Add basic-tutorial-12

Add basic-tutorial-12 from the GStreamer tutorials

tutorials/src/bin/basic-tutorial-12.rs

@@ -0,0 +1,101 @@
+extern crate gstreamer as gst;
+extern crate glib;
+use gst::prelude::*;
+use std::io::Write;
+
+extern crate failure;
+use failure::Error;
+
+
+#[path = "../tutorials-common.rs"]
+mod tutorials_common;
+
+fn tutorial_main() -> Result<(), Error> {
+    // Initialize GStreamer
+    gst::init()?;
+
+    // Build the pipeline
+    let uri =
+        "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm";
+    let pipeline = gst::parse_launch(&format!("playbin uri={}", uri))?;
+
+    let mut is_live = false;
+
+    // Start playing
+    let ret = pipeline.set_state(gst::State::Playing);
+    assert_ne!(ret, gst::StateChangeReturn::Failure);
+    if ret == gst::StateChangeReturn::NoPreroll {
+        is_live = true;
+    }
+
+    let main_loop = glib::MainLoop::new(None, false);
+    let main_loop_clone = main_loop.clone();
+    let pipeline_weak = pipeline.downgrade();
+    let bus = pipeline.get_bus().unwrap();
+    bus.add_watch(move |_, msg| {
+        let pipeline = match pipeline_weak.upgrade() {
+            Some(pipeline) => pipeline,
+            None => return glib::Continue(true),
+        };
+        let main_loop = &main_loop_clone;
+        match msg.view() {
+            gst::MessageView::Error(err) => {
+                println!(
+                    "Error from {:?}: {} ({:?})",
+                    err.get_src().map(|s| s.get_path_string()),
+                    err.get_error(),
+                    err.get_debug()
+                );
+                let _ = pipeline.set_state(gst::State::Ready);
+                main_loop.quit();
+            }
+            gst::MessageView::Eos(..) => {
+                // end-of-stream
+                let _ = pipeline.set_state(gst::State::Ready);
+                main_loop.quit();
+            }
+            gst::MessageView::Buffering(buffering) => {
+                // If the stream is live, we do not care about buffering
+                if is_live {
+                    return glib::Continue(true);
+                }
+
+                let percent = buffering.get_percent();
+                print!("Buffering ({}%)\r", percent);
+                match std::io::stdout().flush() {
+                    Ok(_) => {},
+                    Err(err) => eprintln!("Failed: {}", err),
+                };
+
+                // Wait until buffering is complete before start/resume playing
+                if percent < 100 {
+                    let _ = pipeline.set_state(gst::State::Paused);
+                } else {
+                    let _ = pipeline.set_state(gst::State::Playing);
+                }
+            }
+            gst::MessageView::ClockLost(_) => {
+                // Get a new clock
+                let _ = pipeline.set_state(gst::State::Paused);
+                let _ = pipeline.set_state(gst::State::Playing);
+            }
+            _ => (),
+        }
+        glib::Continue(true)
+    });
+
+    main_loop.run();
+
+    bus.remove_watch();
+    let ret = pipeline.set_state(gst::State::Null);
+    assert_ne!(ret, gst::StateChangeReturn::Failure);
+
+    Ok(())
+}
+
+fn main() {
+    match tutorials_common::run(tutorial_main) {
+        Ok(_) => {},
+        Err(err) => eprintln!("Failed: {}", err),
+    }
+}