cannam@124: #ifndef PORTAUDIO_H cannam@124: #define PORTAUDIO_H cannam@124: /* cannam@124: * $Id: portaudio.h 1859 2012-09-01 00:10:13Z philburk $ cannam@124: * PortAudio Portable Real-Time Audio Library cannam@124: * PortAudio API Header File cannam@124: * Latest version available at: http://www.portaudio.com/ cannam@124: * cannam@124: * Copyright (c) 1999-2002 Ross Bencina and Phil Burk cannam@124: * cannam@124: * Permission is hereby granted, free of charge, to any person obtaining cannam@124: * a copy of this software and associated documentation files cannam@124: * (the "Software"), to deal in the Software without restriction, cannam@124: * including without limitation the rights to use, copy, modify, merge, cannam@124: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@124: * and to permit persons to whom the Software is furnished to do so, cannam@124: * subject to the following conditions: cannam@124: * cannam@124: * The above copyright notice and this permission notice shall be cannam@124: * included in all copies or substantial portions of the Software. cannam@124: * cannam@124: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@124: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@124: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@124: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@124: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@124: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@124: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@124: */ cannam@124: cannam@124: /* cannam@124: * The text above constitutes the entire PortAudio license; however, cannam@124: * the PortAudio community also makes the following non-binding requests: cannam@124: * cannam@124: * Any person wishing to distribute modifications to the Software is cannam@124: * requested to send the modifications to the original developer so that cannam@124: * they can be incorporated into the canonical version. It is also cannam@124: * requested that these non-binding requests be included along with the cannam@124: * license above. cannam@124: */ cannam@124: cannam@124: /** @file cannam@124: @ingroup public_header cannam@124: @brief The portable PortAudio API. cannam@124: */ cannam@124: cannam@124: cannam@124: #ifdef __cplusplus cannam@124: extern "C" cannam@124: { cannam@124: #endif /* __cplusplus */ cannam@124: cannam@124: cannam@124: /** Retrieve the release number of the currently running PortAudio build, cannam@124: eg 1900. cannam@124: */ cannam@124: int Pa_GetVersion( void ); cannam@124: cannam@124: cannam@124: /** Retrieve a textual description of the current PortAudio build, cannam@124: eg "PortAudio V19-devel 13 October 2002". cannam@124: */ cannam@124: const char* Pa_GetVersionText( void ); cannam@124: cannam@124: cannam@124: /** Error codes returned by PortAudio functions. cannam@124: Note that with the exception of paNoError, all PaErrorCodes are negative. cannam@124: */ cannam@124: cannam@124: typedef int PaError; cannam@124: typedef enum PaErrorCode cannam@124: { cannam@124: paNoError = 0, cannam@124: cannam@124: paNotInitialized = -10000, cannam@124: paUnanticipatedHostError, cannam@124: paInvalidChannelCount, cannam@124: paInvalidSampleRate, cannam@124: paInvalidDevice, cannam@124: paInvalidFlag, cannam@124: paSampleFormatNotSupported, cannam@124: paBadIODeviceCombination, cannam@124: paInsufficientMemory, cannam@124: paBufferTooBig, cannam@124: paBufferTooSmall, cannam@124: paNullCallback, cannam@124: paBadStreamPtr, cannam@124: paTimedOut, cannam@124: paInternalError, cannam@124: paDeviceUnavailable, cannam@124: paIncompatibleHostApiSpecificStreamInfo, cannam@124: paStreamIsStopped, cannam@124: paStreamIsNotStopped, cannam@124: paInputOverflowed, cannam@124: paOutputUnderflowed, cannam@124: paHostApiNotFound, cannam@124: paInvalidHostApi, cannam@124: paCanNotReadFromACallbackStream, cannam@124: paCanNotWriteToACallbackStream, cannam@124: paCanNotReadFromAnOutputOnlyStream, cannam@124: paCanNotWriteToAnInputOnlyStream, cannam@124: paIncompatibleStreamHostApi, cannam@124: paBadBufferPtr cannam@124: } PaErrorCode; cannam@124: cannam@124: cannam@124: /** Translate the supplied PortAudio error code into a human readable cannam@124: message. cannam@124: */ cannam@124: const char *Pa_GetErrorText( PaError errorCode ); cannam@124: cannam@124: cannam@124: /** Library initialization function - call this before using PortAudio. cannam@124: This function initializes internal data structures and prepares underlying cannam@124: host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(), cannam@124: and Pa_GetErrorText(), this function MUST be called before using any other cannam@124: PortAudio API functions. cannam@124: cannam@124: If Pa_Initialize() is called multiple times, each successful cannam@124: call must be matched with a corresponding call to Pa_Terminate(). cannam@124: Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not cannam@124: required to be fully nested. cannam@124: cannam@124: Note that if Pa_Initialize() returns an error code, Pa_Terminate() should cannam@124: NOT be called. cannam@124: cannam@124: @return paNoError if successful, otherwise an error code indicating the cause cannam@124: of failure. cannam@124: cannam@124: @see Pa_Terminate cannam@124: */ cannam@124: PaError Pa_Initialize( void ); cannam@124: cannam@124: cannam@124: /** Library termination function - call this when finished using PortAudio. cannam@124: This function deallocates all resources allocated by PortAudio since it was cannam@124: initialized by a call to Pa_Initialize(). In cases where Pa_Initialise() has cannam@124: been called multiple times, each call must be matched with a corresponding call cannam@124: to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically cannam@124: close any PortAudio streams that are still open. cannam@124: cannam@124: Pa_Terminate() MUST be called before exiting a program which uses PortAudio. cannam@124: Failure to do so may result in serious resource leaks, such as audio devices cannam@124: not being available until the next reboot. cannam@124: cannam@124: @return paNoError if successful, otherwise an error code indicating the cause cannam@124: of failure. cannam@124: cannam@124: @see Pa_Initialize cannam@124: */ cannam@124: PaError Pa_Terminate( void ); cannam@124: cannam@124: cannam@124: cannam@124: /** The type used to refer to audio devices. Values of this type usually cannam@124: range from 0 to (Pa_GetDeviceCount()-1), and may also take on the PaNoDevice cannam@124: and paUseHostApiSpecificDeviceSpecification values. cannam@124: cannam@124: @see Pa_GetDeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification cannam@124: */ cannam@124: typedef int PaDeviceIndex; cannam@124: cannam@124: cannam@124: /** A special PaDeviceIndex value indicating that no device is available, cannam@124: or should be used. cannam@124: cannam@124: @see PaDeviceIndex cannam@124: */ cannam@124: #define paNoDevice ((PaDeviceIndex)-1) cannam@124: cannam@124: cannam@124: /** A special PaDeviceIndex value indicating that the device(s) to be used cannam@124: are specified in the host api specific stream info structure. cannam@124: cannam@124: @see PaDeviceIndex cannam@124: */ cannam@124: #define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2) cannam@124: cannam@124: cannam@124: /* Host API enumeration mechanism */ cannam@124: cannam@124: /** The type used to enumerate to host APIs at runtime. Values of this type cannam@124: range from 0 to (Pa_GetHostApiCount()-1). cannam@124: cannam@124: @see Pa_GetHostApiCount cannam@124: */ cannam@124: typedef int PaHostApiIndex; cannam@124: cannam@124: cannam@124: /** Retrieve the number of available host APIs. Even if a host API is cannam@124: available it may have no devices available. cannam@124: cannam@124: @return A non-negative value indicating the number of available host APIs cannam@124: or, a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@124: or an error is encountered. cannam@124: cannam@124: @see PaHostApiIndex cannam@124: */ cannam@124: PaHostApiIndex Pa_GetHostApiCount( void ); cannam@124: cannam@124: cannam@124: /** Retrieve the index of the default host API. The default host API will be cannam@124: the lowest common denominator host API on the current platform and is cannam@124: unlikely to provide the best performance. cannam@124: cannam@124: @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1) cannam@124: indicating the default host API index or, a PaErrorCode (which are always cannam@124: negative) if PortAudio is not initialized or an error is encountered. cannam@124: */ cannam@124: PaHostApiIndex Pa_GetDefaultHostApi( void ); cannam@124: cannam@124: cannam@124: /** Unchanging unique identifiers for each supported host API. This type cannam@124: is used in the PaHostApiInfo structure. The values are guaranteed to be cannam@124: unique and to never change, thus allowing code to be written that cannam@124: conditionally uses host API specific extensions. cannam@124: cannam@124: New type ids will be allocated when support for a host API reaches cannam@124: "public alpha" status, prior to that developers should use the cannam@124: paInDevelopment type id. cannam@124: cannam@124: @see PaHostApiInfo cannam@124: */ cannam@124: typedef enum PaHostApiTypeId cannam@124: { cannam@124: paInDevelopment=0, /* use while developing support for a new host API */ cannam@124: paDirectSound=1, cannam@124: paMME=2, cannam@124: paASIO=3, cannam@124: paSoundManager=4, cannam@124: paCoreAudio=5, cannam@124: paOSS=7, cannam@124: paALSA=8, cannam@124: paAL=9, cannam@124: paBeOS=10, cannam@124: paWDMKS=11, cannam@124: paJACK=12, cannam@124: paWASAPI=13, cannam@124: paAudioScienceHPI=14 cannam@124: } PaHostApiTypeId; cannam@124: cannam@124: cannam@124: /** A structure containing information about a particular host API. */ cannam@124: cannam@124: typedef struct PaHostApiInfo cannam@124: { cannam@124: /** this is struct version 1 */ cannam@124: int structVersion; cannam@124: /** The well known unique identifier of this host API @see PaHostApiTypeId */ cannam@124: PaHostApiTypeId type; cannam@124: /** A textual description of the host API for display on user interfaces. */ cannam@124: const char *name; cannam@124: cannam@124: /** The number of devices belonging to this host API. This field may be cannam@124: used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate cannam@124: all devices for this host API. cannam@124: @see Pa_HostApiDeviceIndexToDeviceIndex cannam@124: */ cannam@124: int deviceCount; cannam@124: cannam@124: /** The default input device for this host API. The value will be a cannam@124: device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice cannam@124: if no default input device is available. cannam@124: */ cannam@124: PaDeviceIndex defaultInputDevice; cannam@124: cannam@124: /** The default output device for this host API. The value will be a cannam@124: device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice cannam@124: if no default output device is available. cannam@124: */ cannam@124: PaDeviceIndex defaultOutputDevice; cannam@124: cannam@124: } PaHostApiInfo; cannam@124: cannam@124: cannam@124: /** Retrieve a pointer to a structure containing information about a specific cannam@124: host Api. cannam@124: cannam@124: @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) cannam@124: cannam@124: @return A pointer to an immutable PaHostApiInfo structure describing cannam@124: a specific host API. If the hostApi parameter is out of range or an error cannam@124: is encountered, the function returns NULL. cannam@124: cannam@124: The returned structure is owned by the PortAudio implementation and must not cannam@124: be manipulated or freed. The pointer is only guaranteed to be valid between cannam@124: calls to Pa_Initialize() and Pa_Terminate(). cannam@124: */ cannam@124: const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi ); cannam@124: cannam@124: cannam@124: /** Convert a static host API unique identifier, into a runtime cannam@124: host API index. cannam@124: cannam@124: @param type A unique host API identifier belonging to the PaHostApiTypeId cannam@124: enumeration. cannam@124: cannam@124: @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or, cannam@124: a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@124: or an error is encountered. cannam@124: cannam@124: The paHostApiNotFound error code indicates that the host API specified by the cannam@124: type parameter is not available. cannam@124: cannam@124: @see PaHostApiTypeId cannam@124: */ cannam@124: PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type ); cannam@124: cannam@124: cannam@124: /** Convert a host-API-specific device index to standard PortAudio device index. cannam@124: This function may be used in conjunction with the deviceCount field of cannam@124: PaHostApiInfo to enumerate all devices for the specified host API. cannam@124: cannam@124: @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) cannam@124: cannam@124: @param hostApiDeviceIndex A valid per-host device index in the range cannam@124: 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) cannam@124: cannam@124: @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1) cannam@124: or, a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@124: or an error is encountered. cannam@124: cannam@124: A paInvalidHostApi error code indicates that the host API index specified by cannam@124: the hostApi parameter is out of range. cannam@124: cannam@124: A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter cannam@124: is out of range. cannam@124: cannam@124: @see PaHostApiInfo cannam@124: */ cannam@124: PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi, cannam@124: int hostApiDeviceIndex ); cannam@124: cannam@124: cannam@124: cannam@124: /** Structure used to return information about a host error condition. cannam@124: */ cannam@124: typedef struct PaHostErrorInfo{ cannam@124: PaHostApiTypeId hostApiType; /**< the host API which returned the error code */ cannam@124: long errorCode; /**< the error code returned */ cannam@124: const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */ cannam@124: }PaHostErrorInfo; cannam@124: cannam@124: cannam@124: /** Return information about the last host error encountered. The error cannam@124: information returned by Pa_GetLastHostErrorInfo() will never be modified cannam@124: asynchronously by errors occurring in other PortAudio owned threads cannam@124: (such as the thread that manages the stream callback.) cannam@124: cannam@124: This function is provided as a last resort, primarily to enhance debugging cannam@124: by providing clients with access to all available error information. cannam@124: cannam@124: @return A pointer to an immutable structure constraining information about cannam@124: the host error. The values in this structure will only be valid if a cannam@124: PortAudio function has previously returned the paUnanticipatedHostError cannam@124: error code. cannam@124: */ cannam@124: const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void ); cannam@124: cannam@124: cannam@124: cannam@124: /* Device enumeration and capabilities */ cannam@124: cannam@124: /** Retrieve the number of available devices. The number of available devices cannam@124: may be zero. cannam@124: cannam@124: @return A non-negative value indicating the number of available devices or, cannam@124: a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@124: or an error is encountered. cannam@124: */ cannam@124: PaDeviceIndex Pa_GetDeviceCount( void ); cannam@124: cannam@124: cannam@124: /** Retrieve the index of the default input device. The result can be cannam@124: used in the inputDevice parameter to Pa_OpenStream(). cannam@124: cannam@124: @return The default input device index for the default host API, or paNoDevice cannam@124: if no default input device is available or an error was encountered. cannam@124: */ cannam@124: PaDeviceIndex Pa_GetDefaultInputDevice( void ); cannam@124: cannam@124: cannam@124: /** Retrieve the index of the default output device. The result can be cannam@124: used in the outputDevice parameter to Pa_OpenStream(). cannam@124: cannam@124: @return The default output device index for the default host API, or paNoDevice cannam@124: if no default output device is available or an error was encountered. cannam@124: cannam@124: @note cannam@124: On the PC, the user can specify a default device by cannam@124: setting an environment variable. For example, to use device #1. cannam@124: 
cannam@124:  set PA_RECOMMENDED_OUTPUT_DEVICE=1
cannam@124:
cannam@124: The user should first determine the available device ids by using cannam@124: the supplied application "pa_devs". cannam@124: */ cannam@124: PaDeviceIndex Pa_GetDefaultOutputDevice( void ); cannam@124: cannam@124: cannam@124: /** The type used to represent monotonic time in seconds. PaTime is cannam@124: used for the fields of the PaStreamCallbackTimeInfo argument to the cannam@124: PaStreamCallback and as the result of Pa_GetStreamTime(). cannam@124: cannam@124: PaTime values have unspecified origin. cannam@124: cannam@124: @see PaStreamCallback, PaStreamCallbackTimeInfo, Pa_GetStreamTime cannam@124: */ cannam@124: typedef double PaTime; cannam@124: cannam@124: cannam@124: /** A type used to specify one or more sample formats. Each value indicates cannam@124: a possible format for sound data passed to and from the stream callback, cannam@124: Pa_ReadStream and Pa_WriteStream. cannam@124: cannam@124: The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8 cannam@124: and aUInt8 are usually implemented by all implementations. cannam@124: cannam@124: The floating point representation (paFloat32) uses +1.0 and -1.0 as the cannam@124: maximum and minimum respectively. cannam@124: cannam@124: paUInt8 is an unsigned 8 bit format where 128 is considered "ground" cannam@124: cannam@124: The paNonInterleaved flag indicates that audio data is passed as an array cannam@124: of pointers to separate buffers, one buffer for each channel. Usually, cannam@124: when this flag is not used, audio data is passed as a single buffer with cannam@124: all channels interleaved. cannam@124: cannam@124: @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo cannam@124: @see paFloat32, paInt16, paInt32, paInt24, paInt8 cannam@124: @see paUInt8, paCustomFormat, paNonInterleaved cannam@124: */ cannam@124: typedef unsigned long PaSampleFormat; cannam@124: cannam@124: cannam@124: #define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */ cannam@124: #define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */ cannam@124: #define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */ cannam@124: #define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */ cannam@124: #define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */ cannam@124: #define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */ cannam@124: #define paCustomFormat ((PaSampleFormat) 0x00010000) /**< @see PaSampleFormat */ cannam@124: cannam@124: #define paNonInterleaved ((PaSampleFormat) 0x80000000) /**< @see PaSampleFormat */ cannam@124: cannam@124: /** A structure providing information and capabilities of PortAudio devices. cannam@124: Devices may support input, output or both input and output. cannam@124: */ cannam@124: typedef struct PaDeviceInfo cannam@124: { cannam@124: int structVersion; /* this is struct version 2 */ cannam@124: const char *name; cannam@124: PaHostApiIndex hostApi; /**< note this is a host API index, not a type id*/ cannam@124: cannam@124: int maxInputChannels; cannam@124: int maxOutputChannels; cannam@124: cannam@124: /** Default latency values for interactive performance. */ cannam@124: PaTime defaultLowInputLatency; cannam@124: PaTime defaultLowOutputLatency; cannam@124: /** Default latency values for robust non-interactive applications (eg. playing sound files). */ cannam@124: PaTime defaultHighInputLatency; cannam@124: PaTime defaultHighOutputLatency; cannam@124: cannam@124: double defaultSampleRate; cannam@124: } PaDeviceInfo; cannam@124: cannam@124: cannam@124: /** Retrieve a pointer to a PaDeviceInfo structure containing information cannam@124: about the specified device. cannam@124: @return A pointer to an immutable PaDeviceInfo structure. If the device cannam@124: parameter is out of range the function returns NULL. cannam@124: cannam@124: @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1) cannam@124: cannam@124: @note PortAudio manages the memory referenced by the returned pointer, cannam@124: the client must not manipulate or free the memory. The pointer is only cannam@124: guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate(). cannam@124: cannam@124: @see PaDeviceInfo, PaDeviceIndex cannam@124: */ cannam@124: const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device ); cannam@124: cannam@124: cannam@124: /** Parameters for one direction (input or output) of a stream. cannam@124: */ cannam@124: typedef struct PaStreamParameters cannam@124: { cannam@124: /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1) cannam@124: specifying the device to be used or the special constant cannam@124: paUseHostApiSpecificDeviceSpecification which indicates that the actual cannam@124: device(s) to use are specified in hostApiSpecificStreamInfo. cannam@124: This field must not be set to paNoDevice. cannam@124: */ cannam@124: PaDeviceIndex device; cannam@124: cannam@124: /** The number of channels of sound to be delivered to the cannam@124: stream callback or accessed by Pa_ReadStream() or Pa_WriteStream(). cannam@124: It can range from 1 to the value of maxInputChannels in the cannam@124: PaDeviceInfo record for the device specified by the device parameter. cannam@124: */ cannam@124: int channelCount; cannam@124: cannam@124: /** The sample format of the buffer provided to the stream callback, cannam@124: a_ReadStream() or Pa_WriteStream(). It may be any of the formats described cannam@124: by the PaSampleFormat enumeration. cannam@124: */ cannam@124: PaSampleFormat sampleFormat; cannam@124: cannam@124: /** The desired latency in seconds. Where practical, implementations should cannam@124: configure their latency based on these parameters, otherwise they may cannam@124: choose the closest viable latency instead. Unless the suggested latency cannam@124: is greater than the absolute upper limit for the device implementations cannam@124: should round the suggestedLatency up to the next practical value - ie to cannam@124: provide an equal or higher latency than suggestedLatency wherever possible. cannam@124: Actual latency values for an open stream may be retrieved using the cannam@124: inputLatency and outputLatency fields of the PaStreamInfo structure cannam@124: returned by Pa_GetStreamInfo(). cannam@124: @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo cannam@124: */ cannam@124: PaTime suggestedLatency; cannam@124: cannam@124: /** An optional pointer to a host api specific data structure cannam@124: containing additional information for device setup and/or stream processing. cannam@124: hostApiSpecificStreamInfo is never required for correct operation, cannam@124: if not used it should be set to NULL. cannam@124: */ cannam@124: void *hostApiSpecificStreamInfo; cannam@124: cannam@124: } PaStreamParameters; cannam@124: cannam@124: cannam@124: /** Return code for Pa_IsFormatSupported indicating success. */ cannam@124: #define paFormatIsSupported (0) cannam@124: cannam@124: /** Determine whether it would be possible to open a stream with the specified cannam@124: parameters. cannam@124: cannam@124: @param inputParameters A structure that describes the input parameters used to cannam@124: open a stream. The suggestedLatency field is ignored. See PaStreamParameters cannam@124: for a description of these parameters. inputParameters must be NULL for cannam@124: output-only streams. cannam@124: cannam@124: @param outputParameters A structure that describes the output parameters used cannam@124: to open a stream. The suggestedLatency field is ignored. See PaStreamParameters cannam@124: for a description of these parameters. outputParameters must be NULL for cannam@124: input-only streams. cannam@124: cannam@124: @param sampleRate The required sampleRate. For full-duplex streams it is the cannam@124: sample rate for both input and output cannam@124: cannam@124: @return Returns 0 if the format is supported, and an error code indicating why cannam@124: the format is not supported otherwise. The constant paFormatIsSupported is cannam@124: provided to compare with the return value for success. cannam@124: cannam@124: @see paFormatIsSupported, PaStreamParameters cannam@124: */ cannam@124: PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters, cannam@124: const PaStreamParameters *outputParameters, cannam@124: double sampleRate ); cannam@124: cannam@124: cannam@124: cannam@124: /* Streaming types and functions */ cannam@124: cannam@124: cannam@124: /** cannam@124: A single PaStream can provide multiple channels of real-time cannam@124: streaming audio input and output to a client application. A stream cannam@124: provides access to audio hardware represented by one or more cannam@124: PaDevices. Depending on the underlying Host API, it may be possible cannam@124: to open multiple streams using the same device, however this behavior cannam@124: is implementation defined. Portable applications should assume that cannam@124: a PaDevice may be simultaneously used by at most one PaStream. cannam@124: cannam@124: Pointers to PaStream objects are passed between PortAudio functions that cannam@124: operate on streams. cannam@124: cannam@124: @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream, cannam@124: Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive, cannam@124: Pa_GetStreamTime, Pa_GetStreamCpuLoad cannam@124: cannam@124: */ cannam@124: typedef void PaStream; cannam@124: cannam@124: cannam@124: /** Can be passed as the framesPerBuffer parameter to Pa_OpenStream() cannam@124: or Pa_OpenDefaultStream() to indicate that the stream callback will cannam@124: accept buffers of any size. cannam@124: */ cannam@124: #define paFramesPerBufferUnspecified (0) cannam@124: cannam@124: cannam@124: /** Flags used to control the behavior of a stream. They are passed as cannam@124: parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be cannam@124: ORed together. cannam@124: cannam@124: @see Pa_OpenStream, Pa_OpenDefaultStream cannam@124: @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput, cannam@124: paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags cannam@124: */ cannam@124: typedef unsigned long PaStreamFlags; cannam@124: cannam@124: /** @see PaStreamFlags */ cannam@124: #define paNoFlag ((PaStreamFlags) 0) cannam@124: cannam@124: /** Disable default clipping of out of range samples. cannam@124: @see PaStreamFlags cannam@124: */ cannam@124: #define paClipOff ((PaStreamFlags) 0x00000001) cannam@124: cannam@124: /** Disable default dithering. cannam@124: @see PaStreamFlags cannam@124: */ cannam@124: #define paDitherOff ((PaStreamFlags) 0x00000002) cannam@124: cannam@124: /** Flag requests that where possible a full duplex stream will not discard cannam@124: overflowed input samples without calling the stream callback. This flag is cannam@124: only valid for full duplex callback streams and only when used in combination cannam@124: with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using cannam@124: this flag incorrectly results in a paInvalidFlag error being returned from cannam@124: Pa_OpenStream and Pa_OpenDefaultStream. cannam@124: cannam@124: @see PaStreamFlags, paFramesPerBufferUnspecified cannam@124: */ cannam@124: #define paNeverDropInput ((PaStreamFlags) 0x00000004) cannam@124: cannam@124: /** Call the stream callback to fill initial output buffers, rather than the cannam@124: default behavior of priming the buffers with zeros (silence). This flag has cannam@124: no effect for input-only and blocking read/write streams. cannam@124: cannam@124: @see PaStreamFlags cannam@124: */ cannam@124: #define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008) cannam@124: cannam@124: /** A mask specifying the platform specific bits. cannam@124: @see PaStreamFlags cannam@124: */ cannam@124: #define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000) cannam@124: cannam@124: /** cannam@124: Timing information for the buffers passed to the stream callback. cannam@124: cannam@124: Time values are expressed in seconds and are synchronised with the time base used by Pa_GetStreamTime() for the associated stream. cannam@124: cannam@124: @see PaStreamCallback, Pa_GetStreamTime cannam@124: */ cannam@124: typedef struct PaStreamCallbackTimeInfo{ cannam@124: PaTime inputBufferAdcTime; /**< The time when the first sample of the input buffer was captured at the ADC input */ cannam@124: PaTime currentTime; /**< The time when the stream callback was invoked */ cannam@124: PaTime outputBufferDacTime; /**< The time when the first sample of the output buffer will output the DAC */ cannam@124: } PaStreamCallbackTimeInfo; cannam@124: cannam@124: cannam@124: /** cannam@124: Flag bit constants for the statusFlags to PaStreamCallback. cannam@124: cannam@124: @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow, cannam@124: paPrimingOutput cannam@124: */ cannam@124: typedef unsigned long PaStreamCallbackFlags; cannam@124: cannam@124: /** In a stream opened with paFramesPerBufferUnspecified, indicates that cannam@124: input data is all silence (zeros) because no real data is available. In a cannam@124: stream opened without paFramesPerBufferUnspecified, it indicates that one or cannam@124: more zero samples have been inserted into the input buffer to compensate cannam@124: for an input underflow. cannam@124: @see PaStreamCallbackFlags cannam@124: */ cannam@124: #define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001) cannam@124: cannam@124: /** In a stream opened with paFramesPerBufferUnspecified, indicates that data cannam@124: prior to the first sample of the input buffer was discarded due to an cannam@124: overflow, possibly because the stream callback is using too much CPU time. cannam@124: Otherwise indicates that data prior to one or more samples in the cannam@124: input buffer was discarded. cannam@124: @see PaStreamCallbackFlags cannam@124: */ cannam@124: #define paInputOverflow ((PaStreamCallbackFlags) 0x00000002) cannam@124: cannam@124: /** Indicates that output data (or a gap) was inserted, possibly because the cannam@124: stream callback is using too much CPU time. cannam@124: @see PaStreamCallbackFlags cannam@124: */ cannam@124: #define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004) cannam@124: cannam@124: /** Indicates that output data will be discarded because no room is available. cannam@124: @see PaStreamCallbackFlags cannam@124: */ cannam@124: #define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008) cannam@124: cannam@124: /** Some of all of the output data will be used to prime the stream, input cannam@124: data may be zero. cannam@124: @see PaStreamCallbackFlags cannam@124: */ cannam@124: #define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010) cannam@124: cannam@124: /** cannam@124: Allowable return values for the PaStreamCallback. cannam@124: @see PaStreamCallback cannam@124: */ cannam@124: typedef enum PaStreamCallbackResult cannam@124: { cannam@124: paContinue=0, /**< Signal that the stream should continue invoking the callback and processing audio. */ cannam@124: paComplete=1, /**< Signal that the stream should stop invoking the callback and finish once all output samples have played. */ cannam@124: paAbort=2 /**< Signal that the stream should stop invoking the callback and finish as soon as possible. */ cannam@124: } PaStreamCallbackResult; cannam@124: cannam@124: cannam@124: /** cannam@124: Functions of type PaStreamCallback are implemented by PortAudio clients. cannam@124: They consume, process or generate audio in response to requests from an cannam@124: active PortAudio stream. cannam@124: cannam@124: When a stream is running, PortAudio calls the stream callback periodically. cannam@124: The callback function is responsible for processing buffers of audio samples cannam@124: passed via the input and output parameters. cannam@124: cannam@124: The PortAudio stream callback runs at very high or real-time priority. cannam@124: It is required to consistently meet its time deadlines. Do not allocate cannam@124: memory, access the file system, call library functions or call other functions cannam@124: from the stream callback that may block or take an unpredictable amount of cannam@124: time to complete. cannam@124: cannam@124: In order for a stream to maintain glitch-free operation the callback cannam@124: must consume and return audio data faster than it is recorded and/or cannam@124: played. PortAudio anticipates that each callback invocation may execute for cannam@124: a duration approaching the duration of frameCount audio frames at the stream cannam@124: sample rate. It is reasonable to expect to be able to utilise 70% or more of cannam@124: the available CPU time in the PortAudio callback. However, due to buffer size cannam@124: adaption and other factors, not all host APIs are able to guarantee audio cannam@124: stability under heavy CPU load with arbitrary fixed callback buffer sizes. cannam@124: When high callback CPU utilisation is required the most robust behavior cannam@124: can be achieved by using paFramesPerBufferUnspecified as the cannam@124: Pa_OpenStream() framesPerBuffer parameter. cannam@124: cannam@124: @param input and @param output are either arrays of interleaved samples or; cannam@124: if non-interleaved samples were requested using the paNonInterleaved sample cannam@124: format flag, an array of buffer pointers, one non-interleaved buffer for cannam@124: each channel. cannam@124: cannam@124: The format, packing and number of channels used by the buffers are cannam@124: determined by parameters to Pa_OpenStream(). cannam@124: cannam@124: @param frameCount The number of sample frames to be processed by cannam@124: the stream callback. cannam@124: cannam@124: @param timeInfo Timestamps indicating the ADC capture time of the first sample cannam@124: in the input buffer, the DAC output time of the first sample in the output buffer cannam@124: and the time the callback was invoked. cannam@124: See PaStreamCallbackTimeInfo and Pa_GetStreamTime() cannam@124: cannam@124: @param statusFlags Flags indicating whether input and/or output buffers cannam@124: have been inserted or will be dropped to overcome underflow or overflow cannam@124: conditions. cannam@124: cannam@124: @param userData The value of a user supplied pointer passed to cannam@124: Pa_OpenStream() intended for storing synthesis data etc. cannam@124: cannam@124: @return cannam@124: The stream callback should return one of the values in the cannam@124: ::PaStreamCallbackResult enumeration. To ensure that the callback continues cannam@124: to be called, it should return paContinue (0). Either paComplete or paAbort cannam@124: can be returned to finish stream processing, after either of these values is cannam@124: returned the callback will not be called again. If paAbort is returned the cannam@124: stream will finish as soon as possible. If paComplete is returned, the stream cannam@124: will continue until all buffers generated by the callback have been played. cannam@124: This may be useful in applications such as soundfile players where a specific cannam@124: duration of output is required. However, it is not necessary to utilize this cannam@124: mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also cannam@124: be used to stop the stream. The callback must always fill the entire output cannam@124: buffer irrespective of its return value. cannam@124: cannam@124: @see Pa_OpenStream, Pa_OpenDefaultStream cannam@124: cannam@124: @note With the exception of Pa_GetStreamCpuLoad() it is not permissible to call cannam@124: PortAudio API functions from within the stream callback. cannam@124: */ cannam@124: typedef int PaStreamCallback( cannam@124: const void *input, void *output, cannam@124: unsigned long frameCount, cannam@124: const PaStreamCallbackTimeInfo* timeInfo, cannam@124: PaStreamCallbackFlags statusFlags, cannam@124: void *userData ); cannam@124: cannam@124: cannam@124: /** Opens a stream for either input, output or both. cannam@124: cannam@124: @param stream The address of a PaStream pointer which will receive cannam@124: a pointer to the newly opened stream. cannam@124: cannam@124: @param inputParameters A structure that describes the input parameters used by cannam@124: the opened stream. See PaStreamParameters for a description of these parameters. cannam@124: inputParameters must be NULL for output-only streams. cannam@124: cannam@124: @param outputParameters A structure that describes the output parameters used by cannam@124: the opened stream. See PaStreamParameters for a description of these parameters. cannam@124: outputParameters must be NULL for input-only streams. cannam@124: cannam@124: @param sampleRate The desired sampleRate. For full-duplex streams it is the cannam@124: sample rate for both input and output cannam@124: cannam@124: @param framesPerBuffer The number of frames passed to the stream callback cannam@124: function, or the preferred block granularity for a blocking read/write stream. cannam@124: The special value paFramesPerBufferUnspecified (0) may be used to request that cannam@124: the stream callback will receive an optimal (and possibly varying) number of cannam@124: frames based on host requirements and the requested latency settings. cannam@124: Note: With some host APIs, the use of non-zero framesPerBuffer for a callback cannam@124: stream may introduce an additional layer of buffering which could introduce cannam@124: additional latency. PortAudio guarantees that the additional latency cannam@124: will be kept to the theoretical minimum however, it is strongly recommended cannam@124: that a non-zero framesPerBuffer value only be used when your algorithm cannam@124: requires a fixed number of frames per stream callback. cannam@124: cannam@124: @param streamFlags Flags which modify the behavior of the streaming process. cannam@124: This parameter may contain a combination of flags ORed together. Some flags may cannam@124: only be relevant to certain buffer formats. cannam@124: cannam@124: @param streamCallback A pointer to a client supplied function that is responsible cannam@124: for processing and filling input and output buffers. If this parameter is NULL cannam@124: the stream will be opened in 'blocking read/write' mode. In blocking mode, cannam@124: the client can receive sample data using Pa_ReadStream and write sample data cannam@124: using Pa_WriteStream, the number of samples that may be read or written cannam@124: without blocking is returned by Pa_GetStreamReadAvailable and cannam@124: Pa_GetStreamWriteAvailable respectively. cannam@124: cannam@124: @param userData A client supplied pointer which is passed to the stream callback cannam@124: function. It could for example, contain a pointer to instance data necessary cannam@124: for processing the audio buffers. This parameter is ignored if streamCallback cannam@124: is NULL. cannam@124: cannam@124: @return cannam@124: Upon success Pa_OpenStream() returns paNoError and places a pointer to a cannam@124: valid PaStream in the stream argument. The stream is inactive (stopped). cannam@124: If a call to Pa_OpenStream() fails, a non-zero error code is returned (see cannam@124: PaError for possible error codes) and the value of stream is invalid. cannam@124: cannam@124: @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream, cannam@124: Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable cannam@124: */ cannam@124: PaError Pa_OpenStream( PaStream** stream, cannam@124: const PaStreamParameters *inputParameters, cannam@124: const PaStreamParameters *outputParameters, cannam@124: double sampleRate, cannam@124: unsigned long framesPerBuffer, cannam@124: PaStreamFlags streamFlags, cannam@124: PaStreamCallback *streamCallback, cannam@124: void *userData ); cannam@124: cannam@124: cannam@124: /** A simplified version of Pa_OpenStream() that opens the default input cannam@124: and/or output devices. cannam@124: cannam@124: @param stream The address of a PaStream pointer which will receive cannam@124: a pointer to the newly opened stream. cannam@124: cannam@124: @param numInputChannels The number of channels of sound that will be supplied cannam@124: to the stream callback or returned by Pa_ReadStream. It can range from 1 to cannam@124: the value of maxInputChannels in the PaDeviceInfo record for the default input cannam@124: device. If 0 the stream is opened as an output-only stream. cannam@124: cannam@124: @param numOutputChannels The number of channels of sound to be delivered to the cannam@124: stream callback or passed to Pa_WriteStream. It can range from 1 to the value cannam@124: of maxOutputChannels in the PaDeviceInfo record for the default output device. cannam@124: If 0 the stream is opened as an output-only stream. cannam@124: cannam@124: @param sampleFormat The sample format of both the input and output buffers cannam@124: provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. cannam@124: sampleFormat may be any of the formats described by the PaSampleFormat cannam@124: enumeration. cannam@124: cannam@124: @param sampleRate Same as Pa_OpenStream parameter of the same name. cannam@124: @param framesPerBuffer Same as Pa_OpenStream parameter of the same name. cannam@124: @param streamCallback Same as Pa_OpenStream parameter of the same name. cannam@124: @param userData Same as Pa_OpenStream parameter of the same name. cannam@124: cannam@124: @return As for Pa_OpenStream cannam@124: cannam@124: @see Pa_OpenStream, PaStreamCallback cannam@124: */ cannam@124: PaError Pa_OpenDefaultStream( PaStream** stream, cannam@124: int numInputChannels, cannam@124: int numOutputChannels, cannam@124: PaSampleFormat sampleFormat, cannam@124: double sampleRate, cannam@124: unsigned long framesPerBuffer, cannam@124: PaStreamCallback *streamCallback, cannam@124: void *userData ); cannam@124: cannam@124: cannam@124: /** Closes an audio stream. If the audio stream is active it cannam@124: discards any pending buffers as if Pa_AbortStream() had been called. cannam@124: */ cannam@124: PaError Pa_CloseStream( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Functions of type PaStreamFinishedCallback are implemented by PortAudio cannam@124: clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback cannam@124: function. Once registered they are called when the stream becomes inactive cannam@124: (ie once a call to Pa_StopStream() will not block). cannam@124: A stream will become inactive after the stream callback returns non-zero, cannam@124: or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio cannam@124: output, if the stream callback returns paComplete, or Pa_StopStream is called, cannam@124: the stream finished callback will not be called until all generated sample data cannam@124: has been played. cannam@124: cannam@124: @param userData The userData parameter supplied to Pa_OpenStream() cannam@124: cannam@124: @see Pa_SetStreamFinishedCallback cannam@124: */ cannam@124: typedef void PaStreamFinishedCallback( void *userData ); cannam@124: cannam@124: cannam@124: /** Register a stream finished callback function which will be called when the cannam@124: stream becomes inactive. See the description of PaStreamFinishedCallback for cannam@124: further details about when the callback will be called. cannam@124: cannam@124: @param stream a pointer to a PaStream that is in the stopped state - if the cannam@124: stream is not stopped, the stream's finished callback will remain unchanged cannam@124: and an error code will be returned. cannam@124: cannam@124: @param streamFinishedCallback a pointer to a function with the same signature cannam@124: as PaStreamFinishedCallback, that will be called when the stream becomes cannam@124: inactive. Passing NULL for this parameter will un-register a previously cannam@124: registered stream finished callback function. cannam@124: cannam@124: @return on success returns paNoError, otherwise an error code indicating the cause cannam@124: of the error. cannam@124: cannam@124: @see PaStreamFinishedCallback cannam@124: */ cannam@124: PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback ); cannam@124: cannam@124: cannam@124: /** Commences audio processing. cannam@124: */ cannam@124: PaError Pa_StartStream( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Terminates audio processing. It waits until all pending cannam@124: audio buffers have been played before it returns. cannam@124: */ cannam@124: PaError Pa_StopStream( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Terminates audio processing immediately without waiting for pending cannam@124: buffers to complete. cannam@124: */ cannam@124: PaError Pa_AbortStream( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Determine whether the stream is stopped. cannam@124: A stream is considered to be stopped prior to a successful call to cannam@124: Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. cannam@124: If a stream callback returns a value other than paContinue the stream is NOT cannam@124: considered to be stopped. cannam@124: cannam@124: @return Returns one (1) when the stream is stopped, zero (0) when cannam@124: the stream is running or, a PaErrorCode (which are always negative) if cannam@124: PortAudio is not initialized or an error is encountered. cannam@124: cannam@124: @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive cannam@124: */ cannam@124: PaError Pa_IsStreamStopped( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Determine whether the stream is active. cannam@124: A stream is active after a successful call to Pa_StartStream(), until it cannam@124: becomes inactive either as a result of a call to Pa_StopStream() or cannam@124: Pa_AbortStream(), or as a result of a return value other than paContinue from cannam@124: the stream callback. In the latter case, the stream is considered inactive cannam@124: after the last buffer has finished playing. cannam@124: cannam@124: @return Returns one (1) when the stream is active (ie playing or recording cannam@124: audio), zero (0) when not playing or, a PaErrorCode (which are always negative) cannam@124: if PortAudio is not initialized or an error is encountered. cannam@124: cannam@124: @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped cannam@124: */ cannam@124: PaError Pa_IsStreamActive( PaStream *stream ); cannam@124: cannam@124: cannam@124: cannam@124: /** A structure containing unchanging information about an open stream. cannam@124: @see Pa_GetStreamInfo cannam@124: */ cannam@124: cannam@124: typedef struct PaStreamInfo cannam@124: { cannam@124: /** this is struct version 1 */ cannam@124: int structVersion; cannam@124: cannam@124: /** The input latency of the stream in seconds. This value provides the most cannam@124: accurate estimate of input latency available to the implementation. It may cannam@124: differ significantly from the suggestedLatency value passed to Pa_OpenStream(). cannam@124: The value of this field will be zero (0.) for output-only streams. cannam@124: @see PaTime cannam@124: */ cannam@124: PaTime inputLatency; cannam@124: cannam@124: /** The output latency of the stream in seconds. This value provides the most cannam@124: accurate estimate of output latency available to the implementation. It may cannam@124: differ significantly from the suggestedLatency value passed to Pa_OpenStream(). cannam@124: The value of this field will be zero (0.) for input-only streams. cannam@124: @see PaTime cannam@124: */ cannam@124: PaTime outputLatency; cannam@124: cannam@124: /** The sample rate of the stream in Hertz (samples per second). In cases cannam@124: where the hardware sample rate is inaccurate and PortAudio is aware of it, cannam@124: the value of this field may be different from the sampleRate parameter cannam@124: passed to Pa_OpenStream(). If information about the actual hardware sample cannam@124: rate is not available, this field will have the same value as the sampleRate cannam@124: parameter passed to Pa_OpenStream(). cannam@124: */ cannam@124: double sampleRate; cannam@124: cannam@124: } PaStreamInfo; cannam@124: cannam@124: cannam@124: /** Retrieve a pointer to a PaStreamInfo structure containing information cannam@124: about the specified stream. cannam@124: @return A pointer to an immutable PaStreamInfo structure. If the stream cannam@124: parameter is invalid, or an error is encountered, the function returns NULL. cannam@124: cannam@124: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@124: cannam@124: @note PortAudio manages the memory referenced by the returned pointer, cannam@124: the client must not manipulate or free the memory. The pointer is only cannam@124: guaranteed to be valid until the specified stream is closed. cannam@124: cannam@124: @see PaStreamInfo cannam@124: */ cannam@124: const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Returns the current time in seconds for a stream according to the same clock used cannam@124: to generate callback PaStreamCallbackTimeInfo timestamps. The time values are cannam@124: monotonically increasing and have unspecified origin. cannam@124: cannam@124: Pa_GetStreamTime returns valid time values for the entire life of the stream, cannam@124: from when the stream is opened until it is closed. Starting and stopping the stream cannam@124: does not affect the passage of time returned by Pa_GetStreamTime. cannam@124: cannam@124: This time may be used for synchronizing other events to the audio stream, for cannam@124: example synchronizing audio to MIDI. cannam@124: cannam@124: @return The stream's current time in seconds, or 0 if an error occurred. cannam@124: cannam@124: @see PaTime, PaStreamCallback, PaStreamCallbackTimeInfo cannam@124: */ cannam@124: PaTime Pa_GetStreamTime( PaStream *stream ); cannam@124: cannam@124: cannam@124: /** Retrieve CPU usage information for the specified stream. cannam@124: The "CPU Load" is a fraction of total CPU time consumed by a callback stream's cannam@124: audio processing routines including, but not limited to the client supplied cannam@124: stream callback. This function does not work with blocking read/write streams. cannam@124: cannam@124: This function may be called from the stream callback function or the cannam@124: application. cannam@124: cannam@124: @return cannam@124: A floating point value, typically between 0.0 and 1.0, where 1.0 indicates cannam@124: that the stream callback is consuming the maximum number of CPU cycles possible cannam@124: to maintain real-time operation. A value of 0.5 would imply that PortAudio and cannam@124: the stream callback was consuming roughly 50% of the available CPU time. The cannam@124: return value may exceed 1.0. A value of 0.0 will always be returned for a cannam@124: blocking read/write stream, or if an error occurs. cannam@124: */ cannam@124: double Pa_GetStreamCpuLoad( PaStream* stream ); cannam@124: cannam@124: cannam@124: /** Read samples from an input stream. The function doesn't return until cannam@124: the entire buffer has been filled - this may involve waiting for the operating cannam@124: system to supply the data. cannam@124: cannam@124: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@124: cannam@124: @param buffer A pointer to a buffer of sample frames. The buffer contains cannam@124: samples in the format specified by the inputParameters->sampleFormat field cannam@124: used to open the stream, and the number of channels specified by cannam@124: inputParameters->numChannels. If non-interleaved samples were requested using cannam@124: the paNonInterleaved sample format flag, buffer is a pointer to the first element cannam@124: of an array of buffer pointers, one non-interleaved buffer for each channel. cannam@124: cannam@124: @param frames The number of frames to be read into buffer. This parameter cannam@124: is not constrained to a specific range, however high performance applications cannam@124: will want to match this parameter to the framesPerBuffer parameter used cannam@124: when opening the stream. cannam@124: cannam@124: @return On success PaNoError will be returned, or PaInputOverflowed if input cannam@124: data was discarded by PortAudio after the previous call and before this call. cannam@124: */ cannam@124: PaError Pa_ReadStream( PaStream* stream, cannam@124: void *buffer, cannam@124: unsigned long frames ); cannam@124: cannam@124: cannam@124: /** Write samples to an output stream. This function doesn't return until the cannam@124: entire buffer has been consumed - this may involve waiting for the operating cannam@124: system to consume the data. cannam@124: cannam@124: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@124: cannam@124: @param buffer A pointer to a buffer of sample frames. The buffer contains cannam@124: samples in the format specified by the outputParameters->sampleFormat field cannam@124: used to open the stream, and the number of channels specified by cannam@124: outputParameters->numChannels. If non-interleaved samples were requested using cannam@124: the paNonInterleaved sample format flag, buffer is a pointer to the first element cannam@124: of an array of buffer pointers, one non-interleaved buffer for each channel. cannam@124: cannam@124: @param frames The number of frames to be written from buffer. This parameter cannam@124: is not constrained to a specific range, however high performance applications cannam@124: will want to match this parameter to the framesPerBuffer parameter used cannam@124: when opening the stream. cannam@124: cannam@124: @return On success PaNoError will be returned, or paOutputUnderflowed if cannam@124: additional output data was inserted after the previous call and before this cannam@124: call. cannam@124: */ cannam@124: PaError Pa_WriteStream( PaStream* stream, cannam@124: const void *buffer, cannam@124: unsigned long frames ); cannam@124: cannam@124: cannam@124: /** Retrieve the number of frames that can be read from the stream without cannam@124: waiting. cannam@124: cannam@124: @return Returns a non-negative value representing the maximum number of frames cannam@124: that can be read from the stream without blocking or busy waiting or, a cannam@124: PaErrorCode (which are always negative) if PortAudio is not initialized or an cannam@124: error is encountered. cannam@124: */ cannam@124: signed long Pa_GetStreamReadAvailable( PaStream* stream ); cannam@124: cannam@124: cannam@124: /** Retrieve the number of frames that can be written to the stream without cannam@124: waiting. cannam@124: cannam@124: @return Returns a non-negative value representing the maximum number of frames cannam@124: that can be written to the stream without blocking or busy waiting or, a cannam@124: PaErrorCode (which are always negative) if PortAudio is not initialized or an cannam@124: error is encountered. cannam@124: */ cannam@124: signed long Pa_GetStreamWriteAvailable( PaStream* stream ); cannam@124: cannam@124: cannam@124: /* Miscellaneous utilities */ cannam@124: cannam@124: cannam@124: /** Retrieve the size of a given sample format in bytes. cannam@124: cannam@124: @return The size in bytes of a single sample in the specified format, cannam@124: or paSampleFormatNotSupported if the format is not supported. cannam@124: */ cannam@124: PaError Pa_GetSampleSize( PaSampleFormat format ); cannam@124: cannam@124: cannam@124: /** Put the caller to sleep for at least 'msec' milliseconds. This function is cannam@124: provided only as a convenience for authors of portable code (such as the tests cannam@124: and examples in the PortAudio distribution.) cannam@124: cannam@124: The function may sleep longer than requested so don't rely on this for accurate cannam@124: musical timing. cannam@124: */ cannam@124: void Pa_Sleep( long msec ); cannam@124: cannam@124: cannam@124: cannam@124: #ifdef __cplusplus cannam@124: } cannam@124: #endif /* __cplusplus */ cannam@124: #endif /* PORTAUDIO_H */