppSink) -> Result<(), gstreamer::FlowError> + Send + 'static,
     {