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

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