Update readme

Cargo.toml

@@ -1,11 +1,9 @@
 [package]
-name = "${REPO_NAME_LOWER}"
+name = "dfmt-test"
 license = "MPL-2.0"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
 gst = { package = "gstreamer", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs", features = ["v1_20"] }
 gst-video = { package = "gstreamer-video", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
@@ -13,7 +11,8 @@ gst-audio = { package = "gstreamer-audio", git = "https://gitlab.freedesktop.org
 gst-app = { package = "gstreamer-app", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
 anyhow = "1"
 ctrlc = "3.2"
+rand = "0.8.5"
 tokio = { version = "1.17", features = ["full"] }
-axum = "0.5"
+axum = "0.6"
 tower = "0.4"
-tower-http = { version = "0.3", features = ["add-extension"] }
+tower-http = { version = "0.4" }

README.md

@@ -1,3 +1,29 @@
-# ${REPO_NAME}
+# Audio Commands using DTMF
 
-${REPO_DESCRIPTION}
+This is a simple example of how to use DTMF elements of GStreamer with ergonomic Rust code.
+
+## Installation
+
+You will need to install the following dependencies from homebrew:
+
+```bash
+brew install gst-plugins-base gst-plugins-good gst-plugins-bad gst-plugins-ugly gst-libav
+```
+
+Edit the gst-plugins-bad formula to add the following line:
+
+```ruby
+depends_on "spandsp"
+```
+
+Set the following environment variables:
+
+```bash
+export HOMEBREW_NO_INSTALL_FROM_API=1
+```
+
+Then reinstall the formula from source:
+
+```bash
+brew reinstall --build-from-source gst-plugins-bad
+```

src/main.rs

@@ -4,20 +4,103 @@ use anyhow::Result;
 use gst::glib;
 use gst::glib::once_cell::sync::Lazy;
 use gst::prelude::*;
-use std::{process, thread};
+use rand::prelude::*;
+use std::thread;
+use std::thread::sleep;
 use tokio::runtime::Builder;
 
 static CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
     gst::DebugCategory::new("main", gst::DebugColorFlags::empty(), Some("Main function"))
 });
 
+#[derive(Debug, Clone, Copy)]
+struct DtmfEvent(i32);
+
+impl TryFrom<&gst::StructureRef> for DtmfEvent {
+    type Error = anyhow::Error;
+
+    fn try_from(structure: &gst::StructureRef) -> anyhow::Result<Self> {
+        let name = structure.name().to_string();
+        if name != "dtmf-event" {
+            anyhow::bail!("Not a dtmf-event structure: {name}");
+        }
+        let number = structure.get::<i32>("number")?;
+        Ok(Self(number))
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+enum DtmfCommand {
+    Start(i32),
+    End(Option<i32>),
+}
+
+impl DtmfCommand {
+    fn start(number: i32) -> Self {
+        Self::Start(number)
+    }
+
+    fn end(self) -> Self {
+        match self {
+            Self::Start(number) => Self::End(Some(number)),
+            Self::End(_) => self,
+        }
+    }
+}
+
+impl TryFrom<&gst::StructureRef> for DtmfCommand {
+    type Error = anyhow::Error;
+
+    fn try_from(structure: &gst::StructureRef) -> anyhow::Result<Self> {
+        let name = structure.name().to_string();
+        if !name.starts_with("dtmf-event") {
+            anyhow::bail!("Not a dtmf-event structure: {name}");
+        }
+        let number = structure.get_optional::<i32>("number")?;
+        if structure.get::<bool>("start")? {
+            Ok(Self::Start(number.ok_or_else(|| {
+                anyhow::anyhow!("No number specified for start DTMF command")
+            })?))
+        } else {
+            Ok(Self::End(number))
+        }
+    }
+}
+
+impl TryFrom<DtmfCommand> for gst::Structure {
+    type Error = anyhow::Error;
+
+    fn try_from(event: DtmfCommand) -> anyhow::Result<Self> {
+        let structure = match event {
+            DtmfCommand::Start(number) => gst::Structure::builder("dtmf-event")
+                .field("type", 1)
+                .field("start", true)
+                .field("number", number)
+                .field("volume", 36)
+                .build(),
+            DtmfCommand::End(number) => {
+                let Some(number) = number else {
+                    anyhow::bail!("Cannot send end DTMF command without a specified number");
+                };
+                gst::Structure::builder("dtmf-event")
+                    .field("type", 1)
+                    .field("start", false)
+                    .field("number", number)
+                    .build()
+            }
+        };
+        Ok(structure)
+    }
+}
+
 fn main() -> Result<()> {
     gst::init()?;
 
     let pipeline = gst::parse_launch(
         r#"
 
-    videotestsrc ! videoconvert ! timeoverlay shaded-background=true ! gtksink
+    dtmfsrc name=src ! mix.
+    audiotestsrc freq=0 ! audiomixer name=mix ! dtmfdetect ! audioconvert ! autoaudiosink name=audiosink
 
     "#,
     )?
@@ -27,8 +110,6 @@ fn main() -> Result<()> {
     let context = glib::MainContext::default();
     let main_loop = glib::MainLoop::new(Some(&context), false);
 
-    pipeline.set_state(gst::State::Playing)?;
-
     let bus = pipeline.bus().unwrap();
     bus.add_watch({
         let main_loop = main_loop.clone();
@@ -38,7 +119,7 @@ fn main() -> Result<()> {
             match msg.view() {
                 MessageView::Eos(..) => main_loop.quit(),
                 MessageView::Error(err) => {
-                    gst::error!(CAT, obj: &err.src().unwrap(),
+                    gst::error!(CAT, obj: err.src().unwrap(),
                         "Error from {:?}: {} ({:?})",
                         err.src().map(|s| s.path_string()),
                         err.error(),
@@ -46,6 +127,45 @@ fn main() -> Result<()> {
                     );
                     main_loop.quit();
                 }
+                MessageView::Element(element) => {
+                    match element.structure().unwrap().name().as_str() {
+                        "dtmf-event" => {
+                            let dtmf_event = DtmfEvent::try_from(element.structure().unwrap())
+                                .expect("Failed to parse DTMF event");
+                            gst::info!(CAT, "Detected DTMF event: {:?}", dtmf_event);
+                        }
+                        "dtmf-event-processed" => {
+                            let dtmf_cmd = match DtmfCommand::try_from(element.structure().unwrap())
+                            {
+                                Ok(ev) => ev,
+                                Err(err) => {
+                                    gst::error!(
+                                        CAT,
+                                        "Failed to parse DTMF event {:?} with error: {:?}",
+                                        element.structure().unwrap(),
+                                        err
+                                    );
+                                    return glib::Continue(true);
+                                }
+                            };
+                            match dtmf_cmd {
+                                DtmfCommand::Start(number) => {
+                                    gst::info!(CAT, "Processed DTMF event {}", number);
+                                }
+                                DtmfCommand::End(_) => {
+                                    gst::info!(CAT, "Processed ending DTMF event");
+                                }
+                            }
+                        }
+                        _ => {
+                            gst::error!(
+                                CAT,
+                                "Received unknown event: {:?}",
+                                element.structure().unwrap().name()
+                            );
+                        }
+                    }
+                }
                 _ => (),
             };
             glib::Continue(true)
@@ -53,6 +173,50 @@ fn main() -> Result<()> {
     })
     .expect("Failed to add bus watch");
 
+    thread::spawn({
+        let pipeline_weak = pipeline.downgrade();
+        move || {
+            let Some(pipeline) = pipeline_weak.upgrade() else {
+                gst::error!(CAT, "Pipeline gone...");
+                return;
+            };
+
+            let source = pipeline.by_name("src").unwrap();
+
+            // wait pipeline to be running
+            let bus = pipeline.bus().unwrap();
+            while let Some(msg) = bus.timed_pop(None) {
+                use gst::MessageView;
+                if let MessageView::StateChanged(state_changed) = msg.view() {
+                    if state_changed.src().unwrap() == &source
+                        && state_changed.current() == gst::State::Playing
+                    {
+                        break;
+                    }
+                }
+            }
+            gst::info!(CAT, "Pipeline is running");
+
+            let mut rng = rand::thread_rng();
+            loop {
+                let dtmf_cmd = DtmfCommand::start(rng.gen_range(0..15));
+
+                source.send_event(gst::event::CustomUpstream::new(
+                    dtmf_cmd.try_into().unwrap(),
+                ));
+                gst::info!(CAT, "Sent DTMF event {:?}", dtmf_cmd);
+
+                sleep(std::time::Duration::from_millis(10));
+
+                source.send_event(gst::event::CustomUpstream::new(
+                    dtmf_cmd.end().try_into().unwrap(),
+                ));
+
+                sleep(std::time::Duration::from_millis(1000));
+            }
+        }
+    });
+
     thread::spawn({
         let pipeline_weak = pipeline.downgrade();
         move || {
@@ -66,12 +230,12 @@ fn main() -> Result<()> {
         }
     });
 
+    pipeline.set_state(gst::State::Playing)?;
+
     ctrlc::set_handler({
-        let pipeline_weak = pipeline.downgrade();
+        let main_loop = main_loop.clone();
         move || {
-            let pipeline = pipeline_weak.upgrade().unwrap();
-            pipeline.set_state(gst::State::Null).unwrap();
-            process::exit(0);
+            main_loop.quit();
         }
     })?;