summaryrefslogtreecommitdiff
path: root/thirdparty/rtaudio/RtAudio.h
blob: 4392e95f3275ba07778503f7a6d267821ecd5bee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
// -GODOT- Start

#ifdef RTAUDIO_ENABLED

#if defined(OSX_ENABLED)
    #define __MACOSX_CORE__
#elif defined(UNIX_ENABLED)
    #define __LINUX_ALSA__
#elif defined(WINDOWS_ENABLED)
    #if defined(WINRT_ENABLED)
        #define __RTAUDIO_DUMMY__
    #else
        #define __WINDOWS_DS__
    #endif
#endif

// -GODOT- End

/************************************************************************/
/*! \class RtAudio
    \brief Realtime audio i/o C++ classes.

    RtAudio provides a common API (Application Programming Interface)
    for realtime audio input/output across Linux (native ALSA, Jack,
    and OSS), Macintosh OS X (CoreAudio and Jack), and Windows
    (DirectSound, ASIO and WASAPI) operating systems.

    RtAudio WWW site: http://www.music.mcgill.ca/~gary/rtaudio/

    RtAudio: realtime audio i/o C++ classes
    Copyright (c) 2001-2016 Gary P. Scavone

    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation files
    (the "Software"), to deal in the Software without restriction,
    including without limitation the rights to use, copy, modify, merge,
    publish, distribute, sublicense, and/or sell copies of the Software,
    and to permit persons to whom the Software is furnished to do so,
    subject to the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    Any person wishing to distribute modifications to the Software is
    asked to send the modifications to the original developer so that
    they can be incorporated into the canonical version.  This is,
    however, not a binding provision of this license.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/************************************************************************/

/*!
  \file RtAudio.h
 */

#ifndef __RTAUDIO_H
#define __RTAUDIO_H

#define RTAUDIO_VERSION "4.1.2"

#include <string>
#include <vector>
#include <exception>
#include <iostream>

/*! \typedef typedef unsigned long RtAudioFormat;
    \brief RtAudio data format type.

    Support for signed integers and floats.  Audio data fed to/from an
    RtAudio stream is assumed to ALWAYS be in host byte order.  The
    internal routines will automatically take care of any necessary
    byte-swapping between the host format and the soundcard.  Thus,
    endian-ness is not a concern in the following format definitions.

    - \e RTAUDIO_SINT8:   8-bit signed integer.
    - \e RTAUDIO_SINT16:  16-bit signed integer.
    - \e RTAUDIO_SINT24:  24-bit signed integer.
    - \e RTAUDIO_SINT32:  32-bit signed integer.
    - \e RTAUDIO_FLOAT32: Normalized between plus/minus 1.0.
    - \e RTAUDIO_FLOAT64: Normalized between plus/minus 1.0.
*/
typedef unsigned long RtAudioFormat;
static const RtAudioFormat RTAUDIO_SINT8 = 0x1;    // 8-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT16 = 0x2;   // 16-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT24 = 0x4;   // 24-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT32 = 0x8;   // 32-bit signed integer.
static const RtAudioFormat RTAUDIO_FLOAT32 = 0x10; // Normalized between plus/minus 1.0.
static const RtAudioFormat RTAUDIO_FLOAT64 = 0x20; // Normalized between plus/minus 1.0.

/*! \typedef typedef unsigned long RtAudioStreamFlags;
    \brief RtAudio stream option flags.

    The following flags can be OR'ed together to allow a client to
    make changes to the default stream behavior:

    - \e RTAUDIO_NONINTERLEAVED:   Use non-interleaved buffers (default = interleaved).
    - \e RTAUDIO_MINIMIZE_LATENCY: Attempt to set stream parameters for lowest possible latency.
    - \e RTAUDIO_HOG_DEVICE:       Attempt grab device for exclusive use.
    - \e RTAUDIO_ALSA_USE_DEFAULT: Use the "default" PCM device (ALSA only).

    By default, RtAudio streams pass and receive audio data from the
    client in an interleaved format.  By passing the
    RTAUDIO_NONINTERLEAVED flag to the openStream() function, audio
    data will instead be presented in non-interleaved buffers.  In
    this case, each buffer argument in the RtAudioCallback function
    will point to a single array of data, with \c nFrames samples for
    each channel concatenated back-to-back.  For example, the first
    sample of data for the second channel would be located at index \c
    nFrames (assuming the \c buffer pointer was recast to the correct
    data type for the stream).

    Certain audio APIs offer a number of parameters that influence the
    I/O latency of a stream.  By default, RtAudio will attempt to set
    these parameters internally for robust (glitch-free) performance
    (though some APIs, like Windows Direct Sound, make this difficult).
    By passing the RTAUDIO_MINIMIZE_LATENCY flag to the openStream()
    function, internal stream settings will be influenced in an attempt
    to minimize stream latency, though possibly at the expense of stream
    performance.

    If the RTAUDIO_HOG_DEVICE flag is set, RtAudio will attempt to
    open the input and/or output stream device(s) for exclusive use.
    Note that this is not possible with all supported audio APIs.

    If the RTAUDIO_SCHEDULE_REALTIME flag is set, RtAudio will attempt
    to select realtime scheduling (round-robin) for the callback thread.

    If the RTAUDIO_ALSA_USE_DEFAULT flag is set, RtAudio will attempt to
    open the "default" PCM device when using the ALSA API. Note that this
    will override any specified input or output device id.
*/
typedef unsigned int RtAudioStreamFlags;
static const RtAudioStreamFlags RTAUDIO_NONINTERLEAVED = 0x1;    // Use non-interleaved buffers (default = interleaved).
static const RtAudioStreamFlags RTAUDIO_MINIMIZE_LATENCY = 0x2;  // Attempt to set stream parameters for lowest possible latency.
static const RtAudioStreamFlags RTAUDIO_HOG_DEVICE = 0x4;        // Attempt grab device and prevent use by others.
static const RtAudioStreamFlags RTAUDIO_SCHEDULE_REALTIME = 0x8; // Try to select realtime scheduling for callback thread.
static const RtAudioStreamFlags RTAUDIO_ALSA_USE_DEFAULT = 0x10; // Use the "default" PCM device (ALSA only).

/*! \typedef typedef unsigned long RtAudioStreamStatus;
    \brief RtAudio stream status (over- or underflow) flags.

    Notification of a stream over- or underflow is indicated by a
    non-zero stream \c status argument in the RtAudioCallback function.
    The stream status can be one of the following two options,
    depending on whether the stream is open for output and/or input:

    - \e RTAUDIO_INPUT_OVERFLOW:   Input data was discarded because of an overflow condition at the driver.
    - \e RTAUDIO_OUTPUT_UNDERFLOW: The output buffer ran low, likely producing a break in the output sound.
*/
typedef unsigned int RtAudioStreamStatus;
static const RtAudioStreamStatus RTAUDIO_INPUT_OVERFLOW = 0x1;    // Input data was discarded because of an overflow condition at the driver.
static const RtAudioStreamStatus RTAUDIO_OUTPUT_UNDERFLOW = 0x2;  // The output buffer ran low, likely causing a gap in the output sound.

//! RtAudio callback function prototype.
/*!
   All RtAudio clients must create a function of type RtAudioCallback
   to read and/or write data from/to the audio stream.  When the
   underlying audio system is ready for new input or output data, this
   function will be invoked.

   \param outputBuffer For output (or duplex) streams, the client
          should write \c nFrames of audio sample frames into this
          buffer.  This argument should be recast to the datatype
          specified when the stream was opened.  For input-only
          streams, this argument will be NULL.

   \param inputBuffer For input (or duplex) streams, this buffer will
          hold \c nFrames of input audio sample frames.  This
          argument should be recast to the datatype specified when the
          stream was opened.  For output-only streams, this argument
          will be NULL.

   \param nFrames The number of sample frames of input or output
          data in the buffers.  The actual buffer size in bytes is
          dependent on the data type and number of channels in use.

   \param streamTime The number of seconds that have elapsed since the
          stream was started.

   \param status If non-zero, this argument indicates a data overflow
          or underflow condition for the stream.  The particular
          condition can be determined by comparison with the
          RtAudioStreamStatus flags.

   \param userData A pointer to optional data provided by the client
          when opening the stream (default = NULL).

   To continue normal stream operation, the RtAudioCallback function
   should return a value of zero.  To stop the stream and drain the
   output buffer, the function should return a value of one.  To abort
   the stream immediately, the client should return a value of two.
 */
typedef int (*RtAudioCallback)( void *outputBuffer, void *inputBuffer,
                                unsigned int nFrames,
                                double streamTime,
                                RtAudioStreamStatus status,
                                void *userData );

/************************************************************************/
/*! \class RtAudioError
    \brief Exception handling class for RtAudio.

    The RtAudioError class is quite simple but it does allow errors to be
    "caught" by RtAudioError::Type. See the RtAudio documentation to know
    which methods can throw an RtAudioError.
*/
/************************************************************************/

class RtAudioError : public std::exception
{
 public:
  //! Defined RtAudioError types.
  enum Type {
    WARNING,           /*!< A non-critical error. */
    DEBUG_WARNING,     /*!< A non-critical error which might be useful for debugging. */
    UNSPECIFIED,       /*!< The default, unspecified error type. */
    NO_DEVICES_FOUND,  /*!< No devices found on system. */
    INVALID_DEVICE,    /*!< An invalid device ID was specified. */
    MEMORY_ERROR,      /*!< An error occured during memory allocation. */
    INVALID_PARAMETER, /*!< An invalid parameter was specified to a function. */
    INVALID_USE,       /*!< The function was called incorrectly. */
    DRIVER_ERROR,      /*!< A system driver error occured. */
    SYSTEM_ERROR,      /*!< A system error occured. */
    THREAD_ERROR       /*!< A thread error occured. */
  };

  //! The constructor.
  RtAudioError( const std::string& message, Type type = RtAudioError::UNSPECIFIED ) throw() : message_(message), type_(type) {}

  //! The destructor.
  virtual ~RtAudioError( void ) throw() {}

  //! Prints thrown error message to stderr.
  virtual void printMessage( void ) const throw() { std::cerr << '\n' << message_ << "\n\n"; }

  //! Returns the thrown error message type.
  virtual const Type& getType(void) const throw() { return type_; }

  //! Returns the thrown error message string.
  virtual const std::string& getMessage(void) const throw() { return message_; }

  //! Returns the thrown error message as a c-style string.
  virtual const char* what( void ) const throw() { return message_.c_str(); }

 protected:
  std::string message_;
  Type type_;
};

//! RtAudio error callback function prototype.
/*!
    \param type Type of error.
    \param errorText Error description.
 */
typedef void (*RtAudioErrorCallback)( RtAudioError::Type type, const std::string &errorText );

// **************************************************************** //
//
// RtAudio class declaration.
//
// RtAudio is a "controller" used to select an available audio i/o
// interface.  It presents a common API for the user to call but all
// functionality is implemented by the class RtApi and its
// subclasses.  RtAudio creates an instance of an RtApi subclass
// based on the user's API choice.  If no choice is made, RtAudio
// attempts to make a "logical" API selection.
//
// **************************************************************** //

class RtApi;

class RtAudio
{
 public:

  //! Audio API specifier arguments.
  enum Api {
    UNSPECIFIED,    /*!< Search for a working compiled API. */
    LINUX_ALSA,     /*!< The Advanced Linux Sound Architecture API. */
    LINUX_PULSE,    /*!< The Linux PulseAudio API. */
    LINUX_OSS,      /*!< The Linux Open Sound System API. */
    UNIX_JACK,      /*!< The Jack Low-Latency Audio Server API. */
    MACOSX_CORE,    /*!< Macintosh OS-X Core Audio API. */
    WINDOWS_WASAPI, /*!< The Microsoft WASAPI API. */
    WINDOWS_ASIO,   /*!< The Steinberg Audio Stream I/O API. */
    WINDOWS_DS,     /*!< The Microsoft Direct Sound API. */
    RTAUDIO_DUMMY   /*!< A compilable but non-functional API. */
  };

  //! The public device information structure for returning queried values.
  struct DeviceInfo {
    bool probed;                  /*!< true if the device capabilities were successfully probed. */
    std::string name;             /*!< Character string device identifier. */
    unsigned int outputChannels;  /*!< Maximum output channels supported by device. */
    unsigned int inputChannels;   /*!< Maximum input channels supported by device. */
    unsigned int duplexChannels;  /*!< Maximum simultaneous input/output channels supported by device. */
    bool isDefaultOutput;         /*!< true if this is the default output device. */
    bool isDefaultInput;          /*!< true if this is the default input device. */
    std::vector<unsigned int> sampleRates; /*!< Supported sample rates (queried from list of standard rates). */
    unsigned int preferredSampleRate; /*!< Preferred sample rate, eg. for WASAPI the system sample rate. */
    RtAudioFormat nativeFormats;  /*!< Bit mask of supported data formats. */

    // Default constructor.
    DeviceInfo()
      :probed(false), outputChannels(0), inputChannels(0), duplexChannels(0),
       isDefaultOutput(false), isDefaultInput(false), preferredSampleRate(0), nativeFormats(0) {}
  };

  //! The structure for specifying input or ouput stream parameters.
  struct StreamParameters {
    unsigned int deviceId;     /*!< Device index (0 to getDeviceCount() - 1). */
    unsigned int nChannels;    /*!< Number of channels. */
    unsigned int firstChannel; /*!< First channel index on device (default = 0). */

    // Default constructor.
    StreamParameters()
      : deviceId(0), nChannels(0), firstChannel(0) {}
  };

  //! The structure for specifying stream options.
  /*!
    The following flags can be OR'ed together to allow a client to
    make changes to the default stream behavior:

    - \e RTAUDIO_NONINTERLEAVED:    Use non-interleaved buffers (default = interleaved).
    - \e RTAUDIO_MINIMIZE_LATENCY:  Attempt to set stream parameters for lowest possible latency.
    - \e RTAUDIO_HOG_DEVICE:        Attempt grab device for exclusive use.
    - \e RTAUDIO_SCHEDULE_REALTIME: Attempt to select realtime scheduling for callback thread.
    - \e RTAUDIO_ALSA_USE_DEFAULT:  Use the "default" PCM device (ALSA only).

    By default, RtAudio streams pass and receive audio data from the
    client in an interleaved format.  By passing the
    RTAUDIO_NONINTERLEAVED flag to the openStream() function, audio
    data will instead be presented in non-interleaved buffers.  In
    this case, each buffer argument in the RtAudioCallback function
    will point to a single array of data, with \c nFrames samples for
    each channel concatenated back-to-back.  For example, the first
    sample of data for the second channel would be located at index \c
    nFrames (assuming the \c buffer pointer was recast to the correct
    data type for the stream).

    Certain audio APIs offer a number of parameters that influence the
    I/O latency of a stream.  By default, RtAudio will attempt to set
    these parameters internally for robust (glitch-free) performance
    (though some APIs, like Windows Direct Sound, make this difficult).
    By passing the RTAUDIO_MINIMIZE_LATENCY flag to the openStream()
    function, internal stream settings will be influenced in an attempt
    to minimize stream latency, though possibly at the expense of stream
    performance.

    If the RTAUDIO_HOG_DEVICE flag is set, RtAudio will attempt to
    open the input and/or output stream device(s) for exclusive use.
    Note that this is not possible with all supported audio APIs.

    If the RTAUDIO_SCHEDULE_REALTIME flag is set, RtAudio will attempt
    to select realtime scheduling (round-robin) for the callback thread.
    The \c priority parameter will only be used if the RTAUDIO_SCHEDULE_REALTIME
    flag is set. It defines the thread's realtime priority.

    If the RTAUDIO_ALSA_USE_DEFAULT flag is set, RtAudio will attempt to
    open the "default" PCM device when using the ALSA API. Note that this
    will override any specified input or output device id.

    The \c numberOfBuffers parameter can be used to control stream
    latency in the Windows DirectSound, Linux OSS, and Linux Alsa APIs
    only.  A value of two is usually the smallest allowed.  Larger
    numbers can potentially result in more robust stream performance,
    though likely at the cost of stream latency.  The value set by the
    user is replaced during execution of the RtAudio::openStream()
    function by the value actually used by the system.

    The \c streamName parameter can be used to set the client name
    when using the Jack API.  By default, the client name is set to
    RtApiJack.  However, if you wish to create multiple instances of
    RtAudio with Jack, each instance must have a unique client name.
  */
  struct StreamOptions {
    RtAudioStreamFlags flags;      /*!< A bit-mask of stream flags (RTAUDIO_NONINTERLEAVED, RTAUDIO_MINIMIZE_LATENCY, RTAUDIO_HOG_DEVICE, RTAUDIO_ALSA_USE_DEFAULT). */
    unsigned int numberOfBuffers;  /*!< Number of stream buffers. */
    std::string streamName;        /*!< A stream name (currently used only in Jack). */
    int priority;                  /*!< Scheduling priority of callback thread (only used with flag RTAUDIO_SCHEDULE_REALTIME). */

    // Default constructor.
    StreamOptions()
    : flags(0), numberOfBuffers(0), priority(0) {}
  };

  //! A static function to determine the current RtAudio version.
  static std::string getVersion( void ) throw();

  //! A static function to determine the available compiled audio APIs.
  /*!
    The values returned in the std::vector can be compared against
    the enumerated list values.  Note that there can be more than one
    API compiled for certain operating systems.
  */
  static void getCompiledApi( std::vector<RtAudio::Api> &apis ) throw();

  //! The class constructor.
  /*!
    The constructor performs minor initialization tasks.  An exception
    can be thrown if no API support is compiled.

    If no API argument is specified and multiple API support has been
    compiled, the default order of use is JACK, ALSA, OSS (Linux
    systems) and ASIO, DS (Windows systems).
  */
  RtAudio( RtAudio::Api api=UNSPECIFIED );

  //! The destructor.
  /*!
    If a stream is running or open, it will be stopped and closed
    automatically.
  */
  ~RtAudio() throw();

  //! Returns the audio API specifier for the current instance of RtAudio.
  RtAudio::Api getCurrentApi( void ) throw();

  //! A public function that queries for the number of audio devices available.
  /*!
    This function performs a system query of available devices each time it
    is called, thus supporting devices connected \e after instantiation. If
    a system error occurs during processing, a warning will be issued.
  */
  unsigned int getDeviceCount( void ) throw();

  //! Return an RtAudio::DeviceInfo structure for a specified device number.
  /*!

    Any device integer between 0 and getDeviceCount() - 1 is valid.
    If an invalid argument is provided, an RtAudioError (type = INVALID_USE)
    will be thrown.  If a device is busy or otherwise unavailable, the
    structure member "probed" will have a value of "false" and all
    other members are undefined.  If the specified device is the
    current default input or output device, the corresponding
    "isDefault" member will have a value of "true".
  */
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );

  //! A function that returns the index of the default output device.
  /*!
    If the underlying audio API does not provide a "default
    device", or if no devices are available, the return value will be
    0.  Note that this is a valid device identifier and it is the
    client's responsibility to verify that a device is available
    before attempting to open a stream.
  */
  unsigned int getDefaultOutputDevice( void ) throw();

  //! A function that returns the index of the default input device.
  /*!
    If the underlying audio API does not provide a "default
    device", or if no devices are available, the return value will be
    0.  Note that this is a valid device identifier and it is the
    client's responsibility to verify that a device is available
    before attempting to open a stream.
  */
  unsigned int getDefaultInputDevice( void ) throw();

  //! A public function for opening a stream with the specified parameters.
  /*!
    An RtAudioError (type = SYSTEM_ERROR) is thrown if a stream cannot be
    opened with the specified parameters or an error occurs during
    processing.  An RtAudioError (type = INVALID_USE) is thrown if any
    invalid device ID or channel number parameters are specified.

    \param outputParameters Specifies output stream parameters to use
           when opening a stream, including a device ID, number of channels,
           and starting channel number.  For input-only streams, this
           argument should be NULL.  The device ID is an index value between
           0 and getDeviceCount() - 1.
    \param inputParameters Specifies input stream parameters to use
           when opening a stream, including a device ID, number of channels,
           and starting channel number.  For output-only streams, this
           argument should be NULL.  The device ID is an index value between
           0 and getDeviceCount() - 1.
    \param format An RtAudioFormat specifying the desired sample data format.
    \param sampleRate The desired sample rate (sample frames per second).
    \param *bufferFrames A pointer to a value indicating the desired
           internal buffer size in sample frames.  The actual value
           used by the device is returned via the same pointer.  A
           value of zero can be specified, in which case the lowest
           allowable value is determined.
    \param callback A client-defined function that will be invoked
           when input data is available and/or output data is needed.
    \param userData An optional pointer to data that can be accessed
           from within the callback function.
    \param options An optional pointer to a structure containing various
           global stream options, including a list of OR'ed RtAudioStreamFlags
           and a suggested number of stream buffers that can be used to
           control stream latency.  More buffers typically result in more
           robust performance, though at a cost of greater latency.  If a
           value of zero is specified, a system-specific median value is
           chosen.  If the RTAUDIO_MINIMIZE_LATENCY flag bit is set, the
           lowest allowable value is used.  The actual value used is
           returned via the structure argument.  The parameter is API dependent.
    \param errorCallback A client-defined function that will be invoked
           when an error has occured.
  */
  void openStream( RtAudio::StreamParameters *outputParameters,
                   RtAudio::StreamParameters *inputParameters,
                   RtAudioFormat format, unsigned int sampleRate,
                   unsigned int *bufferFrames, RtAudioCallback callback,
                   void *userData = NULL, RtAudio::StreamOptions *options = NULL, RtAudioErrorCallback errorCallback = NULL );

  //! A function that closes a stream and frees any associated stream memory.
  /*!
    If a stream is not open, this function issues a warning and
    returns (no exception is thrown).
  */
  void closeStream( void ) throw();

  //! A function that starts a stream.
  /*!
    An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
    during processing.  An RtAudioError (type = INVALID_USE) is thrown if a
    stream is not open.  A warning is issued if the stream is already
    running.
  */
  void startStream( void );

  //! Stop a stream, allowing any samples remaining in the output queue to be played.
  /*!
    An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
    during processing.  An RtAudioError (type = INVALID_USE) is thrown if a
    stream is not open.  A warning is issued if the stream is already
    stopped.
  */
  void stopStream( void );

  //! Stop a stream, discarding any samples remaining in the input/output queue.
  /*!
    An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
    during processing.  An RtAudioError (type = INVALID_USE) is thrown if a
    stream is not open.  A warning is issued if the stream is already
    stopped.
  */
  void abortStream( void );

  //! Returns true if a stream is open and false if not.
  bool isStreamOpen( void ) const throw();

  //! Returns true if the stream is running and false if it is stopped or not open.
  bool isStreamRunning( void ) const throw();

  //! Returns the number of elapsed seconds since the stream was started.
  /*!
    If a stream is not open, an RtAudioError (type = INVALID_USE) will be thrown.
  */
  double getStreamTime( void );

  //! Set the stream time to a time in seconds greater than or equal to 0.0.
  /*!
    If a stream is not open, an RtAudioError (type = INVALID_USE) will be thrown.
  */
  void setStreamTime( double time );

  //! Returns the internal stream latency in sample frames.
  /*!
    The stream latency refers to delay in audio input and/or output
    caused by internal buffering by the audio system and/or hardware.
    For duplex streams, the returned value will represent the sum of
    the input and output latencies.  If a stream is not open, an
    RtAudioError (type = INVALID_USE) will be thrown.  If the API does not
    report latency, the return value will be zero.
  */
  long getStreamLatency( void );

 //! Returns actual sample rate in use by the stream.
 /*!
   On some systems, the sample rate used may be slightly different
   than that specified in the stream parameters.  If a stream is not
   open, an RtAudioError (type = INVALID_USE) will be thrown.
 */
  unsigned int getStreamSampleRate( void );

  //! Specify whether warning messages should be printed to stderr.
  void showWarnings( bool value = true ) throw();

 protected:

  void openRtApi( RtAudio::Api api );
  RtApi *rtapi_;
};

// Operating system dependent thread functionality.
#if defined(__WINDOWS_DS__) || defined(__WINDOWS_ASIO__) || defined(__WINDOWS_WASAPI__)

  #ifndef NOMINMAX
    #define NOMINMAX
  #endif
  #include <windows.h>
  #include <process.h>

  typedef uintptr_t ThreadHandle;
  typedef CRITICAL_SECTION StreamMutex;

#elif defined(__LINUX_ALSA__) || defined(__LINUX_PULSE__) || defined(__UNIX_JACK__) || defined(__LINUX_OSS__) || defined(__MACOSX_CORE__)
  // Using pthread library for various flavors of unix.
  #include <pthread.h>

  typedef pthread_t ThreadHandle;
  typedef pthread_mutex_t StreamMutex;

#else // Setup for "dummy" behavior

  #define __RTAUDIO_DUMMY__
  typedef int ThreadHandle;
  typedef int StreamMutex;

#endif

// This global structure type is used to pass callback information
// between the private RtAudio stream structure and global callback
// handling functions.
struct CallbackInfo {
  void *object;    // Used as a "this" pointer.
  ThreadHandle thread;
  void *callback;
  void *userData;
  void *errorCallback;
  void *apiInfo;   // void pointer for API specific callback information
  bool isRunning;
  bool doRealtime;
  int priority;

  // Default constructor.
  CallbackInfo()
  :object(0), callback(0), userData(0), errorCallback(0), apiInfo(0), isRunning(false), doRealtime(false) {}
};

// **************************************************************** //
//
// RtApi class declaration.
//
// Subclasses of RtApi contain all API- and OS-specific code necessary
// to fully implement the RtAudio API.
//
// Note that RtApi is an abstract base class and cannot be
// explicitly instantiated.  The class RtAudio will create an
// instance of an RtApi subclass (RtApiOss, RtApiAlsa,
// RtApiJack, RtApiCore, RtApiDs, or RtApiAsio).
//
// **************************************************************** //

#pragma pack(push, 1)
class S24 {

 protected:
  unsigned char c3[3];

 public:
  S24() {}

  S24& operator = ( const int& i ) {
    c3[0] = (i & 0x000000ff);
    c3[1] = (i & 0x0000ff00) >> 8;
    c3[2] = (i & 0x00ff0000) >> 16;
    return *this;
  }

  S24( const S24& v ) { *this = v; }
  S24( const double& d ) { *this = (int) d; }
  S24( const float& f ) { *this = (int) f; }
  S24( const signed short& s ) { *this = (int) s; }
  S24( const char& c ) { *this = (int) c; }

  int asInt() {
    int i = c3[0] | (c3[1] << 8) | (c3[2] << 16);
    if (i & 0x800000) i |= ~0xffffff;
    return i;
  }
};
#pragma pack(pop)

#if defined( HAVE_GETTIMEOFDAY )
  #include <sys/time.h>
#endif

#include <sstream>

class RtApi
{
public:

  RtApi();
  virtual ~RtApi();
  virtual RtAudio::Api getCurrentApi( void ) = 0;
  virtual unsigned int getDeviceCount( void ) = 0;
  virtual RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) = 0;
  virtual unsigned int getDefaultInputDevice( void );
  virtual unsigned int getDefaultOutputDevice( void );
  void openStream( RtAudio::StreamParameters *outputParameters,
                   RtAudio::StreamParameters *inputParameters,
                   RtAudioFormat format, unsigned int sampleRate,
                   unsigned int *bufferFrames, RtAudioCallback callback,
                   void *userData, RtAudio::StreamOptions *options,
                   RtAudioErrorCallback errorCallback );
  virtual void closeStream( void );
  virtual void startStream( void ) = 0;
  virtual void stopStream( void ) = 0;
  virtual void abortStream( void ) = 0;
  long getStreamLatency( void );
  unsigned int getStreamSampleRate( void );
  virtual double getStreamTime( void );
  virtual void setStreamTime( double time );
  bool isStreamOpen( void ) const { return stream_.state != STREAM_CLOSED; }
  bool isStreamRunning( void ) const { return stream_.state == STREAM_RUNNING; }
  void showWarnings( bool value ) { showWarnings_ = value; }


protected:

  static const unsigned int MAX_SAMPLE_RATES;
  static const unsigned int SAMPLE_RATES[];

  enum { FAILURE, SUCCESS };

  enum StreamState {
    STREAM_STOPPED,
    STREAM_STOPPING,
    STREAM_RUNNING,
    STREAM_CLOSED = -50
  };

  enum StreamMode {
    OUTPUT,
    INPUT,
    DUPLEX,
    UNINITIALIZED = -75
  };

  // A protected structure used for buffer conversion.
  struct ConvertInfo {
    int channels;
    int inJump, outJump;
    RtAudioFormat inFormat, outFormat;
    std::vector<int> inOffset;
    std::vector<int> outOffset;
  };

  // A protected structure for audio streams.
  struct RtApiStream {
    unsigned int device[2];    // Playback and record, respectively.
    void *apiHandle;           // void pointer for API specific stream handle information
    StreamMode mode;           // OUTPUT, INPUT, or DUPLEX.
    StreamState state;         // STOPPED, RUNNING, or CLOSED
    char *userBuffer[2];       // Playback and record, respectively.
    char *deviceBuffer;
    bool doConvertBuffer[2];   // Playback and record, respectively.
    bool userInterleaved;
    bool deviceInterleaved[2]; // Playback and record, respectively.
    bool doByteSwap[2];        // Playback and record, respectively.
    unsigned int sampleRate;
    unsigned int bufferSize;
    unsigned int nBuffers;
    unsigned int nUserChannels[2];    // Playback and record, respectively.
    unsigned int nDeviceChannels[2];  // Playback and record channels, respectively.
    unsigned int channelOffset[2];    // Playback and record, respectively.
    unsigned long latency[2];         // Playback and record, respectively.
    RtAudioFormat userFormat;
    RtAudioFormat deviceFormat[2];    // Playback and record, respectively.
    StreamMutex mutex;
    CallbackInfo callbackInfo;
    ConvertInfo convertInfo[2];
    double streamTime;         // Number of elapsed seconds since the stream started.

#if defined(HAVE_GETTIMEOFDAY)
    struct timeval lastTickTimestamp;
#endif

    RtApiStream()
      :apiHandle(0), deviceBuffer(0) { device[0] = 11111; device[1] = 11111; }
  };

  typedef S24 Int24;
  typedef signed short Int16;
  typedef signed int Int32;
  typedef float Float32;
  typedef double Float64;

  std::ostringstream errorStream_;
  std::string errorText_;
  bool showWarnings_;
  RtApiStream stream_;
  bool firstErrorOccurred_;

  /*!
    Protected, api-specific method that attempts to open a device
    with the given parameters.  This function MUST be implemented by
    all subclasses.  If an error is encountered during the probe, a
    "warning" message is reported and FAILURE is returned. A
    successful probe is indicated by a return value of SUCCESS.
  */
  virtual bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                                unsigned int firstChannel, unsigned int sampleRate,
                                RtAudioFormat format, unsigned int *bufferSize,
                                RtAudio::StreamOptions *options );

  //! A protected function used to increment the stream time.
  void tickStreamTime( void );

  //! Protected common method to clear an RtApiStream structure.
  void clearStreamInfo();

  /*!
    Protected common method that throws an RtAudioError (type =
    INVALID_USE) if a stream is not open.
  */
  void verifyStream( void );

  //! Protected common error method to allow global control over error handling.
  void error( RtAudioError::Type type );

  /*!
    Protected method used to perform format, channel number, and/or interleaving
    conversions between the user and device buffers.
  */
  void convertBuffer( char *outBuffer, char *inBuffer, ConvertInfo &info );

  //! Protected common method used to perform byte-swapping on buffers.
  void byteSwapBuffer( char *buffer, unsigned int samples, RtAudioFormat format );

  //! Protected common method that returns the number of bytes for a given format.
  unsigned int formatBytes( RtAudioFormat format );

  //! Protected common method that sets up the parameters for buffer conversion.
  void setConvertInfo( StreamMode mode, unsigned int firstChannel );
};

// **************************************************************** //
//
// Inline RtAudio definitions.
//
// **************************************************************** //

inline RtAudio::Api RtAudio :: getCurrentApi( void ) throw() { return rtapi_->getCurrentApi(); }
inline unsigned int RtAudio :: getDeviceCount( void ) throw() { return rtapi_->getDeviceCount(); }
inline RtAudio::DeviceInfo RtAudio :: getDeviceInfo( unsigned int device ) { return rtapi_->getDeviceInfo( device ); }
inline unsigned int RtAudio :: getDefaultInputDevice( void ) throw() { return rtapi_->getDefaultInputDevice(); }
inline unsigned int RtAudio :: getDefaultOutputDevice( void ) throw() { return rtapi_->getDefaultOutputDevice(); }
inline void RtAudio :: closeStream( void ) throw() { return rtapi_->closeStream(); }
inline void RtAudio :: startStream( void ) { return rtapi_->startStream(); }
inline void RtAudio :: stopStream( void )  { return rtapi_->stopStream(); }
inline void RtAudio :: abortStream( void ) { return rtapi_->abortStream(); }
inline bool RtAudio :: isStreamOpen( void ) const throw() { return rtapi_->isStreamOpen(); }
inline bool RtAudio :: isStreamRunning( void ) const throw() { return rtapi_->isStreamRunning(); }
inline long RtAudio :: getStreamLatency( void ) { return rtapi_->getStreamLatency(); }
inline unsigned int RtAudio :: getStreamSampleRate( void ) { return rtapi_->getStreamSampleRate(); }
inline double RtAudio :: getStreamTime( void ) { return rtapi_->getStreamTime(); }
inline void RtAudio :: setStreamTime( double time ) { return rtapi_->setStreamTime( time ); }
inline void RtAudio :: showWarnings( bool value ) throw() { rtapi_->showWarnings( value ); }

// RtApi Subclass prototypes.

#if defined(__MACOSX_CORE__)

#include <CoreAudio/AudioHardware.h>

class RtApiCore: public RtApi
{
public:

  RtApiCore();
  ~RtApiCore();
  RtAudio::Api getCurrentApi( void ) { return RtAudio::MACOSX_CORE; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  unsigned int getDefaultOutputDevice( void );
  unsigned int getDefaultInputDevice( void );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );
  long getStreamLatency( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  bool callbackEvent( AudioDeviceID deviceId,
                      const AudioBufferList *inBufferList,
                      const AudioBufferList *outBufferList );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
  static const char* getErrorCode( OSStatus code );
};

#endif

#if defined(__UNIX_JACK__)

class RtApiJack: public RtApi
{
public:

  RtApiJack();
  ~RtApiJack();
  RtAudio::Api getCurrentApi( void ) { return RtAudio::UNIX_JACK; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );
  long getStreamLatency( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  bool callbackEvent( unsigned long nframes );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__WINDOWS_ASIO__)

class RtApiAsio: public RtApi
{
public:

  RtApiAsio();
  ~RtApiAsio();
  RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_ASIO; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );
  long getStreamLatency( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  bool callbackEvent( long bufferIndex );

  private:

  std::vector<RtAudio::DeviceInfo> devices_;
  void saveDeviceInfo( void );
  bool coInitialized_;
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__WINDOWS_DS__)

class RtApiDs: public RtApi
{
public:

  RtApiDs();
  ~RtApiDs();
  RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_DS; }
  unsigned int getDeviceCount( void );
  unsigned int getDefaultOutputDevice( void );
  unsigned int getDefaultInputDevice( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );
  long getStreamLatency( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  void callbackEvent( void );

  private:

  bool coInitialized_;
  bool buffersRolling;
  long duplexPrerollBytes;
  std::vector<struct DsDevice> dsDevices;
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__WINDOWS_WASAPI__)

struct IMMDeviceEnumerator;

class RtApiWasapi : public RtApi
{
public:
  RtApiWasapi();
  ~RtApiWasapi();

  RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_WASAPI; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  unsigned int getDefaultOutputDevice( void );
  unsigned int getDefaultInputDevice( void );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );

private:
  bool coInitialized_;
  IMMDeviceEnumerator* deviceEnumerator_;

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int* bufferSize,
                        RtAudio::StreamOptions* options );

  static DWORD WINAPI runWasapiThread( void* wasapiPtr );
  static DWORD WINAPI stopWasapiThread( void* wasapiPtr );
  static DWORD WINAPI abortWasapiThread( void* wasapiPtr );
  void wasapiThread();
};

#endif

#if defined(__LINUX_ALSA__)

class RtApiAlsa: public RtApi
{
public:

  RtApiAlsa();
  ~RtApiAlsa();
  RtAudio::Api getCurrentApi() { return RtAudio::LINUX_ALSA; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  void callbackEvent( void );

  private:

  std::vector<RtAudio::DeviceInfo> devices_;
  void saveDeviceInfo( void );
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__LINUX_PULSE__)

class RtApiPulse: public RtApi
{
public:
  ~RtApiPulse();
  RtAudio::Api getCurrentApi() { return RtAudio::LINUX_PULSE; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  void callbackEvent( void );

  private:

  std::vector<RtAudio::DeviceInfo> devices_;
  void saveDeviceInfo( void );
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__LINUX_OSS__)

class RtApiOss: public RtApi
{
public:

  RtApiOss();
  ~RtApiOss();
  RtAudio::Api getCurrentApi() { return RtAudio::LINUX_OSS; }
  unsigned int getDeviceCount( void );
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
  void closeStream( void );
  void startStream( void );
  void stopStream( void );
  void abortStream( void );

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesireable results!
  void callbackEvent( void );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options );
};

#endif

#if defined(__RTAUDIO_DUMMY__)

class RtApiDummy: public RtApi
{
public:

  RtApiDummy() { errorText_ = "RtApiDummy: This class provides no functionality."; error( RtAudioError::WARNING ); }
  RtAudio::Api getCurrentApi( void ) { return RtAudio::RTAUDIO_DUMMY; }
  unsigned int getDeviceCount( void ) { return 0; }
  RtAudio::DeviceInfo getDeviceInfo( unsigned int /*device*/ ) { RtAudio::DeviceInfo info; return info; }
  void closeStream( void ) {}
  void startStream( void ) {}
  void stopStream( void ) {}
  void abortStream( void ) {}

  private:

  bool probeDeviceOpen( unsigned int /*device*/, StreamMode /*mode*/, unsigned int /*channels*/,
                        unsigned int /*firstChannel*/, unsigned int /*sampleRate*/,
                        RtAudioFormat /*format*/, unsigned int * /*bufferSize*/,
                        RtAudio::StreamOptions * /*options*/ ) { return false; }
};

#endif

#endif

// Indentation settings for Vim and Emacs
//
// Local Variables:
// c-basic-offset: 2
// indent-tabs-mode: nil
// End:
//
// vim: et sts=2 sw=2

#endif // RTAUDIO_ENABLED -GODOT-