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1 // NOTE: Copy this file to portaudio.h in order to compile with V19 portaudio
2
3 #ifndef PORTAUDIO_H
4 #define PORTAUDIO_H
5 /*
6 * $Id: portaudio.h 1061 2006-06-19 22:46:41Z lschwardt $
7 * PortAudio Portable Real-Time Audio Library
8 * PortAudio API Header File
9 * Latest version available at: http://www.portaudio.com/
10 *
11 * Copyright (c) 1999-2002 Ross Bencina and Phil Burk
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files
15 * (the "Software"), to deal in the Software without restriction,
16 * including without limitation the rights to use, copy, modify, merge,
17 * publish, distribute, sublicense, and/or sell copies of the Software,
18 * and to permit persons to whom the Software is furnished to do so,
19 * subject to the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * Any person wishing to distribute modifications to the Software is
25 * requested to send the modifications to the original developer so that
26 * they can be incorporated into the canonical version.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
31 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
32 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
33 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
34 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
35 */
36
37 /** @file
38 @brief The PortAudio API.
39 */
40
41
42 #ifdef __cplusplus
43 extern "C"
44 {
45 #endif /* __cplusplus */
46
47
48 /** Retrieve the release number of the currently running PortAudio build,
49 eg 1900.
50 */
51 int Pa_GetVersion( void );
52
53
54 /** Retrieve a textual description of the current PortAudio build,
55 eg "PortAudio V19-devel 13 October 2002".
56 */
57 const char* Pa_GetVersionText( void );
58
59
60 /** Error codes returned by PortAudio functions.
61 Note that with the exception of paNoError, all PaErrorCodes are negative.
62 */
63
64 typedef int PaError;
65 typedef enum PaErrorCode
66 {
67 paNoError = 0,
68
69 paNotInitialized = -10000,
70 paUnanticipatedHostError,
71 paInvalidChannelCount,
72 paInvalidSampleRate,
73 paInvalidDevice,
74 paInvalidFlag,
75 paSampleFormatNotSupported,
76 paBadIODeviceCombination,
77 paInsufficientMemory,
78 paBufferTooBig,
79 paBufferTooSmall,
80 paNullCallback,
81 paBadStreamPtr,
82 paTimedOut,
83 paInternalError,
84 paDeviceUnavailable,
85 paIncompatibleHostApiSpecificStreamInfo,
86 paStreamIsStopped,
87 paStreamIsNotStopped,
88 paInputOverflowed,
89 paOutputUnderflowed,
90 paHostApiNotFound,
91 paInvalidHostApi,
92 paCanNotReadFromACallbackStream, /**< @todo review error code name */
93 paCanNotWriteToACallbackStream, /**< @todo review error code name */
94 paCanNotReadFromAnOutputOnlyStream, /**< @todo review error code name */
95 paCanNotWriteToAnInputOnlyStream, /**< @todo review error code name */
96 paIncompatibleStreamHostApi,
97 paBadBufferPtr
98 } PaErrorCode;
99
100
101 /** Translate the supplied PortAudio error code into a human readable
102 message.
103 */
104 const char *Pa_GetErrorText( PaError errorCode );
105
106
107 /** Library initialization function - call this before using PortAudio.
108 This function initialises internal data structures and prepares underlying
109 host APIs for use. This function MUST be called before using any other
110 PortAudio API functions.
111
112 If Pa_Initialize() is called multiple times, each successful
113 call must be matched with a corresponding call to Pa_Terminate().
114 Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not
115 required to be fully nested.
116
117 Note that if Pa_Initialize() returns an error code, Pa_Terminate() should
118 NOT be called.
119
120 @return paNoError if successful, otherwise an error code indicating the cause
121 of failure.
122
123 @see Pa_Terminate
124 */
125 PaError Pa_Initialize( void );
126
127
128 /** Library termination function - call this when finished using PortAudio.
129 This function deallocates all resources allocated by PortAudio since it was
130 initializied by a call to Pa_Initialize(). In cases where Pa_Initialise() has
131 been called multiple times, each call must be matched with a corresponding call
132 to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically
133 close any PortAudio streams that are still open.
134
135 Pa_Terminate() MUST be called before exiting a program which uses PortAudio.
136 Failure to do so may result in serious resource leaks, such as audio devices
137 not being available until the next reboot.
138
139 @return paNoError if successful, otherwise an error code indicating the cause
140 of failure.
141
142 @see Pa_Initialize
143 */
144 PaError Pa_Terminate( void );
145
146
147
148 /** The type used to refer to audio devices. Values of this type usually
149 range from 0 to (Pa_DeviceCount-1), and may also take on the PaNoDevice
150 and paUseHostApiSpecificDeviceSpecification values.
151
152 @see Pa_DeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification
153 */
154 typedef int PaDeviceIndex;
155
156
157 /** A special PaDeviceIndex value indicating that no device is available,
158 or should be used.
159
160 @see PaDeviceIndex
161 */
162 #define paNoDevice ((PaDeviceIndex)-1)
163
164
165 /** A special PaDeviceIndex value indicating that the device(s) to be used
166 are specified in the host api specific stream info structure.
167
168 @see PaDeviceIndex
169 */
170 #define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2)
171
172
173 /* Host API enumeration mechanism */
174
175 /** The type used to enumerate to host APIs at runtime. Values of this type
176 range from 0 to (Pa_GetHostApiCount()-1).
177
178 @see Pa_GetHostApiCount
179 */
180 typedef int PaHostApiIndex;
181
182
183 /** Retrieve the number of available host APIs. Even if a host API is
184 available it may have no devices available.
185
186 @return A non-negative value indicating the number of available host APIs
187 or, a PaErrorCode (which are always negative) if PortAudio is not initialized
188 or an error is encountered.
189
190 @see PaHostApiIndex
191 */
192 PaHostApiIndex Pa_GetHostApiCount( void );
193
194
195 /** Retrieve the index of the default host API. The default host API will be
196 the lowest common denominator host API on the current platform and is
197 unlikely to provide the best performance.
198
199 @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1)
200 indicating the default host API index or, a PaErrorCode (which are always
201 negative) if PortAudio is not initialized or an error is encountered.
202 */
203 PaHostApiIndex Pa_GetDefaultHostApi( void );
204
205
206 /** Unchanging unique identifiers for each supported host API. This type
207 is used in the PaHostApiInfo structure. The values are guaranteed to be
208 unique and to never change, thus allowing code to be written that
209 conditionally uses host API specific extensions.
210
211 New type ids will be allocated when support for a host API reaches
212 "public alpha" status, prior to that developers should use the
213 paInDevelopment type id.
214
215 @see PaHostApiInfo
216 */
217 typedef enum PaHostApiTypeId
218 {
219 paInDevelopment=0, /* use while developing support for a new host API */
220 paDirectSound=1,
221 paMME=2,
222 paASIO=3,
223 paSoundManager=4,
224 paCoreAudio=5,
225 paOSS=7,
226 paALSA=8,
227 paAL=9,
228 paBeOS=10,
229 paWDMKS=11,
230 paJACK=12,
231 paWASAPI=13,
232 paAudioScienceHPI=14
233 } PaHostApiTypeId;
234
235
236 /** A structure containing information about a particular host API. */
237
238 typedef struct PaHostApiInfo
239 {
240 /** this is struct version 1 */
241 int structVersion;
242 /** The well known unique identifier of this host API @see PaHostApiTypeId */
243 PaHostApiTypeId type;
244 /** A textual description of the host API for display on user interfaces. */
245 const char *name;
246
247 /** The number of devices belonging to this host API. This field may be
248 used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate
249 all devices for this host API.
250 @see Pa_HostApiDeviceIndexToDeviceIndex
251 */
252 int deviceCount;
253
254 /** The default input device for this host API. The value will be a
255 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice
256 if no default input device is available.
257 */
258 PaDeviceIndex defaultInputDevice;
259
260 /** The default output device for this host API. The value will be a
261 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice
262 if no default output device is available.
263 */
264 PaDeviceIndex defaultOutputDevice;
265
266 } PaHostApiInfo;
267
268
269 /** Retrieve a pointer to a structure containing information about a specific
270 host Api.
271
272 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1)
273
274 @return A pointer to an immutable PaHostApiInfo structure describing
275 a specific host API. If the hostApi parameter is out of range or an error
276 is encountered, the function returns NULL.
277
278 The returned structure is owned by the PortAudio implementation and must not
279 be manipulated or freed. The pointer is only guaranteed to be valid between
280 calls to Pa_Initialize() and Pa_Terminate().
281 */
282 const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi );
283
284
285 /** Convert a static host API unique identifier, into a runtime
286 host API index.
287
288 @param type A unique host API identifier belonging to the PaHostApiTypeId
289 enumeration.
290
291 @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or,
292 a PaErrorCode (which are always negative) if PortAudio is not initialized
293 or an error is encountered.
294
295 The paHostApiNotFound error code indicates that the host API specified by the
296 type parameter is not available.
297
298 @see PaHostApiTypeId
299 */
300 PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type );
301
302
303 /** Convert a host-API-specific device index to standard PortAudio device index.
304 This function may be used in conjunction with the deviceCount field of
305 PaHostApiInfo to enumerate all devices for the specified host API.
306
307 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1)
308
309 @param hostApiDeviceIndex A valid per-host device index in the range
310 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1)
311
312 @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1)
313 or, a PaErrorCode (which are always negative) if PortAudio is not initialized
314 or an error is encountered.
315
316 A paInvalidHostApi error code indicates that the host API index specified by
317 the hostApi parameter is out of range.
318
319 A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter
320 is out of range.
321
322 @see PaHostApiInfo
323 */
324 PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi,
325 int hostApiDeviceIndex );
326
327
328
329 /** Structure used to return information about a host error condition.
330 */
331 typedef struct PaHostErrorInfo{
332 PaHostApiTypeId hostApiType; /**< the host API which returned the error code */
333 long errorCode; /**< the error code returned */
334 const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */
335 }PaHostErrorInfo;
336
337
338 /** Return information about the last host error encountered. The error
339 information returned by Pa_GetLastHostErrorInfo() will never be modified
340 asyncronously by errors occurring in other PortAudio owned threads
341 (such as the thread that manages the stream callback.)
342
343 This function is provided as a last resort, primarily to enhance debugging
344 by providing clients with access to all available error information.
345
346 @return A pointer to an immutable structure constaining information about
347 the host error. The values in this structure will only be valid if a
348 PortAudio function has previously returned the paUnanticipatedHostError
349 error code.
350 */
351 const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void );
352
353
354
355 /* Device enumeration and capabilities */
356
357 /** Retrieve the number of available devices. The number of available devices
358 may be zero.
359
360 @return A non-negative value indicating the number of available devices or,
361 a PaErrorCode (which are always negative) if PortAudio is not initialized
362 or an error is encountered.
363 */
364 PaDeviceIndex Pa_GetDeviceCount( void );
365
366
367 /** Retrieve the index of the default input device. The result can be
368 used in the inputDevice parameter to Pa_OpenStream().
369
370 @return The default input device index for the default host API, or paNoDevice
371 if no default input device is available or an error was encountered.
372 */
373 PaDeviceIndex Pa_GetDefaultInputDevice( void );
374
375
376 /** Retrieve the index of the default output device. The result can be
377 used in the outputDevice parameter to Pa_OpenStream().
378
379 @return The default output device index for the defualt host API, or paNoDevice
380 if no default output device is available or an error was encountered.
381
382 @note
383 On the PC, the user can specify a default device by
384 setting an environment variable. For example, to use device #1.
385 <pre>
386 set PA_RECOMMENDED_OUTPUT_DEVICE=1
387 </pre>
388 The user should first determine the available device ids by using
389 the supplied application "pa_devs".
390 */
391 PaDeviceIndex Pa_GetDefaultOutputDevice( void );
392
393
394 /** The type used to represent monotonic time in seconds that can be used
395 for syncronisation. The type is used for the outTime argument to the
396 PaStreamCallback and as the result of Pa_GetStreamTime().
397
398 @see PaStreamCallback, Pa_GetStreamTime
399 */
400 typedef double PaTime;
401
402
403 /** A type used to specify one or more sample formats. Each value indicates
404 a possible format for sound data passed to and from the stream callback,
405 Pa_ReadStream and Pa_WriteStream.
406
407 The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8
408 and aUInt8 are usually implemented by all implementations.
409
410 The floating point representation (paFloat32) uses +1.0 and -1.0 as the
411 maximum and minimum respectively.
412
413 paUInt8 is an unsigned 8 bit format where 128 is considered "ground"
414
415 The paNonInterleaved flag indicates that a multichannel buffer is passed
416 as a set of non-interleaved pointers.
417
418 @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo
419 @see paFloat32, paInt16, paInt32, paInt24, paInt8
420 @see paUInt8, paCustomFormat, paNonInterleaved
421 */
422 typedef unsigned long PaSampleFormat;
423
424
425 #define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */
426 #define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */
427 #define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */
428 #define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */
429 #define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */
430 #define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */
431 #define paCustomFormat ((PaSampleFormat) 0x00010000)/**< @see PaSampleFormat */
432
433 #define paNonInterleaved ((PaSampleFormat) 0x80000000)
434
435 /** A structure providing information and capabilities of PortAudio devices.
436 Devices may support input, output or both input and output.
437 */
438 typedef struct PaDeviceInfo
439 {
440 int structVersion; /* this is struct version 2 */
441 const char *name;
442 PaHostApiIndex hostApi; /* note this is a host API index, not a type id*/
443
444 int maxInputChannels;
445 int maxOutputChannels;
446
447 /* Default latency values for interactive performance. */
448 PaTime defaultLowInputLatency;
449 PaTime defaultLowOutputLatency;
450 /* Default latency values for robust non-interactive applications (eg. playing sound files). */
451 PaTime defaultHighInputLatency;
452 PaTime defaultHighOutputLatency;
453
454 double defaultSampleRate;
455 } PaDeviceInfo;
456
457
458 /** Retrieve a pointer to a PaDeviceInfo structure containing information
459 about the specified device.
460 @return A pointer to an immutable PaDeviceInfo structure. If the device
461 parameter is out of range the function returns NULL.
462
463 @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1)
464
465 @note PortAudio manages the memory referenced by the returned pointer,
466 the client must not manipulate or free the memory. The pointer is only
467 guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate().
468
469 @see PaDeviceInfo, PaDeviceIndex
470 */
471 const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device );
472
473
474 /** Parameters for one direction (input or output) of a stream.
475 */
476 typedef struct PaStreamParameters
477 {
478 /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1)
479 specifying the device to be used or the special constant
480 paUseHostApiSpecificDeviceSpecification which indicates that the actual
481 device(s) to use are specified in hostApiSpecificStreamInfo.
482 This field must not be set to paNoDevice.
483 */
484 PaDeviceIndex device;
485
486 /** The number of channels of sound to be delivered to the
487 stream callback or accessed by Pa_ReadStream() or Pa_WriteStream().
488 It can range from 1 to the value of maxInputChannels in the
489 PaDeviceInfo record for the device specified by the device parameter.
490 */
491 int channelCount;
492
493 /** The sample format of the buffer provided to the stream callback,
494 a_ReadStream() or Pa_WriteStream(). It may be any of the formats described
495 by the PaSampleFormat enumeration.
496 */
497 PaSampleFormat sampleFormat;
498
499 /** The desired latency in seconds. Where practical, implementations should
500 configure their latency based on these parameters, otherwise they may
501 choose the closest viable latency instead. Unless the suggested latency
502 is greater than the absolute upper limit for the device implementations
503 should round the suggestedLatency up to the next practial value - ie to
504 provide an equal or higher latency than suggestedLatency wherever possibe.
505 Actual latency values for an open stream may be retrieved using the
506 inputLatency and outputLatency fields of the PaStreamInfo structure
507 returned by Pa_GetStreamInfo().
508 @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo
509 */
510 PaTime suggestedLatency;
511
512 /** An optional pointer to a host api specific data structure
513 containing additional information for device setup and/or stream processing.
514 hostApiSpecificStreamInfo is never required for correct operation,
515 if not used it should be set to NULL.
516 */
517 void *hostApiSpecificStreamInfo;
518
519 } PaStreamParameters;
520
521
522 /** Return code for Pa_IsFormatSupported indicating success. */
523 #define paFormatIsSupported (0)
524
525 /** Determine whether it would be possible to open a stream with the specified
526 parameters.
527
528 @param inputParameters A structure that describes the input parameters used to
529 open a stream. The suggestedLatency field is ignored. See PaStreamParameters
530 for a description of these parameters. inputParameters must be NULL for
531 output-only streams.
532
533 @param outputParameters A structure that describes the output parameters used
534 to open a stream. The suggestedLatency field is ignored. See PaStreamParameters
535 for a description of these parameters. outputParameters must be NULL for
536 input-only streams.
537
538 @param sampleRate The required sampleRate. For full-duplex streams it is the
539 sample rate for both input and output
540
541 @return Returns 0 if the format is supported, and an error code indicating why
542 the format is not supported otherwise. The constant paFormatIsSupported is
543 provided to compare with the return value for success.
544
545 @see paFormatIsSupported, PaStreamParameters
546 */
547 PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters,
548 const PaStreamParameters *outputParameters,
549 double sampleRate );
550
551
552
553 /* Streaming types and functions */
554
555
556 /**
557 A single PaStream can provide multiple channels of real-time
558 streaming audio input and output to a client application. A stream
559 provides access to audio hardware represented by one or more
560 PaDevices. Depending on the underlying Host API, it may be possible
561 to open multiple streams using the same device, however this behavior
562 is implementation defined. Portable applications should assume that
563 a PaDevice may be simultaneously used by at most one PaStream.
564
565 Pointers to PaStream objects are passed between PortAudio functions that
566 operate on streams.
567
568 @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream,
569 Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive,
570 Pa_GetStreamTime, Pa_GetStreamCpuLoad
571
572 */
573 typedef void PaStream;
574
575
576 /** Can be passed as the framesPerBuffer parameter to Pa_OpenStream()
577 or Pa_OpenDefaultStream() to indicate that the stream callback will
578 accept buffers of any size.
579 */
580 #define paFramesPerBufferUnspecified (0)
581
582
583 /** Flags used to control the behavior of a stream. They are passed as
584 parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be
585 ORed together.
586
587 @see Pa_OpenStream, Pa_OpenDefaultStream
588 @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput,
589 paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags
590 */
591 typedef unsigned long PaStreamFlags;
592
593 /** @see PaStreamFlags */
594 #define paNoFlag ((PaStreamFlags) 0)
595
596 /** Disable default clipping of out of range samples.
597 @see PaStreamFlags
598 */
599 #define paClipOff ((PaStreamFlags) 0x00000001)
600
601 /** Disable default dithering.
602 @see PaStreamFlags
603 */
604 #define paDitherOff ((PaStreamFlags) 0x00000002)
605
606 /** Flag requests that where possible a full duplex stream will not discard
607 overflowed input samples without calling the stream callback. This flag is
608 only valid for full duplex callback streams and only when used in combination
609 with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using
610 this flag incorrectly results in a paInvalidFlag error being returned from
611 Pa_OpenStream and Pa_OpenDefaultStream.
612
613 @see PaStreamFlags, paFramesPerBufferUnspecified
614 */
615 #define paNeverDropInput ((PaStreamFlags) 0x00000004)
616
617 /** Call the stream callback to fill initial output buffers, rather than the
618 default behavior of priming the buffers with zeros (silence). This flag has
619 no effect for input-only and blocking read/write streams.
620
621 @see PaStreamFlags
622 */
623 #define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008)
624
625 /** A mask specifying the platform specific bits.
626 @see PaStreamFlags
627 */
628 #define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000)
629
630 /**
631 Timing information for the buffers passed to the stream callback.
632 */
633 typedef struct PaStreamCallbackTimeInfo{
634 PaTime inputBufferAdcTime;
635 PaTime currentTime;
636 PaTime outputBufferDacTime;
637 } PaStreamCallbackTimeInfo;
638
639
640 /**
641 Flag bit constants for the statusFlags to PaStreamCallback.
642
643 @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow,
644 paPrimingOutput
645 */
646 typedef unsigned long PaStreamCallbackFlags;
647
648 /** In a stream opened with paFramesPerBufferUnspecified, indicates that
649 input data is all silence (zeros) because no real data is available. In a
650 stream opened without paFramesPerBufferUnspecified, it indicates that one or
651 more zero samples have been inserted into the input buffer to compensate
652 for an input underflow.
653 @see PaStreamCallbackFlags
654 */
655 #define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001)
656
657 /** In a stream opened with paFramesPerBufferUnspecified, indicates that data
658 prior to the first sample of the input buffer was discarded due to an
659 overflow, possibly because the stream callback is using too much CPU time.
660 Otherwise indicates that data prior to one or more samples in the
661 input buffer was discarded.
662 @see PaStreamCallbackFlags
663 */
664 #define paInputOverflow ((PaStreamCallbackFlags) 0x00000002)
665
666 /** Indicates that output data (or a gap) was inserted, possibly because the
667 stream callback is using too much CPU time.
668 @see PaStreamCallbackFlags
669 */
670 #define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004)
671
672 /** Indicates that output data will be discarded because no room is available.
673 @see PaStreamCallbackFlags
674 */
675 #define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008)
676
677 /** Some of all of the output data will be used to prime the stream, input
678 data may be zero.
679 @see PaStreamCallbackFlags
680 */
681 #define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010)
682
683 /**
684 Allowable return values for the PaStreamCallback.
685 @see PaStreamCallback
686 */
687 typedef enum PaStreamCallbackResult
688 {
689 paContinue=0,
690 paComplete=1,
691 paAbort=2
692 } PaStreamCallbackResult;
693
694
695 /**
696 Functions of type PaStreamCallback are implemented by PortAudio clients.
697 They consume, process or generate audio in response to requests from an
698 active PortAudio stream.
699
700 @param input and @param output are arrays of interleaved samples,
701 the format, packing and number of channels used by the buffers are
702 determined by parameters to Pa_OpenStream().
703
704 @param frameCount The number of sample frames to be processed by
705 the stream callback.
706
707 @param timeInfo The time in seconds when the first sample of the input
708 buffer was received at the audio input, the time in seconds when the first
709 sample of the output buffer will begin being played at the audio output, and
710 the time in seconds when the stream callback was called.
711 See also Pa_GetStreamTime()
712
713 @param statusFlags Flags indicating whether input and/or output buffers
714 have been inserted or will be dropped to overcome underflow or overflow
715 conditions.
716
717 @param userData The value of a user supplied pointer passed to
718 Pa_OpenStream() intended for storing synthesis data etc.
719
720 @return
721 The stream callback should return one of the values in the
722 PaStreamCallbackResult enumeration. To ensure that the callback continues
723 to be called, it should return paContinue (0). Either paComplete or paAbort
724 can be returned to finish stream processing, after either of these values is
725 returned the callback will not be called again. If paAbort is returned the
726 stream will finish as soon as possible. If paComplete is returned, the stream
727 will continue until all buffers generated by the callback have been played.
728 This may be useful in applications such as soundfile players where a specific
729 duration of output is required. However, it is not necessary to utilise this
730 mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also
731 be used to stop the stream. The callback must always fill the entire output
732 buffer irrespective of its return value.
733
734 @see Pa_OpenStream, Pa_OpenDefaultStream
735
736 @note With the exception of Pa_GetStreamCpuLoad() it is not permissable to call
737 PortAudio API functions from within the stream callback.
738 */
739 typedef int PaStreamCallback(
740 const void *input, void *output,
741 unsigned long frameCount,
742 const PaStreamCallbackTimeInfo* timeInfo,
743 PaStreamCallbackFlags statusFlags,
744 void *userData );
745
746
747 /** Opens a stream for either input, output or both.
748
749 @param stream The address of a PaStream pointer which will receive
750 a pointer to the newly opened stream.
751
752 @param inputParameters A structure that describes the input parameters used by
753 the opened stream. See PaStreamParameters for a description of these parameters.
754 inputParameters must be NULL for output-only streams.
755
756 @param outputParameters A structure that describes the output parameters used by
757 the opened stream. See PaStreamParameters for a description of these parameters.
758 outputParameters must be NULL for input-only streams.
759
760 @param sampleRate The desired sampleRate. For full-duplex streams it is the
761 sample rate for both input and output
762
763 @param framesPerBuffer The number of frames passed to the stream callback
764 function, or the preferred block granularity for a blocking read/write stream.
765 The special value paFramesPerBufferUnspecified (0) may be used to request that
766 the stream callback will recieve an optimal (and possibly varying) number of
767 frames based on host requirements and the requested latency settings.
768 Note: With some host APIs, the use of non-zero framesPerBuffer for a callback
769 stream may introduce an additional layer of buffering which could introduce
770 additional latency. PortAudio guarantees that the additional latency
771 will be kept to the theoretical minimum however, it is strongly recommended
772 that a non-zero framesPerBuffer value only be used when your algorithm
773 requires a fixed number of frames per stream callback.
774
775 @param streamFlags Flags which modify the behaviour of the streaming process.
776 This parameter may contain a combination of flags ORed together. Some flags may
777 only be relevant to certain buffer formats.
778
779 @param streamCallback A pointer to a client supplied function that is responsible
780 for processing and filling input and output buffers. If this parameter is NULL
781 the stream will be opened in 'blocking read/write' mode. In blocking mode,
782 the client can receive sample data using Pa_ReadStream and write sample data
783 using Pa_WriteStream, the number of samples that may be read or written
784 without blocking is returned by Pa_GetStreamReadAvailable and
785 Pa_GetStreamWriteAvailable respectively.
786
787 @param userData A client supplied pointer which is passed to the stream callback
788 function. It could for example, contain a pointer to instance data necessary
789 for processing the audio buffers. This parameter is ignored if streamCallback
790 is NULL.
791
792 @return
793 Upon success Pa_OpenStream() returns paNoError and places a pointer to a
794 valid PaStream in the stream argument. The stream is inactive (stopped).
795 If a call to Pa_OpenStream() fails, a non-zero error code is returned (see
796 PaError for possible error codes) and the value of stream is invalid.
797
798 @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream,
799 Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable
800 */
801 PaError Pa_OpenStream( PaStream** stream,
802 const PaStreamParameters *inputParameters,
803 const PaStreamParameters *outputParameters,
804 double sampleRate,
805 unsigned long framesPerBuffer,
806 PaStreamFlags streamFlags,
807 PaStreamCallback *streamCallback,
808 void *userData );
809
810
811 /** A simplified version of Pa_OpenStream() that opens the default input
812 and/or output devices.
813
814 @param stream The address of a PaStream pointer which will receive
815 a pointer to the newly opened stream.
816
817 @param numInputChannels The number of channels of sound that will be supplied
818 to the stream callback or returned by Pa_ReadStream. It can range from 1 to
819 the value of maxInputChannels in the PaDeviceInfo record for the default input
820 device. If 0 the stream is opened as an output-only stream.
821
822 @param numOutputChannels The number of channels of sound to be delivered to the
823 stream callback or passed to Pa_WriteStream. It can range from 1 to the value
824 of maxOutputChannels in the PaDeviceInfo record for the default output dvice.
825 If 0 the stream is opened as an output-only stream.
826
827 @param sampleFormat The sample format of both the input and output buffers
828 provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream.
829 sampleFormat may be any of the formats described by the PaSampleFormat
830 enumeration.
831
832 @param sampleRate Same as Pa_OpenStream parameter of the same name.
833 @param framesPerBuffer Same as Pa_OpenStream parameter of the same name.
834 @param streamCallback Same as Pa_OpenStream parameter of the same name.
835 @param userData Same as Pa_OpenStream parameter of the same name.
836
837 @return As for Pa_OpenStream
838
839 @see Pa_OpenStream, PaStreamCallback
840 */
841 PaError Pa_OpenDefaultStream( PaStream** stream,
842 int numInputChannels,
843 int numOutputChannels,
844 PaSampleFormat sampleFormat,
845 double sampleRate,
846 unsigned long framesPerBuffer,
847 PaStreamCallback *streamCallback,
848 void *userData );
849
850
851 /** Closes an audio stream. If the audio stream is active it
852 discards any pending buffers as if Pa_AbortStream() had been called.
853 */
854 PaError Pa_CloseStream( PaStream *stream );
855
856
857 /** Functions of type PaStreamFinishedCallback are implemented by PortAudio
858 clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback
859 function. Once registered they are called when the stream becomes inactive
860 (ie once a call to Pa_StopStream() will not block).
861 A stream will become inactive after the stream callback returns non-zero,
862 or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio
863 output, if the stream callback returns paComplete, or Pa_StopStream is called,
864 the stream finished callback will not be called until all generated sample data
865 has been played.
866
867 @param userData The userData parameter supplied to Pa_OpenStream()
868
869 @see Pa_SetStreamFinishedCallback
870 */
871 typedef void PaStreamFinishedCallback( void *userData );
872
873
874 /** Register a stream finished callback function which will be called when the
875 stream becomes inactive. See the description of PaStreamFinishedCallback for
876 further details about when the callback will be called.
877
878 @param stream a pointer to a PaStream that is in the stopped state - if the
879 stream is not stopped, the stream's finished callback will remain unchanged
880 and an error code will be returned.
881
882 @param streamFinishedCallback a pointer to a function with the same signature
883 as PaStreamFinishedCallback, that will be called when the stream becomes
884 inactive. Passing NULL for this parameter will un-register a previously
885 registered stream finished callback function.
886
887 @return on success returns paNoError, otherwise an error code indicating the cause
888 of the error.
889
890 @see PaStreamFinishedCallback
891 */
892 PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback );
893
894
895 /** Commences audio processing.
896 */
897 PaError Pa_StartStream( PaStream *stream );
898
899
900 /** Terminates audio processing. It waits until all pending
901 audio buffers have been played before it returns.
902 */
903 PaError Pa_StopStream( PaStream *stream );
904
905
906 /** Terminates audio processing immediately without waiting for pending
907 buffers to complete.
908 */
909 PaError Pa_AbortStream( PaStream *stream );
910
911
912 /** Determine whether the stream is stopped.
913 A stream is considered to be stopped prior to a successful call to
914 Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream.
915 If a stream callback returns a value other than paContinue the stream is NOT
916 considered to be stopped.
917
918 @return Returns one (1) when the stream is stopped, zero (0) when
919 the stream is running or, a PaErrorCode (which are always negative) if
920 PortAudio is not initialized or an error is encountered.
921
922 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive
923 */
924 PaError Pa_IsStreamStopped( PaStream *stream );
925
926
927 /** Determine whether the stream is active.
928 A stream is active after a successful call to Pa_StartStream(), until it
929 becomes inactive either as a result of a call to Pa_StopStream() or
930 Pa_AbortStream(), or as a result of a return value other than paContinue from
931 the stream callback. In the latter case, the stream is considered inactive
932 after the last buffer has finished playing.
933
934 @return Returns one (1) when the stream is active (ie playing or recording
935 audio), zero (0) when not playing or, a PaErrorCode (which are always negative)
936 if PortAudio is not initialized or an error is encountered.
937
938 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped
939 */
940 PaError Pa_IsStreamActive( PaStream *stream );
941
942
943
944 /** A structure containing unchanging information about an open stream.
945 @see Pa_GetStreamInfo
946 */
947
948 typedef struct PaStreamInfo
949 {
950 /** this is struct version 1 */
951 int structVersion;
952
953 /** The input latency of the stream in seconds. This value provides the most
954 accurate estimate of input latency available to the implementation. It may
955 differ significantly from the suggestedLatency value passed to Pa_OpenStream().
956 The value of this field will be zero (0.) for output-only streams.
957 @see PaTime
958 */
959 PaTime inputLatency;
960
961 /** The output latency of the stream in seconds. This value provides the most
962 accurate estimate of output latency available to the implementation. It may
963 differ significantly from the suggestedLatency value passed to Pa_OpenStream().
964 The value of this field will be zero (0.) for input-only streams.
965 @see PaTime
966 */
967 PaTime outputLatency;
968
969 /** The sample rate of the stream in Hertz (samples per second). In cases
970 where the hardware sample rate is inaccurate and PortAudio is aware of it,
971 the value of this field may be different from the sampleRate parameter
972 passed to Pa_OpenStream(). If information about the actual hardware sample
973 rate is not available, this field will have the same value as the sampleRate
974 parameter passed to Pa_OpenStream().
975 */
976 double sampleRate;
977
978 } PaStreamInfo;
979
980
981 /** Retrieve a pointer to a PaStreamInfo structure containing information
982 about the specified stream.
983 @return A pointer to an immutable PaStreamInfo structure. If the stream
984 parameter invalid, or an error is encountered, the function returns NULL.
985
986 @param stream A pointer to an open stream previously created with Pa_OpenStream.
987
988 @note PortAudio manages the memory referenced by the returned pointer,
989 the client must not manipulate or free the memory. The pointer is only
990 guaranteed to be valid until the specified stream is closed.
991
992 @see PaStreamInfo
993 */
994 const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream );
995
996
997 /** Determine the current time for the stream according to the same clock used
998 to generate buffer timestamps. This time may be used for syncronising other
999 events to the audio stream, for example synchronizing audio to MIDI.
1000
1001 @return The stream's current time in seconds, or 0 if an error occurred.
1002
1003 @see PaTime, PaStreamCallback
1004 */
1005 PaTime Pa_GetStreamTime( PaStream *stream );
1006
1007
1008 /** Retrieve CPU usage information for the specified stream.
1009 The "CPU Load" is a fraction of total CPU time consumed by a callback stream's
1010 audio processing routines including, but not limited to the client supplied
1011 stream callback. This function does not work with blocking read/write streams.
1012
1013 This function may be called from the stream callback function or the
1014 application.
1015
1016 @return
1017 A floating point value, typically between 0.0 and 1.0, where 1.0 indicates
1018 that the stream callback is consuming the maximum number of CPU cycles possible
1019 to maintain real-time operation. A value of 0.5 would imply that PortAudio and
1020 the stream callback was consuming roughly 50% of the available CPU time. The
1021 return value may exceed 1.0. A value of 0.0 will always be returned for a
1022 blocking read/write stream, or if an error occurrs.
1023 */
1024 double Pa_GetStreamCpuLoad( PaStream* stream );
1025
1026
1027 /** Read samples from an input stream. The function doesn't return until
1028 the entire buffer has been filled - this may involve waiting for the operating
1029 system to supply the data.
1030
1031 @param stream A pointer to an open stream previously created with Pa_OpenStream.
1032
1033 @param buffer A pointer to a buffer of sample frames. The buffer contains
1034 samples in the format specified by the inputParameters->sampleFormat field
1035 used to open the stream, and the number of channels specified by
1036 inputParameters->numChannels. If non-interleaved samples were requested,
1037 buffer is a pointer to the first element of an array of non-interleaved
1038 buffer pointers, one for each channel.
1039
1040 @param frames The number of frames to be read into buffer. This parameter
1041 is not constrained to a specific range, however high performance applications
1042 will want to match this parameter to the framesPerBuffer parameter used
1043 when opening the stream.
1044
1045 @return On success PaNoError will be returned, or PaInputOverflowed if input
1046 data was discarded by PortAudio after the previous call and before this call.
1047 */
1048 PaError Pa_ReadStream( PaStream* stream,
1049 void *buffer,
1050 unsigned long frames );
1051
1052
1053 /** Write samples to an output stream. This function doesn't return until the
1054 entire buffer has been consumed - this may involve waiting for the operating
1055 system to consume the data.
1056
1057 @param stream A pointer to an open stream previously created with Pa_OpenStream.
1058
1059 @param buffer A pointer to a buffer of sample frames. The buffer contains
1060 samples in the format specified by the outputParameters->sampleFormat field
1061 used to open the stream, and the number of channels specified by
1062 outputParameters->numChannels. If non-interleaved samples were requested,
1063 buffer is a pointer to the first element of an array of non-interleaved
1064 buffer pointers, one for each channel.
1065
1066 @param frames The number of frames to be written from buffer. This parameter
1067 is not constrained to a specific range, however high performance applications
1068 will want to match this parameter to the framesPerBuffer parameter used
1069 when opening the stream.
1070
1071 @return On success PaNoError will be returned, or paOutputUnderflowed if
1072 additional output data was inserted after the previous call and before this
1073 call.
1074 */
1075 PaError Pa_WriteStream( PaStream* stream,
1076 const void *buffer,
1077 unsigned long frames );
1078
1079
1080 /** Retrieve the number of frames that can be read from the stream without
1081 waiting.
1082
1083 @return Returns a non-negative value representing the maximum number of frames
1084 that can be read from the stream without blocking or busy waiting or, a
1085 PaErrorCode (which are always negative) if PortAudio is not initialized or an
1086 error is encountered.
1087 */
1088 signed long Pa_GetStreamReadAvailable( PaStream* stream );
1089
1090
1091 /** Retrieve the number of frames that can be written to the stream without
1092 waiting.
1093
1094 @return Returns a non-negative value representing the maximum number of frames
1095 that can be written to the stream without blocking or busy waiting or, a
1096 PaErrorCode (which are always negative) if PortAudio is not initialized or an
1097 error is encountered.
1098 */
1099 signed long Pa_GetStreamWriteAvailable( PaStream* stream );
1100
1101
1102 /* Miscellaneous utilities */
1103
1104
1105 /** Retrieve the size of a given sample format in bytes.
1106
1107 @return The size in bytes of a single sample in the specified format,
1108 or paSampleFormatNotSupported if the format is not supported.
1109 */
1110 PaError Pa_GetSampleSize( PaSampleFormat format );
1111
1112
1113 /** Put the caller to sleep for at least 'msec' milliseconds. This function is
1114 provided only as a convenience for authors of portable code (such as the tests
1115 and examples in the PortAudio distribution.)
1116
1117 The function may sleep longer than requested so don't rely on this for accurate
1118 musical timing.
1119 */
1120 void Pa_Sleep( long msec );
1121
1122
1123
1124 #ifdef __cplusplus
1125 }
1126 #endif /* __cplusplus */
1127 #endif /* PORTAUDIO_H */

   
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