add info cmd to example client, README update

README.md

@@ -63,12 +63,24 @@ Help welcome!
 Try the `mp4` example. It streams from an RTSP server to a `.mp4` file until
 you hit ctrl-C.
 
-```
+```shell
 $ cargo run --example client mp4 --url rtsp://ip.address.goes.here/ --username admin --password test out.mp4
 ...
 ^C
 ```
 
+## Example client
+
+```shell
+$ cargo run --example client <CMD>
+```
+
+Where CMD:
+
+* **info** - Get info about available streams and exit
+* **mp4** - Write RTSP streams to mp4 file, exit with Ctrl+C
+* **metadata** - Get realtime onvif metadata if available, exit with Ctrl+C
+
 ## Acknowledgements
 
 This builds on the whole Rust ecosystem. A couple folks have been especially

examples/client/main.rs

@@ -28,8 +28,12 @@ struct Source {
 
 #[derive(StructOpt)]
 enum Cmd {
+    /// Write available audio and video streams to mp4 file
     Mp4(mp4::Opts),
+    /// Get realtime metadata of onvif stream, use Ctrl+C to stop
     Metadata(metadata::Opts),
+    /// Get info about available streams and exit
+    Info(metadata::Opts),
 }
 
 fn init_logging() -> mylog::Handle {
@@ -78,6 +82,7 @@ async fn main_inner() -> Result<(), Error> {
     let cmd = Cmd::from_args();
     match cmd {
         Cmd::Mp4(opts) => mp4::run(opts).await,
-        Cmd::Metadata(opts) => metadata::run(opts).await,
+        Cmd::Metadata(opts) => metadata::run(opts, false).await,
+        Cmd::Info(opts) => metadata::run(opts, true).await,
     }
 }

examples/client/metadata.rs

@@ -14,16 +14,16 @@ pub struct Opts {
     src: super::Source,
 }
 
-pub async fn run(opts: Opts) -> Result<(), Error> {
+pub async fn run(opts: Opts, is_info: bool) -> Result<(), Error> {
     let session_group = Arc::new(SessionGroup::default());
-    let r = run_inner(opts, session_group.clone()).await;
+    let r = run_inner(opts, session_group.clone(), is_info).await;
     if let Err(e) = session_group.await_teardown().await {
         error!("TEARDOWN failed: {}", e);
     }
     r
 }
 
-async fn run_inner(opts: Opts, session_group: Arc<SessionGroup>) -> Result<(), Error> {
+async fn run_inner(opts: Opts, session_group: Arc<SessionGroup>, is_info: bool) -> Result<(), Error> {
     let stop = tokio::signal::ctrl_c();
 
     let creds = super::creds(opts.src.username, opts.src.password);
@@ -35,6 +35,12 @@ async fn run_inner(opts: Opts, session_group: Arc<SessionGroup>) -> Result<(), E
             .session_group(session_group),
     )
     .await?;
+    if is_info {
+        for stream in session.streams() {
+            println!("{}", stream);
+        }
+        return Ok(());
+    }
     let onvif_stream_i = session
         .streams()
         .iter()