Cturner/add tutorial 9 (#142)

Add basic-tutorial 9

tutorials/Cargo.toml

@@ -11,7 +11,9 @@ gstreamer = { path = "../gstreamer" }
 gstreamer-audio = { path = "../gstreamer-audio" }
 gstreamer-video = { path = "../gstreamer-video" }
 gstreamer-app = { path = "../gstreamer-app" }
+gstreamer-pbutils = { path = "../gstreamer-pbutils" }
 byte-slice-cast = "0.2"
+failure = "0.1.0"
 
 [badges]
 travis-ci = { repository = "sdroege/gstreamer-rs", branch = "master" }

tutorials/src/bin/basic-tutorial-9.rs

+extern crate failure;
+use failure::Error;
+
+extern crate glib;
+extern crate gstreamer as gst;
+extern crate gstreamer_pbutils as gst_pbutils;
+use gst_pbutils::{
+    prelude::*, Discoverer, DiscovererContainerInfo, DiscovererInfo, DiscovererResult,
+    DiscovererStreamInfo,
+};
+
+use std::env;
+
+#[path = "../tutorials-common.rs"]
+mod tutorials_common;
+
+fn send_value_as_str(v: &glib::SendValue) -> Option<String> {
+    if let Some(s) = v.get::<&str>() {
+        Some(s.to_string())
+    } else if let Some(serialized) = v.serialize() {
+        Some(serialized)
+    } else {
+        None
+    }
+}
+
+fn print_stream_info(info: &DiscovererStreamInfo, depth: usize) {
+    let caps_str = if let Some(caps) = info.get_caps() {
+        if caps.is_fixed() {
+            gst_pbutils::pb_utils_get_codec_description(&caps)
+                .unwrap_or_else(|| String::from("unknown codec"))
+        } else {
+            caps.to_string()
+        }
+    } else {
+        String::new()
+    };
+
+    let stream_nick = info.get_stream_type_nick();
+    println!(
+        "{stream_nick:>indent$}: {caps_str}",
+        stream_nick = stream_nick,
+        indent = 2 * depth + stream_nick.len(),
+        caps_str = caps_str
+    );
+
+    if let Some(tags) = info.get_tags() {
+        println!("{:indent$}Tags:", " ", indent = 2 * depth);
+        for (tag, values) in tags.iter_generic() {
+            let mut tags_str = format!(
+                "{tag:>indent$}: ",
+                tag = tag,
+                indent = 2 * (2 + depth) + tag.len()
+            );
+            let mut tag_num = 0;
+            for value in values {
+                if let Some(s) = send_value_as_str(value) {
+                    if tag_num > 0 {
+                        tags_str.push_str(", ")
+                    }
+                    tags_str.push_str(&s[..]);
+                    tag_num += 1;
+                }
+            }
+
+            println!("{}", tags_str);
+        }
+    };
+}
+
+/* Print information regarding a stream and its substreams, if any */
+fn print_topology(info: &DiscovererStreamInfo, depth: usize) {
+    print_stream_info(info, depth);
+
+    if let Some(next) = info.get_next() {
+        print_topology(&next, depth + 1);
+    } else if let Some(container_info) = info.downcast_ref::<DiscovererContainerInfo>() {
+        for stream in container_info.get_streams() {
+            print_topology(&stream, depth + 1);
+        }
+    }
+}
+
+fn on_connect_discovered(
+    _discoverer: &Discoverer,
+    discoverer_info: &DiscovererInfo,
+    error: &Option<glib::Error>,
+) {
+    let uri = discoverer_info.get_uri().unwrap();
+    match discoverer_info.get_result() {
+        DiscovererResult::Ok => println!("Discovered {}", uri),
+        DiscovererResult::UriInvalid => println!("Invalid uri {}", uri),
+        DiscovererResult::Error => if let Some(msg) = error {
+            println!("{}", msg);
+        } else {
+            println!("Unknown error")
+        },
+        DiscovererResult::Timeout => println!("Timeout"),
+        DiscovererResult::Busy => println!("Busy"),
+        DiscovererResult::MissingPlugins => if let Some(s) = discoverer_info.get_misc() {
+            println!("{}", s);
+        },
+        _ => println!("Unknown result"),
+    }
+
+    if discoverer_info.get_result() != DiscovererResult::Ok {
+        return;
+    }
+
+    println!("Duration: {}", discoverer_info.get_duration());
+
+    if let Some(tags) = discoverer_info.get_tags() {
+        println!("Tags:");
+        for (tag, values) in tags.iter_generic() {
+            print!("  {}: ", tag);
+            values.for_each(|v| {
+                if let Some(s) = send_value_as_str(v) {
+                    println!("{}", s)
+                }
+            })
+        }
+    }
+
+    println!(
+        "Seekable: {}",
+        if discoverer_info.get_seekable() {
+            "yes"
+        } else {
+            "no"
+        }
+    );
+
+    println!("Stream information:");
+
+    if let Some(stream_info) = discoverer_info.get_stream_info() {
+        print_topology(&stream_info, 1);
+    }
+}
+
+fn run_discoverer() -> Result<(), Error> {
+    gst::init()?;
+
+    let args: Vec<_> = env::args().collect();
+    let uri: &str = if args.len() == 2 {
+        args[1].as_ref()
+    } else {
+        "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm"
+    };
+
+    println!("Discovering {}", uri);
+
+    let loop_ = glib::MainLoop::new(None, false);
+    let timeout = 5 * gst::SECOND;
+    let discoverer = gst_pbutils::Discoverer::new(timeout)?;
+    discoverer.connect_discovered(on_connect_discovered);
+    let loop_clone = loop_.clone();
+    discoverer.connect_finished(move |_| {
+        println!("\nFinished discovering");
+        loop_clone.quit();
+    });
+    discoverer.start();
+    discoverer.discover_uri_async(uri)?;
+
+    loop_.run();
+
+    discoverer.stop();
+
+    Ok(())
+}
+
+fn tutorial_main() {
+    match run_discoverer() {
+        Ok(_) => {}
+        Err(err) => eprintln!("Failed to run discovery: {}", err),
+    }
+}
+
+fn main() {
+    // tutorials_common::run is only required to set up the application environment on macOS
+    // (but not necessary in normal Cocoa applications where this is set up automatically)
+    tutorials_common::run(tutorial_main);
+}