1 #ifndef PORTAUDIO_H 2 #define PORTAUDIO_H 3 /* 4 * $Id: portaudio.h 1745 2011-08-25 17:44:01Z rossb $ 5 * PortAudio Portable Real-Time Audio Library 6 * PortAudio API Header File 7 * Latest version available at: http://www.portaudio.com/ 8 * 9 * Copyright (c) 1999-2002 Ross Bencina and Phil Burk 10 * 11 * Permission is hereby granted, free of charge, to any person obtaining 12 * a copy of this software and associated documentation files 13 * (the "Software"), to deal in the Software without restriction, 14 * including without limitation the rights to use, copy, modify, merge, 15 * publish, distribute, sublicense, and/or sell copies of the Software, 16 * and to permit persons to whom the Software is furnished to do so, 17 * subject to the following conditions: 18 * 19 * The above copyright notice and this permission notice shall be 20 * included in all copies or substantial portions of the Software. 21 * 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 25 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 26 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 27 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 28 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 29 */ 30 31 /* 32 * The text above constitutes the entire PortAudio license; however, 33 * the PortAudio community also makes the following non-binding requests: 34 * 35 * Any person wishing to distribute modifications to the Software is 36 * requested to send the modifications to the original developer so that 37 * they can be incorporated into the canonical version. It is also 38 * requested that these non-binding requests be included along with the 39 * license above. 40 */ 41 42 /** @file 43 @ingroup public_header 44 @brief The portable PortAudio API. 45 */ 46 47 48 #ifdef __cplusplus 49 extern "C" 50 { 51 #endif /* __cplusplus */ 52 53 54 /** Retrieve the release number of the currently running PortAudio build, 55 eg 1900. 56 */ 57 int Pa_GetVersion( void ); 58 59 60 /** Retrieve a textual description of the current PortAudio build, 61 eg "PortAudio V19-devel 13 October 2002". 62 */ 63 const char* Pa_GetVersionText( void ); 64 65 66 /** Error codes returned by PortAudio functions. 67 Note that with the exception of paNoError, all PaErrorCodes are negative. 68 */ 69 70 typedef int PaError; 71 typedef enum PaErrorCode 72 { 73 paNoError = 0, 74 75 paNotInitialized = -10000, 76 paUnanticipatedHostError, 77 paInvalidChannelCount, 78 paInvalidSampleRate, 79 paInvalidDevice, 80 paInvalidFlag, 81 paSampleFormatNotSupported, 82 paBadIODeviceCombination, 83 paInsufficientMemory, 84 paBufferTooBig, 85 paBufferTooSmall, 86 paNullCallback, 87 paBadStreamPtr, 88 paTimedOut, 89 paInternalError, 90 paDeviceUnavailable, 91 paIncompatibleHostApiSpecificStreamInfo, 92 paStreamIsStopped, 93 paStreamIsNotStopped, 94 paInputOverflowed, 95 paOutputUnderflowed, 96 paHostApiNotFound, 97 paInvalidHostApi, 98 paCanNotReadFromACallbackStream, 99 paCanNotWriteToACallbackStream, 100 paCanNotReadFromAnOutputOnlyStream, 101 paCanNotWriteToAnInputOnlyStream, 102 paIncompatibleStreamHostApi, 103 paBadBufferPtr 104 } PaErrorCode; 105 106 107 /** Translate the supplied PortAudio error code into a human readable 108 message. 109 */ 110 const char *Pa_GetErrorText( PaError errorCode ); 111 112 113 /** Library initialization function - call this before using PortAudio. 114 This function initializes internal data structures and prepares underlying 115 host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(), 116 and Pa_GetErrorText(), this function MUST be called before using any other 117 PortAudio API functions. 118 119 If Pa_Initialize() is called multiple times, each successful 120 call must be matched with a corresponding call to Pa_Terminate(). 121 Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not 122 required to be fully nested. 123 124 Note that if Pa_Initialize() returns an error code, Pa_Terminate() should 125 NOT be called. 126 127 @return paNoError if successful, otherwise an error code indicating the cause 128 of failure. 129 130 @see Pa_Terminate 131 */ 132 PaError Pa_Initialize( void ); 133 134 135 /** Library termination function - call this when finished using PortAudio. 136 This function deallocates all resources allocated by PortAudio since it was 137 initialized by a call to Pa_Initialize(). In cases where Pa_Initialise() has 138 been called multiple times, each call must be matched with a corresponding call 139 to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically 140 close any PortAudio streams that are still open. 141 142 Pa_Terminate() MUST be called before exiting a program which uses PortAudio. 143 Failure to do so may result in serious resource leaks, such as audio devices 144 not being available until the next reboot. 145 146 @return paNoError if successful, otherwise an error code indicating the cause 147 of failure. 148 149 @see Pa_Initialize 150 */ 151 PaError Pa_Terminate( void ); 152 153 154 155 /** The type used to refer to audio devices. Values of this type usually 156 range from 0 to (Pa_GetDeviceCount()-1), and may also take on the PaNoDevice 157 and paUseHostApiSpecificDeviceSpecification values. 158 159 @see Pa_GetDeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification 160 */ 161 typedef int PaDeviceIndex; 162 163 164 /** A special PaDeviceIndex value indicating that no device is available, 165 or should be used. 166 167 @see PaDeviceIndex 168 */ 169 #define paNoDevice ((PaDeviceIndex)-1) 170 171 172 /** A special PaDeviceIndex value indicating that the device(s) to be used 173 are specified in the host api specific stream info structure. 174 175 @see PaDeviceIndex 176 */ 177 #define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2) 178 179 180 /* Host API enumeration mechanism */ 181 182 /** The type used to enumerate to host APIs at runtime. Values of this type 183 range from 0 to (Pa_GetHostApiCount()-1). 184 185 @see Pa_GetHostApiCount 186 */ 187 typedef int PaHostApiIndex; 188 189 190 /** Retrieve the number of available host APIs. Even if a host API is 191 available it may have no devices available. 192 193 @return A non-negative value indicating the number of available host APIs 194 or, a PaErrorCode (which are always negative) if PortAudio is not initialized 195 or an error is encountered. 196 197 @see PaHostApiIndex 198 */ 199 PaHostApiIndex Pa_GetHostApiCount( void ); 200 201 202 /** Retrieve the index of the default host API. The default host API will be 203 the lowest common denominator host API on the current platform and is 204 unlikely to provide the best performance. 205 206 @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1) 207 indicating the default host API index or, a PaErrorCode (which are always 208 negative) if PortAudio is not initialized or an error is encountered. 209 */ 210 PaHostApiIndex Pa_GetDefaultHostApi( void ); 211 212 213 /** Unchanging unique identifiers for each supported host API. This type 214 is used in the PaHostApiInfo structure. The values are guaranteed to be 215 unique and to never change, thus allowing code to be written that 216 conditionally uses host API specific extensions. 217 218 New type ids will be allocated when support for a host API reaches 219 "public alpha" status, prior to that developers should use the 220 paInDevelopment type id. 221 222 @see PaHostApiInfo 223 */ 224 typedef enum PaHostApiTypeId 225 { 226 paInDevelopment=0, /* use while developing support for a new host API */ 227 paDirectSound=1, 228 paMME=2, 229 paASIO=3, 230 paSoundManager=4, 231 paCoreAudio=5, 232 paOSS=7, 233 paALSA=8, 234 paAL=9, 235 paBeOS=10, 236 paWDMKS=11, 237 paJACK=12, 238 paWASAPI=13, 239 paAudioScienceHPI=14 240 } PaHostApiTypeId; 241 242 243 /** A structure containing information about a particular host API. */ 244 245 typedef struct PaHostApiInfo 246 { 247 /** this is struct version 1 */ 248 int structVersion; 249 /** The well known unique identifier of this host API @see PaHostApiTypeId */ 250 PaHostApiTypeId type; 251 /** A textual description of the host API for display on user interfaces. */ 252 const char *name; 253 254 /** The number of devices belonging to this host API. This field may be 255 used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate 256 all devices for this host API. 257 @see Pa_HostApiDeviceIndexToDeviceIndex 258 */ 259 int deviceCount; 260 261 /** The default input device for this host API. The value will be a 262 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice 263 if no default input device is available. 264 */ 265 PaDeviceIndex defaultInputDevice; 266 267 /** The default output device for this host API. The value will be a 268 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice 269 if no default output device is available. 270 */ 271 PaDeviceIndex defaultOutputDevice; 272 273 } PaHostApiInfo; 274 275 276 /** Retrieve a pointer to a structure containing information about a specific 277 host Api. 278 279 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) 280 281 @return A pointer to an immutable PaHostApiInfo structure describing 282 a specific host API. If the hostApi parameter is out of range or an error 283 is encountered, the function returns NULL. 284 285 The returned structure is owned by the PortAudio implementation and must not 286 be manipulated or freed. The pointer is only guaranteed to be valid between 287 calls to Pa_Initialize() and Pa_Terminate(). 288 */ 289 const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi ); 290 291 292 /** Convert a static host API unique identifier, into a runtime 293 host API index. 294 295 @param type A unique host API identifier belonging to the PaHostApiTypeId 296 enumeration. 297 298 @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or, 299 a PaErrorCode (which are always negative) if PortAudio is not initialized 300 or an error is encountered. 301 302 The paHostApiNotFound error code indicates that the host API specified by the 303 type parameter is not available. 304 305 @see PaHostApiTypeId 306 */ 307 PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type ); 308 309 310 /** Convert a host-API-specific device index to standard PortAudio device index. 311 This function may be used in conjunction with the deviceCount field of 312 PaHostApiInfo to enumerate all devices for the specified host API. 313 314 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) 315 316 @param hostApiDeviceIndex A valid per-host device index in the range 317 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) 318 319 @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1) 320 or, a PaErrorCode (which are always negative) if PortAudio is not initialized 321 or an error is encountered. 322 323 A paInvalidHostApi error code indicates that the host API index specified by 324 the hostApi parameter is out of range. 325 326 A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter 327 is out of range. 328 329 @see PaHostApiInfo 330 */ 331 PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi, 332 int hostApiDeviceIndex ); 333 334 335 336 /** Structure used to return information about a host error condition. 337 */ 338 typedef struct PaHostErrorInfo{ 339 PaHostApiTypeId hostApiType; /**< the host API which returned the error code */ 340 long errorCode; /**< the error code returned */ 341 const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */ 342 }PaHostErrorInfo; 343 344 345 /** Return information about the last host error encountered. The error 346 information returned by Pa_GetLastHostErrorInfo() will never be modified 347 asynchronously by errors occurring in other PortAudio owned threads 348 (such as the thread that manages the stream callback.) 349 350 This function is provided as a last resort, primarily to enhance debugging 351 by providing clients with access to all available error information. 352 353 @return A pointer to an immutable structure constraining information about 354 the host error. The values in this structure will only be valid if a 355 PortAudio function has previously returned the paUnanticipatedHostError 356 error code. 357 */ 358 const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void ); 359 360 361 362 /* Device enumeration and capabilities */ 363 364 /** Retrieve the number of available devices. The number of available devices 365 may be zero. 366 367 @return A non-negative value indicating the number of available devices or, 368 a PaErrorCode (which are always negative) if PortAudio is not initialized 369 or an error is encountered. 370 */ 371 PaDeviceIndex Pa_GetDeviceCount( void ); 372 373 374 /** Retrieve the index of the default input device. The result can be 375 used in the inputDevice parameter to Pa_OpenStream(). 376 377 @return The default input device index for the default host API, or paNoDevice 378 if no default input device is available or an error was encountered. 379 */ 380 PaDeviceIndex Pa_GetDefaultInputDevice( void ); 381 382 383 /** Retrieve the index of the default output device. The result can be 384 used in the outputDevice parameter to Pa_OpenStream(). 385 386 @return The default output device index for the default host API, or paNoDevice 387 if no default output device is available or an error was encountered. 388 389 @note 390 On the PC, the user can specify a default device by 391 setting an environment variable. For example, to use device #1. 392 <pre> 393 set PA_RECOMMENDED_OUTPUT_DEVICE=1 394 </pre> 395 The user should first determine the available device ids by using 396 the supplied application "pa_devs". 397 */ 398 PaDeviceIndex Pa_GetDefaultOutputDevice( void ); 399 400 401 /** The type used to represent monotonic time in seconds. PaTime is 402 used for the fields of the PaStreamCallbackTimeInfo argument to the 403 PaStreamCallback and as the result of Pa_GetStreamTime(). 404 405 PaTime values have unspecified origin. 406 407 @see PaStreamCallback, PaStreamCallbackTimeInfo, Pa_GetStreamTime 408 */ 409 typedef double PaTime; 410 411 412 /** A type used to specify one or more sample formats. Each value indicates 413 a possible format for sound data passed to and from the stream callback, 414 Pa_ReadStream and Pa_WriteStream. 415 416 The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8 417 and aUInt8 are usually implemented by all implementations. 418 419 The floating point representation (paFloat32) uses +1.0 and -1.0 as the 420 maximum and minimum respectively. 421 422 paUInt8 is an unsigned 8 bit format where 128 is considered "ground" 423 424 The paNonInterleaved flag indicates that audio data is passed as an array 425 of pointers to separate buffers, one buffer for each channel. Usually, 426 when this flag is not used, audio data is passed as a single buffer with 427 all channels interleaved. 428 429 @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo 430 @see paFloat32, paInt16, paInt32, paInt24, paInt8 431 @see paUInt8, paCustomFormat, paNonInterleaved 432 */ 433 typedef unsigned long PaSampleFormat; 434 435 436 #define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */ 437 #define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */ 438 #define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */ 439 #define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */ 440 #define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */ 441 #define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */ 442 #define paCustomFormat ((PaSampleFormat) 0x00010000) /**< @see PaSampleFormat */ 443 444 #define paNonInterleaved ((PaSampleFormat) 0x80000000) /**< @see PaSampleFormat */ 445 446 /** A structure providing information and capabilities of PortAudio devices. 447 Devices may support input, output or both input and output. 448 */ 449 typedef struct PaDeviceInfo 450 { 451 int structVersion; /* this is struct version 2 */ 452 const char *name; 453 PaHostApiIndex hostApi; /**< note this is a host API index, not a type id*/ 454 455 int maxInputChannels; 456 int maxOutputChannels; 457 458 /** Default latency values for interactive performance. */ 459 PaTime defaultLowInputLatency; 460 PaTime defaultLowOutputLatency; 461 /** Default latency values for robust non-interactive applications (eg. playing sound files). */ 462 PaTime defaultHighInputLatency; 463 PaTime defaultHighOutputLatency; 464 465 double defaultSampleRate; 466 } PaDeviceInfo; 467 468 469 /** Retrieve a pointer to a PaDeviceInfo structure containing information 470 about the specified device. 471 @return A pointer to an immutable PaDeviceInfo structure. If the device 472 parameter is out of range the function returns NULL. 473 474 @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1) 475 476 @note PortAudio manages the memory referenced by the returned pointer, 477 the client must not manipulate or free the memory. The pointer is only 478 guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate(). 479 480 @see PaDeviceInfo, PaDeviceIndex 481 */ 482 const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device ); 483 484 485 /** Parameters for one direction (input or output) of a stream. 486 */ 487 typedef struct PaStreamParameters 488 { 489 /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1) 490 specifying the device to be used or the special constant 491 paUseHostApiSpecificDeviceSpecification which indicates that the actual 492 device(s) to use are specified in hostApiSpecificStreamInfo. 493 This field must not be set to paNoDevice. 494 */ 495 PaDeviceIndex device; 496 497 /** The number of channels of sound to be delivered to the 498 stream callback or accessed by Pa_ReadStream() or Pa_WriteStream(). 499 It can range from 1 to the value of maxInputChannels in the 500 PaDeviceInfo record for the device specified by the device parameter. 501 */ 502 int channelCount; 503 504 /** The sample format of the buffer provided to the stream callback, 505 a_ReadStream() or Pa_WriteStream(). It may be any of the formats described 506 by the PaSampleFormat enumeration. 507 */ 508 PaSampleFormat sampleFormat; 509 510 /** The desired latency in seconds. Where practical, implementations should 511 configure their latency based on these parameters, otherwise they may 512 choose the closest viable latency instead. Unless the suggested latency 513 is greater than the absolute upper limit for the device implementations 514 should round the suggestedLatency up to the next practical value - ie to 515 provide an equal or higher latency than suggestedLatency wherever possible. 516 Actual latency values for an open stream may be retrieved using the 517 inputLatency and outputLatency fields of the PaStreamInfo structure 518 returned by Pa_GetStreamInfo(). 519 @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo 520 */ 521 PaTime suggestedLatency; 522 523 /** An optional pointer to a host api specific data structure 524 containing additional information for device setup and/or stream processing. 525 hostApiSpecificStreamInfo is never required for correct operation, 526 if not used it should be set to NULL. 527 */ 528 void *hostApiSpecificStreamInfo; 529 530 } PaStreamParameters; 531 532 533 /** Return code for Pa_IsFormatSupported indicating success. */ 534 #define paFormatIsSupported (0) 535 536 /** Determine whether it would be possible to open a stream with the specified 537 parameters. 538 539 @param inputParameters A structure that describes the input parameters used to 540 open a stream. The suggestedLatency field is ignored. See PaStreamParameters 541 for a description of these parameters. inputParameters must be NULL for 542 output-only streams. 543 544 @param outputParameters A structure that describes the output parameters used 545 to open a stream. The suggestedLatency field is ignored. See PaStreamParameters 546 for a description of these parameters. outputParameters must be NULL for 547 input-only streams. 548 549 @param sampleRate The required sampleRate. For full-duplex streams it is the 550 sample rate for both input and output 551 552 @return Returns 0 if the format is supported, and an error code indicating why 553 the format is not supported otherwise. The constant paFormatIsSupported is 554 provided to compare with the return value for success. 555 556 @see paFormatIsSupported, PaStreamParameters 557 */ 558 PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters, 559 const PaStreamParameters *outputParameters, 560 double sampleRate ); 561 562 563 564 /* Streaming types and functions */ 565 566 567 /** 568 A single PaStream can provide multiple channels of real-time 569 streaming audio input and output to a client application. A stream 570 provides access to audio hardware represented by one or more 571 PaDevices. Depending on the underlying Host API, it may be possible 572 to open multiple streams using the same device, however this behavior 573 is implementation defined. Portable applications should assume that 574 a PaDevice may be simultaneously used by at most one PaStream. 575 576 Pointers to PaStream objects are passed between PortAudio functions that 577 operate on streams. 578 579 @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream, 580 Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive, 581 Pa_GetStreamTime, Pa_GetStreamCpuLoad 582 583 */ 584 typedef void PaStream; 585 586 587 /** Can be passed as the framesPerBuffer parameter to Pa_OpenStream() 588 or Pa_OpenDefaultStream() to indicate that the stream callback will 589 accept buffers of any size. 590 */ 591 #define paFramesPerBufferUnspecified (0) 592 593 594 /** Flags used to control the behavior of a stream. They are passed as 595 parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be 596 ORed together. 597 598 @see Pa_OpenStream, Pa_OpenDefaultStream 599 @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput, 600 paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags 601 */ 602 typedef unsigned long PaStreamFlags; 603 604 /** @see PaStreamFlags */ 605 #define paNoFlag ((PaStreamFlags) 0) 606 607 /** Disable default clipping of out of range samples. 608 @see PaStreamFlags 609 */ 610 #define paClipOff ((PaStreamFlags) 0x00000001) 611 612 /** Disable default dithering. 613 @see PaStreamFlags 614 */ 615 #define paDitherOff ((PaStreamFlags) 0x00000002) 616 617 /** Flag requests that where possible a full duplex stream will not discard 618 overflowed input samples without calling the stream callback. This flag is 619 only valid for full duplex callback streams and only when used in combination 620 with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using 621 this flag incorrectly results in a paInvalidFlag error being returned from 622 Pa_OpenStream and Pa_OpenDefaultStream. 623 624 @see PaStreamFlags, paFramesPerBufferUnspecified 625 */ 626 #define paNeverDropInput ((PaStreamFlags) 0x00000004) 627 628 /** Call the stream callback to fill initial output buffers, rather than the 629 default behavior of priming the buffers with zeros (silence). This flag has 630 no effect for input-only and blocking read/write streams. 631 632 @see PaStreamFlags 633 */ 634 #define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008) 635 636 /** A mask specifying the platform specific bits. 637 @see PaStreamFlags 638 */ 639 #define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000) 640 641 /** 642 Timing information for the buffers passed to the stream callback. 643 644 Time values are expressed in seconds and are synchronised with the time base used by Pa_GetStreamTime() for the associated stream. 645 646 @see PaStreamCallback, Pa_GetStreamTime 647 */ 648 typedef struct PaStreamCallbackTimeInfo{ 649 PaTime inputBufferAdcTime; /**< The time when the first sample of the input buffer was captured at the ADC input */ 650 PaTime currentTime; /**< The time when the stream callback was invoked */ 651 PaTime outputBufferDacTime; /**< The time when the first sample of the output buffer will output the DAC */ 652 } PaStreamCallbackTimeInfo; 653 654 655 /** 656 Flag bit constants for the statusFlags to PaStreamCallback. 657 658 @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow, 659 paPrimingOutput 660 */ 661 typedef unsigned long PaStreamCallbackFlags; 662 663 /** In a stream opened with paFramesPerBufferUnspecified, indicates that 664 input data is all silence (zeros) because no real data is available. In a 665 stream opened without paFramesPerBufferUnspecified, it indicates that one or 666 more zero samples have been inserted into the input buffer to compensate 667 for an input underflow. 668 @see PaStreamCallbackFlags 669 */ 670 #define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001) 671 672 /** In a stream opened with paFramesPerBufferUnspecified, indicates that data 673 prior to the first sample of the input buffer was discarded due to an 674 overflow, possibly because the stream callback is using too much CPU time. 675 Otherwise indicates that data prior to one or more samples in the 676 input buffer was discarded. 677 @see PaStreamCallbackFlags 678 */ 679 #define paInputOverflow ((PaStreamCallbackFlags) 0x00000002) 680 681 /** Indicates that output data (or a gap) was inserted, possibly because the 682 stream callback is using too much CPU time. 683 @see PaStreamCallbackFlags 684 */ 685 #define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004) 686 687 /** Indicates that output data will be discarded because no room is available. 688 @see PaStreamCallbackFlags 689 */ 690 #define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008) 691 692 /** Some of all of the output data will be used to prime the stream, input 693 data may be zero. 694 @see PaStreamCallbackFlags 695 */ 696 #define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010) 697 698 /** 699 Allowable return values for the PaStreamCallback. 700 @see PaStreamCallback 701 */ 702 typedef enum PaStreamCallbackResult 703 { 704 paContinue=0, /**< Signal that the stream should continue invoking the callback and processing audio. */ 705 paComplete=1, /**< Signal that the stream should stop invoking the callback and finish once all output samples have played. */ 706 paAbort=2 /**< Signal that the stream should stop invoking the callback and finish as soon as possible. */ 707 } PaStreamCallbackResult; 708 709 710 /** 711 Functions of type PaStreamCallback are implemented by PortAudio clients. 712 They consume, process or generate audio in response to requests from an 713 active PortAudio stream. 714 715 When a stream is running, PortAudio calls the stream callback periodically. 716 The callback function is responsible for processing buffers of audio samples 717 passed via the input and output parameters. 718 719 The PortAudio stream callback runs at very high or real-time priority. 720 It is required to consistently meet its time deadlines. Do not allocate 721 memory, access the file system, call library functions or call other functions 722 from the stream callback that may block or take an unpredictable amount of 723 time to complete. 724 725 In order for a stream to maintain glitch-free operation the callback 726 must consume and return audio data faster than it is recorded and/or 727 played. PortAudio anticipates that each callback invocation may execute for 728 a duration approaching the duration of frameCount audio frames at the stream 729 sample rate. It is reasonable to expect to be able to utilise 70% or more of 730 the available CPU time in the PortAudio callback. However, due to buffer size 731 adaption and other factors, not all host APIs are able to guarantee audio 732 stability under heavy CPU load with arbitrary fixed callback buffer sizes. 733 When high callback CPU utilisation is required the most robust behavior 734 can be achieved by using paFramesPerBufferUnspecified as the 735 Pa_OpenStream() framesPerBuffer parameter. 736 737 @param input and @param output are either arrays of interleaved samples or; 738 if non-interleaved samples were requested using the paNonInterleaved sample 739 format flag, an array of buffer pointers, one non-interleaved buffer for 740 each channel. 741 742 The format, packing and number of channels used by the buffers are 743 determined by parameters to Pa_OpenStream(). 744 745 @param frameCount The number of sample frames to be processed by 746 the stream callback. 747 748 @param timeInfo Timestamps indicating the ADC capture time of the first sample 749 in the input buffer, the DAC output time of the first sample in the output buffer 750 and the time the callback was invoked. 751 See PaStreamCallbackTimeInfo and Pa_GetStreamTime() 752 753 @param statusFlags Flags indicating whether input and/or output buffers 754 have been inserted or will be dropped to overcome underflow or overflow 755 conditions. 756 757 @param userData The value of a user supplied pointer passed to 758 Pa_OpenStream() intended for storing synthesis data etc. 759 760 @return 761 The stream callback should return one of the values in the 762 ::PaStreamCallbackResult enumeration. To ensure that the callback continues 763 to be called, it should return paContinue (0). Either paComplete or paAbort 764 can be returned to finish stream processing, after either of these values is 765 returned the callback will not be called again. If paAbort is returned the 766 stream will finish as soon as possible. If paComplete is returned, the stream 767 will continue until all buffers generated by the callback have been played. 768 This may be useful in applications such as soundfile players where a specific 769 duration of output is required. However, it is not necessary to utilize this 770 mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also 771 be used to stop the stream. The callback must always fill the entire output 772 buffer irrespective of its return value. 773 774 @see Pa_OpenStream, Pa_OpenDefaultStream 775 776 @note With the exception of Pa_GetStreamCpuLoad() it is not permissible to call 777 PortAudio API functions from within the stream callback. 778 */ 779 typedef int PaStreamCallback( 780 const void *input, void *output, 781 unsigned long frameCount, 782 const PaStreamCallbackTimeInfo* timeInfo, 783 PaStreamCallbackFlags statusFlags, 784 void *userData ); 785 786 787 /** Opens a stream for either input, output or both. 788 789 @param stream The address of a PaStream pointer which will receive 790 a pointer to the newly opened stream. 791 792 @param inputParameters A structure that describes the input parameters used by 793 the opened stream. See PaStreamParameters for a description of these parameters. 794 inputParameters must be NULL for output-only streams. 795 796 @param outputParameters A structure that describes the output parameters used by 797 the opened stream. See PaStreamParameters for a description of these parameters. 798 outputParameters must be NULL for input-only streams. 799 800 @param sampleRate The desired sampleRate. For full-duplex streams it is the 801 sample rate for both input and output 802 803 @param framesPerBuffer The number of frames passed to the stream callback 804 function, or the preferred block granularity for a blocking read/write stream. 805 The special value paFramesPerBufferUnspecified (0) may be used to request that 806 the stream callback will receive an optimal (and possibly varying) number of 807 frames based on host requirements and the requested latency settings. 808 Note: With some host APIs, the use of non-zero framesPerBuffer for a callback 809 stream may introduce an additional layer of buffering which could introduce 810 additional latency. PortAudio guarantees that the additional latency 811 will be kept to the theoretical minimum however, it is strongly recommended 812 that a non-zero framesPerBuffer value only be used when your algorithm 813 requires a fixed number of frames per stream callback. 814 815 @param streamFlags Flags which modify the behavior of the streaming process. 816 This parameter may contain a combination of flags ORed together. Some flags may 817 only be relevant to certain buffer formats. 818 819 @param streamCallback A pointer to a client supplied function that is responsible 820 for processing and filling input and output buffers. If this parameter is NULL 821 the stream will be opened in 'blocking read/write' mode. In blocking mode, 822 the client can receive sample data using Pa_ReadStream and write sample data 823 using Pa_WriteStream, the number of samples that may be read or written 824 without blocking is returned by Pa_GetStreamReadAvailable and 825 Pa_GetStreamWriteAvailable respectively. 826 827 @param userData A client supplied pointer which is passed to the stream callback 828 function. It could for example, contain a pointer to instance data necessary 829 for processing the audio buffers. This parameter is ignored if streamCallback 830 is NULL. 831 832 @return 833 Upon success Pa_OpenStream() returns paNoError and places a pointer to a 834 valid PaStream in the stream argument. The stream is inactive (stopped). 835 If a call to Pa_OpenStream() fails, a non-zero error code is returned (see 836 PaError for possible error codes) and the value of stream is invalid. 837 838 @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream, 839 Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable 840 */ 841 PaError Pa_OpenStream( PaStream** stream, 842 const PaStreamParameters *inputParameters, 843 const PaStreamParameters *outputParameters, 844 double sampleRate, 845 unsigned long framesPerBuffer, 846 PaStreamFlags streamFlags, 847 PaStreamCallback *streamCallback, 848 void *userData ); 849 850 851 /** A simplified version of Pa_OpenStream() that opens the default input 852 and/or output devices. 853 854 @param stream The address of a PaStream pointer which will receive 855 a pointer to the newly opened stream. 856 857 @param numInputChannels The number of channels of sound that will be supplied 858 to the stream callback or returned by Pa_ReadStream. It can range from 1 to 859 the value of maxInputChannels in the PaDeviceInfo record for the default input 860 device. If 0 the stream is opened as an output-only stream. 861 862 @param numOutputChannels The number of channels of sound to be delivered to the 863 stream callback or passed to Pa_WriteStream. It can range from 1 to the value 864 of maxOutputChannels in the PaDeviceInfo record for the default output device. 865 If 0 the stream is opened as an output-only stream. 866 867 @param sampleFormat The sample format of both the input and output buffers 868 provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. 869 sampleFormat may be any of the formats described by the PaSampleFormat 870 enumeration. 871 872 @param sampleRate Same as Pa_OpenStream parameter of the same name. 873 @param framesPerBuffer Same as Pa_OpenStream parameter of the same name. 874 @param streamCallback Same as Pa_OpenStream parameter of the same name. 875 @param userData Same as Pa_OpenStream parameter of the same name. 876 877 @return As for Pa_OpenStream 878 879 @see Pa_OpenStream, PaStreamCallback 880 */ 881 PaError Pa_OpenDefaultStream( PaStream** stream, 882 int numInputChannels, 883 int numOutputChannels, 884 PaSampleFormat sampleFormat, 885 double sampleRate, 886 unsigned long framesPerBuffer, 887 PaStreamCallback *streamCallback, 888 void *userData ); 889 890 891 /** Closes an audio stream. If the audio stream is active it 892 discards any pending buffers as if Pa_AbortStream() had been called. 893 */ 894 PaError Pa_CloseStream( PaStream *stream ); 895 896 897 /** Functions of type PaStreamFinishedCallback are implemented by PortAudio 898 clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback 899 function. Once registered they are called when the stream becomes inactive 900 (ie once a call to Pa_StopStream() will not block). 901 A stream will become inactive after the stream callback returns non-zero, 902 or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio 903 output, if the stream callback returns paComplete, or Pa_StopStream is called, 904 the stream finished callback will not be called until all generated sample data 905 has been played. 906 907 @param userData The userData parameter supplied to Pa_OpenStream() 908 909 @see Pa_SetStreamFinishedCallback 910 */ 911 typedef void PaStreamFinishedCallback( void *userData ); 912 913 914 /** Register a stream finished callback function which will be called when the 915 stream becomes inactive. See the description of PaStreamFinishedCallback for 916 further details about when the callback will be called. 917 918 @param stream a pointer to a PaStream that is in the stopped state - if the 919 stream is not stopped, the stream's finished callback will remain unchanged 920 and an error code will be returned. 921 922 @param streamFinishedCallback a pointer to a function with the same signature 923 as PaStreamFinishedCallback, that will be called when the stream becomes 924 inactive. Passing NULL for this parameter will un-register a previously 925 registered stream finished callback function. 926 927 @return on success returns paNoError, otherwise an error code indicating the cause 928 of the error. 929 930 @see PaStreamFinishedCallback 931 */ 932 PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback ); 933 934 935 /** Commences audio processing. 936 */ 937 PaError Pa_StartStream( PaStream *stream ); 938 939 940 /** Terminates audio processing. It waits until all pending 941 audio buffers have been played before it returns. 942 */ 943 PaError Pa_StopStream( PaStream *stream ); 944 945 946 /** Terminates audio processing immediately without waiting for pending 947 buffers to complete. 948 */ 949 PaError Pa_AbortStream( PaStream *stream ); 950 951 952 /** Determine whether the stream is stopped. 953 A stream is considered to be stopped prior to a successful call to 954 Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. 955 If a stream callback returns a value other than paContinue the stream is NOT 956 considered to be stopped. 957 958 @return Returns one (1) when the stream is stopped, zero (0) when 959 the stream is running or, a PaErrorCode (which are always negative) if 960 PortAudio is not initialized or an error is encountered. 961 962 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive 963 */ 964 PaError Pa_IsStreamStopped( PaStream *stream ); 965 966 967 /** Determine whether the stream is active. 968 A stream is active after a successful call to Pa_StartStream(), until it 969 becomes inactive either as a result of a call to Pa_StopStream() or 970 Pa_AbortStream(), or as a result of a return value other than paContinue from 971 the stream callback. In the latter case, the stream is considered inactive 972 after the last buffer has finished playing. 973 974 @return Returns one (1) when the stream is active (ie playing or recording 975 audio), zero (0) when not playing or, a PaErrorCode (which are always negative) 976 if PortAudio is not initialized or an error is encountered. 977 978 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped 979 */ 980 PaError Pa_IsStreamActive( PaStream *stream ); 981 982 983 984 /** A structure containing unchanging information about an open stream. 985 @see Pa_GetStreamInfo 986 */ 987 988 typedef struct PaStreamInfo 989 { 990 /** this is struct version 1 */ 991 int structVersion; 992 993 /** The input latency of the stream in seconds. This value provides the most 994 accurate estimate of input latency available to the implementation. It may 995 differ significantly from the suggestedLatency value passed to Pa_OpenStream(). 996 The value of this field will be zero (0.) for output-only streams. 997 @see PaTime 998 */ 999 PaTime inputLatency; 1000 1001 /** The output latency of the stream in seconds. This value provides the most 1002 accurate estimate of output latency available to the implementation. It may 1003 differ significantly from the suggestedLatency value passed to Pa_OpenStream(). 1004 The value of this field will be zero (0.) for input-only streams. 1005 @see PaTime 1006 */ 1007 PaTime outputLatency; 1008 1009 /** The sample rate of the stream in Hertz (samples per second). In cases 1010 where the hardware sample rate is inaccurate and PortAudio is aware of it, 1011 the value of this field may be different from the sampleRate parameter 1012 passed to Pa_OpenStream(). If information about the actual hardware sample 1013 rate is not available, this field will have the same value as the sampleRate 1014 parameter passed to Pa_OpenStream(). 1015 */ 1016 double sampleRate; 1017 1018 } PaStreamInfo; 1019 1020 1021 /** Retrieve a pointer to a PaStreamInfo structure containing information 1022 about the specified stream. 1023 @return A pointer to an immutable PaStreamInfo structure. If the stream 1024 parameter invalid, or an error is encountered, the function returns NULL. 1025 1026 @param stream A pointer to an open stream previously created with Pa_OpenStream. 1027 1028 @note PortAudio manages the memory referenced by the returned pointer, 1029 the client must not manipulate or free the memory. The pointer is only 1030 guaranteed to be valid until the specified stream is closed. 1031 1032 @see PaStreamInfo 1033 */ 1034 const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream ); 1035 1036 1037 /** Returns the current time in seconds for a stream according to the same clock used 1038 to generate callback PaStreamCallbackTimeInfo timestamps. The time values are 1039 monotonically increasing and have unspecified origin. 1040 1041 Pa_GetStreamTime returns valid time values for the entire life of the stream, 1042 from when the stream is opened until it is closed. Starting and stopping the stream 1043 does not affect the passage of time returned by Pa_GetStreamTime. 1044 1045 This time may be used for synchronizing other events to the audio stream, for 1046 example synchronizing audio to MIDI. 1047 1048 @return The stream's current time in seconds, or 0 if an error occurred. 1049 1050 @see PaTime, PaStreamCallback, PaStreamCallbackTimeInfo 1051 */ 1052 PaTime Pa_GetStreamTime( PaStream *stream ); 1053 1054 1055 /** Retrieve CPU usage information for the specified stream. 1056 The "CPU Load" is a fraction of total CPU time consumed by a callback stream's 1057 audio processing routines including, but not limited to the client supplied 1058 stream callback. This function does not work with blocking read/write streams. 1059 1060 This function may be called from the stream callback function or the 1061 application. 1062 1063 @return 1064 A floating point value, typically between 0.0 and 1.0, where 1.0 indicates 1065 that the stream callback is consuming the maximum number of CPU cycles possible 1066 to maintain real-time operation. A value of 0.5 would imply that PortAudio and 1067 the stream callback was consuming roughly 50% of the available CPU time. The 1068 return value may exceed 1.0. A value of 0.0 will always be returned for a 1069 blocking read/write stream, or if an error occurs. 1070 */ 1071 double Pa_GetStreamCpuLoad( PaStream* stream ); 1072 1073 1074 /** Read samples from an input stream. The function doesn't return until 1075 the entire buffer has been filled - this may involve waiting for the operating 1076 system to supply the data. 1077 1078 @param stream A pointer to an open stream previously created with Pa_OpenStream. 1079 1080 @param buffer A pointer to a buffer of sample frames. The buffer contains 1081 samples in the format specified by the inputParameters->sampleFormat field 1082 used to open the stream, and the number of channels specified by 1083 inputParameters->numChannels. If non-interleaved samples were requested using 1084 the paNonInterleaved sample format flag, buffer is a pointer to the first element 1085 of an array of buffer pointers, one non-interleaved buffer for each channel. 1086 1087 @param frames The number of frames to be read into buffer. This parameter 1088 is not constrained to a specific range, however high performance applications 1089 will want to match this parameter to the framesPerBuffer parameter used 1090 when opening the stream. 1091 1092 @return On success PaNoError will be returned, or PaInputOverflowed if input 1093 data was discarded by PortAudio after the previous call and before this call. 1094 */ 1095 PaError Pa_ReadStream( PaStream* stream, 1096 void *buffer, 1097 unsigned long frames ); 1098 1099 1100 /** Write samples to an output stream. This function doesn't return until the 1101 entire buffer has been consumed - this may involve waiting for the operating 1102 system to consume the data. 1103 1104 @param stream A pointer to an open stream previously created with Pa_OpenStream. 1105 1106 @param buffer A pointer to a buffer of sample frames. The buffer contains 1107 samples in the format specified by the outputParameters->sampleFormat field 1108 used to open the stream, and the number of channels specified by 1109 outputParameters->numChannels. If non-interleaved samples were requested using 1110 the paNonInterleaved sample format flag, buffer is a pointer to the first element 1111 of an array of buffer pointers, one non-interleaved buffer for each channel. 1112 1113 @param frames The number of frames to be written from buffer. This parameter 1114 is not constrained to a specific range, however high performance applications 1115 will want to match this parameter to the framesPerBuffer parameter used 1116 when opening the stream. 1117 1118 @return On success PaNoError will be returned, or paOutputUnderflowed if 1119 additional output data was inserted after the previous call and before this 1120 call. 1121 */ 1122 PaError Pa_WriteStream( PaStream* stream, 1123 const void *buffer, 1124 unsigned long frames ); 1125 1126 1127 /** Retrieve the number of frames that can be read from the stream without 1128 waiting. 1129 1130 @return Returns a non-negative value representing the maximum number of frames 1131 that can be read from the stream without blocking or busy waiting or, a 1132 PaErrorCode (which are always negative) if PortAudio is not initialized or an 1133 error is encountered. 1134 */ 1135 signed long Pa_GetStreamReadAvailable( PaStream* stream ); 1136 1137 1138 /** Retrieve the number of frames that can be written to the stream without 1139 waiting. 1140 1141 @return Returns a non-negative value representing the maximum number of frames 1142 that can be written to the stream without blocking or busy waiting or, a 1143 PaErrorCode (which are always negative) if PortAudio is not initialized or an 1144 error is encountered. 1145 */ 1146 signed long Pa_GetStreamWriteAvailable( PaStream* stream ); 1147 1148 1149 /* Miscellaneous utilities */ 1150 1151 1152 /** Retrieve the size of a given sample format in bytes. 1153 1154 @return The size in bytes of a single sample in the specified format, 1155 or paSampleFormatNotSupported if the format is not supported. 1156 */ 1157 PaError Pa_GetSampleSize( PaSampleFormat format ); 1158 1159 1160 /** Put the caller to sleep for at least 'msec' milliseconds. This function is 1161 provided only as a convenience for authors of portable code (such as the tests 1162 and examples in the PortAudio distribution.) 1163 1164 The function may sleep longer than requested so don't rely on this for accurate 1165 musical timing. 1166 */ 1167 void Pa_Sleep( long msec ); 1168 1169 1170 1171 #ifdef __cplusplus 1172 } 1173 #endif /* __cplusplus */ 1174 #endif /* PORTAUDIO_H */ 1175