code.octet-stream.net Git - m17rt/blob - m17app/src/soundmodem.rs

   1 use crate::error::M17Error;
   2 use crate::tnc::{Tnc, TncError};
   3 use log::debug;
   4 use m17core::kiss::MAX_FRAME_LEN;
   5 use m17core::modem::{Demodulator, Modulator, ModulatorAction, SoftDemodulator, SoftModulator};
   6 use m17core::tnc::SoftTnc;
   7 use std::collections::VecDeque;
   8 use std::fs::File;
   9 use std::io::{self, ErrorKind, Read, Write};
  10 use std::path::PathBuf;
  11 use std::sync::mpsc::{channel, sync_channel, Receiver, Sender, SyncSender, TryRecvError};
  12 use std::sync::RwLock;
  13 use std::sync::{Arc, Mutex};
  14 use std::time::{Duration, Instant};
  15
  16 pub struct Soundmodem {
  17     event_tx: SyncSender<SoundmodemEvent>,
  18     kiss_out_rx: Arc<Mutex<Receiver<Arc<[u8]>>>>,
  19     partial_kiss_out: Arc<Mutex<Option<PartialKissOut>>>,
  20 }
  21
  22 impl Soundmodem {
  23     pub fn new<I: InputSource, O: OutputSink, P: Ptt>(input: I, output: O, ptt: P) -> Self {
  24         // must create TNC here
  25         let (event_tx, event_rx) = sync_channel(128);
  26         let (kiss_out_tx, kiss_out_rx) = sync_channel(128);
  27         spawn_soundmodem_worker(
  28             event_tx.clone(),
  29             event_rx,
  30             kiss_out_tx,
  31             Box::new(input),
  32             Box::new(output),
  33             Box::new(ptt),
  34         );
  35         Self {
  36             event_tx,
  37             kiss_out_rx: Arc::new(Mutex::new(kiss_out_rx)),
  38             partial_kiss_out: Arc::new(Mutex::new(None)),
  39         }
  40     }
  41 }
  42
  43 struct PartialKissOut {
  44     output: Arc<[u8]>,
  45     idx: usize,
  46 }
  47
  48 impl Read for Soundmodem {
  49     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
  50         {
  51             let mut partial_kiss_out = self.partial_kiss_out.lock().unwrap();
  52             if let Some(partial) = partial_kiss_out.as_mut() {
  53                 let remaining = partial.output.len() - partial.idx;
  54                 let to_write = remaining.min(buf.len());
  55                 buf[0..to_write]
  56                     .copy_from_slice(&partial.output[partial.idx..(partial.idx + to_write)]);
  57                 if to_write == remaining {
  58                     *partial_kiss_out = None;
  59                 } else {
  60                     partial.idx += to_write;
  61                 }
  62                 return Ok(to_write);
  63             }
  64         }
  65         let output = {
  66             let rx = self.kiss_out_rx.lock().unwrap();
  67             rx.recv()
  68                 .map_err(|s| io::Error::new(ErrorKind::Other, format!("{:?}", s)))?
  69         };
  70         let to_write = output.len().min(buf.len());
  71         buf[0..to_write].copy_from_slice(&output[0..to_write]);
  72         if to_write != output.len() {
  73             *self.partial_kiss_out.lock().unwrap() = Some(PartialKissOut {
  74                 output,
  75                 idx: to_write,
  76             })
  77         }
  78         Ok(to_write)
  79     }
  80 }
  81
  82 impl Write for Soundmodem {
  83     fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
  84         let _ = self.event_tx.try_send(SoundmodemEvent::Kiss(buf.into()));
  85         Ok(buf.len())
  86     }
  87
  88     fn flush(&mut self) -> std::io::Result<()> {
  89         Ok(())
  90     }
  91 }
  92
  93 impl Tnc for Soundmodem {
  94     fn try_clone(&mut self) -> Result<Self, TncError> {
  95         Ok(Self {
  96             event_tx: self.event_tx.clone(),
  97             kiss_out_rx: self.kiss_out_rx.clone(),
  98             partial_kiss_out: self.partial_kiss_out.clone(),
  99         })
 100     }
 101
 102     fn start(&mut self) -> Result<(), TncError> {
 103         let _ = self.event_tx.send(SoundmodemEvent::Start);
 104         Ok(())
 105     }
 106
 107     fn close(&mut self) -> Result<(), TncError> {
 108         let _ = self.event_tx.send(SoundmodemEvent::Close);
 109         Ok(())
 110     }
 111 }
 112
 113 pub enum SoundmodemEvent {
 114     Kiss(Arc<[u8]>),
 115     BasebandInput(Arc<[i16]>),
 116     Start,
 117     Close,
 118     DidReadFromOutputBuffer { len: usize, timestamp: Instant },
 119     OutputUnderrun,
 120 }
 121
 122 fn spawn_soundmodem_worker(
 123     event_tx: SyncSender<SoundmodemEvent>,
 124     event_rx: Receiver<SoundmodemEvent>,
 125     kiss_out_tx: SyncSender<Arc<[u8]>>,
 126     input: Box<dyn InputSource>,
 127     output: Box<dyn OutputSink>,
 128     mut ptt_driver: Box<dyn Ptt>,
 129 ) {
 130     std::thread::spawn(move || {
 131         // TODO: should be able to provide a custom Demodulator for a soundmodem
 132         let mut demodulator = SoftDemodulator::new();
 133         let mut modulator = SoftModulator::new();
 134         let mut tnc = SoftTnc::new();
 135         let mut buf = [0u8; MAX_FRAME_LEN];
 136         let out_buffer = Arc::new(RwLock::new(OutputBuffer::new()));
 137         let mut out_samples = [0i16; 1024];
 138         let start = Instant::now();
 139         let mut ptt = false;
 140         while let Ok(ev) = event_rx.recv() {
 141             // Update clock on TNC before we do anything
 142             let sample_time = start.elapsed();
 143             let secs = sample_time.as_secs();
 144             let nanos = sample_time.subsec_nanos();
 145             // Accurate to within approx 1 sample
 146             let now_samples = 48000 * secs + (nanos as u64 / 20833);
 147             tnc.set_now(now_samples);
 148
 149             // Handle event
 150             match ev {
 151                 SoundmodemEvent::Kiss(k) => {
 152                     let _n = tnc.write_kiss(&k);
 153                     // TODO: what does it mean if we fail to write it all?
 154                     // Probably we have to read frames for tx first - revisit this during tx
 155                 }
 156                 SoundmodemEvent::BasebandInput(b) => {
 157                     for sample in &*b {
 158                         if let Some(frame) = demodulator.demod(*sample) {
 159                             tnc.handle_frame(frame);
 160                             loop {
 161                                 let n = tnc.read_kiss(&mut buf);
 162                                 if n > 0 {
 163                                     let _ = kiss_out_tx.try_send(buf[0..n].into());
 164                                 } else {
 165                                     break;
 166                                 }
 167                             }
 168                         }
 169                     }
 170                     tnc.set_data_carrier_detect(demodulator.data_carrier_detect());
 171                 }
 172                 SoundmodemEvent::Start => {
 173                     input.start(event_tx.clone());
 174                     output.start(event_tx.clone(), out_buffer.clone());
 175                 }
 176                 SoundmodemEvent::Close => {
 177                     ptt_driver.ptt_off();
 178                     break;
 179                 }
 180                 SoundmodemEvent::DidReadFromOutputBuffer { len, timestamp } => {
 181                     let (occupied, internal_latency) = {
 182                         let out_buffer = out_buffer.read().unwrap();
 183                         (out_buffer.samples.len(), out_buffer.latency)
 184                     };
 185                     let internal_latency = (internal_latency.as_secs_f32() * 48000.0) as usize;
 186                     let dynamic_latency =
 187                         len.saturating_sub((timestamp.elapsed().as_secs_f32() * 48000.0) as usize);
 188                     modulator.update_output_buffer(
 189                         occupied,
 190                         48000,
 191                         internal_latency + dynamic_latency,
 192                     );
 193                 }
 194                 SoundmodemEvent::OutputUnderrun => {
 195                     // TODO: cancel transmission, send empty data frame to host
 196                 }
 197             }
 198
 199             // Update PTT state
 200             let new_ptt = tnc.ptt();
 201             if new_ptt != ptt {
 202                 if new_ptt {
 203                     ptt_driver.ptt_on();
 204                 } else {
 205                     ptt_driver.ptt_off();
 206                 }
 207             }
 208             ptt = new_ptt;
 209
 210             // Let the modulator do what it wants
 211             while let Some(action) = modulator.run() {
 212                 match action {
 213                     ModulatorAction::SetIdle(idling) => {
 214                         out_buffer.write().unwrap().idling = idling;
 215                     }
 216                     ModulatorAction::GetNextFrame => {
 217                         modulator.provide_next_frame(tnc.read_tx_frame());
 218                     }
 219                     ModulatorAction::ReadOutput => loop {
 220                         let n = modulator.read_output_samples(&mut out_samples);
 221                         if n == 0 {
 222                             break;
 223                         }
 224                         let mut out_buffer = out_buffer.write().unwrap();
 225                         for s in &out_samples[0..n] {
 226                             out_buffer.samples.push_back(*s);
 227                         }
 228                     },
 229                     ModulatorAction::TransmissionWillEnd(in_samples) => {
 230                         tnc.set_tx_end_time(in_samples);
 231                     }
 232                 }
 233             }
 234         }
 235     });
 236 }
 237
 238 pub trait InputSource: Send + Sync + 'static {
 239     fn start(&self, samples: SyncSender<SoundmodemEvent>);
 240     fn close(&self);
 241 }
 242
 243 pub struct InputRrcFile {
 244     baseband: Arc<[u8]>,
 245     end_tx: Mutex<Option<Sender<()>>>,
 246 }
 247
 248 impl InputRrcFile {
 249     pub fn new(path: PathBuf) -> Result<Self, M17Error> {
 250         let mut file = File::open(&path).map_err(|_| M17Error::InvalidRrcPath(path.clone()))?;
 251         let mut baseband = vec![];
 252         file.read_to_end(&mut baseband)
 253             .map_err(|_| M17Error::RrcReadFailed(path))?;
 254         Ok(Self {
 255             baseband: baseband.into(),
 256             end_tx: Mutex::new(None),
 257         })
 258     }
 259 }
 260
 261 impl InputSource for InputRrcFile {
 262     fn start(&self, samples: SyncSender<SoundmodemEvent>) {
 263         let (end_tx, end_rx) = channel();
 264         let baseband = self.baseband.clone();
 265         std::thread::spawn(move || {
 266             // assuming 48 kHz for now
 267             const TICK: Duration = Duration::from_millis(25);
 268             const SAMPLES_PER_TICK: usize = 1200;
 269
 270             let mut next_tick = Instant::now() + TICK;
 271             let mut buf = [0i16; SAMPLES_PER_TICK];
 272             let mut idx = 0;
 273
 274             for sample in baseband
 275                 .chunks(2)
 276                 .map(|pair| i16::from_le_bytes([pair[0], pair[1]]))
 277             {
 278                 buf[idx] = sample;
 279                 idx += 1;
 280                 if idx == SAMPLES_PER_TICK {
 281                     if let Err(e) = samples.try_send(SoundmodemEvent::BasebandInput(buf.into())) {
 282                         debug!("overflow feeding soundmodem: {e:?}");
 283                     }
 284                     next_tick += TICK;
 285                     idx = 0;
 286                     std::thread::sleep(next_tick.duration_since(Instant::now()));
 287                 }
 288                 if end_rx.try_recv() != Err(TryRecvError::Empty) {
 289                     break;
 290                 }
 291             }
 292         });
 293         *self.end_tx.lock().unwrap() = Some(end_tx);
 294     }
 295
 296     fn close(&self) {
 297         let _ = self.end_tx.lock().unwrap().take();
 298     }
 299 }
 300
 301 pub struct NullInputSource {
 302     end_tx: Mutex<Option<Sender<()>>>,
 303 }
 304
 305 impl NullInputSource {
 306     pub fn new() -> Self {
 307         Self {
 308             end_tx: Mutex::new(None),
 309         }
 310     }
 311 }
 312
 313 impl InputSource for NullInputSource {
 314     fn start(&self, samples: SyncSender<SoundmodemEvent>) {
 315         let (end_tx, end_rx) = channel();
 316         std::thread::spawn(move || {
 317             // assuming 48 kHz for now
 318             const TICK: Duration = Duration::from_millis(25);
 319             const SAMPLES_PER_TICK: usize = 1200;
 320             let mut next_tick = Instant::now() + TICK;
 321
 322             loop {
 323                 std::thread::sleep(next_tick.duration_since(Instant::now()));
 324                 next_tick += TICK;
 325                 if end_rx.try_recv() != Err(TryRecvError::Empty) {
 326                     break;
 327                 }
 328                 if let Err(e) = samples.try_send(SoundmodemEvent::BasebandInput(
 329                     [0i16; SAMPLES_PER_TICK].into(),
 330                 )) {
 331                     debug!("overflow feeding soundmodem: {e:?}");
 332                 }
 333             }
 334         });
 335         *self.end_tx.lock().unwrap() = Some(end_tx);
 336     }
 337
 338     fn close(&self) {
 339         let _ = self.end_tx.lock().unwrap().take();
 340     }
 341 }
 342
 343 impl Default for NullInputSource {
 344     fn default() -> Self {
 345         Self::new()
 346     }
 347 }
 348
 349 pub struct OutputBuffer {
 350     pub idling: bool,
 351     // TODO: something more efficient
 352     pub samples: VecDeque<i16>,
 353     pub latency: Duration,
 354 }
 355
 356 impl OutputBuffer {
 357     pub fn new() -> Self {
 358         Self {
 359             idling: true,
 360             samples: VecDeque::new(),
 361             latency: Duration::ZERO,
 362         }
 363     }
 364 }
 365
 366 impl Default for OutputBuffer {
 367     fn default() -> Self {
 368         Self::new()
 369     }
 370 }
 371
 372 pub trait OutputSink: Send + Sync + 'static {
 373     fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>);
 374     fn close(&self);
 375 }
 376
 377 pub struct OutputRrcFile {
 378     path: PathBuf,
 379     end_tx: Mutex<Option<Sender<()>>>,
 380 }
 381
 382 impl OutputRrcFile {
 383     pub fn new(path: PathBuf) -> Self {
 384         Self {
 385             path,
 386             end_tx: Mutex::new(None),
 387         }
 388     }
 389 }
 390
 391 impl OutputSink for OutputRrcFile {
 392     fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>) {
 393         let (end_tx, end_rx) = channel();
 394         let path = self.path.clone();
 395         std::thread::spawn(move || {
 396             // TODO: error handling
 397             let mut file = File::create(path).unwrap();
 398
 399             // assuming 48 kHz for now
 400             const TICK: Duration = Duration::from_millis(25);
 401             const SAMPLES_PER_TICK: usize = 1200;
 402
 403             // flattened BE i16s for writing
 404             let mut buf = [0u8; SAMPLES_PER_TICK * 2];
 405             let mut next_tick = Instant::now() + TICK;
 406
 407             loop {
 408                 std::thread::sleep(next_tick.duration_since(Instant::now()));
 409                 next_tick += TICK;
 410                 if end_rx.try_recv() != Err(TryRecvError::Empty) {
 411                     break;
 412                 }
 413                 // For now only write deliberately modulated (non-idling) samples
 414                 // Multiple transmissions will get smooshed together
 415                 let mut buf_used = 0;
 416
 417                 let mut buffer = buffer.write().unwrap();
 418                 for out in buf.chunks_mut(2) {
 419                     if let Some(s) = buffer.samples.pop_front() {
 420                         let be = s.to_le_bytes();
 421                         out.copy_from_slice(&[be[0], be[1]]);
 422                         buf_used += 2;
 423                     } else if !buffer.idling {
 424                         debug!("output rrc file had underrun");
 425                         let _ = event_tx.send(SoundmodemEvent::OutputUnderrun);
 426                         break;
 427                     }
 428                 }
 429                 if let Err(e) = file.write_all(&buf[0..buf_used]) {
 430                     debug!("failed to write to rrc file: {e:?}");
 431                     break;
 432                 }
 433                 let _ = event_tx.send(SoundmodemEvent::DidReadFromOutputBuffer {
 434                     len: buf_used / 2,
 435                     timestamp: Instant::now(),
 436                 });
 437             }
 438         });
 439         *self.end_tx.lock().unwrap() = Some(end_tx);
 440     }
 441
 442     fn close(&self) {
 443         let _ = self.end_tx.lock().unwrap().take();
 444     }
 445 }
 446
 447 pub struct NullOutputSink {
 448     end_tx: Mutex<Option<Sender<()>>>,
 449 }
 450
 451 impl NullOutputSink {
 452     pub fn new() -> Self {
 453         Self {
 454             end_tx: Mutex::new(None),
 455         }
 456     }
 457 }
 458
 459 impl Default for NullOutputSink {
 460     fn default() -> Self {
 461         Self::new()
 462     }
 463 }
 464
 465 impl OutputSink for NullOutputSink {
 466     fn start(&self, event_tx: SyncSender<SoundmodemEvent>, buffer: Arc<RwLock<OutputBuffer>>) {
 467         let (end_tx, end_rx) = channel();
 468         std::thread::spawn(move || {
 469             // assuming 48 kHz for now
 470             const TICK: Duration = Duration::from_millis(25);
 471             const SAMPLES_PER_TICK: usize = 1200;
 472             let mut next_tick = Instant::now() + TICK;
 473
 474             loop {
 475                 std::thread::sleep(next_tick.duration_since(Instant::now()));
 476                 next_tick += TICK;
 477                 if end_rx.try_recv() != Err(TryRecvError::Empty) {
 478                     break;
 479                 }
 480
 481                 let mut buffer = buffer.write().unwrap();
 482                 let mut taken = 0;
 483                 for _ in 0..SAMPLES_PER_TICK {
 484                     if buffer.samples.pop_front().is_none() {
 485                         if !buffer.idling {
 486                             debug!("null output had underrun");
 487                             let _ = event_tx.send(SoundmodemEvent::OutputUnderrun);
 488                             break;
 489                         }
 490                     } else {
 491                         taken += 1;
 492                     }
 493                 }
 494                 let _ = event_tx.send(SoundmodemEvent::DidReadFromOutputBuffer {
 495                     len: taken,
 496                     timestamp: Instant::now(),
 497                 });
 498             }
 499         });
 500         *self.end_tx.lock().unwrap() = Some(end_tx);
 501     }
 502
 503     fn close(&self) {
 504         let _ = self.end_tx.lock().unwrap().take();
 505     }
 506 }
 507
 508 pub trait Ptt: Send + 'static {
 509     fn ptt_on(&mut self);
 510     fn ptt_off(&mut self);
 511 }
 512
 513 /// There is no PTT because this TNC will never make transmissions on a real radio.
 514 pub struct NullPtt;
 515
 516 impl NullPtt {
 517     pub fn new() -> Self {
 518         Self
 519     }
 520 }
 521
 522 impl Default for NullPtt {
 523     fn default() -> Self {
 524         Self::new()
 525     }
 526 }
 527
 528 impl Ptt for NullPtt {
 529     fn ptt_on(&mut self) {}
 530     fn ptt_off(&mut self) {}
 531 }