1 /************************************************************************/
3 \brief Realtime audio i/o C++ classes.
5 RtAudio provides a common API (Application Programming Interface)
6 for realtime audio input/output across Linux (native ALSA, Jack,
7 and OSS), Macintosh OS X (CoreAudio and Jack), and Windows
8 (DirectSound, ASIO and WASAPI) operating systems.
10 RtAudio WWW site: http://www.music.mcgill.ca/~gary/rtaudio/
12 RtAudio: realtime audio i/o C++ classes
13 Copyright (c) 2001-2017 Gary P. Scavone
15 Permission is hereby granted, free of charge, to any person
16 obtaining a copy of this software and associated documentation files
17 (the "Software"), to deal in the Software without restriction,
18 including without limitation the rights to use, copy, modify, merge,
19 publish, distribute, sublicense, and/or sell copies of the Software,
20 and to permit persons to whom the Software is furnished to do so,
21 subject to the following conditions:
23 The above copyright notice and this permission notice shall be
24 included in all copies or substantial portions of the Software.
26 Any person wishing to distribute modifications to the Software is
27 asked to send the modifications to the original developer so that
28 they can be incorporated into the canonical version. This is,
29 however, not a binding provision of this license.
31 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
34 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
35 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
36 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
39 /************************************************************************/
48 #define RTAUDIO_VERSION "5.0.0"
50 #if defined _WIN32 || defined __CYGWIN__
51 #define RTAUDIO_DLL_PUBLIC
54 #define RTAUDIO_DLL_PUBLIC __attribute__( (visibility( "default" )) )
56 #define RTAUDIO_DLL_PUBLIC
65 /*! \typedef typedef unsigned long RtAudioFormat;
66 \brief RtAudio data format type.
68 Support for signed integers and floats. Audio data fed to/from an
69 RtAudio stream is assumed to ALWAYS be in host byte order. The
70 internal routines will automatically take care of any necessary
71 byte-swapping between the host format and the soundcard. Thus,
72 endian-ness is not a concern in the following format definitions.
74 - \e RTAUDIO_SINT8: 8-bit signed integer.
75 - \e RTAUDIO_SINT16: 16-bit signed integer.
76 - \e RTAUDIO_SINT24: 24-bit signed integer.
77 - \e RTAUDIO_SINT32: 32-bit signed integer.
78 - \e RTAUDIO_FLOAT32: Normalized between plus/minus 1.0.
79 - \e RTAUDIO_FLOAT64: Normalized between plus/minus 1.0.
81 typedef unsigned long RtAudioFormat;
82 static const RtAudioFormat RTAUDIO_SINT8 = 0x1; // 8-bit signed integer.
83 static const RtAudioFormat RTAUDIO_SINT16 = 0x2; // 16-bit signed integer.
84 static const RtAudioFormat RTAUDIO_SINT24 = 0x4; // 24-bit signed integer.
85 static const RtAudioFormat RTAUDIO_SINT32 = 0x8; // 32-bit signed integer.
86 static const RtAudioFormat RTAUDIO_FLOAT32 = 0x10; // Normalized between plus/minus 1.0.
87 static const RtAudioFormat RTAUDIO_FLOAT64 = 0x20; // Normalized between plus/minus 1.0.
89 /*! \typedef typedef unsigned long RtAudioStreamFlags;
90 \brief RtAudio stream option flags.
92 The following flags can be OR'ed together to allow a client to
93 make changes to the default stream behavior:
95 - \e RTAUDIO_NONINTERLEAVED: Use non-interleaved buffers (default = interleaved).
96 - \e RTAUDIO_MINIMIZE_LATENCY: Attempt to set stream parameters for lowest possible latency.
97 - \e RTAUDIO_HOG_DEVICE: Attempt grab device for exclusive use.
98 - \e RTAUDIO_ALSA_USE_DEFAULT: Use the "default" PCM device (ALSA only).
99 - \e RTAUDIO_JACK_DONT_CONNECT: Do not automatically connect ports (JACK only).
101 By default, RtAudio streams pass and receive audio data from the
102 client in an interleaved format. By passing the
103 RTAUDIO_NONINTERLEAVED flag to the openStream() function, audio
104 data will instead be presented in non-interleaved buffers. In
105 this case, each buffer argument in the RtAudioCallback function
106 will point to a single array of data, with \c nFrames samples for
107 each channel concatenated back-to-back. For example, the first
108 sample of data for the second channel would be located at index \c
109 nFrames (assuming the \c buffer pointer was recast to the correct
110 data type for the stream).
112 Certain audio APIs offer a number of parameters that influence the
113 I/O latency of a stream. By default, RtAudio will attempt to set
114 these parameters internally for robust (glitch-free) performance
115 (though some APIs, like Windows Direct Sound, make this difficult).
116 By passing the RTAUDIO_MINIMIZE_LATENCY flag to the openStream()
117 function, internal stream settings will be influenced in an attempt
118 to minimize stream latency, though possibly at the expense of stream
121 If the RTAUDIO_HOG_DEVICE flag is set, RtAudio will attempt to
122 open the input and/or output stream device(s) for exclusive use.
123 Note that this is not possible with all supported audio APIs.
125 If the RTAUDIO_SCHEDULE_REALTIME flag is set, RtAudio will attempt
126 to select realtime scheduling (round-robin) for the callback thread.
128 If the RTAUDIO_ALSA_USE_DEFAULT flag is set, RtAudio will attempt to
129 open the "default" PCM device when using the ALSA API. Note that this
130 will override any specified input or output device id.
132 If the RTAUDIO_JACK_DONT_CONNECT flag is set, RtAudio will not attempt
133 to automatically connect the ports of the client to the audio device.
135 typedef unsigned int RtAudioStreamFlags;
136 static const RtAudioStreamFlags RTAUDIO_NONINTERLEAVED = 0x1; // Use non-interleaved buffers (default = interleaved).
137 static const RtAudioStreamFlags RTAUDIO_MINIMIZE_LATENCY = 0x2; // Attempt to set stream parameters for lowest possible latency.
138 static const RtAudioStreamFlags RTAUDIO_HOG_DEVICE = 0x4; // Attempt grab device and prevent use by others.
139 static const RtAudioStreamFlags RTAUDIO_SCHEDULE_REALTIME = 0x8; // Try to select realtime scheduling for callback thread.
140 static const RtAudioStreamFlags RTAUDIO_ALSA_USE_DEFAULT = 0x10; // Use the "default" PCM device (ALSA only).
141 static const RtAudioStreamFlags RTAUDIO_JACK_DONT_CONNECT = 0x20; // Do not automatically connect ports (JACK only).
143 /*! \typedef typedef unsigned long RtAudioStreamStatus;
144 \brief RtAudio stream status (over- or underflow) flags.
146 Notification of a stream over- or underflow is indicated by a
147 non-zero stream \c status argument in the RtAudioCallback function.
148 The stream status can be one of the following two options,
149 depending on whether the stream is open for output and/or input:
151 - \e RTAUDIO_INPUT_OVERFLOW: Input data was discarded because of an overflow condition at the driver.
152 - \e RTAUDIO_OUTPUT_UNDERFLOW: The output buffer ran low, likely producing a break in the output sound.
154 typedef unsigned int RtAudioStreamStatus;
155 static const RtAudioStreamStatus RTAUDIO_INPUT_OVERFLOW = 0x1; // Input data was discarded because of an overflow condition at the driver.
156 static const RtAudioStreamStatus RTAUDIO_OUTPUT_UNDERFLOW = 0x2; // The output buffer ran low, likely causing a gap in the output sound.
158 //! RtAudio callback function prototype.
160 All RtAudio clients must create a function of type RtAudioCallback
161 to read and/or write data from/to the audio stream. When the
162 underlying audio system is ready for new input or output data, this
163 function will be invoked.
165 \param outputBuffer For output (or duplex) streams, the client
166 should write \c nFrames of audio sample frames into this
167 buffer. This argument should be recast to the datatype
168 specified when the stream was opened. For input-only
169 streams, this argument will be NULL.
171 \param inputBuffer For input (or duplex) streams, this buffer will
172 hold \c nFrames of input audio sample frames. This
173 argument should be recast to the datatype specified when the
174 stream was opened. For output-only streams, this argument
177 \param nFrames The number of sample frames of input or output
178 data in the buffers. The actual buffer size in bytes is
179 dependent on the data type and number of channels in use.
181 \param streamTime The number of seconds that have elapsed since the
184 \param status If non-zero, this argument indicates a data overflow
185 or underflow condition for the stream. The particular
186 condition can be determined by comparison with the
187 RtAudioStreamStatus flags.
189 \param userData A pointer to optional data provided by the client
190 when opening the stream (default = NULL).
192 To continue normal stream operation, the RtAudioCallback function
193 should return a value of zero. To stop the stream and drain the
194 output buffer, the function should return a value of one. To abort
195 the stream immediately, the client should return a value of two.
197 typedef int (*RtAudioCallback)( void *outputBuffer, void *inputBuffer,
198 unsigned int nFrames,
200 RtAudioStreamStatus status,
203 /************************************************************************/
204 /*! \class RtAudioError
205 \brief Exception handling class for RtAudio.
207 The RtAudioError class is quite simple but it does allow errors to be
208 "caught" by RtAudioError::Type. See the RtAudio documentation to know
209 which methods can throw an RtAudioError.
211 /************************************************************************/
213 class RTAUDIO_DLL_PUBLIC RtAudioError : public std::runtime_error
216 //! Defined RtAudioError types.
218 WARNING, /*!< A non-critical error. */
219 DEBUG_WARNING, /*!< A non-critical error which might be useful for debugging. */
220 UNSPECIFIED, /*!< The default, unspecified error type. */
221 NO_DEVICES_FOUND, /*!< No devices found on system. */
222 INVALID_DEVICE, /*!< An invalid device ID was specified. */
223 MEMORY_ERROR, /*!< An error occured during memory allocation. */
224 INVALID_PARAMETER, /*!< An invalid parameter was specified to a function. */
225 INVALID_USE, /*!< The function was called incorrectly. */
226 DRIVER_ERROR, /*!< A system driver error occured. */
227 SYSTEM_ERROR, /*!< A system error occured. */
228 THREAD_ERROR /*!< A thread error occured. */
232 RtAudioError( const std::string& message,
233 Type type = RtAudioError::UNSPECIFIED )
234 : std::runtime_error(message), type_(type) {}
236 //! Prints thrown error message to stderr.
237 virtual void printMessage( void ) const
238 { std::cerr << '\n' << what() << "\n\n"; }
240 //! Returns the thrown error message type.
241 virtual const Type& getType(void) const { return type_; }
243 //! Returns the thrown error message string.
244 virtual const std::string getMessage(void) const
245 { return std::string(what()); }
251 //! RtAudio error callback function prototype.
253 \param type Type of error.
254 \param errorText Error description.
256 typedef void (*RtAudioErrorCallback)( RtAudioError::Type type, const std::string &errorText );
258 // **************************************************************** //
260 // RtAudio class declaration.
262 // RtAudio is a "controller" used to select an available audio i/o
263 // interface. It presents a common API for the user to call but all
264 // functionality is implemented by the class RtApi and its
265 // subclasses. RtAudio creates an instance of an RtApi subclass
266 // based on the user's API choice. If no choice is made, RtAudio
267 // attempts to make a "logical" API selection.
269 // **************************************************************** //
273 class RTAUDIO_DLL_PUBLIC RtAudio
277 //! Audio API specifier arguments.
279 UNSPECIFIED, /*!< Search for a working compiled API. */
280 LINUX_ALSA, /*!< The Advanced Linux Sound Architecture API. */
281 LINUX_PULSE, /*!< The Linux PulseAudio API. */
282 LINUX_OSS, /*!< The Linux Open Sound System API. */
283 UNIX_JACK, /*!< The Jack Low-Latency Audio Server API. */
284 MACOSX_CORE, /*!< Macintosh OS-X Core Audio API. */
285 WINDOWS_WASAPI, /*!< The Microsoft WASAPI API. */
286 WINDOWS_ASIO, /*!< The Steinberg Audio Stream I/O API. */
287 WINDOWS_DS, /*!< The Microsoft Direct Sound API. */
288 RTAUDIO_DUMMY /*!< A compilable but non-functional API. */
291 //! The public device information structure for returning queried values.
293 bool probed; /*!< true if the device capabilities were successfully probed. */
294 std::string name; /*!< Character string device identifier. */
295 unsigned int outputChannels; /*!< Maximum output channels supported by device. */
296 unsigned int inputChannels; /*!< Maximum input channels supported by device. */
297 unsigned int duplexChannels; /*!< Maximum simultaneous input/output channels supported by device. */
298 bool isDefaultOutput; /*!< true if this is the default output device. */
299 bool isDefaultInput; /*!< true if this is the default input device. */
300 std::vector<unsigned int> sampleRates; /*!< Supported sample rates (queried from list of standard rates). */
301 unsigned int preferredSampleRate; /*!< Preferred sample rate, eg. for WASAPI the system sample rate. */
302 RtAudioFormat nativeFormats; /*!< Bit mask of supported data formats. */
304 // Default constructor.
306 :probed(false), outputChannels(0), inputChannels(0), duplexChannels(0),
307 isDefaultOutput(false), isDefaultInput(false), preferredSampleRate(0), nativeFormats(0) {}
310 //! The structure for specifying input or ouput stream parameters.
311 struct StreamParameters {
312 unsigned int deviceId; /*!< Device index (0 to getDeviceCount() - 1). */
313 unsigned int nChannels; /*!< Number of channels. */
314 unsigned int firstChannel; /*!< First channel index on device (default = 0). */
316 // Default constructor.
318 : deviceId(0), nChannels(0), firstChannel(0) {}
321 //! The structure for specifying stream options.
323 The following flags can be OR'ed together to allow a client to
324 make changes to the default stream behavior:
326 - \e RTAUDIO_NONINTERLEAVED: Use non-interleaved buffers (default = interleaved).
327 - \e RTAUDIO_MINIMIZE_LATENCY: Attempt to set stream parameters for lowest possible latency.
328 - \e RTAUDIO_HOG_DEVICE: Attempt grab device for exclusive use.
329 - \e RTAUDIO_SCHEDULE_REALTIME: Attempt to select realtime scheduling for callback thread.
330 - \e RTAUDIO_ALSA_USE_DEFAULT: Use the "default" PCM device (ALSA only).
332 By default, RtAudio streams pass and receive audio data from the
333 client in an interleaved format. By passing the
334 RTAUDIO_NONINTERLEAVED flag to the openStream() function, audio
335 data will instead be presented in non-interleaved buffers. In
336 this case, each buffer argument in the RtAudioCallback function
337 will point to a single array of data, with \c nFrames samples for
338 each channel concatenated back-to-back. For example, the first
339 sample of data for the second channel would be located at index \c
340 nFrames (assuming the \c buffer pointer was recast to the correct
341 data type for the stream).
343 Certain audio APIs offer a number of parameters that influence the
344 I/O latency of a stream. By default, RtAudio will attempt to set
345 these parameters internally for robust (glitch-free) performance
346 (though some APIs, like Windows Direct Sound, make this difficult).
347 By passing the RTAUDIO_MINIMIZE_LATENCY flag to the openStream()
348 function, internal stream settings will be influenced in an attempt
349 to minimize stream latency, though possibly at the expense of stream
352 If the RTAUDIO_HOG_DEVICE flag is set, RtAudio will attempt to
353 open the input and/or output stream device(s) for exclusive use.
354 Note that this is not possible with all supported audio APIs.
356 If the RTAUDIO_SCHEDULE_REALTIME flag is set, RtAudio will attempt
357 to select realtime scheduling (round-robin) for the callback thread.
358 The \c priority parameter will only be used if the RTAUDIO_SCHEDULE_REALTIME
359 flag is set. It defines the thread's realtime priority.
361 If the RTAUDIO_ALSA_USE_DEFAULT flag is set, RtAudio will attempt to
362 open the "default" PCM device when using the ALSA API. Note that this
363 will override any specified input or output device id.
365 The \c numberOfBuffers parameter can be used to control stream
366 latency in the Windows DirectSound, Linux OSS, and Linux Alsa APIs
367 only. A value of two is usually the smallest allowed. Larger
368 numbers can potentially result in more robust stream performance,
369 though likely at the cost of stream latency. The value set by the
370 user is replaced during execution of the RtAudio::openStream()
371 function by the value actually used by the system.
373 The \c streamName parameter can be used to set the client name
374 when using the Jack API. By default, the client name is set to
375 RtApiJack. However, if you wish to create multiple instances of
376 RtAudio with Jack, each instance must have a unique client name.
378 struct StreamOptions {
379 RtAudioStreamFlags flags; /*!< A bit-mask of stream flags (RTAUDIO_NONINTERLEAVED, RTAUDIO_MINIMIZE_LATENCY, RTAUDIO_HOG_DEVICE, RTAUDIO_ALSA_USE_DEFAULT). */
380 unsigned int numberOfBuffers; /*!< Number of stream buffers. */
381 std::string streamName; /*!< A stream name (currently used only in Jack). */
382 int priority; /*!< Scheduling priority of callback thread (only used with flag RTAUDIO_SCHEDULE_REALTIME). */
384 // Default constructor.
386 : flags(0), numberOfBuffers(0), priority(0) {}
389 //! A static function to determine the current RtAudio version.
390 static std::string getVersion( void );
392 //! A static function to determine the available compiled audio APIs.
394 The values returned in the std::vector can be compared against
395 the enumerated list values. Note that there can be more than one
396 API compiled for certain operating systems.
398 static void getCompiledApi( std::vector<RtAudio::Api> &apis );
400 //! Return the name of a specified compiled audio API.
402 This obtains a short lower-case name used for identification purposes.
403 This value is guaranteed to remain identical across library versions.
404 If the API is unknown or not compiled, this function will return
407 static const std::string &getCompiledApiName( RtAudio::Api api );
409 //! Return the display name of a specified compiled audio API.
411 This obtains a long name used for display purposes.
412 If the API is unknown or not compiled, this function will return
415 static const std::string &getCompiledApiDisplayName( RtAudio::Api api );
417 //! Return the compiled audio API having the given name.
419 A case insensitive comparison will check the specified name
420 against the list of compiled APIs, and return the one which
421 matches. On failure, the function returns UNSPECIFIED.
423 static RtAudio::Api getCompiledApiByName( const std::string &name );
425 //! The class constructor.
427 The constructor performs minor initialization tasks. An exception
428 can be thrown if no API support is compiled.
430 If no API argument is specified and multiple API support has been
431 compiled, the default order of use is JACK, ALSA, OSS (Linux
432 systems) and ASIO, DS (Windows systems).
434 RtAudio( RtAudio::Api api=UNSPECIFIED );
438 If a stream is running or open, it will be stopped and closed
443 //! Returns the audio API specifier for the current instance of RtAudio.
444 RtAudio::Api getCurrentApi( void );
446 //! A public function that queries for the number of audio devices available.
448 This function performs a system query of available devices each time it
449 is called, thus supporting devices connected \e after instantiation. If
450 a system error occurs during processing, a warning will be issued.
452 unsigned int getDeviceCount( void );
454 //! Return an RtAudio::DeviceInfo structure for a specified device number.
457 Any device integer between 0 and getDeviceCount() - 1 is valid.
458 If an invalid argument is provided, an RtAudioError (type = INVALID_USE)
459 will be thrown. If a device is busy or otherwise unavailable, the
460 structure member "probed" will have a value of "false" and all
461 other members are undefined. If the specified device is the
462 current default input or output device, the corresponding
463 "isDefault" member will have a value of "true".
465 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
467 //! A function that returns the index of the default output device.
469 If the underlying audio API does not provide a "default
470 device", or if no devices are available, the return value will be
471 0. Note that this is a valid device identifier and it is the
472 client's responsibility to verify that a device is available
473 before attempting to open a stream.
475 unsigned int getDefaultOutputDevice( void );
477 //! A function that returns the index of the default input device.
479 If the underlying audio API does not provide a "default
480 device", or if no devices are available, the return value will be
481 0. Note that this is a valid device identifier and it is the
482 client's responsibility to verify that a device is available
483 before attempting to open a stream.
485 unsigned int getDefaultInputDevice( void );
487 //! A public function for opening a stream with the specified parameters.
489 An RtAudioError (type = SYSTEM_ERROR) is thrown if a stream cannot be
490 opened with the specified parameters or an error occurs during
491 processing. An RtAudioError (type = INVALID_USE) is thrown if any
492 invalid device ID or channel number parameters are specified.
494 \param outputParameters Specifies output stream parameters to use
495 when opening a stream, including a device ID, number of channels,
496 and starting channel number. For input-only streams, this
497 argument should be NULL. The device ID is an index value between
498 0 and getDeviceCount() - 1.
499 \param inputParameters Specifies input stream parameters to use
500 when opening a stream, including a device ID, number of channels,
501 and starting channel number. For output-only streams, this
502 argument should be NULL. The device ID is an index value between
503 0 and getDeviceCount() - 1.
504 \param format An RtAudioFormat specifying the desired sample data format.
505 \param sampleRate The desired sample rate (sample frames per second).
506 \param *bufferFrames A pointer to a value indicating the desired
507 internal buffer size in sample frames. The actual value
508 used by the device is returned via the same pointer. A
509 value of zero can be specified, in which case the lowest
510 allowable value is determined.
511 \param callback A client-defined function that will be invoked
512 when input data is available and/or output data is needed.
513 \param userData An optional pointer to data that can be accessed
514 from within the callback function.
515 \param options An optional pointer to a structure containing various
516 global stream options, including a list of OR'ed RtAudioStreamFlags
517 and a suggested number of stream buffers that can be used to
518 control stream latency. More buffers typically result in more
519 robust performance, though at a cost of greater latency. If a
520 value of zero is specified, a system-specific median value is
521 chosen. If the RTAUDIO_MINIMIZE_LATENCY flag bit is set, the
522 lowest allowable value is used. The actual value used is
523 returned via the structure argument. The parameter is API dependent.
524 \param errorCallback A client-defined function that will be invoked
525 when an error has occured.
527 void openStream( RtAudio::StreamParameters *outputParameters,
528 RtAudio::StreamParameters *inputParameters,
529 RtAudioFormat format, unsigned int sampleRate,
530 unsigned int *bufferFrames, RtAudioCallback callback,
531 void *userData = NULL, RtAudio::StreamOptions *options = NULL, RtAudioErrorCallback errorCallback = NULL );
533 //! A function that closes a stream and frees any associated stream memory.
535 If a stream is not open, this function issues a warning and
536 returns (no exception is thrown).
538 void closeStream( void );
540 //! A function that starts a stream.
542 An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
543 during processing. An RtAudioError (type = INVALID_USE) is thrown if a
544 stream is not open. A warning is issued if the stream is already
547 void startStream( void );
549 //! Stop a stream, allowing any samples remaining in the output queue to be played.
551 An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
552 during processing. An RtAudioError (type = INVALID_USE) is thrown if a
553 stream is not open. A warning is issued if the stream is already
556 void stopStream( void );
558 //! Stop a stream, discarding any samples remaining in the input/output queue.
560 An RtAudioError (type = SYSTEM_ERROR) is thrown if an error occurs
561 during processing. An RtAudioError (type = INVALID_USE) is thrown if a
562 stream is not open. A warning is issued if the stream is already
565 void abortStream( void );
567 //! Returns true if a stream is open and false if not.
568 bool isStreamOpen( void ) const;
570 //! Returns true if the stream is running and false if it is stopped or not open.
571 bool isStreamRunning( void ) const;
573 //! Returns the number of elapsed seconds since the stream was started.
575 If a stream is not open, an RtAudioError (type = INVALID_USE) will be thrown.
577 double getStreamTime( void );
579 //! Set the stream time to a time in seconds greater than or equal to 0.0.
581 If a stream is not open, an RtAudioError (type = INVALID_USE) will be thrown.
583 void setStreamTime( double time );
585 //! Returns the internal stream latency in sample frames.
587 The stream latency refers to delay in audio input and/or output
588 caused by internal buffering by the audio system and/or hardware.
589 For duplex streams, the returned value will represent the sum of
590 the input and output latencies. If a stream is not open, an
591 RtAudioError (type = INVALID_USE) will be thrown. If the API does not
592 report latency, the return value will be zero.
594 long getStreamLatency( void );
596 //! Returns actual sample rate in use by the stream.
598 On some systems, the sample rate used may be slightly different
599 than that specified in the stream parameters. If a stream is not
600 open, an RtAudioError (type = INVALID_USE) will be thrown.
602 unsigned int getStreamSampleRate( void );
604 //! Specify whether warning messages should be printed to stderr.
605 void showWarnings( bool value = true );
609 void openRtApi( RtAudio::Api api );
613 // Operating system dependent thread functionality.
614 #if defined(__WINDOWS_DS__) || defined(__WINDOWS_ASIO__) || defined(__WINDOWS_WASAPI__)
622 typedef uintptr_t ThreadHandle;
623 typedef CRITICAL_SECTION StreamMutex;
625 #elif defined(__LINUX_ALSA__) || defined(__LINUX_PULSE__) || defined(__UNIX_JACK__) || defined(__LINUX_OSS__) || defined(__MACOSX_CORE__)
626 // Using pthread library for various flavors of unix.
629 typedef pthread_t ThreadHandle;
630 typedef pthread_mutex_t StreamMutex;
632 #else // Setup for "dummy" behavior
634 #define __RTAUDIO_DUMMY__
635 typedef int ThreadHandle;
636 typedef int StreamMutex;
640 // This global structure type is used to pass callback information
641 // between the private RtAudio stream structure and global callback
642 // handling functions.
643 struct CallbackInfo {
644 void *object; // Used as a "this" pointer.
649 void *apiInfo; // void pointer for API specific callback information
654 // Default constructor.
656 :object(0), callback(0), userData(0), errorCallback(0), apiInfo(0), isRunning(false), doRealtime(false), priority(0) {}
659 // **************************************************************** //
661 // RtApi class declaration.
663 // Subclasses of RtApi contain all API- and OS-specific code necessary
664 // to fully implement the RtAudio API.
666 // Note that RtApi is an abstract base class and cannot be
667 // explicitly instantiated. The class RtAudio will create an
668 // instance of an RtApi subclass (RtApiOss, RtApiAlsa,
669 // RtApiJack, RtApiCore, RtApiDs, or RtApiAsio).
671 // **************************************************************** //
673 #pragma pack(push, 1)
682 S24& operator = ( const int& i ) {
683 c3[0] = (i & 0x000000ff);
684 c3[1] = (i & 0x0000ff00) >> 8;
685 c3[2] = (i & 0x00ff0000) >> 16;
689 S24( const S24& v ) { *this = v; }
690 S24( const double& d ) { *this = (int) d; }
691 S24( const float& f ) { *this = (int) f; }
692 S24( const signed short& s ) { *this = (int) s; }
693 S24( const char& c ) { *this = (int) c; }
696 int i = c3[0] | (c3[1] << 8) | (c3[2] << 16);
697 if (i & 0x800000) i |= ~0xffffff;
703 #if defined( HAVE_GETTIMEOFDAY )
704 #include <sys/time.h>
709 class RTAUDIO_DLL_PUBLIC RtApi
715 virtual RtAudio::Api getCurrentApi( void ) = 0;
716 virtual unsigned int getDeviceCount( void ) = 0;
717 virtual RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) = 0;
718 virtual unsigned int getDefaultInputDevice( void );
719 virtual unsigned int getDefaultOutputDevice( void );
720 void openStream( RtAudio::StreamParameters *outputParameters,
721 RtAudio::StreamParameters *inputParameters,
722 RtAudioFormat format, unsigned int sampleRate,
723 unsigned int *bufferFrames, RtAudioCallback callback,
724 void *userData, RtAudio::StreamOptions *options,
725 RtAudioErrorCallback errorCallback );
726 virtual void closeStream( void );
727 virtual void startStream( void ) = 0;
728 virtual void stopStream( void ) = 0;
729 virtual void abortStream( void ) = 0;
730 long getStreamLatency( void );
731 unsigned int getStreamSampleRate( void );
732 virtual double getStreamTime( void );
733 virtual void setStreamTime( double time );
734 bool isStreamOpen( void ) const { return stream_.state != STREAM_CLOSED; }
735 bool isStreamRunning( void ) const { return stream_.state == STREAM_RUNNING; }
736 void showWarnings( bool value ) { showWarnings_ = value; }
741 static const unsigned int MAX_SAMPLE_RATES;
742 static const unsigned int SAMPLE_RATES[];
744 enum { FAILURE, SUCCESS };
760 // A protected structure used for buffer conversion.
764 RtAudioFormat inFormat, outFormat;
765 std::vector<int> inOffset;
766 std::vector<int> outOffset;
769 // A protected structure for audio streams.
771 unsigned int device[2]; // Playback and record, respectively.
772 void *apiHandle; // void pointer for API specific stream handle information
773 StreamMode mode; // OUTPUT, INPUT, or DUPLEX.
774 StreamState state; // STOPPED, RUNNING, or CLOSED
775 char *userBuffer[2]; // Playback and record, respectively.
777 bool doConvertBuffer[2]; // Playback and record, respectively.
778 bool userInterleaved;
779 bool deviceInterleaved[2]; // Playback and record, respectively.
780 bool doByteSwap[2]; // Playback and record, respectively.
781 unsigned int sampleRate;
782 unsigned int bufferSize;
783 unsigned int nBuffers;
784 unsigned int nUserChannels[2]; // Playback and record, respectively.
785 unsigned int nDeviceChannels[2]; // Playback and record channels, respectively.
786 unsigned int channelOffset[2]; // Playback and record, respectively.
787 unsigned long latency[2]; // Playback and record, respectively.
788 RtAudioFormat userFormat;
789 RtAudioFormat deviceFormat[2]; // Playback and record, respectively.
791 CallbackInfo callbackInfo;
792 ConvertInfo convertInfo[2];
793 double streamTime; // Number of elapsed seconds since the stream started.
795 #if defined(HAVE_GETTIMEOFDAY)
796 struct timeval lastTickTimestamp;
800 :apiHandle(0), deviceBuffer(0) { device[0] = 11111; device[1] = 11111; }
804 typedef signed short Int16;
805 typedef signed int Int32;
806 typedef float Float32;
807 typedef double Float64;
809 std::ostringstream errorStream_;
810 std::string errorText_;
813 bool firstErrorOccurred_;
816 Protected, api-specific method that attempts to open a device
817 with the given parameters. This function MUST be implemented by
818 all subclasses. If an error is encountered during the probe, a
819 "warning" message is reported and FAILURE is returned. A
820 successful probe is indicated by a return value of SUCCESS.
822 virtual bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
823 unsigned int firstChannel, unsigned int sampleRate,
824 RtAudioFormat format, unsigned int *bufferSize,
825 RtAudio::StreamOptions *options );
827 //! A protected function used to increment the stream time.
828 void tickStreamTime( void );
830 //! Protected common method to clear an RtApiStream structure.
831 void clearStreamInfo();
834 Protected common method that throws an RtAudioError (type =
835 INVALID_USE) if a stream is not open.
837 void verifyStream( void );
839 //! Protected common error method to allow global control over error handling.
840 void error( RtAudioError::Type type );
843 Protected method used to perform format, channel number, and/or interleaving
844 conversions between the user and device buffers.
846 void convertBuffer( char *outBuffer, char *inBuffer, ConvertInfo &info );
848 //! Protected common method used to perform byte-swapping on buffers.
849 void byteSwapBuffer( char *buffer, unsigned int samples, RtAudioFormat format );
851 //! Protected common method that returns the number of bytes for a given format.
852 unsigned int formatBytes( RtAudioFormat format );
854 //! Protected common method that sets up the parameters for buffer conversion.
855 void setConvertInfo( StreamMode mode, unsigned int firstChannel );
858 // **************************************************************** //
860 // Inline RtAudio definitions.
862 // **************************************************************** //
864 inline RtAudio::Api RtAudio :: getCurrentApi( void ) { return rtapi_->getCurrentApi(); }
865 inline unsigned int RtAudio :: getDeviceCount( void ) { return rtapi_->getDeviceCount(); }
866 inline RtAudio::DeviceInfo RtAudio :: getDeviceInfo( unsigned int device ) { return rtapi_->getDeviceInfo( device ); }
867 inline unsigned int RtAudio :: getDefaultInputDevice( void ) { return rtapi_->getDefaultInputDevice(); }
868 inline unsigned int RtAudio :: getDefaultOutputDevice( void ) { return rtapi_->getDefaultOutputDevice(); }
869 inline void RtAudio :: closeStream( void ) { return rtapi_->closeStream(); }
870 inline void RtAudio :: startStream( void ) { return rtapi_->startStream(); }
871 inline void RtAudio :: stopStream( void ) { return rtapi_->stopStream(); }
872 inline void RtAudio :: abortStream( void ) { return rtapi_->abortStream(); }
873 inline bool RtAudio :: isStreamOpen( void ) const { return rtapi_->isStreamOpen(); }
874 inline bool RtAudio :: isStreamRunning( void ) const { return rtapi_->isStreamRunning(); }
875 inline long RtAudio :: getStreamLatency( void ) { return rtapi_->getStreamLatency(); }
876 inline unsigned int RtAudio :: getStreamSampleRate( void ) { return rtapi_->getStreamSampleRate(); }
877 inline double RtAudio :: getStreamTime( void ) { return rtapi_->getStreamTime(); }
878 inline void RtAudio :: setStreamTime( double time ) { return rtapi_->setStreamTime( time ); }
879 inline void RtAudio :: showWarnings( bool value ) { rtapi_->showWarnings( value ); }
881 // RtApi Subclass prototypes.
883 #if defined(__MACOSX_CORE__)
885 #include <CoreAudio/AudioHardware.h>
887 class RtApiCore: public RtApi
893 RtAudio::Api getCurrentApi( void ) { return RtAudio::MACOSX_CORE; }
894 unsigned int getDeviceCount( void );
895 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
896 unsigned int getDefaultOutputDevice( void );
897 unsigned int getDefaultInputDevice( void );
898 void closeStream( void );
899 void startStream( void );
900 void stopStream( void );
901 void abortStream( void );
902 long getStreamLatency( void );
904 // This function is intended for internal use only. It must be
905 // public because it is called by the internal callback handler,
906 // which is not a member of RtAudio. External use of this function
907 // will most likely produce highly undesireable results!
908 bool callbackEvent( AudioDeviceID deviceId,
909 const AudioBufferList *inBufferList,
910 const AudioBufferList *outBufferList );
914 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
915 unsigned int firstChannel, unsigned int sampleRate,
916 RtAudioFormat format, unsigned int *bufferSize,
917 RtAudio::StreamOptions *options );
918 static const char* getErrorCode( OSStatus code );
923 #if defined(__UNIX_JACK__)
925 class RtApiJack: public RtApi
931 RtAudio::Api getCurrentApi( void ) { return RtAudio::UNIX_JACK; }
932 unsigned int getDeviceCount( void );
933 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
934 void closeStream( void );
935 void startStream( void );
936 void stopStream( void );
937 void abortStream( void );
938 long getStreamLatency( void );
940 // This function is intended for internal use only. It must be
941 // public because it is called by the internal callback handler,
942 // which is not a member of RtAudio. External use of this function
943 // will most likely produce highly undesireable results!
944 bool callbackEvent( unsigned long nframes );
948 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
949 unsigned int firstChannel, unsigned int sampleRate,
950 RtAudioFormat format, unsigned int *bufferSize,
951 RtAudio::StreamOptions *options );
953 bool shouldAutoconnect_;
958 #if defined(__WINDOWS_ASIO__)
960 class RtApiAsio: public RtApi
966 RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_ASIO; }
967 unsigned int getDeviceCount( void );
968 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
969 void closeStream( void );
970 void startStream( void );
971 void stopStream( void );
972 void abortStream( void );
973 long getStreamLatency( void );
975 // This function is intended for internal use only. It must be
976 // public because it is called by the internal callback handler,
977 // which is not a member of RtAudio. External use of this function
978 // will most likely produce highly undesireable results!
979 bool callbackEvent( long bufferIndex );
983 std::vector<RtAudio::DeviceInfo> devices_;
984 void saveDeviceInfo( void );
986 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
987 unsigned int firstChannel, unsigned int sampleRate,
988 RtAudioFormat format, unsigned int *bufferSize,
989 RtAudio::StreamOptions *options );
994 #if defined(__WINDOWS_DS__)
996 class RtApiDs: public RtApi
1002 RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_DS; }
1003 unsigned int getDeviceCount( void );
1004 unsigned int getDefaultOutputDevice( void );
1005 unsigned int getDefaultInputDevice( void );
1006 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
1007 void closeStream( void );
1008 void startStream( void );
1009 void stopStream( void );
1010 void abortStream( void );
1011 long getStreamLatency( void );
1013 // This function is intended for internal use only. It must be
1014 // public because it is called by the internal callback handler,
1015 // which is not a member of RtAudio. External use of this function
1016 // will most likely produce highly undesireable results!
1017 void callbackEvent( void );
1021 bool coInitialized_;
1022 bool buffersRolling;
1023 long duplexPrerollBytes;
1024 std::vector<struct DsDevice> dsDevices;
1025 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
1026 unsigned int firstChannel, unsigned int sampleRate,
1027 RtAudioFormat format, unsigned int *bufferSize,
1028 RtAudio::StreamOptions *options );
1033 #if defined(__WINDOWS_WASAPI__)
1035 struct IMMDeviceEnumerator;
1037 class RtApiWasapi : public RtApi
1043 RtAudio::Api getCurrentApi( void ) { return RtAudio::WINDOWS_WASAPI; }
1044 unsigned int getDeviceCount( void );
1045 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
1046 unsigned int getDefaultOutputDevice( void );
1047 unsigned int getDefaultInputDevice( void );
1048 void closeStream( void );
1049 void startStream( void );
1050 void stopStream( void );
1051 void abortStream( void );
1054 bool coInitialized_;
1055 IMMDeviceEnumerator* deviceEnumerator_;
1057 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
1058 unsigned int firstChannel, unsigned int sampleRate,
1059 RtAudioFormat format, unsigned int* bufferSize,
1060 RtAudio::StreamOptions* options );
1062 static DWORD WINAPI runWasapiThread( void* wasapiPtr );
1063 static DWORD WINAPI stopWasapiThread( void* wasapiPtr );
1064 static DWORD WINAPI abortWasapiThread( void* wasapiPtr );
1065 void wasapiThread();
1070 #if defined(__LINUX_ALSA__)
1072 class RtApiAlsa: public RtApi
1078 RtAudio::Api getCurrentApi() { return RtAudio::LINUX_ALSA; }
1079 unsigned int getDeviceCount( void );
1080 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
1081 void closeStream( void );
1082 void startStream( void );
1083 void stopStream( void );
1084 void abortStream( void );
1086 // This function is intended for internal use only. It must be
1087 // public because it is called by the internal callback handler,
1088 // which is not a member of RtAudio. External use of this function
1089 // will most likely produce highly undesireable results!
1090 void callbackEvent( void );
1094 std::vector<RtAudio::DeviceInfo> devices_;
1095 void saveDeviceInfo( void );
1096 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
1097 unsigned int firstChannel, unsigned int sampleRate,
1098 RtAudioFormat format, unsigned int *bufferSize,
1099 RtAudio::StreamOptions *options );
1104 #if defined(__LINUX_PULSE__)
1106 class RtApiPulse: public RtApi
1110 RtAudio::Api getCurrentApi() { return RtAudio::LINUX_PULSE; }
1111 unsigned int getDeviceCount( void );
1112 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
1113 void closeStream( void );
1114 void startStream( void );
1115 void stopStream( void );
1116 void abortStream( void );
1118 // This function is intended for internal use only. It must be
1119 // public because it is called by the internal callback handler,
1120 // which is not a member of RtAudio. External use of this function
1121 // will most likely produce highly undesireable results!
1122 void callbackEvent( void );
1126 std::vector<RtAudio::DeviceInfo> devices_;
1127 void saveDeviceInfo( void );
1128 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
1129 unsigned int firstChannel, unsigned int sampleRate,
1130 RtAudioFormat format, unsigned int *bufferSize,
1131 RtAudio::StreamOptions *options );
1136 #if defined(__LINUX_OSS__)
1138 class RtApiOss: public RtApi
1144 RtAudio::Api getCurrentApi() { return RtAudio::LINUX_OSS; }
1145 unsigned int getDeviceCount( void );
1146 RtAudio::DeviceInfo getDeviceInfo( unsigned int device );
1147 void closeStream( void );
1148 void startStream( void );
1149 void stopStream( void );
1150 void abortStream( void );
1152 // This function is intended for internal use only. It must be
1153 // public because it is called by the internal callback handler,
1154 // which is not a member of RtAudio. External use of this function
1155 // will most likely produce highly undesireable results!
1156 void callbackEvent( void );
1160 bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
1161 unsigned int firstChannel, unsigned int sampleRate,
1162 RtAudioFormat format, unsigned int *bufferSize,
1163 RtAudio::StreamOptions *options );
1168 #if defined(__RTAUDIO_DUMMY__)
1170 class RtApiDummy: public RtApi
1174 RtApiDummy() { errorText_ = "RtApiDummy: This class provides no functionality."; error( RtAudioError::WARNING ); }
1175 RtAudio::Api getCurrentApi( void ) { return RtAudio::RTAUDIO_DUMMY; }
1176 unsigned int getDeviceCount( void ) { return 0; }
1177 RtAudio::DeviceInfo getDeviceInfo( unsigned int /*device*/ ) { RtAudio::DeviceInfo info; return info; }
1178 void closeStream( void ) {}
1179 void startStream( void ) {}
1180 void stopStream( void ) {}
1181 void abortStream( void ) {}
1185 bool probeDeviceOpen( unsigned int /*device*/, StreamMode /*mode*/, unsigned int /*channels*/,
1186 unsigned int /*firstChannel*/, unsigned int /*sampleRate*/,
1187 RtAudioFormat /*format*/, unsigned int * /*bufferSize*/,
1188 RtAudio::StreamOptions * /*options*/ ) { return false; }
1195 // Indentation settings for Vim and Emacs
1198 // c-basic-offset: 2
1199 // indent-tabs-mode: nil
1202 // vim: et sts=2 sw=2