feat(gst): implement Playbin3 wrapper with basic playback functionality

gst/src/playbin3.rs

@@ -0,0 +1,65 @@
+use crate::*;
+pub struct Playbin3 {
+    inner: gstreamer::Element,
+}
+
+impl Drop for Playbin3 {
+    fn drop(&mut self) {
+        let _ = self.inner.set_state(gstreamer::State::Null);
+    }
+}
+
+impl Playbin3 {
+    pub fn new(name: impl AsRef<str>) -> Result<Self> {
+        use gstreamer::prelude::*;
+        gstreamer::ElementFactory::make("playbin3")
+            .name(name.as_ref())
+            .build()
+            .map(|element| Playbin3 { inner: element })
+            .change_context(Error)
+    }
+
+    pub fn with_uri(self, uri: impl AsRef<str>) -> Self {
+        use gstreamer::prelude::*;
+        self.inner.set_property("uri", uri.as_ref());
+        self
+    }
+
+    pub fn sample(&self) -> Option<Sample> {
+        use gstreamer::prelude::*;
+        self.inner
+            .property::<Option<gstreamer::Sample>>("sample")
+            // // .and_then(|v| v.get::<gstreamer::Sample>().ok())
+            .map(|sample| Sample { sample })
+    }
+
+    pub fn play(&self) -> Result<()> {
+        use gstreamer::prelude::*;
+        self.inner
+            .set_state(gstreamer::State::Playing)
+            .change_context(Error)
+            .attach("Failed to set playbin3 to Playing state")?;
+        Ok(())
+    }
+    pub fn bus(&self) -> Result<Bus> {
+        let bus = self
+            .inner
+            .bus()
+            .ok_or(Error)
+            .attach("Failed to get bus from playbin3")?;
+        Ok(Bus { bus })
+    }
+}
+
+#[test]
+fn test_playbin3() {
+    use gstreamer::prelude::*;
+    gstreamer::init().unwrap();
+    let playbin3 = Playbin3::new("test_playbin3").unwrap().with_uri(
+        "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm",
+    );
+    playbin3.play().unwrap();
+    let bus = playbin3.bus().unwrap();
+    for msg in bus.iter_timed(None) {}
+    // std::thread::sleep(std::time::Duration::from_secs(5));
+}