]> code.octet-stream.net Git - m17rt/blobdiff - m17app/src/soundmodem.rs
Fix timing bugs and add documentation
[m17rt] / m17app / src / soundmodem.rs
index 4970d9207b06d40c52e6ab17d879c3172734fb48..391bfadde1b66b2ee33c1b7a336991aabe126e19 100644 (file)
@@ -1,18 +1,14 @@
-use std::io::{self, ErrorKind, Read, Write};
-use std::sync::RwLock;
-use std::collections::VecDeque;
 use crate::tnc::{Tnc, TncError};
-use cpal::traits::DeviceTrait;
-use cpal::traits::HostTrait;
-use cpal::traits::StreamTrait;
-use cpal::{SampleFormat, SampleRate};
 use log::debug;
 use m17core::kiss::MAX_FRAME_LEN;
 use m17core::modem::{Demodulator, Modulator, ModulatorAction, SoftDemodulator, SoftModulator};
 use m17core::tnc::SoftTnc;
+use std::collections::VecDeque;
 use std::fs::File;
+use std::io::{self, ErrorKind, Read, Write};
 use std::path::PathBuf;
 use std::sync::mpsc::{channel, sync_channel, Receiver, Sender, SyncSender, TryRecvError};
+use std::sync::RwLock;
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
 
@@ -23,11 +19,18 @@ pub struct Soundmodem {
 }
 
 impl Soundmodem {
-    pub fn new_with_input_and_output<I: InputSource, O: OutputSink>(input: I, output: O) -> Self {
+    pub fn new<I: InputSource, O: OutputSink, P: Ptt>(input: I, output: O, ptt: P) -> Self {
         // must create TNC here
         let (event_tx, event_rx) = sync_channel(128);
         let (kiss_out_tx, kiss_out_rx) = sync_channel(128);
-        spawn_soundmodem_worker(event_tx.clone(), event_rx, kiss_out_tx, Box::new(input), Box::new(output));
+        spawn_soundmodem_worker(
+            event_tx.clone(),
+            event_rx,
+            kiss_out_tx,
+            Box::new(input),
+            Box::new(output),
+            Box::new(ptt),
+        );
         Self {
             event_tx,
             kiss_out_rx: Arc::new(Mutex::new(kiss_out_rx)),
@@ -111,10 +114,7 @@ pub enum SoundmodemEvent {
     BasebandInput(Arc<[i16]>),
     Start,
     Close,
-    DidReadFromOutputBuffer {
-        len: usize,
-        timestamp: Instant,
-    },
+    DidReadFromOutputBuffer { len: usize, timestamp: Instant },
     OutputUnderrun,
 }
 
@@ -124,6 +124,7 @@ fn spawn_soundmodem_worker(
     kiss_out_tx: SyncSender<Arc<[u8]>>,
     input: Box<dyn InputSource>,
     output: Box<dyn OutputSink>,
+    mut ptt_driver: Box<dyn Ptt>,
 ) {
     std::thread::spawn(move || {
         // TODO: should be able to provide a custom Demodulator for a soundmodem
@@ -134,11 +135,16 @@ fn spawn_soundmodem_worker(
         let out_buffer = Arc::new(RwLock::new(OutputBuffer::new()));
         let mut out_samples = [0i16; 1024];
         let start = Instant::now();
+        let mut ptt = false;
         while let Ok(ev) = event_rx.recv() {
             // Update clock on TNC before we do anything
-            let sample_time = (start.elapsed().as_nanos() / 48000) as u64;
-            tnc.set_now(sample_time);
-            
+            let sample_time = start.elapsed();
+            let secs = sample_time.as_secs();
+            let nanos = sample_time.subsec_nanos();
+            // Accurate to within approx 1 sample
+            let now_samples = 48000 * secs + (nanos as u64 / 20833);
+            tnc.set_now(now_samples);
+
             // Handle event
             match ev {
                 SoundmodemEvent::Kiss(k) => {
@@ -165,47 +171,63 @@ fn spawn_soundmodem_worker(
                 SoundmodemEvent::Start => {
                     input.start(event_tx.clone());
                     output.start(event_tx.clone(), out_buffer.clone());
-                },
-                SoundmodemEvent::Close => break,
+                }
+                SoundmodemEvent::Close => {
+                    ptt_driver.ptt_off();
+                    break;
+                }
                 SoundmodemEvent::DidReadFromOutputBuffer { len, timestamp } => {
                     let (occupied, internal_latency) = {
                         let out_buffer = out_buffer.read().unwrap();
                         (out_buffer.samples.len(), out_buffer.latency)
                     };
                     let internal_latency = (internal_latency.as_secs_f32() * 48000.0) as usize;
-                    let dynamic_latency = len.saturating_sub((timestamp.elapsed().as_secs_f32() * 48000.0) as usize);
-                    modulator.update_output_buffer(occupied, 48000, internal_latency + dynamic_latency);
-                },
+                    let dynamic_latency =
+                        len.saturating_sub((timestamp.elapsed().as_secs_f32() * 48000.0) as usize);
+                    modulator.update_output_buffer(
+                        occupied,
+                        48000,
+                        internal_latency + dynamic_latency,
+                    );
+                }
                 SoundmodemEvent::OutputUnderrun => {
                     // TODO: cancel transmission, send empty data frame to host
                 }
             }
-            
+
+            // Update PTT state
+            let new_ptt = tnc.ptt();
+            if new_ptt != ptt {
+                if new_ptt {
+                    ptt_driver.ptt_on();
+                } else {
+                    ptt_driver.ptt_off();
+                }
+            }
+            ptt = new_ptt;
+
             // Let the modulator do what it wants
             while let Some(action) = modulator.run() {
                 match action {
                     ModulatorAction::SetIdle(idling) => {
                         out_buffer.write().unwrap().idling = idling;
-                    },
+                    }
                     ModulatorAction::GetNextFrame => {
                         modulator.provide_next_frame(tnc.read_tx_frame());
-                    },
-                    ModulatorAction::ReadOutput => {
-                        loop {
-                            let n = modulator.read_output_samples(&mut out_samples);
-                            if n == 0 {
-                                break;
-                            }
-                            let mut out_buffer = out_buffer.write().unwrap();
-                            for s in &out_samples[0..n] {
-                                out_buffer.samples.push_back(*s);
-                            }
+                    }
+                    ModulatorAction::ReadOutput => loop {
+                        let n = modulator.read_output_samples(&mut out_samples);
+                        if n == 0 {
+                            break;
+                        }
+                        let mut out_buffer = out_buffer.write().unwrap();
+                        for s in &out_samples[0..n] {
+                            out_buffer.samples.push_back(*s);
                         }
-                        
                     },
                     ModulatorAction::TransmissionWillEnd(in_samples) => {
                         tnc.set_tx_end_time(in_samples);
-                    },
+                    }
                 }
             }
         }
@@ -217,73 +239,6 @@ pub trait InputSource: Send + Sync + 'static {
     fn close(&self);
 }
 
-pub struct InputSoundcard {
-    // TODO: allow for inversion both here and in output
-    cpal_name: Option<String>,
-    end_tx: Mutex<Option<Sender<()>>>,
-}
-
-impl InputSoundcard {
-    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 InputSource for InputSoundcard {
-    fn start(&self, samples: SyncSender<SoundmodemEvent>) {
-        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.input_devices()
-                    .unwrap()
-                    .find(|d| d.name().unwrap() == name)
-                    .unwrap()
-            } else {
-                host.default_input_device().unwrap()
-            };
-            let mut configs = device.supported_input_configs().unwrap();
-            let config = configs
-                .find(|c| c.channels() == 1 && c.sample_format() == SampleFormat::I16)
-                .unwrap()
-                .with_sample_rate(SampleRate(48000));
-            let stream = device
-                .build_input_stream(
-                    &config.into(),
-                    move |data: &[i16], _info: &cpal::InputCallbackInfo| {
-                        debug!("input has given us {} samples", data.len());
-                        let out: Vec<i16> = data.iter().map(|s| *s).collect();
-                        let _ = samples.try_send(SoundmodemEvent::BasebandInput(out.into()));
-                    },
-                    |e| {
-                        // TODO: abort?
-                        debug!("error occurred in soundcard input: {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();
-    }
-}
-
 pub struct InputRrcFile {
     path: PathBuf,
     end_tx: Mutex<Option<Sender<()>>>,
@@ -326,7 +281,7 @@ impl InputSource for InputRrcFile {
                     if let Err(e) = samples.try_send(SoundmodemEvent::BasebandInput(buf.into())) {
                         debug!("overflow feeding soundmodem: {e:?}");
                     }
-                    next_tick = next_tick + TICK;
+                    next_tick += TICK;
                     idx = 0;
                     std::thread::sleep(next_tick.duration_since(Instant::now()));
                 }
@@ -343,11 +298,59 @@ impl InputSource for InputRrcFile {
     }
 }
 
+pub struct NullInputSource {
+    end_tx: Mutex<Option<Sender<()>>>,
+}
+
+impl NullInputSource {
+    pub fn new() -> Self {
+        Self {
+            end_tx: Mutex::new(None),
+        }
+    }
+}
+
+impl InputSource for NullInputSource {
+    fn start(&self, samples: SyncSender<SoundmodemEvent>) {
+        let (end_tx, end_rx) = channel();
+        std::thread::spawn(move || {
+            // assuming 48 kHz for now
+            const TICK: Duration = Duration::from_millis(25);
+            const SAMPLES_PER_TICK: usize = 1200;
+            let mut next_tick = Instant::now() + TICK;
+
+            loop {
+                std::thread::sleep(next_tick.duration_since(Instant::now()));
+                next_tick += TICK;
+                if end_rx.try_recv() != Err(TryRecvError::Empty) {
+                    break;
+                }
+                if let Err(e) = samples.try_send(SoundmodemEvent::BasebandInput(
+                    [0i16; SAMPLES_PER_TICK].into(),
+                )) {
+                    debug!("overflow feeding soundmodem: {e:?}");
+                }
+            }
+        });
+        *self.end_tx.lock().unwrap() = Some(end_tx);
+    }
+
+    fn close(&self) {
+        let _ = self.end_tx.lock().unwrap().take();
+    }
+}
+
+impl Default for NullInputSource {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 pub struct OutputBuffer {
-    idling: bool,
+    pub idling: bool,
     // TODO: something more efficient
-    samples: VecDeque<i16>,
-    latency: Duration,
+    pub samples: VecDeque<i16>,
+    pub latency: Duration,
 }
 
 impl OutputBuffer {
@@ -360,6 +363,12 @@ impl OutputBuffer {
     }
 }
 
+impl Default for OutputBuffer {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 pub trait OutputSink: Send + Sync + 'static {
     fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>);
     fn close(&self);
@@ -397,30 +406,35 @@ impl OutputSink for OutputRrcFile {
 
             loop {
                 std::thread::sleep(next_tick.duration_since(Instant::now()));
-                next_tick = next_tick + TICK;
+                next_tick += TICK;
                 if end_rx.try_recv() != Err(TryRecvError::Empty) {
                     break;
                 }
-                
+                // For now only write deliberately modulated (non-idling) samples
+                // Multiple transmissions will get smooshed together
+                let mut buf_used = 0;
+
                 let mut buffer = buffer.write().unwrap();
                 for out in buf.chunks_mut(2) {
                     if let Some(s) = buffer.samples.pop_front() {
-                        let be = s.to_be_bytes();
+                        let be = s.to_le_bytes();
                         out.copy_from_slice(&[be[0], be[1]]);
-                    } else if buffer.idling {
-                        out.copy_from_slice(&[0, 0]);
-                    } else {
+                        buf_used += 2;
+                    } else if !buffer.idling {
                         debug!("output rrc file had underrun");
                         let _ = event_tx.send(SoundmodemEvent::OutputUnderrun);
                         break;
                     }
                 }
-                if let Err(e) = file.write_all(&buf) {
+                if let Err(e) = file.write_all(&buf[0..buf_used]) {
                     debug!("failed to write to rrc file: {e:?}");
                     break;
                 }
+                let _ = event_tx.send(SoundmodemEvent::DidReadFromOutputBuffer {
+                    len: buf_used / 2,
+                    timestamp: Instant::now(),
+                });
             }
-            
         });
         *self.end_tx.lock().unwrap() = Some(end_tx);
     }
@@ -429,3 +443,89 @@ impl OutputSink for OutputRrcFile {
         let _ = self.end_tx.lock().unwrap().take();
     }
 }
+
+pub struct NullOutputSink {
+    end_tx: Mutex<Option<Sender<()>>>,
+}
+
+impl NullOutputSink {
+    pub fn new() -> Self {
+        Self {
+            end_tx: Mutex::new(None),
+        }
+    }
+}
+
+impl Default for NullOutputSink {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl OutputSink for NullOutputSink {
+    fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>) {
+        let (end_tx, end_rx) = channel();
+        std::thread::spawn(move || {
+            // assuming 48 kHz for now
+            const TICK: Duration = Duration::from_millis(25);
+            const SAMPLES_PER_TICK: usize = 1200;
+            let mut next_tick = Instant::now() + TICK;
+
+            loop {
+                std::thread::sleep(next_tick.duration_since(Instant::now()));
+                next_tick += TICK;
+                if end_rx.try_recv() != Err(TryRecvError::Empty) {
+                    break;
+                }
+
+                let mut buffer = buffer.write().unwrap();
+                let mut taken = 0;
+                for _ in 0..SAMPLES_PER_TICK {
+                    if buffer.samples.pop_front().is_none() {
+                        if !buffer.idling {
+                            debug!("null output had underrun");
+                            let _ = event_tx.send(SoundmodemEvent::OutputUnderrun);
+                            break;
+                        }
+                    } else {
+                        taken += 1;
+                    }
+                }
+                let _ = event_tx.send(SoundmodemEvent::DidReadFromOutputBuffer {
+                    len: taken,
+                    timestamp: Instant::now(),
+                });
+            }
+        });
+        *self.end_tx.lock().unwrap() = Some(end_tx);
+    }
+
+    fn close(&self) {
+        let _ = self.end_tx.lock().unwrap().take();
+    }
+}
+
+pub trait Ptt: Send + 'static {
+    fn ptt_on(&mut self);
+    fn ptt_off(&mut self);
+}
+
+/// There is no PTT because this TNC will never make transmissions on a real radio.
+pub struct NullPtt;
+
+impl NullPtt {
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl Default for NullPtt {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Ptt for NullPtt {
+    fn ptt_on(&mut self) {}
+    fn ptt_off(&mut self) {}
+}