1 2 #ifndef PORTAUDIO_H 3 #define PORTAUDIO_H 4 /* 5 * $Id: portaudio.h,v 1.1 2006/06/10 21:30:51 dmazzoni Exp $ 6 * PortAudio Portable Real-Time Audio Library 7 * PortAudio API Header File 8 * Latest version available at: http://www.portaudio.com/ 9 * 10 * Copyright (c) 1999-2002 Ross Bencina and Phil Burk 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining 13 * a copy of this software and associated documentation files 14 * (the "Software"), to deal in the Software without restriction, 15 * including without limitation the rights to use, copy, modify, merge, 16 * publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, 18 * subject to the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be 21 * included in all copies or substantial portions of the Software. 22 * 23 * Any person wishing to distribute modifications to the Software is 24 * requested to send the modifications to the original developer so that 25 * they can be incorporated into the canonical version. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 28 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 29 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 30 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 31 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 32 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 33 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 34 */ 35 36 /** @file 37 @brief The PortAudio API. 38 */ 39 40 41 #ifdef __cplusplus 42 extern "C" 43 { 44 #endif /* __cplusplus */ 45 46 47 /** Retrieve the release number of the currently running PortAudio build, 48 eg 1900. 49 */ 50 int Pa_GetVersion( void ); 51 52 53 /** Retrieve a textual description of the current PortAudio build, 54 eg "PortAudio V19-devel 13 October 2002". 55 */ 56 const char* Pa_GetVersionText( void ); 57 58 59 /** Error codes returned by PortAudio functions. 60 Note that with the exception of paNoError, all PaErrorCodes are negative. 61 */ 62 63 typedef int PaError; 64 typedef enum PaErrorCode 65 { 66 paNoError = 0, 67 68 paNotInitialized = -10000, 69 paUnanticipatedHostError, 70 paInvalidChannelCount, 71 paInvalidSampleRate, 72 paInvalidDevice, 73 paInvalidFlag, 74 paSampleFormatNotSupported, 75 paBadIODeviceCombination, 76 paInsufficientMemory, 77 paBufferTooBig, 78 paBufferTooSmall, 79 paNullCallback, 80 paBadStreamPtr, 81 paTimedOut, 82 paInternalError, 83 paDeviceUnavailable, 84 paIncompatibleHostApiSpecificStreamInfo, 85 paStreamIsStopped, 86 paStreamIsNotStopped, 87 paInputOverflowed, 88 paOutputUnderflowed, 89 paHostApiNotFound, 90 paInvalidHostApi, 91 paCanNotReadFromACallbackStream, /**< @todo review error code name */ 92 paCanNotWriteToACallbackStream, /**< @todo review error code name */ 93 paCanNotReadFromAnOutputOnlyStream, /**< @todo review error code name */ 94 paCanNotWriteToAnInputOnlyStream, /**< @todo review error code name */ 95 paIncompatibleStreamHostApi, 96 paBadBufferPtr 97 } PaErrorCode; 98 99 100 /** Translate the supplied PortAudio error code into a human readable 101 message. 102 */ 103 const char *Pa_GetErrorText( PaError errorCode ); 104 105 106 /** Library initialization function - call this before using PortAudio. 107 This function initialises internal data structures and prepares underlying 108 host APIs for use. This function MUST be called before using any other 109 PortAudio API functions. 110 111 If Pa_Initialize() is called multiple times, each successful 112 call must be matched with a corresponding call to Pa_Terminate(). 113 Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not 114 required to be fully nested. 115 116 Note that if Pa_Initialize() returns an error code, Pa_Terminate() should 117 NOT be called. 118 119 @return paNoError if successful, otherwise an error code indicating the cause 120 of failure. 121 122 @see Pa_Terminate 123 */ 124 PaError Pa_Initialize( void ); 125 126 127 /** Library termination function - call this when finished using PortAudio. 128 This function deallocates all resources allocated by PortAudio since it was 129 initializied by a call to Pa_Initialize(). In cases where Pa_Initialise() has 130 been called multiple times, each call must be matched with a corresponding call 131 to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically 132 close any PortAudio streams that are still open. 133 134 Pa_Terminate() MUST be called before exiting a program which uses PortAudio. 135 Failure to do so may result in serious resource leaks, such as audio devices 136 not being available until the next reboot. 137 138 @return paNoError if successful, otherwise an error code indicating the cause 139 of failure. 140 141 @see Pa_Initialize 142 */ 143 PaError Pa_Terminate( void ); 144 145 146 147 /** The type used to refer to audio devices. Values of this type usually 148 range from 0 to (Pa_DeviceCount-1), and may also take on the PaNoDevice 149 and paUseHostApiSpecificDeviceSpecification values. 150 151 @see Pa_DeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification 152 */ 153 typedef int PaDeviceIndex; 154 155 156 /** A special PaDeviceIndex value indicating that no device is available, 157 or should be used. 158 159 @see PaDeviceIndex 160 */ 161 #define paNoDevice ((PaDeviceIndex)-1) 162 163 164 /** A special PaDeviceIndex value indicating that the device(s) to be used 165 are specified in the host api specific stream info structure. 166 167 @see PaDeviceIndex 168 */ 169 #define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2) 170 171 172 /* Host API enumeration mechanism */ 173 174 /** The type used to enumerate to host APIs at runtime. Values of this type 175 range from 0 to (Pa_GetHostApiCount()-1). 176 177 @see Pa_GetHostApiCount 178 */ 179 typedef int PaHostApiIndex; 180 181 182 /** Retrieve the number of available host APIs. Even if a host API is 183 available it may have no devices available. 184 185 @return A non-negative value indicating the number of available host APIs 186 or, a PaErrorCode (which are always negative) if PortAudio is not initialized 187 or an error is encountered. 188 189 @see PaHostApiIndex 190 */ 191 PaHostApiIndex Pa_GetHostApiCount( void ); 192 193 194 /** Retrieve the index of the default host API. The default host API will be 195 the lowest common denominator host API on the current platform and is 196 unlikely to provide the best performance. 197 198 @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1) 199 indicating the default host API index or, a PaErrorCode (which are always 200 negative) if PortAudio is not initialized or an error is encountered. 201 */ 202 PaHostApiIndex Pa_GetDefaultHostApi( void ); 203 204 205 /** Unchanging unique identifiers for each supported host API. This type 206 is used in the PaHostApiInfo structure. The values are guaranteed to be 207 unique and to never change, thus allowing code to be written that 208 conditionally uses host API specific extensions. 209 210 New type ids will be allocated when support for a host API reaches 211 "public alpha" status, prior to that developers should use the 212 paInDevelopment type id. 213 214 @see PaHostApiInfo 215 */ 216 typedef enum PaHostApiTypeId 217 { 218 paInDevelopment=0, /* use while developing support for a new host API */ 219 paDirectSound=1, 220 paMME=2, 221 paASIO=3, 222 paSoundManager=4, 223 paCoreAudio=5, 224 paOSS=7, 225 paALSA=8, 226 paAL=9, 227 paBeOS=10, 228 paWDMKS=11, 229 paJACK=12, 230 paWASAPI=13 231 } PaHostApiTypeId; 232 233 234 /** A structure containing information about a particular host API. */ 235 236 typedef struct PaHostApiInfo 237 { 238 /** this is struct version 1 */ 239 int structVersion; 240 /** The well known unique identifier of this host API @see PaHostApiTypeId */ 241 PaHostApiTypeId type; 242 /** A textual description of the host API for display on user interfaces. */ 243 const char *name; 244 245 /** The number of devices belonging to this host API. This field may be 246 used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate 247 all devices for this host API. 248 @see Pa_HostApiDeviceIndexToDeviceIndex 249 */ 250 int deviceCount; 251 252 /** The default input device for this host API. The value will be a 253 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice 254 if no default input device is available. 255 */ 256 PaDeviceIndex defaultInputDevice; 257 258 /** The default output device for this host API. The value will be a 259 device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice 260 if no default output device is available. 261 */ 262 PaDeviceIndex defaultOutputDevice; 263 264 } PaHostApiInfo; 265 266 267 /** Retrieve a pointer to a structure containing information about a specific 268 host Api. 269 270 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) 271 272 @return A pointer to an immutable PaHostApiInfo structure describing 273 a specific host API. If the hostApi parameter is out of range or an error 274 is encountered, the function returns NULL. 275 276 The returned structure is owned by the PortAudio implementation and must not 277 be manipulated or freed. The pointer is only guaranteed to be valid between 278 calls to Pa_Initialize() and Pa_Terminate(). 279 */ 280 const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi ); 281 282 283 /** Convert a static host API unique identifier, into a runtime 284 host API index. 285 286 @param type A unique host API identifier belonging to the PaHostApiTypeId 287 enumeration. 288 289 @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or, 290 a PaErrorCode (which are always negative) if PortAudio is not initialized 291 or an error is encountered. 292 293 The paHostApiNotFound error code indicates that the host API specified by the 294 type parameter is not available. 295 296 @see PaHostApiTypeId 297 */ 298 PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type ); 299 300 301 /** Convert a host-API-specific device index to standard PortAudio device index. 302 This function may be used in conjunction with the deviceCount field of 303 PaHostApiInfo to enumerate all devices for the specified host API. 304 305 @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) 306 307 @param hostApiDeviceIndex A valid per-host device index in the range 308 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) 309 310 @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1) 311 or, a PaErrorCode (which are always negative) if PortAudio is not initialized 312 or an error is encountered. 313 314 A paInvalidHostApi error code indicates that the host API index specified by 315 the hostApi parameter is out of range. 316 317 A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter 318 is out of range. 319 320 @see PaHostApiInfo 321 */ 322 PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi, 323 int hostApiDeviceIndex ); 324 325 326 327 /** Structure used to return information about a host error condition. 328 */ 329 typedef struct PaHostErrorInfo{ 330 PaHostApiTypeId hostApiType; /**< the host API which returned the error code */ 331 long errorCode; /**< the error code returned */ 332 const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */ 333 }PaHostErrorInfo; 334 335 336 /** Return information about the last host error encountered. The error 337 information returned by Pa_GetLastHostErrorInfo() will never be modified 338 asyncronously by errors occurring in other PortAudio owned threads 339 (such as the thread that manages the stream callback.) 340 341 This function is provided as a last resort, primarily to enhance debugging 342 by providing clients with access to all available error information. 343 344 @return A pointer to an immutable structure constaining information about 345 the host error. The values in this structure will only be valid if a 346 PortAudio function has previously returned the paUnanticipatedHostError 347 error code. 348 */ 349 const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void ); 350 351 352 353 /* Device enumeration and capabilities */ 354 355 /** Retrieve the number of available devices. The number of available devices 356 may be zero. 357 358 @return A non-negative value indicating the number of available devices or, 359 a PaErrorCode (which are always negative) if PortAudio is not initialized 360 or an error is encountered. 361 */ 362 PaDeviceIndex Pa_GetDeviceCount( void ); 363 364 365 /** Retrieve the index of the default input device. The result can be 366 used in the inputDevice parameter to Pa_OpenStream(). 367 368 @return The default input device index for the default host API, or paNoDevice 369 if no default input device is available or an error was encountered. 370 */ 371 PaDeviceIndex Pa_GetDefaultInputDevice( void ); 372 373 374 /** Retrieve the index of the default output device. The result can be 375 used in the outputDevice parameter to Pa_OpenStream(). 376 377 @return The default output device index for the defualt host API, or paNoDevice 378 if no default output device is available or an error was encountered. 379 380 @note 381 On the PC, the user can specify a default device by 382 setting an environment variable. For example, to use device #1. 383 <pre> 384 set PA_RECOMMENDED_OUTPUT_DEVICE=1 385 </pre> 386 The user should first determine the available device ids by using 387 the supplied application "pa_devs". 388 */ 389 PaDeviceIndex Pa_GetDefaultOutputDevice( void ); 390 391 392 /** The type used to represent monotonic time in seconds that can be used 393 for syncronisation. The type is used for the outTime argument to the 394 PaStreamCallback and as the result of Pa_GetStreamTime(). 395 396 @see PaStreamCallback, Pa_GetStreamTime 397 */ 398 typedef double PaTime; 399 400 401 /** A type used to specify one or more sample formats. Each value indicates 402 a possible format for sound data passed to and from the stream callback, 403 Pa_ReadStream and Pa_WriteStream. 404 405 The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8 406 and aUInt8 are usually implemented by all implementations. 407 408 The floating point representation (paFloat32) uses +1.0 and -1.0 as the 409 maximum and minimum respectively. 410 411 paUInt8 is an unsigned 8 bit format where 128 is considered "ground" 412 413 The paNonInterleaved flag indicates that a multichannel buffer is passed 414 as a set of non-interleaved pointers. 415 416 @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo 417 @see paFloat32, paInt16, paInt32, paInt24, paInt8 418 @see paUInt8, paCustomFormat, paNonInterleaved 419 */ 420 typedef unsigned long PaSampleFormat; 421 422 423 #define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */ 424 #define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */ 425 #define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */ 426 #define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */ 427 #define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */ 428 #define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */ 429 #define paCustomFormat ((PaSampleFormat) 0x00010000)/**< @see PaSampleFormat */ 430 431 #define paNonInterleaved ((PaSampleFormat) 0x80000000) 432 433 /** A structure providing information and capabilities of PortAudio devices. 434 Devices may support input, output or both input and output. 435 */ 436 typedef struct PaDeviceInfo 437 { 438 int structVersion; /* this is struct version 2 */ 439 const char *name; 440 PaHostApiIndex hostApi; /* note this is a host API index, not a type id*/ 441 442 int maxInputChannels; 443 int maxOutputChannels; 444 445 /* Default latency values for interactive performance. */ 446 PaTime defaultLowInputLatency; 447 PaTime defaultLowOutputLatency; 448 /* Default latency values for robust non-interactive applications (eg. playing sound files). */ 449 PaTime defaultHighInputLatency; 450 PaTime defaultHighOutputLatency; 451 452 double defaultSampleRate; 453 } PaDeviceInfo; 454 455 456 /** Retrieve a pointer to a PaDeviceInfo structure containing information 457 about the specified device. 458 @return A pointer to an immutable PaDeviceInfo structure. If the device 459 parameter is out of range the function returns NULL. 460 461 @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1) 462 463 @note PortAudio manages the memory referenced by the returned pointer, 464 the client must not manipulate or free the memory. The pointer is only 465 guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate(). 466 467 @see PaDeviceInfo, PaDeviceIndex 468 */ 469 const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device ); 470 471 472 /** Parameters for one direction (input or output) of a stream. 473 */ 474 typedef struct PaStreamParameters 475 { 476 /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1) 477 specifying the device to be used or the special constant 478 paUseHostApiSpecificDeviceSpecification which indicates that the actual 479 device(s) to use are specified in hostApiSpecificStreamInfo. 480 This field must not be set to paNoDevice. 481 */ 482 PaDeviceIndex device; 483 484 /** The number of channels of sound to be delivered to the 485 stream callback or accessed by Pa_ReadStream() or Pa_WriteStream(). 486 It can range from 1 to the value of maxInputChannels in the 487 PaDeviceInfo record for the device specified by the device parameter. 488 */ 489 int channelCount; 490 491 /** The sample format of the buffer provided to the stream callback, 492 a_ReadStream() or Pa_WriteStream(). It may be any of the formats described 493 by the PaSampleFormat enumeration. 494 */ 495 PaSampleFormat sampleFormat; 496 497 /** The desired latency in seconds. Where practical, implementations should 498 configure their latency based on these parameters, otherwise they may 499 choose the closest viable latency instead. Unless the suggested latency 500 is greater than the absolute upper limit for the device implementations 501 should round the suggestedLatency up to the next practial value - ie to 502 provide an equal or higher latency than suggestedLatency wherever possibe. 503 Actual latency values for an open stream may be retrieved using the 504 inputLatency and outputLatency fields of the PaStreamInfo structure 505 returned by Pa_GetStreamInfo(). 506 @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo 507 */ 508 PaTime suggestedLatency; 509 510 /** An optional pointer to a host api specific data structure 511 containing additional information for device setup and/or stream processing. 512 hostApiSpecificStreamInfo is never required for correct operation, 513 if not used it should be set to NULL. 514 */ 515 void *hostApiSpecificStreamInfo; 516 517 } PaStreamParameters; 518 519 520 /** Return code for Pa_IsFormatSupported indicating success. */ 521 #define paFormatIsSupported (0) 522 523 /** Determine whether it would be possible to open a stream with the specified 524 parameters. 525 526 @param inputParameters A structure that describes the input parameters used to 527 open a stream. The suggestedLatency field is ignored. See PaStreamParameters 528 for a description of these parameters. inputParameters must be NULL for 529 output-only streams. 530 531 @param outputParameters A structure that describes the output parameters used 532 to open a stream. The suggestedLatency field is ignored. See PaStreamParameters 533 for a description of these parameters. outputParameters must be NULL for 534 input-only streams. 535 536 @param sampleRate The required sampleRate. For full-duplex streams it is the 537 sample rate for both input and output 538 539 @return Returns 0 if the format is supported, and an error code indicating why 540 the format is not supported otherwise. The constant paFormatIsSupported is 541 provided to compare with the return value for success. 542 543 @see paFormatIsSupported, PaStreamParameters 544 */ 545 PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters, 546 const PaStreamParameters *outputParameters, 547 double sampleRate ); 548 549 550 551 /* Streaming types and functions */ 552 553 554 /** 555 A single PaStream can provide multiple channels of real-time 556 streaming audio input and output to a client application. A stream 557 provides access to audio hardware represented by one or more 558 PaDevices. Depending on the underlying Host API, it may be possible 559 to open multiple streams using the same device, however this behavior 560 is implementation defined. Portable applications should assume that 561 a PaDevice may be simultaneously used by at most one PaStream. 562 563 Pointers to PaStream objects are passed between PortAudio functions that 564 operate on streams. 565 566 @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream, 567 Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive, 568 Pa_GetStreamTime, Pa_GetStreamCpuLoad 569 570 */ 571 typedef void PaStream; 572 573 574 /** Can be passed as the framesPerBuffer parameter to Pa_OpenStream() 575 or Pa_OpenDefaultStream() to indicate that the stream callback will 576 accept buffers of any size. 577 */ 578 #define paFramesPerBufferUnspecified (0) 579 580 581 /** Flags used to control the behavior of a stream. They are passed as 582 parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be 583 ORed together. 584 585 @see Pa_OpenStream, Pa_OpenDefaultStream 586 @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput, 587 paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags 588 */ 589 typedef unsigned long PaStreamFlags; 590 591 /** @see PaStreamFlags */ 592 #define paNoFlag ((PaStreamFlags) 0) 593 594 /** Disable default clipping of out of range samples. 595 @see PaStreamFlags 596 */ 597 #define paClipOff ((PaStreamFlags) 0x00000001) 598 599 /** Disable default dithering. 600 @see PaStreamFlags 601 */ 602 #define paDitherOff ((PaStreamFlags) 0x00000002) 603 604 /** Flag requests that where possible a full duplex stream will not discard 605 overflowed input samples without calling the stream callback. This flag is 606 only valid for full duplex callback streams and only when used in combination 607 with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using 608 this flag incorrectly results in a paInvalidFlag error being returned from 609 Pa_OpenStream and Pa_OpenDefaultStream. 610 611 @see PaStreamFlags, paFramesPerBufferUnspecified 612 */ 613 #define paNeverDropInput ((PaStreamFlags) 0x00000004) 614 615 /** Call the stream callback to fill initial output buffers, rather than the 616 default behavior of priming the buffers with zeros (silence). This flag has 617 no effect for input-only and blocking read/write streams. 618 619 @see PaStreamFlags 620 */ 621 #define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008) 622 623 /** A mask specifying the platform specific bits. 624 @see PaStreamFlags 625 */ 626 #define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000) 627 628 /** 629 Timing information for the buffers passed to the stream callback. 630 */ 631 typedef struct PaStreamCallbackTimeInfo{ 632 PaTime inputBufferAdcTime; 633 PaTime currentTime; 634 PaTime outputBufferDacTime; 635 } PaStreamCallbackTimeInfo; 636 637 638 /** 639 Flag bit constants for the statusFlags to PaStreamCallback. 640 641 @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow, 642 paPrimingOutput 643 */ 644 typedef unsigned long PaStreamCallbackFlags; 645 646 /** In a stream opened with paFramesPerBufferUnspecified, indicates that 647 input data is all silence (zeros) because no real data is available. In a 648 stream opened without paFramesPerBufferUnspecified, it indicates that one or 649 more zero samples have been inserted into the input buffer to compensate 650 for an input underflow. 651 @see PaStreamCallbackFlags 652 */ 653 #define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001) 654 655 /** In a stream opened with paFramesPerBufferUnspecified, indicates that data 656 prior to the first sample of the input buffer was discarded due to an 657 overflow, possibly because the stream callback is using too much CPU time. 658 Otherwise indicates that data prior to one or more samples in the 659 input buffer was discarded. 660 @see PaStreamCallbackFlags 661 */ 662 #define paInputOverflow ((PaStreamCallbackFlags) 0x00000002) 663 664 /** Indicates that output data (or a gap) was inserted, possibly because the 665 stream callback is using too much CPU time. 666 @see PaStreamCallbackFlags 667 */ 668 #define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004) 669 670 /** Indicates that output data will be discarded because no room is available. 671 @see PaStreamCallbackFlags 672 */ 673 #define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008) 674 675 /** Some of all of the output data will be used to prime the stream, input 676 data may be zero. 677 @see PaStreamCallbackFlags 678 */ 679 #define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010) 680 681 /** 682 Allowable return values for the PaStreamCallback. 683 @see PaStreamCallback 684 */ 685 typedef enum PaStreamCallbackResult 686 { 687 paContinue=0, 688 paComplete=1, 689 paAbort=2 690 } PaStreamCallbackResult; 691 692 693 /** 694 Functions of type PaStreamCallback are implemented by PortAudio clients. 695 They consume, process or generate audio in response to requests from an 696 active PortAudio stream. 697 698 @param input and @param output are arrays of interleaved samples, 699 the format, packing and number of channels used by the buffers are 700 determined by parameters to Pa_OpenStream(). 701 702 @param frameCount The number of sample frames to be processed by 703 the stream callback. 704 705 @param timeInfo The time in seconds when the first sample of the input 706 buffer was received at the audio input, the time in seconds when the first 707 sample of the output buffer will begin being played at the audio output, and 708 the time in seconds when the stream callback was called. 709 See also Pa_GetStreamTime() 710 711 @param statusFlags Flags indicating whether input and/or output buffers 712 have been inserted or will be dropped to overcome underflow or overflow 713 conditions. 714 715 @param userData The value of a user supplied pointer passed to 716 Pa_OpenStream() intended for storing synthesis data etc. 717 718 @return 719 The stream callback should return one of the values in the 720 PaStreamCallbackResult enumeration. To ensure that the callback continues 721 to be called, it should return paContinue (0). Either paComplete or paAbort 722 can be returned to finish stream processing, after either of these values is 723 returned the callback will not be called again. If paAbort is returned the 724 stream will finish as soon as possible. If paComplete is returned, the stream 725 will continue until all buffers generated by the callback have been played. 726 This may be useful in applications such as soundfile players where a specific 727 duration of output is required. However, it is not necessary to utilise this 728 mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also 729 be used to stop the stream. The callback must always fill the entire output 730 buffer irrespective of its return value. 731 732 @see Pa_OpenStream, Pa_OpenDefaultStream 733 734 @note With the exception of Pa_GetStreamCpuLoad() it is not permissable to call 735 PortAudio API functions from within the stream callback. 736 */ 737 typedef int PaStreamCallback( 738 const void *input, void *output, 739 unsigned long frameCount, 740 const PaStreamCallbackTimeInfo* timeInfo, 741 PaStreamCallbackFlags statusFlags, 742 void *userData ); 743 744 745 /** Opens a stream for either input, output or both. 746 747 @param stream The address of a PaStream pointer which will receive 748 a pointer to the newly opened stream. 749 750 @param inputParameters A structure that describes the input parameters used by 751 the opened stream. See PaStreamParameters for a description of these parameters. 752 inputParameters must be NULL for output-only streams. 753 754 @param outputParameters A structure that describes the output parameters used by 755 the opened stream. See PaStreamParameters for a description of these parameters. 756 outputParameters must be NULL for input-only streams. 757 758 @param sampleRate The desired sampleRate. For full-duplex streams it is the 759 sample rate for both input and output 760 761 @param framesPerBuffer The number of frames passed to the stream callback 762 function, or the preferred block granularity for a blocking read/write stream. 763 The special value paFramesPerBufferUnspecified (0) may be used to request that 764 the stream callback will recieve an optimal (and possibly varying) number of 765 frames based on host requirements and the requested latency settings. 766 Note: With some host APIs, the use of non-zero framesPerBuffer for a callback 767 stream may introduce an additional layer of buffering which could introduce 768 additional latency. PortAudio guarantees that the additional latency 769 will be kept to the theoretical minimum however, it is strongly recommended 770 that a non-zero framesPerBuffer value only be used when your algorithm 771 requires a fixed number of frames per stream callback. 772 773 @param streamFlags Flags which modify the behaviour of the streaming process. 774 This parameter may contain a combination of flags ORed together. Some flags may 775 only be relevant to certain buffer formats. 776 777 @param streamCallback A pointer to a client supplied function that is responsible 778 for processing and filling input and output buffers. If this parameter is NULL 779 the stream will be opened in 'blocking read/write' mode. In blocking mode, 780 the client can receive sample data using Pa_ReadStream and write sample data 781 using Pa_WriteStream, the number of samples that may be read or written 782 without blocking is returned by Pa_GetStreamReadAvailable and 783 Pa_GetStreamWriteAvailable respectively. 784 785 @param userData A client supplied pointer which is passed to the stream callback 786 function. It could for example, contain a pointer to instance data necessary 787 for processing the audio buffers. This parameter is ignored if streamCallback 788 is NULL. 789 790 @return 791 Upon success Pa_OpenStream() returns paNoError and places a pointer to a 792 valid PaStream in the stream argument. The stream is inactive (stopped). 793 If a call to Pa_OpenStream() fails, a non-zero error code is returned (see 794 PaError for possible error codes) and the value of stream is invalid. 795 796 @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream, 797 Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable 798 */ 799 PaError Pa_OpenStream( PaStream** stream, 800 const PaStreamParameters *inputParameters, 801 const PaStreamParameters *outputParameters, 802 double sampleRate, 803 unsigned long framesPerBuffer, 804 PaStreamFlags streamFlags, 805 PaStreamCallback *streamCallback, 806 void *userData ); 807 808 809 /** A simplified version of Pa_OpenStream() that opens the default input 810 and/or output devices. 811 812 @param stream The address of a PaStream pointer which will receive 813 a pointer to the newly opened stream. 814 815 @param numInputChannels The number of channels of sound that will be supplied 816 to the stream callback or returned by Pa_ReadStream. It can range from 1 to 817 the value of maxInputChannels in the PaDeviceInfo record for the default input 818 device. If 0 the stream is opened as an output-only stream. 819 820 @param numOutputChannels The number of channels of sound to be delivered to the 821 stream callback or passed to Pa_WriteStream. It can range from 1 to the value 822 of maxOutputChannels in the PaDeviceInfo record for the default output dvice. 823 If 0 the stream is opened as an output-only stream. 824 825 @param sampleFormat The sample format of both the input and output buffers 826 provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. 827 sampleFormat may be any of the formats described by the PaSampleFormat 828 enumeration. 829 830 @param sampleRate Same as Pa_OpenStream parameter of the same name. 831 @param framesPerBuffer Same as Pa_OpenStream parameter of the same name. 832 @param streamCallback Same as Pa_OpenStream parameter of the same name. 833 @param userData Same as Pa_OpenStream parameter of the same name. 834 835 @return As for Pa_OpenStream 836 837 @see Pa_OpenStream, PaStreamCallback 838 */ 839 PaError Pa_OpenDefaultStream( PaStream** stream, 840 int numInputChannels, 841 int numOutputChannels, 842 PaSampleFormat sampleFormat, 843 double sampleRate, 844 unsigned long framesPerBuffer, 845 PaStreamCallback *streamCallback, 846 void *userData ); 847 848 849 /** Closes an audio stream. If the audio stream is active it 850 discards any pending buffers as if Pa_AbortStream() had been called. 851 */ 852 PaError Pa_CloseStream( PaStream *stream ); 853 854 855 /** Functions of type PaStreamFinishedCallback are implemented by PortAudio 856 clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback 857 function. Once registered they are called when the stream becomes inactive 858 (ie once a call to Pa_StopStream() will not block). 859 A stream will become inactive after the stream callback returns non-zero, 860 or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio 861 output, if the stream callback returns paComplete, or Pa_StopStream is called, 862 the stream finished callback will not be called until all generated sample data 863 has been played. 864 865 @param userData The userData parameter supplied to Pa_OpenStream() 866 867 @see Pa_SetStreamFinishedCallback 868 */ 869 typedef void PaStreamFinishedCallback( void *userData ); 870 871 872 /** Register a stream finished callback function which will be called when the 873 stream becomes inactive. See the description of PaStreamFinishedCallback for 874 further details about when the callback will be called. 875 876 @param stream a pointer to a PaStream that is in the stopped state - if the 877 stream is not stopped, the stream's finished callback will remain unchanged 878 and an error code will be returned. 879 880 @param streamFinishedCallback a pointer to a function with the same signature 881 as PaStreamFinishedCallback, that will be called when the stream becomes 882 inactive. Passing NULL for this parameter will un-register a previously 883 registered stream finished callback function. 884 885 @return on success returns paNoError, otherwise an error code indicating the cause 886 of the error. 887 888 @see PaStreamFinishedCallback 889 */ 890 PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback ); 891 892 893 /** Commences audio processing. 894 */ 895 PaError Pa_StartStream( PaStream *stream ); 896 897 898 /** Terminates audio processing. It waits until all pending 899 audio buffers have been played before it returns. 900 */ 901 PaError Pa_StopStream( PaStream *stream ); 902 903 904 /** Terminates audio processing immediately without waiting for pending 905 buffers to complete. 906 */ 907 PaError Pa_AbortStream( PaStream *stream ); 908 909 910 /** Determine whether the stream is stopped. 911 A stream is considered to be stopped prior to a successful call to 912 Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. 913 If a stream callback returns a value other than paContinue the stream is NOT 914 considered to be stopped. 915 916 @return Returns one (1) when the stream is stopped, zero (0) when 917 the stream is running or, a PaErrorCode (which are always negative) if 918 PortAudio is not initialized or an error is encountered. 919 920 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive 921 */ 922 PaError Pa_IsStreamStopped( PaStream *stream ); 923 924 925 /** Determine whether the stream is active. 926 A stream is active after a successful call to Pa_StartStream(), until it 927 becomes inactive either as a result of a call to Pa_StopStream() or 928 Pa_AbortStream(), or as a result of a return value other than paContinue from 929 the stream callback. In the latter case, the stream is considered inactive 930 after the last buffer has finished playing. 931 932 @return Returns one (1) when the stream is active (ie playing or recording 933 audio), zero (0) when not playing or, a PaErrorCode (which are always negative) 934 if PortAudio is not initialized or an error is encountered. 935 936 @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped 937 */ 938 PaError Pa_IsStreamActive( PaStream *stream ); 939 940 941 942 /** A structure containing unchanging information about an open stream. 943 @see Pa_GetStreamInfo 944 */ 945 946 typedef struct PaStreamInfo 947 { 948 /** this is struct version 1 */ 949 int structVersion; 950 951 /** The input latency of the stream in seconds. This value provides the most 952 accurate estimate of input latency available to the implementation. It may 953 differ significantly from the suggestedLatency value passed to Pa_OpenStream(). 954 The value of this field will be zero (0.) for output-only streams. 955 @see PaTime 956 */ 957 PaTime inputLatency; 958 959 /** The output latency of the stream in seconds. This value provides the most 960 accurate estimate of output latency available to the implementation. It may 961 differ significantly from the suggestedLatency value passed to Pa_OpenStream(). 962 The value of this field will be zero (0.) for input-only streams. 963 @see PaTime 964 */ 965 PaTime outputLatency; 966 967 /** The sample rate of the stream in Hertz (samples per second). In cases 968 where the hardware sample rate is inaccurate and PortAudio is aware of it, 969 the value of this field may be different from the sampleRate parameter 970 passed to Pa_OpenStream(). If information about the actual hardware sample 971 rate is not available, this field will have the same value as the sampleRate 972 parameter passed to Pa_OpenStream(). 973 */ 974 double sampleRate; 975 976 } PaStreamInfo; 977 978 979 /** Retrieve a pointer to a PaStreamInfo structure containing information 980 about the specified stream. 981 @return A pointer to an immutable PaStreamInfo structure. If the stream 982 parameter invalid, or an error is encountered, the function returns NULL. 983 984 @param stream A pointer to an open stream previously created with Pa_OpenStream. 985 986 @note PortAudio manages the memory referenced by the returned pointer, 987 the client must not manipulate or free the memory. The pointer is only 988 guaranteed to be valid until the specified stream is closed. 989 990 @see PaStreamInfo 991 */ 992 const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream ); 993 994 995 /** Determine the current time for the stream according to the same clock used 996 to generate buffer timestamps. This time may be used for syncronising other 997 events to the audio stream, for example synchronizing audio to MIDI. 998 999 @return The stream's current time in seconds, or 0 if an error occurred. 1000 1001 @see PaTime, PaStreamCallback 1002 */ 1003 PaTime Pa_GetStreamTime( PaStream *stream ); 1004 1005 1006 /** Retrieve CPU usage information for the specified stream. 1007 The "CPU Load" is a fraction of total CPU time consumed by a callback stream's 1008 audio processing routines including, but not limited to the client supplied 1009 stream callback. This function does not work with blocking read/write streams. 1010 1011 This function may be called from the stream callback function or the 1012 application. 1013 1014 @return 1015 A floating point value, typically between 0.0 and 1.0, where 1.0 indicates 1016 that the stream callback is consuming the maximum number of CPU cycles possible 1017 to maintain real-time operation. A value of 0.5 would imply that PortAudio and 1018 the stream callback was consuming roughly 50% of the available CPU time. The 1019 return value may exceed 1.0. A value of 0.0 will always be returned for a 1020 blocking read/write stream, or if an error occurrs. 1021 */ 1022 double Pa_GetStreamCpuLoad( PaStream* stream ); 1023 1024 1025 /** Read samples from an input stream. The function doesn't return until 1026 the entire buffer has been filled - this may involve waiting for the operating 1027 system to supply the data. 1028 1029 @param stream A pointer to an open stream previously created with Pa_OpenStream. 1030 1031 @param buffer A pointer to a buffer of sample frames. The buffer contains 1032 samples in the format specified by the inputParameters->sampleFormat field 1033 used to open the stream, and the number of channels specified by 1034 inputParameters->numChannels. If non-interleaved samples were requested, 1035 buffer is a pointer to the first element of an array of non-interleaved 1036 buffer pointers, one for each channel. 1037 1038 @param frames The number of frames to be read into buffer. This parameter 1039 is not constrained to a specific range, however high performance applications 1040 will want to match this parameter to the framesPerBuffer parameter used 1041 when opening the stream. 1042 1043 @return On success PaNoError will be returned, or PaInputOverflowed if input 1044 data was discarded by PortAudio after the previous call and before this call. 1045 */ 1046 PaError Pa_ReadStream( PaStream* stream, 1047 void *buffer, 1048 unsigned long frames ); 1049 1050 1051 /** Write samples to an output stream. This function doesn't return until the 1052 entire buffer has been consumed - this may involve waiting for the operating 1053 system to consume the data. 1054 1055 @param stream A pointer to an open stream previously created with Pa_OpenStream. 1056 1057 @param buffer A pointer to a buffer of sample frames. The buffer contains 1058 samples in the format specified by the outputParameters->sampleFormat field 1059 used to open the stream, and the number of channels specified by 1060 outputParameters->numChannels. If non-interleaved samples were requested, 1061 buffer is a pointer to the first element of an array of non-interleaved 1062 buffer pointers, one for each channel. 1063 1064 @param frames The number of frames to be written from buffer. This parameter 1065 is not constrained to a specific range, however high performance applications 1066 will want to match this parameter to the framesPerBuffer parameter used 1067 when opening the stream. 1068 1069 @return On success PaNoError will be returned, or paOutputUnderflowed if 1070 additional output data was inserted after the previous call and before this 1071 call. 1072 */ 1073 PaError Pa_WriteStream( PaStream* stream, 1074 const void *buffer, 1075 unsigned long frames ); 1076 1077 1078 /** Retrieve the number of frames that can be read from the stream without 1079 waiting. 1080 1081 @return Returns a non-negative value representing the maximum number of frames 1082 that can be read from the stream without blocking or busy waiting or, a 1083 PaErrorCode (which are always negative) if PortAudio is not initialized or an 1084 error is encountered. 1085 */ 1086 signed long Pa_GetStreamReadAvailable( PaStream* stream ); 1087 1088 1089 /** Retrieve the number of frames that can be written to the stream without 1090 waiting. 1091 1092 @return Returns a non-negative value representing the maximum number of frames 1093 that can be written to the stream without blocking or busy waiting or, a 1094 PaErrorCode (which are always negative) if PortAudio is not initialized or an 1095 error is encountered. 1096 */ 1097 signed long Pa_GetStreamWriteAvailable( PaStream* stream ); 1098 1099 1100 /* Miscellaneous utilities */ 1101 1102 1103 /** Retrieve the size of a given sample format in bytes. 1104 1105 @return The size in bytes of a single sample in the specified format, 1106 or paSampleFormatNotSupported if the format is not supported. 1107 */ 1108 PaError Pa_GetSampleSize( PaSampleFormat format ); 1109 1110 1111 /** Put the caller to sleep for at least 'msec' milliseconds. This function is 1112 provided only as a convenience for authors of portable code (such as the tests 1113 and examples in the PortAudio distribution.) 1114 1115 The function may sleep longer than requested so don't rely on this for accurate 1116 musical timing. 1117 */ 1118 void Pa_Sleep( long msec ); 1119 1120 1121 1122 #ifdef __cplusplus 1123 } 1124 #endif /* __cplusplus */ 1125 #endif /* PORTAUDIO_H */ 1126