net/webrtc: add whipclient example

Add a simple example producing both audio and video to make it
work with the whipserver example

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1938>

net/webrtc/Cargo.toml

@@ -129,3 +129,7 @@ required-features = [ "whip" ]
 
 [[example]]
 name = "webrtcsink-define-encoder-bitrates"
+
+[[example]]
+name = "whipclient"
+required-features = [ "whip" ]

net/webrtc/examples/README.md

@@ -271,3 +271,22 @@ https://github.com/M0Rf30/android-udev-rules
    cargo r --example webrtc-precise-sync-send
    ```
 4. Click the `Refresh` button on the Producer List view of the app.
+
+# webrtchttp examples
+
+Collection of webrtchttp examples
+
+## whipserversrc and whipclientsink
+
+An couple of examples to demonstrate how a simple pipeline with both audio and video
+use these elements
+
+1.- Run the WHIP server
+```shell
+  cargo r --example whipserver --features whip http://127.0.0.1:8190
+```
+
+2.- Run the WHIP client
+```shell
+  cargo r --example whipclient --features whip http://127.0.0.1:8190/whip/endpoint
+```

net/webrtc/examples/whipclient.rs

@@ -0,0 +1,64 @@
+use anyhow::Error;
+use clap::Parser;
+use gst::prelude::*;
+
+#[derive(Parser, Debug)]
+struct Args {
+    whip_endpoint: String,
+}
+
+fn main() -> Result<(), Error> {
+    gst::init()?;
+
+    let args = Args::parse();
+
+    let pipeline = gst::Pipeline::builder().build();
+
+    let videotestsrc = gst::ElementFactory::make("videotestsrc").build()?;
+    let audiotestsrc = gst::ElementFactory::make("audiotestsrc").build()?;
+    let vqueue = gst::ElementFactory::make("queue").build()?;
+    let aqueue = gst::ElementFactory::make("queue").build()?;
+    let whipclientsink = gst::ElementFactory::make("whipclientsink").build()?;
+    whipclientsink
+        .dynamic_cast_ref::<gst::ChildProxy>()
+        .unwrap()
+        .set_child_property("signaller::whip-endpoint", args.whip_endpoint);
+
+    pipeline.add_many([&videotestsrc, &vqueue, &whipclientsink])?;
+    gst::Element::link_many([&videotestsrc, &vqueue, &whipclientsink])?;
+
+    pipeline.add_many([&audiotestsrc, &aqueue])?;
+    gst::Element::link_many([&audiotestsrc, &aqueue, &whipclientsink])?;
+
+    pipeline.set_state(gst::State::Playing)?;
+
+    let bus = pipeline.bus().expect("Pipeline should have a bus");
+
+    for msg in bus.iter_timed(gst::ClockTime::NONE) {
+        use gst::MessageView;
+
+        match msg.view() {
+            MessageView::Eos(..) => {
+                println!("EOS");
+                break;
+            }
+            MessageView::Error(err) => {
+                pipeline.set_state(gst::State::Null)?;
+                eprintln!(
+                    "Got error from {}: {} ({})",
+                    msg.src()
+                        .map(|s| String::from(s.path_string()))
+                        .unwrap_or_else(|| "None".into()),
+                    err.error(),
+                    err.debug().unwrap_or_else(|| "".into()),
+                );
+                break;
+            }
+            _ => (),
+        }
+    }
+
+    pipeline.set_state(gst::State::Null)?;
+
+    Ok(())
+}