libs/backends/portaudio/portaudio_io.cc

   1 /*
   2  * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
   3  * Copyright (C) 2015 Tim Mayberry <mojofunk@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <assert.h>
  24 #include <glibmm.h>
  25 #include "portaudio_io.h"
  26
  27 #ifdef WITH_ASIO
  28 #include "pa_asio.h"
  29 #endif
  30
  31 #include "pbd/compose.h"
  32
  33 #include "debug.h"
  34
  35 #define INTERLEAVED_INPUT
  36 #define INTERLEAVED_OUTPUT
  37
  38 using namespace ARDOUR;
  39
  40 PortAudioIO::PortAudioIO ()
  41         : _state (-1)
  42         , _initialized (false)
  43         , _capture_channels (0)
  44         , _playback_channels (0)
  45         , _stream (0)
  46         , _input_buffer (0)
  47         , _output_buffer (0)
  48         , _cur_sample_rate (0)
  49         , _cur_input_latency (0)
  50         , _cur_output_latency (0)
  51         , _host_api_index(-1)
  52 {
  53 }
  54
  55 PortAudioIO::~PortAudioIO ()
  56 {
  57         if (_state == 0) {
  58                 pcm_stop();
  59         }
  60         if (_initialized) {
  61                 Pa_Terminate();
  62         }
  63
  64         clear_device_lists ();
  65
  66         free (_input_buffer); _input_buffer = NULL;
  67         free (_output_buffer); _output_buffer = NULL;
  68 }
  69
  70 std::string
  71 PortAudioIO::control_app_name (int device_id) const
  72 {
  73         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
  74         std::string app_name;
  75
  76         if (info == NULL) {
  77                 DEBUG_AUDIO (string_compose ("Unable to determine Host API from index %1\n",
  78                                              _host_api_index));
  79                 return app_name;
  80         }
  81
  82         PaHostApiTypeId type_id = info->type;
  83
  84 #ifdef WITH_ASIO
  85         if (type_id == paASIO) {
  86                 // is this used for anything, or just acts as a boolean?
  87                 return "PortaudioASIO";
  88         }
  89 #endif
  90
  91         return app_name;
  92 }
  93
  94 void
  95 PortAudioIO::launch_control_app (int device_id)
  96 {
  97 #ifdef WITH_ASIO
  98         PaError err = PaAsio_ShowControlPanel (device_id, NULL);
  99
 100         if (err != paNoError) {
 101                 // error << ?
 102                 DEBUG_AUDIO (string_compose (
 103                     "Unable to show control panel for device with index %1\n", device_id));
 104         }
 105 #endif
 106 }
 107
 108 int
 109 PortAudioIO::available_sample_rates(int device_id, std::vector<float>& sampleRates)
 110 {
 111         static const float ardourRates[] = { 8000.0, 22050.0, 24000.0, 44100.0, 48000.0, 88200.0, 96000.0, 176400.0, 192000.0};
 112
 113         if (!initialize_pa()) return -1;
 114
 115         // TODO use  separate int device_input, int device_output ?!
 116         if (device_id == -1) {
 117                 device_id = get_default_input_device ();
 118         }
 119
 120         DEBUG_AUDIO (
 121             string_compose ("Querying Samplerates for device %1\n", device_id));
 122
 123         sampleRates.clear();
 124         const PaDeviceInfo* nfo = Pa_GetDeviceInfo(device_id);
 125
 126         if (nfo) {
 127                 PaStreamParameters inputParam;
 128                 PaStreamParameters outputParam;
 129
 130                 inputParam.device = device_id;
 131                 inputParam.channelCount = nfo->maxInputChannels;
 132                 inputParam.sampleFormat = paFloat32;
 133                 inputParam.suggestedLatency = 0;
 134                 inputParam.hostApiSpecificStreamInfo = 0;
 135
 136                 outputParam.device = device_id;
 137                 outputParam.channelCount = nfo->maxOutputChannels;
 138                 outputParam.sampleFormat = paFloat32;
 139                 outputParam.suggestedLatency = 0;
 140                 outputParam.hostApiSpecificStreamInfo = 0;
 141
 142                 for (uint32_t i = 0; i < sizeof(ardourRates)/sizeof(float); ++i) {
 143                         if (paFormatIsSupported == Pa_IsFormatSupported(
 144                                                 nfo->maxInputChannels > 0 ? &inputParam : NULL,
 145                                                 nfo->maxOutputChannels > 0 ? &outputParam : NULL,
 146                                                 ardourRates[i])) {
 147                                 sampleRates.push_back (ardourRates[i]);
 148                         }
 149                 }
 150         }
 151
 152         if (sampleRates.empty()) {
 153                 // fill in something..
 154                 sampleRates.push_back (44100.0);
 155                 sampleRates.push_back (48000.0);
 156         }
 157
 158         return 0;
 159 }
 160
 161 #ifdef WITH_ASIO
 162 bool
 163 PortAudioIO::get_asio_buffer_properties (int device_id,
 164                                          long& min_size_frames,
 165                                          long& max_size_frames,
 166                                          long& preferred_size_frames,
 167                                          long& granularity)
 168 {
 169         // we shouldn't really need all these checks but it shouldn't hurt
 170         const PaDeviceInfo* device_info = Pa_GetDeviceInfo(device_id);
 171
 172         if (!device_info) {
 173                 DEBUG_AUDIO (string_compose (
 174                     "Unable to get device info from device index %1\n", device_id));
 175                 return false;
 176         }
 177
 178         const PaHostApiInfo* info = Pa_GetHostApiInfo (device_info->hostApi);
 179
 180         if (info == NULL) {
 181                 DEBUG_AUDIO (string_compose (
 182                     "Unable to determine Host API from device index %1\n", device_id));
 183                 return false;
 184         }
 185
 186         if (info->type != paASIO) {
 187                 DEBUG_AUDIO (string_compose (
 188                     "ERROR device_id %1 is not an ASIO device\n", device_id));
 189                 return false;
 190         }
 191
 192         PaError err = PaAsio_GetAvailableBufferSizes (device_id,
 193                                                       &min_size_frames,
 194                                                       &max_size_frames,
 195                                                       &preferred_size_frames,
 196                                                       &granularity);
 197
 198         if (err != paNoError) {
 199                 DEBUG_AUDIO (string_compose (
 200                     "Unable to determine available buffer sizes for device %1\n", device_id));
 201                 return false;
 202         }
 203         return true;
 204 }
 205
 206 bool
 207 PortAudioIO::get_asio_buffer_sizes (int device_id, std::vector<uint32_t>& buffer_sizes)
 208 {
 209         long min_size_frames = 0;
 210         long max_size_frames = 0;
 211         long preferred_size_frames = 0;
 212         long granularity = 0;
 213
 214         if (!get_asio_buffer_properties (device_id,
 215                                          min_size_frames,
 216                                          max_size_frames,
 217                                          preferred_size_frames,
 218                                          granularity)) {
 219                 DEBUG_AUDIO (string_compose (
 220                     "Unable to get device buffer properties from device index %1\n", device_id));
 221                 return false;
 222         }
 223
 224         DEBUG_AUDIO (string_compose ("ASIO buffer properties for device %1, "
 225                                      "min_size_frames: %2, max_size_frames: %3, "
 226                                      "preferred_size_frames: %4, granularity: %5\n",
 227                                      device_id,
 228                                      min_size_frames,
 229                                      max_size_frames,
 230                                      preferred_size_frames,
 231                                      granularity));
 232
 233 #ifdef USE_ASIO_MIN_MAX_BUFFER_SIZES
 234         if (min_size_frames >= max_size_frames) {
 235                 buffer_sizes.push_back (preferred_size_frames);
 236                 return true;
 237         }
 238
 239         long buffer_size = min_size_frames;
 240         while (buffer_size <= max_size_frames) {
 241                 buffer_sizes.push_back (buffer_size);
 242
 243                 if (granularity <= 0) {
 244                         // buffer sizes are power of 2
 245                         buffer_size = buffer_size * 2;
 246                 } else {
 247                         buffer_size += granularity;
 248                 }
 249         }
 250 #else
 251         buffer_sizes.push_back (preferred_size_frames);
 252 #endif
 253         return true;
 254 }
 255 #endif
 256
 257 bool
 258 PortAudioIO::get_default_buffer_sizes (int device_id, std::vector<uint32_t>& buffer_sizes)
 259 {
 260         static const uint32_t ardourSizes[] = { 64, 128, 256, 512, 1024, 2048, 4096 };
 261         for(uint32_t i = 0; i < sizeof(ardourSizes)/sizeof(uint32_t); ++i) {
 262                 buffer_sizes.push_back (ardourSizes[i]);
 263         }
 264         return true;
 265 }
 266
 267 int
 268 PortAudioIO::available_buffer_sizes(int device_id, std::vector<uint32_t>& buffer_sizes)
 269 {
 270 #ifdef WITH_ASIO
 271         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 272
 273         if (info == NULL) {
 274                 DEBUG_AUDIO (string_compose ("Unable to determine Host API from index %1\n",
 275                                              _host_api_index));
 276                 return -1;
 277         }
 278
 279         PaHostApiTypeId type_id = info->type;
 280
 281         if (type_id == paASIO) {
 282                 if (get_asio_buffer_sizes (device_id, buffer_sizes)) {
 283                         return 0;
 284                 }
 285         }
 286 #endif
 287
 288         get_default_buffer_sizes (device_id, buffer_sizes);
 289
 290         return 0;
 291 }
 292
 293 void
 294 PortAudioIO::input_device_list(std::map<int, std::string> &devices) const
 295 {
 296         for (std::map<int, paDevice*>::const_iterator i = _input_devices.begin ();
 297              i != _input_devices.end ();
 298              ++i) {
 299                 devices.insert (std::pair<int, std::string>(i->first, Glib::locale_to_utf8(i->second->name)));
 300         }
 301 }
 302
 303 void
 304 PortAudioIO::output_device_list(std::map<int, std::string> &devices) const
 305 {
 306         for (std::map<int, paDevice*>::const_iterator i = _output_devices.begin ();
 307              i != _output_devices.end ();
 308              ++i) {
 309                 devices.insert (std::pair<int, std::string>(i->first, Glib::locale_to_utf8(i->second->name)));
 310         }
 311 }
 312
 313 bool
 314 PortAudioIO::initialize_pa ()
 315 {
 316         PaError err = paNoError;
 317
 318         if (!_initialized) {
 319                 err = Pa_Initialize();
 320                 if (err != paNoError) {
 321                         return false;
 322                 }
 323                 _initialized = true;
 324                 _host_api_index = Pa_GetDefaultHostApi ();
 325                 _host_api_name = get_host_api_name_from_index (_host_api_index);
 326         }
 327
 328         return true;
 329 }
 330
 331 void
 332 PortAudioIO::host_api_list (std::vector<std::string>& api_list)
 333 {
 334         if (!initialize_pa()) return;
 335
 336         PaHostApiIndex count = Pa_GetHostApiCount();
 337
 338         if (count < 0) return;
 339
 340         for (int i = 0; i < count; ++i) {
 341                 const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
 342                 if (info->name != NULL) { // possible?
 343                         api_list.push_back (info->name);
 344                 }
 345         }
 346 }
 347
 348 std::string
 349 PortAudioIO::get_host_api_name_from_index (PaHostApiIndex index)
 350 {
 351         std::vector<std::string> api_list;
 352         host_api_list(api_list);
 353         return api_list[index];
 354 }
 355
 356 bool
 357 PortAudioIO::set_host_api (const std::string& host_api_name)
 358 {
 359         PaHostApiIndex new_index = get_host_api_index_from_name (host_api_name);
 360
 361         if (new_index < 0) {
 362                 DEBUG_AUDIO ("Portaudio: Error setting host API\n");
 363                 return false;
 364         }
 365         _host_api_index = new_index;
 366         _host_api_name = host_api_name;
 367         return true;
 368 }
 369
 370 PaHostApiIndex
 371 PortAudioIO::get_host_api_index_from_name (const std::string& name)
 372 {
 373         if (!initialize_pa()) return -1;
 374
 375         PaHostApiIndex count = Pa_GetHostApiCount();
 376
 377         if (count < 0) {
 378                 DEBUG_AUDIO ("Host API count < 0\n");
 379                 return -1;
 380         }
 381
 382         for (int i = 0; i < count; ++i) {
 383                 const PaHostApiInfo* info = Pa_GetHostApiInfo (i);
 384                 if (info != NULL && info->name != NULL) { // possible?
 385                         if (name == info->name) {
 386                                 return i;
 387                         }
 388                 }
 389         }
 390         DEBUG_AUDIO (string_compose ("Unable to get host API from name: %1\n", name));
 391
 392         return -1;
 393 }
 394
 395 PaDeviceIndex
 396 PortAudioIO::get_default_input_device ()
 397 {
 398         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 399         if (info == NULL) return -1;
 400         return info->defaultInputDevice;
 401 }
 402
 403 PaDeviceIndex
 404 PortAudioIO::get_default_output_device ()
 405 {
 406         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 407         if (info == NULL) return -1;
 408         return info->defaultOutputDevice;
 409 }
 410
 411 void
 412 PortAudioIO::clear_device_lists ()
 413 {
 414         for (std::map<int, paDevice*>::const_iterator i = _input_devices.begin (); i != _input_devices.end(); ++i) {
 415                 delete i->second;
 416         }
 417         _input_devices.clear();
 418
 419         for (std::map<int, paDevice*>::const_iterator i = _output_devices.begin (); i != _output_devices.end(); ++i) {
 420                 delete i->second;
 421         }
 422         _output_devices.clear();
 423 }
 424
 425 void
 426 PortAudioIO::add_default_devices ()
 427 {
 428         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 429         if (info == NULL) return;
 430
 431         const PaDeviceInfo* nfo_i = Pa_GetDeviceInfo(get_default_input_device());
 432         const PaDeviceInfo* nfo_o = Pa_GetDeviceInfo(get_default_output_device());
 433         if (nfo_i && nfo_o) {
 434                 _input_devices.insert (std::pair<int, paDevice*> (-1,
 435                                         new paDevice("Default",
 436                                                 nfo_i->maxInputChannels,
 437                                                 nfo_o->maxOutputChannels
 438                                                 )));
 439                 _output_devices.insert (std::pair<int, paDevice*> (-1,
 440                                         new paDevice("Default",
 441                                                 nfo_i->maxInputChannels,
 442                                                 nfo_o->maxOutputChannels
 443                                                 )));
 444         }
 445 }
 446
 447 void
 448 PortAudioIO::add_devices ()
 449 {
 450         const PaHostApiInfo* info = Pa_GetHostApiInfo (_host_api_index);
 451         if (info == NULL) return;
 452
 453         int n_devices = Pa_GetDeviceCount();
 454
 455         DEBUG_AUDIO (string_compose ("PortAudio found %1 devices\n", n_devices));
 456
 457         for (int i = 0 ; i < n_devices; ++i) {
 458                 const PaDeviceInfo* nfo = Pa_GetDeviceInfo(i);
 459
 460                 if (!nfo) continue;
 461                 if (nfo->hostApi != _host_api_index) continue;
 462
 463                 DEBUG_AUDIO (string_compose (" (%1) '%2' '%3' in: %4 (lat: %5 .. %6) out: %7 "
 464                                              "(lat: %8 .. %9) sr:%10\n",
 465                                              i,
 466                                              info->name,
 467                                              nfo->name,
 468                                              nfo->maxInputChannels,
 469                                              nfo->defaultLowInputLatency * 1e3,
 470                                              nfo->defaultHighInputLatency * 1e3,
 471                                              nfo->maxOutputChannels,
 472                                              nfo->defaultLowOutputLatency * 1e3,
 473                                              nfo->defaultHighOutputLatency * 1e3,
 474                                              nfo->defaultSampleRate));
 475
 476                 if ( nfo->maxInputChannels == 0 && nfo->maxOutputChannels == 0) {
 477                         continue;
 478                 }
 479
 480                 if (nfo->maxInputChannels > 0) {
 481                         _input_devices.insert (std::pair<int, paDevice*> (i, new paDevice(
 482                                                         nfo->name,
 483                                                         nfo->maxInputChannels,
 484                                                         nfo->maxOutputChannels
 485                                                         )));
 486                 }
 487                 if (nfo->maxOutputChannels > 0) {
 488                         _output_devices.insert (std::pair<int, paDevice*> (i, new paDevice(
 489                                                         nfo->name,
 490                                                         nfo->maxInputChannels,
 491                                                         nfo->maxOutputChannels
 492                                                         )));
 493                 }
 494         }
 495 }
 496
 497 void
 498 PortAudioIO::discover()
 499 {
 500         DEBUG_AUDIO ("PortAudio: discover\n");
 501         if (!initialize_pa()) return;
 502
 503         clear_device_lists ();
 504         add_devices ();
 505 }
 506
 507 void
 508 PortAudioIO::pcm_stop ()
 509 {
 510         if (_stream) {
 511                 Pa_CloseStream (_stream);
 512         }
 513         _stream = NULL;
 514
 515         _capture_channels = 0;
 516         _playback_channels = 0;
 517         _cur_sample_rate = 0;
 518         _cur_input_latency = 0;
 519         _cur_output_latency = 0;
 520
 521         free (_input_buffer); _input_buffer = NULL;
 522         free (_output_buffer); _output_buffer = NULL;
 523         _state = -1;
 524 }
 525
 526 int
 527 PortAudioIO::pcm_start()
 528 {
 529         PaError err = Pa_StartStream (_stream);
 530
 531         if (err != paNoError) {
 532                 _state = -1;
 533                 return -1;
 534         }
 535         return 0;
 536 }
 537
 538 #ifdef __APPLE__
 539 static uint32_t lower_power_of_two (uint32_t v) {
 540         v--;
 541         v |= v >> 1;
 542         v |= v >> 2;
 543         v |= v >> 4;
 544         v |= v >> 8;
 545         v |= v >> 16;
 546         v++;
 547         return v >> 1;
 548 }
 549 #endif
 550
 551 int
 552 PortAudioIO::pcm_setup (
 553                 int device_input, int device_output,
 554                 double sample_rate, uint32_t samples_per_period)
 555 {
 556         _state = -2;
 557
 558         PaError err = paNoError;
 559         const PaDeviceInfo *nfo_in;
 560         const PaDeviceInfo *nfo_out;
 561         const PaStreamInfo *nfo_s;
 562
 563         if (!initialize_pa()) {
 564                 DEBUG_AUDIO ("PortAudio Initialization Failed\n");
 565                 goto error;
 566         }
 567
 568         if (device_input == -1) {
 569                 device_input = get_default_input_device ();
 570         }
 571         if (device_output == -1) {
 572                 device_output = get_default_output_device ();
 573         }
 574
 575         _capture_channels = 0;
 576         _playback_channels = 0;
 577         _cur_sample_rate = 0;
 578         _cur_input_latency = 0;
 579         _cur_output_latency = 0;
 580
 581         DEBUG_AUDIO (string_compose (
 582             "PortAudio Device IDs: i:%1 o:%2\n", device_input, device_output));
 583
 584         nfo_in = Pa_GetDeviceInfo(device_input);
 585         nfo_out = Pa_GetDeviceInfo(device_output);
 586
 587         if (!nfo_in && ! nfo_out) {
 588                 DEBUG_AUDIO ("PortAudio Cannot Query Device Info\n");
 589                 goto error;
 590         }
 591
 592         if (nfo_in) {
 593                 _capture_channels = nfo_in->maxInputChannels;
 594         }
 595         if (nfo_out) {
 596                 _playback_channels = nfo_out->maxOutputChannels;
 597         }
 598
 599         if(_capture_channels == 0 && _playback_channels == 0) {
 600                 DEBUG_AUDIO ("PortAudio no input or output channels.\n");
 601                 goto error;
 602         }
 603
 604 #ifdef __APPLE__
 605         // pa_mac_core_blocking.c pa_stable_v19_20140130
 606         // BUG: ringbuffer alloc requires power-of-two chn count.
 607         if ((_capture_channels & (_capture_channels - 1)) != 0) {
 608                 DEBUG_AUDIO (
 609                     "Adjusted capture channels to power of two (portaudio rb bug)\n");
 610                 _capture_channels = lower_power_of_two (_capture_channels);
 611         }
 612
 613         if ((_playback_channels & (_playback_channels - 1)) != 0) {
 614                 DEBUG_AUDIO (
 615                     "Adjusted capture channels to power of two (portaudio rb bug)\n");
 616                 _playback_channels = lower_power_of_two (_playback_channels);
 617         }
 618 #endif
 619
 620         DEBUG_AUDIO (string_compose ("PortAudio Channels: in:%1 out:%2\n",
 621                                      _capture_channels,
 622                                      _playback_channels));
 623
 624         PaStreamParameters inputParam;
 625         PaStreamParameters outputParam;
 626
 627         if (nfo_in) {
 628                 inputParam.device = device_input;
 629                 inputParam.channelCount = _capture_channels;
 630 #ifdef INTERLEAVED_INPUT
 631                 inputParam.sampleFormat = paFloat32;
 632 #else
 633                 inputParam.sampleFormat = paFloat32 | paNonInterleaved;
 634 #endif
 635                 inputParam.suggestedLatency = nfo_in->defaultLowInputLatency;
 636                 inputParam.hostApiSpecificStreamInfo = NULL;
 637         }
 638
 639         if (nfo_out) {
 640                 outputParam.device = device_output;
 641                 outputParam.channelCount = _playback_channels;
 642 #ifdef INTERLEAVED_OUTPUT
 643                 outputParam.sampleFormat = paFloat32;
 644 #else
 645                 outputParam.sampleFormat = paFloat32 | paNonInterleaved;
 646 #endif
 647                 outputParam.suggestedLatency = nfo_out->defaultLowOutputLatency;
 648                 outputParam.hostApiSpecificStreamInfo = NULL;
 649         }
 650
 651         // XXX re-consider using callback API, testing needed.
 652         err = Pa_OpenStream (
 653                         &_stream,
 654                         _capture_channels > 0 ? &inputParam: NULL,
 655                         _playback_channels > 0 ? &outputParam: NULL,
 656                         sample_rate,
 657                         samples_per_period,
 658                         paDitherOff,
 659                         NULL, NULL);
 660
 661         if (err != paNoError) {
 662                 DEBUG_AUDIO ("PortAudio failed to start stream.\n");
 663                 goto error;
 664         }
 665
 666         nfo_s = Pa_GetStreamInfo (_stream);
 667         if (!nfo_s) {
 668                 DEBUG_AUDIO ("PortAudio failed to query stream information.\n");
 669                 pcm_stop();
 670                 goto error;
 671         }
 672
 673         _cur_sample_rate = nfo_s->sampleRate;
 674         _cur_input_latency = nfo_s->inputLatency * _cur_sample_rate;
 675         _cur_output_latency = nfo_s->outputLatency * _cur_sample_rate;
 676
 677         DEBUG_AUDIO (string_compose ("PA Sample Rate %1 SPS\n", _cur_sample_rate));
 678
 679         DEBUG_AUDIO (string_compose ("PA Input Latency %1ms, %2 spl\n",
 680                                      1e3 * nfo_s->inputLatency,
 681                                      _cur_input_latency));
 682
 683         DEBUG_AUDIO (string_compose ("PA Output Latency %1ms, %2 spl\n",
 684                                      1e3 * nfo_s->outputLatency,
 685                                      _cur_output_latency));
 686
 687         _state = 0;
 688
 689         if (_capture_channels > 0) {
 690                 _input_buffer = (float*) malloc (samples_per_period * _capture_channels * sizeof(float));
 691                 if (!_input_buffer) {
 692                         DEBUG_AUDIO ("PortAudio failed to allocate input buffer.\n");
 693                         pcm_stop();
 694                         goto error;
 695                 }
 696         }
 697
 698         if (_playback_channels > 0) {
 699                 _output_buffer = (float*) calloc (samples_per_period * _playback_channels, sizeof(float));
 700                 if (!_output_buffer) {
 701                         DEBUG_AUDIO ("PortAudio failed to allocate output buffer.\n");
 702                         pcm_stop();
 703                         goto error;
 704                 }
 705         }
 706
 707         return 0;
 708
 709 error:
 710         _capture_channels = 0;
 711         _playback_channels = 0;
 712         free (_input_buffer); _input_buffer = NULL;
 713         free (_output_buffer); _output_buffer = NULL;
 714         return -1;
 715 }
 716
 717 int
 718 PortAudioIO::next_cycle (uint32_t n_samples)
 719 {
 720         bool xrun = false;
 721         PaError err;
 722         err = Pa_IsStreamActive (_stream);
 723         if (err != 1) {
 724                 //   0: inactive / aborted
 725                 // < 0: error
 726                 return -1;
 727         }
 728
 729         // TODO, check drift..  process part with larger capacity first.
 730         // Pa_GetStreamReadAvailable(_stream) < Pa_GetStreamWriteAvailable(_stream)
 731
 732         if (_playback_channels > 0) {
 733                 err = Pa_WriteStream (_stream, _output_buffer, n_samples);
 734                 if (err) xrun = true;
 735         }
 736
 737         if (_capture_channels > 0) {
 738                 err = Pa_ReadStream (_stream, _input_buffer, n_samples);
 739                 if (err) {
 740                         memset (_input_buffer, 0, sizeof(float) * n_samples * _capture_channels);
 741                         xrun = true;
 742                 }
 743         }
 744
 745
 746         return xrun ? 1 : 0;
 747 }
 748
 749 std::string
 750 PortAudioIO::get_input_channel_name (int device_id, uint32_t channel) const
 751 {
 752 #ifdef WITH_ASIO
 753         const char* channel_name;
 754
 755         // This will return an error for non-ASIO devices so no need to check if
 756         // the device_id corresponds to an ASIO device.
 757         PaError err = PaAsio_GetInputChannelName (device_id, channel, &channel_name);
 758
 759         if (err == paNoError) {
 760                 DEBUG_AUDIO (
 761                     string_compose ("Input channel name for device %1, channel %2 is %3\n",
 762                                     device_id,
 763                                     channel,
 764                                     channel_name));
 765                 return channel_name;
 766         }
 767 #endif
 768         return std::string();
 769 }
 770
 771 std::string
 772 PortAudioIO::get_output_channel_name (int device_id, uint32_t channel) const
 773 {
 774 #ifdef WITH_ASIO
 775         const char* channel_name;
 776
 777         PaError err = PaAsio_GetOutputChannelName (device_id, channel, &channel_name);
 778
 779         if (err == paNoError) {
 780                 DEBUG_AUDIO (
 781                     string_compose ("Output channel name for device %1, channel %2 is %3\n",
 782                                     device_id,
 783                                     channel,
 784                                     channel_name));
 785                 return channel_name;
 786         }
 787 #endif
 788         return std::string();
 789 }
 790
 791 #ifdef INTERLEAVED_INPUT
 792
 793 int
 794 PortAudioIO::get_capture_channel (uint32_t chn, float *input, uint32_t n_samples)
 795 {
 796         assert(chn < _capture_channels);
 797         const uint32_t stride = _capture_channels;
 798         float *ptr = _input_buffer + chn;
 799         while (n_samples-- > 0) {
 800                 *input++ = *ptr;
 801                 ptr += stride;
 802         }
 803         return 0;
 804 }
 805
 806 #else
 807
 808 int
 809 PortAudioIO::get_capture_channel (uint32_t chn, float *input, uint32_t n_samples)
 810 {
 811         assert(chn < _capture_channels);
 812         memcpy((void*)input, &(_input_buffer[chn * n_samples]), n_samples * sizeof(float));
 813         return 0;
 814 }
 815
 816 #endif
 817
 818
 819 #ifdef INTERLEAVED_OUTPUT
 820
 821 int
 822 PortAudioIO::set_playback_channel (uint32_t chn, const float *output, uint32_t n_samples)
 823 {
 824         assert(chn < _playback_channels);
 825         const uint32_t stride = _playback_channels;
 826         float *ptr = _output_buffer + chn;
 827         while (n_samples-- > 0) {
 828                 *ptr = *output++;
 829                 ptr += stride;
 830         }
 831         return 0;
 832 }
 833
 834 #else
 835
 836 int
 837 PortAudioIO::set_playback_channel (uint32_t chn, const float *output, uint32_t n_samples)
 838 {
 839         assert(chn < _playback_channels);
 840         memcpy((void*)&(_output_buffer[chn * n_samples]), (void*)output, n_samples * sizeof(float));
 841         return 0;
 842 }
 843
 844 #endif