rtpbin2/config: add a new-ssrc signal

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1426>

net/rtp/src/rtpbin2/config.rs

@@ -134,12 +134,24 @@ mod imp {
                 _ => unreachable!(),
             }
         }
+
+        fn signals() -> &'static [glib::subclass::Signal] {
+            static SIGNALS: Lazy<Vec<glib::subclass::Signal>> = Lazy::new(|| {
+                vec![glib::subclass::Signal::builder("new-ssrc")
+                    .param_types([u32::static_type()])
+                    .build()]
+            });
+
+            SIGNALS.as_ref()
+        }
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use crate::test_init;
+    use std::sync::{atomic::AtomicBool, Arc};
+
+    use crate::{rtpbin2::session::tests::generate_rtp_packet, test_init};
 
     use super::*;
 
@@ -186,4 +198,42 @@ mod tests {
         let prop = session.property::<gst::Structure>("pt-map");
         assert!(prop.has_name("application/x-rtpbin2-pt-map"));
     }
+
+    #[test]
+    fn new_send_ssrc() {
+        test_init();
+        let ssrc = 0x12345678;
+        let new_ssrc_hit = Arc::new(AtomicBool::new(false));
+        let rtpbin2 = gst::ElementFactory::make("rtpbin2").build().unwrap();
+        let mut h = gst_check::Harness::with_element(
+            &rtpbin2,
+            Some("rtp_send_sink_0"),
+            Some("rtp_send_src_0"),
+        );
+        let session = h
+            .element()
+            .unwrap()
+            .emit_by_name::<gst::glib::Object>("get-session", &[&0u32]);
+        let ssrc_hit = new_ssrc_hit.clone();
+        session.connect("new-ssrc", false, move |args| {
+            let new_ssrc = args[1].get::<u32>().unwrap();
+            ssrc_hit.store(true, std::sync::atomic::Ordering::SeqCst);
+            assert_eq!(new_ssrc, ssrc);
+            None
+        });
+        h.set_src_caps_str("application/x-rtp,payload=96,clock-rate=90000");
+        let mut segment = gst::Segment::new();
+        segment.set_format(gst::Format::Time);
+        h.push_event(gst::event::Segment::builder(&segment).build());
+        let buf1 = gst::Buffer::from_mut_slice(generate_rtp_packet(ssrc, 0x34, 0x10, 16));
+        h.push(buf1.clone()).unwrap();
+        assert!(new_ssrc_hit.load(std::sync::atomic::Ordering::SeqCst));
+        let buf2 = gst::Buffer::from_mut_slice(generate_rtp_packet(ssrc, 0x35, 0x10, 16));
+        h.push(buf2.clone()).unwrap();
+
+        let buf3 = h.pull().unwrap();
+        assert_eq!(buf3, buf1);
+        let buf4 = h.pull().unwrap();
+        assert_eq!(buf4, buf2);
+    }
 }

net/rtp/src/rtpbin2/imp.rs

@@ -1008,7 +1008,11 @@ impl RtpBin2 {
         loop {
             match session_inner.session.handle_recv(&rtp, addr, now) {
                 RecvReply::SsrcCollision(_ssrc) => (), // TODO: handle ssrc collision
-                RecvReply::NewSsrc(_ssrc, _pt) => (),  // TODO: signal new ssrc externally
+                RecvReply::NewSsrc(ssrc, _pt) => {
+                    drop(session_inner);
+                    session.config.emit_by_name::<()>("new-ssrc", &[&ssrc]);
+                    session_inner = session.inner.lock().unwrap();
+                }
                 RecvReply::Hold(hold_id) => {
                     let pt = rtp.payload_type();
                     let ssrc = rtp.ssrc();
@@ -1149,22 +1153,26 @@ impl RtpBin2 {
         };
 
         let session = session.clone();
-        let mut session = session.inner.lock().unwrap();
+        let mut session_inner = session.inner.lock().unwrap();
         drop(state);
 
         let now = Instant::now();
         loop {
-            match session.session.handle_send(&rtp, now) {
+            match session_inner.session.handle_send(&rtp, now) {
                 SendReply::SsrcCollision(_ssrc) => (), // TODO: handle ssrc collision
-                SendReply::NewSsrc(_ssrc, _pt) => (),  // TODO; signal ssrc externally
+                SendReply::NewSsrc(ssrc, _pt) => {
+                    drop(session_inner);
+                    session.config.emit_by_name::<()>("new-ssrc", &[&ssrc]);
+                    session_inner = session.inner.lock().unwrap();
+                }
                 SendReply::Passthrough => break,
                 SendReply::Drop => return Ok(gst::FlowSuccess::Ok),
             }
         }
         // TODO: handle other processing
         drop(mapped);
-        let srcpad = session.rtp_send_srcpad.clone().unwrap();
-        drop(session);
+        let srcpad = session_inner.rtp_send_srcpad.clone().unwrap();
+        drop(session_inner);
         srcpad.push(buffer)
     }
 
@@ -1201,21 +1209,24 @@ impl RtpBin2 {
         };
 
         let session = session.clone();
-        let mut session = session.inner.lock().unwrap();
+        let mut session_inner = session.inner.lock().unwrap();
         let waker = state.rtcp_waker.clone();
         drop(state);
 
         let now = Instant::now();
         let ntp_now = SystemTime::now();
-        let replies = session
-            .session
-            .handle_rtcp_recv(rtcp, mapped.len(), addr, now, ntp_now);
-        let rtp_send_sinkpad = session.rtp_send_sinkpad.clone();
-        drop(session);
+        let replies =
+            session_inner
+                .session
+                .handle_rtcp_recv(rtcp, mapped.len(), addr, now, ntp_now);
+        let rtp_send_sinkpad = session_inner.rtp_send_sinkpad.clone();
+        drop(session_inner);
 
         for reply in replies {
             match reply {
-                RtcpRecvReply::NewSsrc(_ssrc) => (), // TODO: handle new ssrc
+                RtcpRecvReply::NewSsrc(ssrc) => {
+                    session.config.emit_by_name::<()>("new-ssrc", &[&ssrc]);
+                }
                 RtcpRecvReply::SsrcCollision(_ssrc) => (), // TODO: handle ssrc collision
                 RtcpRecvReply::TimerReconsideration => {
                     if let Some(ref waker) = waker {