Add PortAudio libraries and headers
This commit is contained in:
Cameron Gutman
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#ifndef PORTAUDIO_H
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#define PORTAUDIO_H
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/*
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* $Id$
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* PortAudio Portable Real-Time Audio Library
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* PortAudio API Header File
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* Latest version available at: http://www.portaudio.com/
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*
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* Copyright (c) 1999-2002 Ross Bencina and Phil Burk
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files
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* (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
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* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* The text above constitutes the entire PortAudio license; however,
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* the PortAudio community also makes the following non-binding requests:
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*
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* Any person wishing to distribute modifications to the Software is
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* requested to send the modifications to the original developer so that
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* they can be incorporated into the canonical version. It is also
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* requested that these non-binding requests be included along with the
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* license above.
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*/
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/** @file
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@ingroup public_header
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@brief The portable PortAudio API.
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*/
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#ifdef __cplusplus
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extern "C"
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{
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#endif /* __cplusplus */
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/** Retrieve the release number of the currently running PortAudio build.
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For example, for version "19.5.1" this will return 0x00130501.
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@see paMakeVersionNumber
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*/
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int Pa_GetVersion( void );
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/** Retrieve a textual description of the current PortAudio build,
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e.g. "PortAudio V19.5.0-devel, revision 1952M".
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The format of the text may change in the future. Do not try to parse the
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returned string.
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@deprecated As of 19.5.0, use Pa_GetVersionInfo()->versionText instead.
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*/
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const char* Pa_GetVersionText( void );
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/**
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Generate a packed integer version number in the same format used
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by Pa_GetVersion(). Use this to compare a specified version number with
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the currently running version. For example:
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@code
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if( Pa_GetVersion() < paMakeVersionNumber(19,5,1) ) {}
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@endcode
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@see Pa_GetVersion, Pa_GetVersionInfo
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@version Available as of 19.5.0.
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*/
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#define paMakeVersionNumber(major, minor, subminor) \
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(((major)&0xFF)<<16 | ((minor)&0xFF)<<8 | ((subminor)&0xFF))
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/**
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A structure containing PortAudio API version information.
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@see Pa_GetVersionInfo, paMakeVersionNumber
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@version Available as of 19.5.0.
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*/
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typedef struct PaVersionInfo {
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int versionMajor;
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int versionMinor;
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int versionSubMinor;
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/**
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This is currently the Git revision hash but may change in the future.
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The versionControlRevision is updated by running a script before compiling the library.
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If the update does not occur, this value may refer to an earlier revision.
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*/
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const char *versionControlRevision;
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/** Version as a string, for example "PortAudio V19.5.0-devel, revision 1952M" */
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const char *versionText;
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} PaVersionInfo;
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/** Retrieve version information for the currently running PortAudio build.
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@return A pointer to an immutable PaVersionInfo structure.
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@note This function can be called at any time. It does not require PortAudio
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to be initialized. The structure pointed to is statically allocated. Do not
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attempt to free it or modify it.
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@see PaVersionInfo, paMakeVersionNumber
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@version Available as of 19.5.0.
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*/
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const PaVersionInfo* Pa_GetVersionInfo();
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/** Error codes returned by PortAudio functions.
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Note that with the exception of paNoError, all PaErrorCodes are negative.
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*/
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typedef int PaError;
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typedef enum PaErrorCode
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{
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paNoError = 0,
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paNotInitialized = -10000,
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paUnanticipatedHostError,
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paInvalidChannelCount,
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paInvalidSampleRate,
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paInvalidDevice,
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paInvalidFlag,
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paSampleFormatNotSupported,
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paBadIODeviceCombination,
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paInsufficientMemory,
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paBufferTooBig,
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paBufferTooSmall,
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paNullCallback,
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paBadStreamPtr,
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paTimedOut,
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paInternalError,
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paDeviceUnavailable,
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paIncompatibleHostApiSpecificStreamInfo,
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paStreamIsStopped,
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paStreamIsNotStopped,
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paInputOverflowed,
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paOutputUnderflowed,
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paHostApiNotFound,
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paInvalidHostApi,
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paCanNotReadFromACallbackStream,
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paCanNotWriteToACallbackStream,
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paCanNotReadFromAnOutputOnlyStream,
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paCanNotWriteToAnInputOnlyStream,
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paIncompatibleStreamHostApi,
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paBadBufferPtr
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} PaErrorCode;
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/** Translate the supplied PortAudio error code into a human readable
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message.
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*/
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const char *Pa_GetErrorText( PaError errorCode );
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/** Library initialization function - call this before using PortAudio.
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This function initializes internal data structures and prepares underlying
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host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(),
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and Pa_GetErrorText(), this function MUST be called before using any other
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PortAudio API functions.
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If Pa_Initialize() is called multiple times, each successful
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call must be matched with a corresponding call to Pa_Terminate().
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Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not
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required to be fully nested.
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Note that if Pa_Initialize() returns an error code, Pa_Terminate() should
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NOT be called.
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@return paNoError if successful, otherwise an error code indicating the cause
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of failure.
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@see Pa_Terminate
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*/
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PaError Pa_Initialize( void );
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/** Library termination function - call this when finished using PortAudio.
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This function deallocates all resources allocated by PortAudio since it was
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initialized by a call to Pa_Initialize(). In cases where Pa_Initialise() has
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been called multiple times, each call must be matched with a corresponding call
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to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically
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close any PortAudio streams that are still open.
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Pa_Terminate() MUST be called before exiting a program which uses PortAudio.
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Failure to do so may result in serious resource leaks, such as audio devices
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not being available until the next reboot.
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@return paNoError if successful, otherwise an error code indicating the cause
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of failure.
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@see Pa_Initialize
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*/
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PaError Pa_Terminate( void );
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/** The type used to refer to audio devices. Values of this type usually
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range from 0 to (Pa_GetDeviceCount()-1), and may also take on the PaNoDevice
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and paUseHostApiSpecificDeviceSpecification values.
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@see Pa_GetDeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification
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*/
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typedef int PaDeviceIndex;
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/** A special PaDeviceIndex value indicating that no device is available,
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or should be used.
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@see PaDeviceIndex
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*/
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#define paNoDevice ((PaDeviceIndex)-1)
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/** A special PaDeviceIndex value indicating that the device(s) to be used
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are specified in the host api specific stream info structure.
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@see PaDeviceIndex
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*/
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#define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2)
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/* Host API enumeration mechanism */
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/** The type used to enumerate to host APIs at runtime. Values of this type
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range from 0 to (Pa_GetHostApiCount()-1).
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@see Pa_GetHostApiCount
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*/
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typedef int PaHostApiIndex;
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/** Retrieve the number of available host APIs. Even if a host API is
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available it may have no devices available.
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@return A non-negative value indicating the number of available host APIs
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or, a PaErrorCode (which are always negative) if PortAudio is not initialized
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or an error is encountered.
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@see PaHostApiIndex
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*/
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PaHostApiIndex Pa_GetHostApiCount( void );
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/** Retrieve the index of the default host API. The default host API will be
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the lowest common denominator host API on the current platform and is
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unlikely to provide the best performance.
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@return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1)
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indicating the default host API index or, a PaErrorCode (which are always
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negative) if PortAudio is not initialized or an error is encountered.
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*/
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PaHostApiIndex Pa_GetDefaultHostApi( void );
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/** Unchanging unique identifiers for each supported host API. This type
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is used in the PaHostApiInfo structure. The values are guaranteed to be
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unique and to never change, thus allowing code to be written that
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conditionally uses host API specific extensions.
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New type ids will be allocated when support for a host API reaches
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"public alpha" status, prior to that developers should use the
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paInDevelopment type id.
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@see PaHostApiInfo
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*/
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typedef enum PaHostApiTypeId
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{
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paInDevelopment=0, /* use while developing support for a new host API */
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paDirectSound=1,
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paMME=2,
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paASIO=3,
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paSoundManager=4,
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paCoreAudio=5,
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paOSS=7,
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paALSA=8,
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paAL=9,
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paBeOS=10,
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paWDMKS=11,
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paJACK=12,
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paWASAPI=13,
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paAudioScienceHPI=14
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} PaHostApiTypeId;
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/** A structure containing information about a particular host API. */
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typedef struct PaHostApiInfo
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{
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/** this is struct version 1 */
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int structVersion;
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/** The well known unique identifier of this host API @see PaHostApiTypeId */
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PaHostApiTypeId type;
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/** A textual description of the host API for display on user interfaces. */
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const char *name;
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/** The number of devices belonging to this host API. This field may be
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used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate
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all devices for this host API.
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@see Pa_HostApiDeviceIndexToDeviceIndex
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*/
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int deviceCount;
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/** The default input device for this host API. The value will be a
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device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice
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if no default input device is available.
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*/
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PaDeviceIndex defaultInputDevice;
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/** The default output device for this host API. The value will be a
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device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice
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if no default output device is available.
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*/
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PaDeviceIndex defaultOutputDevice;
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} PaHostApiInfo;
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/** Retrieve a pointer to a structure containing information about a specific
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host Api.
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@param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1)
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@return A pointer to an immutable PaHostApiInfo structure describing
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a specific host API. If the hostApi parameter is out of range or an error
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is encountered, the function returns NULL.
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The returned structure is owned by the PortAudio implementation and must not
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be manipulated or freed. The pointer is only guaranteed to be valid between
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calls to Pa_Initialize() and Pa_Terminate().
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*/
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const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi );
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/** Convert a static host API unique identifier, into a runtime
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host API index.
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@param type A unique host API identifier belonging to the PaHostApiTypeId
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enumeration.
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@return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or,
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a PaErrorCode (which are always negative) if PortAudio is not initialized
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or an error is encountered.
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The paHostApiNotFound error code indicates that the host API specified by the
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type parameter is not available.
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@see PaHostApiTypeId
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*/
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PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type );
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/** Convert a host-API-specific device index to standard PortAudio device index.
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This function may be used in conjunction with the deviceCount field of
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PaHostApiInfo to enumerate all devices for the specified host API.
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@param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1)
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@param hostApiDeviceIndex A valid per-host device index in the range
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0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1)
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@return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1)
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or, a PaErrorCode (which are always negative) if PortAudio is not initialized
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or an error is encountered.
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A paInvalidHostApi error code indicates that the host API index specified by
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the hostApi parameter is out of range.
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A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter
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is out of range.
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@see PaHostApiInfo
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*/
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PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi,
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int hostApiDeviceIndex );
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/** Structure used to return information about a host error condition.
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*/
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typedef struct PaHostErrorInfo{
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PaHostApiTypeId hostApiType; /**< the host API which returned the error code */
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long errorCode; /**< the error code returned */
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const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */
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}PaHostErrorInfo;
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/** Return information about the last host error encountered. The error
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information returned by Pa_GetLastHostErrorInfo() will never be modified
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asynchronously by errors occurring in other PortAudio owned threads
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(such as the thread that manages the stream callback.)
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This function is provided as a last resort, primarily to enhance debugging
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by providing clients with access to all available error information.
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@return A pointer to an immutable structure constraining information about
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the host error. The values in this structure will only be valid if a
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PortAudio function has previously returned the paUnanticipatedHostError
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error code.
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*/
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const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void );
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/* Device enumeration and capabilities */
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/** Retrieve the number of available devices. The number of available devices
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may be zero.
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@return A non-negative value indicating the number of available devices or,
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a PaErrorCode (which are always negative) if PortAudio is not initialized
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or an error is encountered.
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*/
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PaDeviceIndex Pa_GetDeviceCount( void );
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/** Retrieve the index of the default input device. The result can be
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used in the inputDevice parameter to Pa_OpenStream().
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@return The default input device index for the default host API, or paNoDevice
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if no default input device is available or an error was encountered.
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*/
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PaDeviceIndex Pa_GetDefaultInputDevice( void );
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/** Retrieve the index of the default output device. The result can be
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used in the outputDevice parameter to Pa_OpenStream().
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@return The default output device index for the default host API, or paNoDevice
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if no default output device is available or an error was encountered.
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@note
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On the PC, the user can specify a default device by
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setting an environment variable. For example, to use device #1.
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<pre>
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set PA_RECOMMENDED_OUTPUT_DEVICE=1
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</pre>
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The user should first determine the available device ids by using
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the supplied application "pa_devs".
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*/
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PaDeviceIndex Pa_GetDefaultOutputDevice( void );
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/** The type used to represent monotonic time in seconds. PaTime is
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used for the fields of the PaStreamCallbackTimeInfo argument to the
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PaStreamCallback and as the result of Pa_GetStreamTime().
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PaTime values have unspecified origin.
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@see PaStreamCallback, PaStreamCallbackTimeInfo, Pa_GetStreamTime
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*/
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typedef double PaTime;
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/** A type used to specify one or more sample formats. Each value indicates
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a possible format for sound data passed to and from the stream callback,
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Pa_ReadStream and Pa_WriteStream.
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The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8
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and aUInt8 are usually implemented by all implementations.
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The floating point representation (paFloat32) uses +1.0 and -1.0 as the
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maximum and minimum respectively.
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paUInt8 is an unsigned 8 bit format where 128 is considered "ground"
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The paNonInterleaved flag indicates that audio data is passed as an array
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of pointers to separate buffers, one buffer for each channel. Usually,
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when this flag is not used, audio data is passed as a single buffer with
|
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all channels interleaved.
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@see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo
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@see paFloat32, paInt16, paInt32, paInt24, paInt8
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||||
@see paUInt8, paCustomFormat, paNonInterleaved
|
||||
*/
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typedef unsigned long PaSampleFormat;
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||||
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#define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */
|
||||
#define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */
|
||||
#define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */
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||||
#define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */
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||||
#define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */
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||||
#define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */
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||||
#define paCustomFormat ((PaSampleFormat) 0x00010000) /**< @see PaSampleFormat */
|
||||
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||||
#define paNonInterleaved ((PaSampleFormat) 0x80000000) /**< @see PaSampleFormat */
|
||||
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||||
/** A structure providing information and capabilities of PortAudio devices.
|
||||
Devices may support input, output or both input and output.
|
||||
*/
|
||||
typedef struct PaDeviceInfo
|
||||
{
|
||||
int structVersion; /* this is struct version 2 */
|
||||
const char *name;
|
||||
PaHostApiIndex hostApi; /**< note this is a host API index, not a type id*/
|
||||
|
||||
int maxInputChannels;
|
||||
int maxOutputChannels;
|
||||
|
||||
/** Default latency values for interactive performance. */
|
||||
PaTime defaultLowInputLatency;
|
||||
PaTime defaultLowOutputLatency;
|
||||
/** Default latency values for robust non-interactive applications (eg. playing sound files). */
|
||||
PaTime defaultHighInputLatency;
|
||||
PaTime defaultHighOutputLatency;
|
||||
|
||||
double defaultSampleRate;
|
||||
} PaDeviceInfo;
|
||||
|
||||
|
||||
/** Retrieve a pointer to a PaDeviceInfo structure containing information
|
||||
about the specified device.
|
||||
@return A pointer to an immutable PaDeviceInfo structure. If the device
|
||||
parameter is out of range the function returns NULL.
|
||||
|
||||
@param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1)
|
||||
|
||||
@note PortAudio manages the memory referenced by the returned pointer,
|
||||
the client must not manipulate or free the memory. The pointer is only
|
||||
guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate().
|
||||
|
||||
@see PaDeviceInfo, PaDeviceIndex
|
||||
*/
|
||||
const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device );
|
||||
|
||||
|
||||
/** Parameters for one direction (input or output) of a stream.
|
||||
*/
|
||||
typedef struct PaStreamParameters
|
||||
{
|
||||
/** A valid device index in the range 0 to (Pa_GetDeviceCount()-1)
|
||||
specifying the device to be used or the special constant
|
||||
paUseHostApiSpecificDeviceSpecification which indicates that the actual
|
||||
device(s) to use are specified in hostApiSpecificStreamInfo.
|
||||
This field must not be set to paNoDevice.
|
||||
*/
|
||||
PaDeviceIndex device;
|
||||
|
||||
/** The number of channels of sound to be delivered to the
|
||||
stream callback or accessed by Pa_ReadStream() or Pa_WriteStream().
|
||||
It can range from 1 to the value of maxInputChannels in the
|
||||
PaDeviceInfo record for the device specified by the device parameter.
|
||||
*/
|
||||
int channelCount;
|
||||
|
||||
/** The sample format of the buffer provided to the stream callback,
|
||||
a_ReadStream() or Pa_WriteStream(). It may be any of the formats described
|
||||
by the PaSampleFormat enumeration.
|
||||
*/
|
||||
PaSampleFormat sampleFormat;
|
||||
|
||||
/** The desired latency in seconds. Where practical, implementations should
|
||||
configure their latency based on these parameters, otherwise they may
|
||||
choose the closest viable latency instead. Unless the suggested latency
|
||||
is greater than the absolute upper limit for the device implementations
|
||||
should round the suggestedLatency up to the next practical value - ie to
|
||||
provide an equal or higher latency than suggestedLatency wherever possible.
|
||||
Actual latency values for an open stream may be retrieved using the
|
||||
inputLatency and outputLatency fields of the PaStreamInfo structure
|
||||
returned by Pa_GetStreamInfo().
|
||||
@see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo
|
||||
*/
|
||||
PaTime suggestedLatency;
|
||||
|
||||
/** An optional pointer to a host api specific data structure
|
||||
containing additional information for device setup and/or stream processing.
|
||||
hostApiSpecificStreamInfo is never required for correct operation,
|
||||
if not used it should be set to NULL.
|
||||
*/
|
||||
void *hostApiSpecificStreamInfo;
|
||||
|
||||
} PaStreamParameters;
|
||||
|
||||
|
||||
/** Return code for Pa_IsFormatSupported indicating success. */
|
||||
#define paFormatIsSupported (0)
|
||||
|
||||
/** Determine whether it would be possible to open a stream with the specified
|
||||
parameters.
|
||||
|
||||
@param inputParameters A structure that describes the input parameters used to
|
||||
open a stream. The suggestedLatency field is ignored. See PaStreamParameters
|
||||
for a description of these parameters. inputParameters must be NULL for
|
||||
output-only streams.
|
||||
|
||||
@param outputParameters A structure that describes the output parameters used
|
||||
to open a stream. The suggestedLatency field is ignored. See PaStreamParameters
|
||||
for a description of these parameters. outputParameters must be NULL for
|
||||
input-only streams.
|
||||
|
||||
@param sampleRate The required sampleRate. For full-duplex streams it is the
|
||||
sample rate for both input and output
|
||||
|
||||
@return Returns 0 if the format is supported, and an error code indicating why
|
||||
the format is not supported otherwise. The constant paFormatIsSupported is
|
||||
provided to compare with the return value for success.
|
||||
|
||||
@see paFormatIsSupported, PaStreamParameters
|
||||
*/
|
||||
PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters,
|
||||
const PaStreamParameters *outputParameters,
|
||||
double sampleRate );
|
||||
|
||||
|
||||
|
||||
/* Streaming types and functions */
|
||||
|
||||
|
||||
/**
|
||||
A single PaStream can provide multiple channels of real-time
|
||||
streaming audio input and output to a client application. A stream
|
||||
provides access to audio hardware represented by one or more
|
||||
PaDevices. Depending on the underlying Host API, it may be possible
|
||||
to open multiple streams using the same device, however this behavior
|
||||
is implementation defined. Portable applications should assume that
|
||||
a PaDevice may be simultaneously used by at most one PaStream.
|
||||
|
||||
Pointers to PaStream objects are passed between PortAudio functions that
|
||||
operate on streams.
|
||||
|
||||
@see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream,
|
||||
Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive,
|
||||
Pa_GetStreamTime, Pa_GetStreamCpuLoad
|
||||
|
||||
*/
|
||||
typedef void PaStream;
|
||||
|
||||
|
||||
/** Can be passed as the framesPerBuffer parameter to Pa_OpenStream()
|
||||
or Pa_OpenDefaultStream() to indicate that the stream callback will
|
||||
accept buffers of any size.
|
||||
*/
|
||||
#define paFramesPerBufferUnspecified (0)
|
||||
|
||||
|
||||
/** Flags used to control the behavior of a stream. They are passed as
|
||||
parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be
|
||||
ORed together.
|
||||
|
||||
@see Pa_OpenStream, Pa_OpenDefaultStream
|
||||
@see paNoFlag, paClipOff, paDitherOff, paNeverDropInput,
|
||||
paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags
|
||||
*/
|
||||
typedef unsigned long PaStreamFlags;
|
||||
|
||||
/** @see PaStreamFlags */
|
||||
#define paNoFlag ((PaStreamFlags) 0)
|
||||
|
||||
/** Disable default clipping of out of range samples.
|
||||
@see PaStreamFlags
|
||||
*/
|
||||
#define paClipOff ((PaStreamFlags) 0x00000001)
|
||||
|
||||
/** Disable default dithering.
|
||||
@see PaStreamFlags
|
||||
*/
|
||||
#define paDitherOff ((PaStreamFlags) 0x00000002)
|
||||
|
||||
/** Flag requests that where possible a full duplex stream will not discard
|
||||
overflowed input samples without calling the stream callback. This flag is
|
||||
only valid for full duplex callback streams and only when used in combination
|
||||
with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using
|
||||
this flag incorrectly results in a paInvalidFlag error being returned from
|
||||
Pa_OpenStream and Pa_OpenDefaultStream.
|
||||
|
||||
@see PaStreamFlags, paFramesPerBufferUnspecified
|
||||
*/
|
||||
#define paNeverDropInput ((PaStreamFlags) 0x00000004)
|
||||
|
||||
/** Call the stream callback to fill initial output buffers, rather than the
|
||||
default behavior of priming the buffers with zeros (silence). This flag has
|
||||
no effect for input-only and blocking read/write streams.
|
||||
|
||||
@see PaStreamFlags
|
||||
*/
|
||||
#define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008)
|
||||
|
||||
/** A mask specifying the platform specific bits.
|
||||
@see PaStreamFlags
|
||||
*/
|
||||
#define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000)
|
||||
|
||||
/**
|
||||
Timing information for the buffers passed to the stream callback.
|
||||
|
||||
Time values are expressed in seconds and are synchronised with the time base used by Pa_GetStreamTime() for the associated stream.
|
||||
|
||||
@see PaStreamCallback, Pa_GetStreamTime
|
||||
*/
|
||||
typedef struct PaStreamCallbackTimeInfo{
|
||||
PaTime inputBufferAdcTime; /**< The time when the first sample of the input buffer was captured at the ADC input */
|
||||
PaTime currentTime; /**< The time when the stream callback was invoked */
|
||||
PaTime outputBufferDacTime; /**< The time when the first sample of the output buffer will output the DAC */
|
||||
} PaStreamCallbackTimeInfo;
|
||||
|
||||
|
||||
/**
|
||||
Flag bit constants for the statusFlags to PaStreamCallback.
|
||||
|
||||
@see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow,
|
||||
paPrimingOutput
|
||||
*/
|
||||
typedef unsigned long PaStreamCallbackFlags;
|
||||
|
||||
/** In a stream opened with paFramesPerBufferUnspecified, indicates that
|
||||
input data is all silence (zeros) because no real data is available. In a
|
||||
stream opened without paFramesPerBufferUnspecified, it indicates that one or
|
||||
more zero samples have been inserted into the input buffer to compensate
|
||||
for an input underflow.
|
||||
@see PaStreamCallbackFlags
|
||||
*/
|
||||
#define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001)
|
||||
|
||||
/** In a stream opened with paFramesPerBufferUnspecified, indicates that data
|
||||
prior to the first sample of the input buffer was discarded due to an
|
||||
overflow, possibly because the stream callback is using too much CPU time.
|
||||
Otherwise indicates that data prior to one or more samples in the
|
||||
input buffer was discarded.
|
||||
@see PaStreamCallbackFlags
|
||||
*/
|
||||
#define paInputOverflow ((PaStreamCallbackFlags) 0x00000002)
|
||||
|
||||
/** Indicates that output data (or a gap) was inserted, possibly because the
|
||||
stream callback is using too much CPU time.
|
||||
@see PaStreamCallbackFlags
|
||||
*/
|
||||
#define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004)
|
||||
|
||||
/** Indicates that output data will be discarded because no room is available.
|
||||
@see PaStreamCallbackFlags
|
||||
*/
|
||||
#define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008)
|
||||
|
||||
/** Some of all of the output data will be used to prime the stream, input
|
||||
data may be zero.
|
||||
@see PaStreamCallbackFlags
|
||||
*/
|
||||
#define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010)
|
||||
|
||||
/**
|
||||
Allowable return values for the PaStreamCallback.
|
||||
@see PaStreamCallback
|
||||
*/
|
||||
typedef enum PaStreamCallbackResult
|
||||
{
|
||||
paContinue=0, /**< Signal that the stream should continue invoking the callback and processing audio. */
|
||||
paComplete=1, /**< Signal that the stream should stop invoking the callback and finish once all output samples have played. */
|
||||
paAbort=2 /**< Signal that the stream should stop invoking the callback and finish as soon as possible. */
|
||||
} PaStreamCallbackResult;
|
||||
|
||||
|
||||
/**
|
||||
Functions of type PaStreamCallback are implemented by PortAudio clients.
|
||||
They consume, process or generate audio in response to requests from an
|
||||
active PortAudio stream.
|
||||
|
||||
When a stream is running, PortAudio calls the stream callback periodically.
|
||||
The callback function is responsible for processing buffers of audio samples
|
||||
passed via the input and output parameters.
|
||||
|
||||
The PortAudio stream callback runs at very high or real-time priority.
|
||||
It is required to consistently meet its time deadlines. Do not allocate
|
||||
memory, access the file system, call library functions or call other functions
|
||||
from the stream callback that may block or take an unpredictable amount of
|
||||
time to complete.
|
||||
|
||||
In order for a stream to maintain glitch-free operation the callback
|
||||
must consume and return audio data faster than it is recorded and/or
|
||||
played. PortAudio anticipates that each callback invocation may execute for
|
||||
a duration approaching the duration of frameCount audio frames at the stream
|
||||
sample rate. It is reasonable to expect to be able to utilise 70% or more of
|
||||
the available CPU time in the PortAudio callback. However, due to buffer size
|
||||
adaption and other factors, not all host APIs are able to guarantee audio
|
||||
stability under heavy CPU load with arbitrary fixed callback buffer sizes.
|
||||
When high callback CPU utilisation is required the most robust behavior
|
||||
can be achieved by using paFramesPerBufferUnspecified as the
|
||||
Pa_OpenStream() framesPerBuffer parameter.
|
||||
|
||||
@param input and @param output are either arrays of interleaved samples or;
|
||||
if non-interleaved samples were requested using the paNonInterleaved sample
|
||||
format flag, an array of buffer pointers, one non-interleaved buffer for
|
||||
each channel.
|
||||
|
||||
The format, packing and number of channels used by the buffers are
|
||||
determined by parameters to Pa_OpenStream().
|
||||
|
||||
@param frameCount The number of sample frames to be processed by
|
||||
the stream callback.
|
||||
|
||||
@param timeInfo Timestamps indicating the ADC capture time of the first sample
|
||||
in the input buffer, the DAC output time of the first sample in the output buffer
|
||||
and the time the callback was invoked.
|
||||
See PaStreamCallbackTimeInfo and Pa_GetStreamTime()
|
||||
|
||||
@param statusFlags Flags indicating whether input and/or output buffers
|
||||
have been inserted or will be dropped to overcome underflow or overflow
|
||||
conditions.
|
||||
|
||||
@param userData The value of a user supplied pointer passed to
|
||||
Pa_OpenStream() intended for storing synthesis data etc.
|
||||
|
||||
@return
|
||||
The stream callback should return one of the values in the
|
||||
::PaStreamCallbackResult enumeration. To ensure that the callback continues
|
||||
to be called, it should return paContinue (0). Either paComplete or paAbort
|
||||
can be returned to finish stream processing, after either of these values is
|
||||
returned the callback will not be called again. If paAbort is returned the
|
||||
stream will finish as soon as possible. If paComplete is returned, the stream
|
||||
will continue until all buffers generated by the callback have been played.
|
||||
This may be useful in applications such as soundfile players where a specific
|
||||
duration of output is required. However, it is not necessary to utilize this
|
||||
mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also
|
||||
be used to stop the stream. The callback must always fill the entire output
|
||||
buffer irrespective of its return value.
|
||||
|
||||
@see Pa_OpenStream, Pa_OpenDefaultStream
|
||||
|
||||
@note With the exception of Pa_GetStreamCpuLoad() it is not permissible to call
|
||||
PortAudio API functions from within the stream callback.
|
||||
*/
|
||||
typedef int PaStreamCallback(
|
||||
const void *input, void *output,
|
||||
unsigned long frameCount,
|
||||
const PaStreamCallbackTimeInfo* timeInfo,
|
||||
PaStreamCallbackFlags statusFlags,
|
||||
void *userData );
|
||||
|
||||
|
||||
/** Opens a stream for either input, output or both.
|
||||
|
||||
@param stream The address of a PaStream pointer which will receive
|
||||
a pointer to the newly opened stream.
|
||||
|
||||
@param inputParameters A structure that describes the input parameters used by
|
||||
the opened stream. See PaStreamParameters for a description of these parameters.
|
||||
inputParameters must be NULL for output-only streams.
|
||||
|
||||
@param outputParameters A structure that describes the output parameters used by
|
||||
the opened stream. See PaStreamParameters for a description of these parameters.
|
||||
outputParameters must be NULL for input-only streams.
|
||||
|
||||
@param sampleRate The desired sampleRate. For full-duplex streams it is the
|
||||
sample rate for both input and output
|
||||
|
||||
@param framesPerBuffer The number of frames passed to the stream callback
|
||||
function, or the preferred block granularity for a blocking read/write stream.
|
||||
The special value paFramesPerBufferUnspecified (0) may be used to request that
|
||||
the stream callback will receive an optimal (and possibly varying) number of
|
||||
frames based on host requirements and the requested latency settings.
|
||||
Note: With some host APIs, the use of non-zero framesPerBuffer for a callback
|
||||
stream may introduce an additional layer of buffering which could introduce
|
||||
additional latency. PortAudio guarantees that the additional latency
|
||||
will be kept to the theoretical minimum however, it is strongly recommended
|
||||
that a non-zero framesPerBuffer value only be used when your algorithm
|
||||
requires a fixed number of frames per stream callback.
|
||||
|
||||
@param streamFlags Flags which modify the behavior of the streaming process.
|
||||
This parameter may contain a combination of flags ORed together. Some flags may
|
||||
only be relevant to certain buffer formats.
|
||||
|
||||
@param streamCallback A pointer to a client supplied function that is responsible
|
||||
for processing and filling input and output buffers. If this parameter is NULL
|
||||
the stream will be opened in 'blocking read/write' mode. In blocking mode,
|
||||
the client can receive sample data using Pa_ReadStream and write sample data
|
||||
using Pa_WriteStream, the number of samples that may be read or written
|
||||
without blocking is returned by Pa_GetStreamReadAvailable and
|
||||
Pa_GetStreamWriteAvailable respectively.
|
||||
|
||||
@param userData A client supplied pointer which is passed to the stream callback
|
||||
function. It could for example, contain a pointer to instance data necessary
|
||||
for processing the audio buffers. This parameter is ignored if streamCallback
|
||||
is NULL.
|
||||
|
||||
@return
|
||||
Upon success Pa_OpenStream() returns paNoError and places a pointer to a
|
||||
valid PaStream in the stream argument. The stream is inactive (stopped).
|
||||
If a call to Pa_OpenStream() fails, a non-zero error code is returned (see
|
||||
PaError for possible error codes) and the value of stream is invalid.
|
||||
|
||||
@see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream,
|
||||
Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable
|
||||
*/
|
||||
PaError Pa_OpenStream( PaStream** stream,
|
||||
const PaStreamParameters *inputParameters,
|
||||
const PaStreamParameters *outputParameters,
|
||||
double sampleRate,
|
||||
unsigned long framesPerBuffer,
|
||||
PaStreamFlags streamFlags,
|
||||
PaStreamCallback *streamCallback,
|
||||
void *userData );
|
||||
|
||||
|
||||
/** A simplified version of Pa_OpenStream() that opens the default input
|
||||
and/or output devices.
|
||||
|
||||
@param stream The address of a PaStream pointer which will receive
|
||||
a pointer to the newly opened stream.
|
||||
|
||||
@param numInputChannels The number of channels of sound that will be supplied
|
||||
to the stream callback or returned by Pa_ReadStream. It can range from 1 to
|
||||
the value of maxInputChannels in the PaDeviceInfo record for the default input
|
||||
device. If 0 the stream is opened as an output-only stream.
|
||||
|
||||
@param numOutputChannels The number of channels of sound to be delivered to the
|
||||
stream callback or passed to Pa_WriteStream. It can range from 1 to the value
|
||||
of maxOutputChannels in the PaDeviceInfo record for the default output device.
|
||||
If 0 the stream is opened as an output-only stream.
|
||||
|
||||
@param sampleFormat The sample format of both the input and output buffers
|
||||
provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream.
|
||||
sampleFormat may be any of the formats described by the PaSampleFormat
|
||||
enumeration.
|
||||
|
||||
@param sampleRate Same as Pa_OpenStream parameter of the same name.
|
||||
@param framesPerBuffer Same as Pa_OpenStream parameter of the same name.
|
||||
@param streamCallback Same as Pa_OpenStream parameter of the same name.
|
||||
@param userData Same as Pa_OpenStream parameter of the same name.
|
||||
|
||||
@return As for Pa_OpenStream
|
||||
|
||||
@see Pa_OpenStream, PaStreamCallback
|
||||
*/
|
||||
PaError Pa_OpenDefaultStream( PaStream** stream,
|
||||
int numInputChannels,
|
||||
int numOutputChannels,
|
||||
PaSampleFormat sampleFormat,
|
||||
double sampleRate,
|
||||
unsigned long framesPerBuffer,
|
||||
PaStreamCallback *streamCallback,
|
||||
void *userData );
|
||||
|
||||
|
||||
/** Closes an audio stream. If the audio stream is active it
|
||||
discards any pending buffers as if Pa_AbortStream() had been called.
|
||||
*/
|
||||
PaError Pa_CloseStream( PaStream *stream );
|
||||
|
||||
|
||||
/** Functions of type PaStreamFinishedCallback are implemented by PortAudio
|
||||
clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback
|
||||
function. Once registered they are called when the stream becomes inactive
|
||||
(ie once a call to Pa_StopStream() will not block).
|
||||
A stream will become inactive after the stream callback returns non-zero,
|
||||
or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio
|
||||
output, if the stream callback returns paComplete, or Pa_StopStream() is called,
|
||||
the stream finished callback will not be called until all generated sample data
|
||||
has been played.
|
||||
|
||||
@param userData The userData parameter supplied to Pa_OpenStream()
|
||||
|
||||
@see Pa_SetStreamFinishedCallback
|
||||
*/
|
||||
typedef void PaStreamFinishedCallback( void *userData );
|
||||
|
||||
|
||||
/** Register a stream finished callback function which will be called when the
|
||||
stream becomes inactive. See the description of PaStreamFinishedCallback for
|
||||
further details about when the callback will be called.
|
||||
|
||||
@param stream a pointer to a PaStream that is in the stopped state - if the
|
||||
stream is not stopped, the stream's finished callback will remain unchanged
|
||||
and an error code will be returned.
|
||||
|
||||
@param streamFinishedCallback a pointer to a function with the same signature
|
||||
as PaStreamFinishedCallback, that will be called when the stream becomes
|
||||
inactive. Passing NULL for this parameter will un-register a previously
|
||||
registered stream finished callback function.
|
||||
|
||||
@return on success returns paNoError, otherwise an error code indicating the cause
|
||||
of the error.
|
||||
|
||||
@see PaStreamFinishedCallback
|
||||
*/
|
||||
PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback );
|
||||
|
||||
|
||||
/** Commences audio processing.
|
||||
*/
|
||||
PaError Pa_StartStream( PaStream *stream );
|
||||
|
||||
|
||||
/** Terminates audio processing. It waits until all pending
|
||||
audio buffers have been played before it returns.
|
||||
*/
|
||||
PaError Pa_StopStream( PaStream *stream );
|
||||
|
||||
|
||||
/** Terminates audio processing immediately without waiting for pending
|
||||
buffers to complete.
|
||||
*/
|
||||
PaError Pa_AbortStream( PaStream *stream );
|
||||
|
||||
|
||||
/** Determine whether the stream is stopped.
|
||||
A stream is considered to be stopped prior to a successful call to
|
||||
Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream.
|
||||
If a stream callback returns a value other than paContinue the stream is NOT
|
||||
considered to be stopped.
|
||||
|
||||
@return Returns one (1) when the stream is stopped, zero (0) when
|
||||
the stream is running or, a PaErrorCode (which are always negative) if
|
||||
PortAudio is not initialized or an error is encountered.
|
||||
|
||||
@see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive
|
||||
*/
|
||||
PaError Pa_IsStreamStopped( PaStream *stream );
|
||||
|
||||
|
||||
/** Determine whether the stream is active.
|
||||
A stream is active after a successful call to Pa_StartStream(), until it
|
||||
becomes inactive either as a result of a call to Pa_StopStream() or
|
||||
Pa_AbortStream(), or as a result of a return value other than paContinue from
|
||||
the stream callback. In the latter case, the stream is considered inactive
|
||||
after the last buffer has finished playing.
|
||||
|
||||
@return Returns one (1) when the stream is active (ie playing or recording
|
||||
audio), zero (0) when not playing or, a PaErrorCode (which are always negative)
|
||||
if PortAudio is not initialized or an error is encountered.
|
||||
|
||||
@see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped
|
||||
*/
|
||||
PaError Pa_IsStreamActive( PaStream *stream );
|
||||
|
||||
|
||||
|
||||
/** A structure containing unchanging information about an open stream.
|
||||
@see Pa_GetStreamInfo
|
||||
*/
|
||||
|
||||
typedef struct PaStreamInfo
|
||||
{
|
||||
/** this is struct version 1 */
|
||||
int structVersion;
|
||||
|
||||
/** The input latency of the stream in seconds. This value provides the most
|
||||
accurate estimate of input latency available to the implementation. It may
|
||||
differ significantly from the suggestedLatency value passed to Pa_OpenStream().
|
||||
The value of this field will be zero (0.) for output-only streams.
|
||||
@see PaTime
|
||||
*/
|
||||
PaTime inputLatency;
|
||||
|
||||
/** The output latency of the stream in seconds. This value provides the most
|
||||
accurate estimate of output latency available to the implementation. It may
|
||||
differ significantly from the suggestedLatency value passed to Pa_OpenStream().
|
||||
The value of this field will be zero (0.) for input-only streams.
|
||||
@see PaTime
|
||||
*/
|
||||
PaTime outputLatency;
|
||||
|
||||
/** The sample rate of the stream in Hertz (samples per second). In cases
|
||||
where the hardware sample rate is inaccurate and PortAudio is aware of it,
|
||||
the value of this field may be different from the sampleRate parameter
|
||||
passed to Pa_OpenStream(). If information about the actual hardware sample
|
||||
rate is not available, this field will have the same value as the sampleRate
|
||||
parameter passed to Pa_OpenStream().
|
||||
*/
|
||||
double sampleRate;
|
||||
|
||||
} PaStreamInfo;
|
||||
|
||||
|
||||
/** Retrieve a pointer to a PaStreamInfo structure containing information
|
||||
about the specified stream.
|
||||
@return A pointer to an immutable PaStreamInfo structure. If the stream
|
||||
parameter is invalid, or an error is encountered, the function returns NULL.
|
||||
|
||||
@param stream A pointer to an open stream previously created with Pa_OpenStream.
|
||||
|
||||
@note PortAudio manages the memory referenced by the returned pointer,
|
||||
the client must not manipulate or free the memory. The pointer is only
|
||||
guaranteed to be valid until the specified stream is closed.
|
||||
|
||||
@see PaStreamInfo
|
||||
*/
|
||||
const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream );
|
||||
|
||||
|
||||
/** Returns the current time in seconds for a stream according to the same clock used
|
||||
to generate callback PaStreamCallbackTimeInfo timestamps. The time values are
|
||||
monotonically increasing and have unspecified origin.
|
||||
|
||||
Pa_GetStreamTime returns valid time values for the entire life of the stream,
|
||||
from when the stream is opened until it is closed. Starting and stopping the stream
|
||||
does not affect the passage of time returned by Pa_GetStreamTime.
|
||||
|
||||
This time may be used for synchronizing other events to the audio stream, for
|
||||
example synchronizing audio to MIDI.
|
||||
|
||||
@return The stream's current time in seconds, or 0 if an error occurred.
|
||||
|
||||
@see PaTime, PaStreamCallback, PaStreamCallbackTimeInfo
|
||||
*/
|
||||
PaTime Pa_GetStreamTime( PaStream *stream );
|
||||
|
||||
|
||||
/** Retrieve CPU usage information for the specified stream.
|
||||
The "CPU Load" is a fraction of total CPU time consumed by a callback stream's
|
||||
audio processing routines including, but not limited to the client supplied
|
||||
stream callback. This function does not work with blocking read/write streams.
|
||||
|
||||
This function may be called from the stream callback function or the
|
||||
application.
|
||||
|
||||
@return
|
||||
A floating point value, typically between 0.0 and 1.0, where 1.0 indicates
|
||||
that the stream callback is consuming the maximum number of CPU cycles possible
|
||||
to maintain real-time operation. A value of 0.5 would imply that PortAudio and
|
||||
the stream callback was consuming roughly 50% of the available CPU time. The
|
||||
return value may exceed 1.0. A value of 0.0 will always be returned for a
|
||||
blocking read/write stream, or if an error occurs.
|
||||
*/
|
||||
double Pa_GetStreamCpuLoad( PaStream* stream );
|
||||
|
||||
|
||||
/** Read samples from an input stream. The function doesn't return until
|
||||
the entire buffer has been filled - this may involve waiting for the operating
|
||||
system to supply the data.
|
||||
|
||||
@param stream A pointer to an open stream previously created with Pa_OpenStream.
|
||||
|
||||
@param buffer A pointer to a buffer of sample frames. The buffer contains
|
||||
samples in the format specified by the inputParameters->sampleFormat field
|
||||
used to open the stream, and the number of channels specified by
|
||||
inputParameters->numChannels. If non-interleaved samples were requested using
|
||||
the paNonInterleaved sample format flag, buffer is a pointer to the first element
|
||||
of an array of buffer pointers, one non-interleaved buffer for each channel.
|
||||
|
||||
@param frames The number of frames to be read into buffer. This parameter
|
||||
is not constrained to a specific range, however high performance applications
|
||||
will want to match this parameter to the framesPerBuffer parameter used
|
||||
when opening the stream.
|
||||
|
||||
@return On success PaNoError will be returned, or PaInputOverflowed if input
|
||||
data was discarded by PortAudio after the previous call and before this call.
|
||||
*/
|
||||
PaError Pa_ReadStream( PaStream* stream,
|
||||
void *buffer,
|
||||
unsigned long frames );
|
||||
|
||||
|
||||
/** Write samples to an output stream. This function doesn't return until the
|
||||
entire buffer has been written - this may involve waiting for the operating
|
||||
system to consume the data.
|
||||
|
||||
@param stream A pointer to an open stream previously created with Pa_OpenStream.
|
||||
|
||||
@param buffer A pointer to a buffer of sample frames. The buffer contains
|
||||
samples in the format specified by the outputParameters->sampleFormat field
|
||||
used to open the stream, and the number of channels specified by
|
||||
outputParameters->numChannels. If non-interleaved samples were requested using
|
||||
the paNonInterleaved sample format flag, buffer is a pointer to the first element
|
||||
of an array of buffer pointers, one non-interleaved buffer for each channel.
|
||||
|
||||
@param frames The number of frames to be written from buffer. This parameter
|
||||
is not constrained to a specific range, however high performance applications
|
||||
will want to match this parameter to the framesPerBuffer parameter used
|
||||
when opening the stream.
|
||||
|
||||
@return On success PaNoError will be returned, or paOutputUnderflowed if
|
||||
additional output data was inserted after the previous call and before this
|
||||
call.
|
||||
*/
|
||||
PaError Pa_WriteStream( PaStream* stream,
|
||||
const void *buffer,
|
||||
unsigned long frames );
|
||||
|
||||
|
||||
/** Retrieve the number of frames that can be read from the stream without
|
||||
waiting.
|
||||
|
||||
@return Returns a non-negative value representing the maximum number of frames
|
||||
that can be read from the stream without blocking or busy waiting or, a
|
||||
PaErrorCode (which are always negative) if PortAudio is not initialized or an
|
||||
error is encountered.
|
||||
*/
|
||||
signed long Pa_GetStreamReadAvailable( PaStream* stream );
|
||||
|
||||
|
||||
/** Retrieve the number of frames that can be written to the stream without
|
||||
waiting.
|
||||
|
||||
@return Returns a non-negative value representing the maximum number of frames
|
||||
that can be written to the stream without blocking or busy waiting or, a
|
||||
PaErrorCode (which are always negative) if PortAudio is not initialized or an
|
||||
error is encountered.
|
||||
*/
|
||||
signed long Pa_GetStreamWriteAvailable( PaStream* stream );
|
||||
|
||||
|
||||
/* Miscellaneous utilities */
|
||||
|
||||
|
||||
/** Retrieve the size of a given sample format in bytes.
|
||||
|
||||
@return The size in bytes of a single sample in the specified format,
|
||||
or paSampleFormatNotSupported if the format is not supported.
|
||||
*/
|
||||
PaError Pa_GetSampleSize( PaSampleFormat format );
|
||||
|
||||
|
||||
/** Put the caller to sleep for at least 'msec' milliseconds. This function is
|
||||
provided only as a convenience for authors of portable code (such as the tests
|
||||
and examples in the PortAudio distribution.)
|
||||
|
||||
The function may sleep longer than requested so don't rely on this for accurate
|
||||
musical timing.
|
||||
*/
|
||||
void Pa_Sleep( long msec );
|
||||
|
||||
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif /* __cplusplus */
|
||||
#endif /* PORTAUDIO_H */
|
||||
Reference in New Issue
Block a user