From: Thomas Karpiniec <tom.karpiniec@outlook.com>
Date: Sat, 18 Jan 2025 03:25:58 +0000 (+1100)
Subject: Support for baseband output to a soundcard
X-Git-Url: https://code.octet-stream.net/m17rt/commitdiff_plain/refs/heads/master?ds=sidebyside;hp=ac1b1b703bd012b82404951be0637dabe4606660

Support for baseband output to a soundcard
---

diff --git a/m17app/src/soundmodem.rs b/m17app/src/soundmodem.rs
index 9c05ada..74c176b 100644
--- a/m17app/src/soundmodem.rs
+++ b/m17app/src/soundmodem.rs
@@ -547,3 +547,93 @@ impl OutputSink for NullOutputSink {
         let _ = self.end_tx.lock().unwrap().take();
     }
 }
+
+pub struct OutputSoundcard {
+    // TODO: allow for inversion both here and in output
+    cpal_name: Option<String>,
+    end_tx: Mutex<Option<Sender<()>>>,
+}
+
+impl OutputSoundcard {
+    pub fn new() -> Self {
+        Self {
+            cpal_name: None,
+            end_tx: Mutex::new(None),
+        }
+    }
+
+    pub fn new_with_card(card_name: String) -> Self {
+        Self {
+            cpal_name: Some(card_name),
+            end_tx: Mutex::new(None),
+        }
+    }
+}
+
+impl OutputSink for OutputSoundcard {
+    fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>) {
+        let (end_tx, end_rx) = channel();
+        let cpal_name = self.cpal_name.clone();
+        std::thread::spawn(move || {
+            let host = cpal::default_host();
+            let device = if let Some(name) = cpal_name.as_deref() {
+                host.output_devices()
+                    .unwrap()
+                    .find(|d| d.name().unwrap() == name)
+                    .unwrap()
+            } else {
+                host.default_output_device().unwrap()
+            };
+            let mut configs = device.supported_output_configs().unwrap();
+            // TODO: more error handling
+            let config = configs
+                .find(|c| c.channels() == 1 && c.sample_format() == SampleFormat::I16)
+                .unwrap()
+                .with_sample_rate(SampleRate(48000));
+            let stream = device
+                .build_output_stream(
+                    &config.into(),
+                    move |data: &mut [i16], info: &cpal::OutputCallbackInfo| {
+                        let mut taken = 0;
+                        let ts = info.timestamp();
+                        let latency = ts
+                            .playback
+                            .duration_since(&ts.callback)
+                            .unwrap_or(Duration::ZERO);
+                        let mut buffer = buffer.write().unwrap();
+                        buffer.latency = latency;
+                        for out in data.iter_mut() {
+                            if let Some(s) = buffer.samples.pop_front() {
+                                *out = s;
+                                taken += 1;
+                            } else if buffer.idling {
+                                *out = 0;
+                            } else {
+                                debug!("output soundcard had underrun");
+                                let _ = event_tx.send(SoundmodemEvent::OutputUnderrun);
+                                break;
+                            }
+                        }
+                        //debug!("latency is {} ms, taken {taken}", latency.as_millis());
+                        let _ = event_tx.send(SoundmodemEvent::DidReadFromOutputBuffer {
+                            len: taken,
+                            timestamp: Instant::now(),
+                        });
+                    },
+                    |e| {
+                        // TODO: abort?
+                        debug!("error occurred in soundcard output: {e:?}");
+                    },
+                    None,
+                )
+                .unwrap();
+            stream.play().unwrap();
+            let _ = end_rx.recv();
+        });
+        *self.end_tx.lock().unwrap() = Some(end_tx);
+    }
+
+    fn close(&self) {
+        let _ = self.end_tx.lock().unwrap().take();
+    }
+}
diff --git a/m17core/src/modem.rs b/m17core/src/modem.rs
index 35a23a7..fe57188 100644
--- a/m17core/src/modem.rs
+++ b/m17core/src/modem.rs
@@ -419,7 +419,7 @@ impl Modulator for SoftModulator {
 
         // if we have pre-TX padding to accommodate TxDelay then expend that first
         if self.tx_delay_padding > 0 {
-            let len = out.len().max(self.tx_delay_padding);
+            let len = out.len().min(self.tx_delay_padding);
             self.tx_delay_padding -= len;
             for x in 0..len {
                 out[x] = 0;
diff --git a/m17core/src/tnc.rs b/m17core/src/tnc.rs
index ee0fa30..7851948 100644
--- a/m17core/src/tnc.rs
+++ b/m17core/src/tnc.rs
@@ -212,6 +212,7 @@ impl SoftTnc {
     }
 
     pub fn set_tx_end_time(&mut self, in_samples: usize) {
+        log::debug!("tnc has been told that tx will complete in {in_samples} samples");
         match self.state {
             State::TxEnding => {
                 self.state = State::TxEndingAtTime(self.now + in_samples as u64);
diff --git a/tools/m17rt-demod/src/main.rs b/tools/m17rt-demod/src/main.rs
index 1125c3a..40ab3db 100755
--- a/tools/m17rt-demod/src/main.rs
+++ b/tools/m17rt-demod/src/main.rs
@@ -6,6 +6,7 @@ use std::path::PathBuf;
 pub fn m17app_test() {
     //let path = PathBuf::from("../../../Data/test_vk7xt.rrc");
     let path = PathBuf::from("../../../Data/mymod.rrc");
+    //let path = PathBuf::from("../../../Data/mymod-noisy.raw");
     let source = InputRrcFile::new(path);
     //let source = InputSoundcard::new();
     let soundmodem = Soundmodem::new_with_input_and_output(source, NullOutputSink::new());
diff --git a/tools/m17rt-mod/src/main.rs b/tools/m17rt-mod/src/main.rs
index 08973cb..968c22a 100644
--- a/tools/m17rt-mod/src/main.rs
+++ b/tools/m17rt-mod/src/main.rs
@@ -1,15 +1,17 @@
 use m17app::app::M17App;
 use m17app::soundmodem::{
-    InputRrcFile, InputSoundcard, NullInputSource, NullOutputSink, OutputRrcFile, Soundmodem,
+    InputRrcFile, InputSoundcard, NullInputSource, NullOutputSink, OutputRrcFile, OutputSoundcard,
+    Soundmodem,
 };
 use m17codec2::{Codec2Adapter, WavePlayer};
 use std::path::PathBuf;
 
 pub fn mod_test() {
     let in_path = PathBuf::from("../../../Data/test_vk7xt_8k.wav");
-    let out_path = PathBuf::from("../../../Data/mymod.rrc");
-    let soundmodem =
-        Soundmodem::new_with_input_and_output(NullInputSource::new(), OutputRrcFile::new(out_path));
+    //let out_path = PathBuf::from("../../../Data/mymod.rrc");
+    //let output = OutputRrcFile::new(out_path);
+    let output = OutputSoundcard::new();
+    let soundmodem = Soundmodem::new_with_input_and_output(NullInputSource::new(), output);
     let app = M17App::new(soundmodem);
     app.start();
     std::thread::sleep(std::time::Duration::from_secs(1));