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 */ 1128