#ifndef PA_STREAM_H #define PA_STREAM_H /* * $Id: pa_stream.h,v 1.1.2.13 2003/11/01 06:37:28 rossbencina Exp $ * Portable Audio I/O Library * stream interface * * Based on the Open Source API proposed by Ross Bencina * Copyright (c) 1999-2002 Ross Bencina, Phil Burk * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * Any person wishing to distribute modifications to the Software is * requested to send the modifications to the original developer so that * they can be incorporated into the canonical version. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /** @file @brief Interface used by pa_front to virtualize functions which operate on streams. */ #include "portaudio.h" #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ #define PA_STREAM_MAGIC (0x18273645) /** A structure representing an (abstract) interface to a host API. Contains pointers to functions which implement the interface. All PaStreamInterface functions are guaranteed to be called with a non-null, valid stream parameter. */ typedef struct { PaError (*Close)( PaStream* stream ); PaError (*Start)( PaStream *stream ); PaError (*Stop)( PaStream *stream ); PaError (*Abort)( PaStream *stream ); PaError (*IsStopped)( PaStream *stream ); PaError (*IsActive)( PaStream *stream ); PaTime (*GetTime)( PaStream *stream ); double (*GetCpuLoad)( PaStream* stream ); PaError (*Read)( PaStream* stream, void *buffer, unsigned long frames ); PaError (*Write)( PaStream* stream, const void *buffer, unsigned long frames ); signed long (*GetReadAvailable)( PaStream* stream ); signed long (*GetWriteAvailable)( PaStream* stream ); } PaUtilStreamInterface; /** Initialize the fields of a PaUtilStreamInterface structure. */ void PaUtil_InitializeStreamInterface( PaUtilStreamInterface *streamInterface, PaError (*Close)( PaStream* ), PaError (*Start)( PaStream* ), PaError (*Stop)( PaStream* ), PaError (*Abort)( PaStream* ), PaError (*IsStopped)( PaStream* ), PaError (*IsActive)( PaStream* ), PaTime (*GetTime)( PaStream* ), double (*GetCpuLoad)( PaStream* ), PaError (*Read)( PaStream* stream, void *buffer, unsigned long frames ), PaError (*Write)( PaStream* stream, const void *buffer, unsigned long frames ), signed long (*GetReadAvailable)( PaStream* stream ), signed long (*GetWriteAvailable)( PaStream* stream ) ); /** Dummy Read function for use in interfaces to a callback based streams. Pass to the Read parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream. */ PaError PaUtil_DummyRead( PaStream* stream, void *buffer, unsigned long frames ); /** Dummy Write function for use in an interfaces to callback based streams. Pass to the Write parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream. */ PaError PaUtil_DummyWrite( PaStream* stream, const void *buffer, unsigned long frames ); /** Dummy GetReadAvailable function for use in interfaces to callback based streams. Pass to the GetReadAvailable parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream. */ signed long PaUtil_DummyGetReadAvailable( PaStream* stream ); /** Dummy GetWriteAvailable function for use in interfaces to callback based streams. Pass to the GetWriteAvailable parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream. */ signed long PaUtil_DummyGetWriteAvailable( PaStream* stream ); /** Dummy GetCpuLoad function for use in an interface to a read/write stream. Pass to the GetCpuLoad parameter of PaUtil_InitializeStreamInterface. @return Returns 0. */ double PaUtil_DummyGetCpuLoad( PaStream* stream ); /** Non host specific data for a stream. This data is used by pa_front to forward to the appropriate functions in the streamInterface structure. */ typedef struct PaUtilStreamRepresentation { unsigned long magic; /**< set to PA_STREAM_MAGIC */ struct PaUtilStreamRepresentation *nextOpenStream; /**< field used by multi-api code */ PaUtilStreamInterface *streamInterface; PaStreamCallback *streamCallback; PaStreamFinishedCallback *streamFinishedCallback; void *userData; PaStreamInfo streamInfo; } PaUtilStreamRepresentation; /** Initialize a PaUtilStreamRepresentation structure. @see PaUtil_InitializeStreamRepresentation */ void PaUtil_InitializeStreamRepresentation( PaUtilStreamRepresentation *streamRepresentation, PaUtilStreamInterface *streamInterface, PaStreamCallback *streamCallback, void *userData ); /** Clean up a PaUtilStreamRepresentation structure previously initialized by a call to PaUtil_InitializeStreamRepresentation. @see PaUtil_InitializeStreamRepresentation */ void PaUtil_TerminateStreamRepresentation( PaUtilStreamRepresentation *streamRepresentation ); /** Check that the stream pointer is valid. @return Returns paNoError if the stream pointer appears to be OK, otherwise returns an error indicating the cause of failure. */ PaError PaUtil_ValidateStreamPointer( PaStream *stream ); /** Cast an opaque stream pointer into a pointer to a PaUtilStreamRepresentation. @see PaUtilStreamRepresentation */ #define PA_STREAM_REP( stream )\ ((PaUtilStreamRepresentation*) (stream) ) /** Cast an opaque stream pointer into a pointer to a PaUtilStreamInterface. @see PaUtilStreamRepresentation, PaUtilStreamInterface */ #define PA_STREAM_INTERFACE( stream )\ PA_STREAM_REP( (stream) )->streamInterface #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* PA_STREAM_H */