cannam@89: #ifndef PORTAUDIO_H cannam@89: #define PORTAUDIO_H cannam@89: /* cannam@89: * $Id: portaudio.h 1745 2011-08-25 17:44:01Z rossb $ cannam@89: * PortAudio Portable Real-Time Audio Library cannam@89: * PortAudio API Header File cannam@89: * Latest version available at: http://www.portaudio.com/ cannam@89: * cannam@89: * Copyright (c) 1999-2002 Ross Bencina and Phil Burk cannam@89: * cannam@89: * Permission is hereby granted, free of charge, to any person obtaining cannam@89: * a copy of this software and associated documentation files cannam@89: * (the "Software"), to deal in the Software without restriction, cannam@89: * including without limitation the rights to use, copy, modify, merge, cannam@89: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@89: * and to permit persons to whom the Software is furnished to do so, cannam@89: * subject to the following conditions: cannam@89: * cannam@89: * The above copyright notice and this permission notice shall be cannam@89: * included in all copies or substantial portions of the Software. cannam@89: * cannam@89: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@89: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@89: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@89: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@89: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@89: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@89: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@89: */ cannam@89: cannam@89: /* cannam@89: * The text above constitutes the entire PortAudio license; however, cannam@89: * the PortAudio community also makes the following non-binding requests: cannam@89: * cannam@89: * Any person wishing to distribute modifications to the Software is cannam@89: * requested to send the modifications to the original developer so that cannam@89: * they can be incorporated into the canonical version. It is also cannam@89: * requested that these non-binding requests be included along with the cannam@89: * license above. cannam@89: */ cannam@89: cannam@89: /** @file cannam@89: @ingroup public_header cannam@89: @brief The portable PortAudio API. cannam@89: */ cannam@89: cannam@89: cannam@89: #ifdef __cplusplus cannam@89: extern "C" cannam@89: { cannam@89: #endif /* __cplusplus */ cannam@89: cannam@89: cannam@89: /** Retrieve the release number of the currently running PortAudio build, cannam@89: eg 1900. cannam@89: */ cannam@89: int Pa_GetVersion( void ); cannam@89: cannam@89: cannam@89: /** Retrieve a textual description of the current PortAudio build, cannam@89: eg "PortAudio V19-devel 13 October 2002". cannam@89: */ cannam@89: const char* Pa_GetVersionText( void ); cannam@89: cannam@89: cannam@89: /** Error codes returned by PortAudio functions. cannam@89: Note that with the exception of paNoError, all PaErrorCodes are negative. cannam@89: */ cannam@89: cannam@89: typedef int PaError; cannam@89: typedef enum PaErrorCode cannam@89: { cannam@89: paNoError = 0, cannam@89: cannam@89: paNotInitialized = -10000, cannam@89: paUnanticipatedHostError, cannam@89: paInvalidChannelCount, cannam@89: paInvalidSampleRate, cannam@89: paInvalidDevice, cannam@89: paInvalidFlag, cannam@89: paSampleFormatNotSupported, cannam@89: paBadIODeviceCombination, cannam@89: paInsufficientMemory, cannam@89: paBufferTooBig, cannam@89: paBufferTooSmall, cannam@89: paNullCallback, cannam@89: paBadStreamPtr, cannam@89: paTimedOut, cannam@89: paInternalError, cannam@89: paDeviceUnavailable, cannam@89: paIncompatibleHostApiSpecificStreamInfo, cannam@89: paStreamIsStopped, cannam@89: paStreamIsNotStopped, cannam@89: paInputOverflowed, cannam@89: paOutputUnderflowed, cannam@89: paHostApiNotFound, cannam@89: paInvalidHostApi, cannam@89: paCanNotReadFromACallbackStream, cannam@89: paCanNotWriteToACallbackStream, cannam@89: paCanNotReadFromAnOutputOnlyStream, cannam@89: paCanNotWriteToAnInputOnlyStream, cannam@89: paIncompatibleStreamHostApi, cannam@89: paBadBufferPtr cannam@89: } PaErrorCode; cannam@89: cannam@89: cannam@89: /** Translate the supplied PortAudio error code into a human readable cannam@89: message. cannam@89: */ cannam@89: const char *Pa_GetErrorText( PaError errorCode ); cannam@89: cannam@89: cannam@89: /** Library initialization function - call this before using PortAudio. cannam@89: This function initializes internal data structures and prepares underlying cannam@89: host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(), cannam@89: and Pa_GetErrorText(), this function MUST be called before using any other cannam@89: PortAudio API functions. cannam@89: cannam@89: If Pa_Initialize() is called multiple times, each successful cannam@89: call must be matched with a corresponding call to Pa_Terminate(). cannam@89: Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not cannam@89: required to be fully nested. cannam@89: cannam@89: Note that if Pa_Initialize() returns an error code, Pa_Terminate() should cannam@89: NOT be called. cannam@89: cannam@89: @return paNoError if successful, otherwise an error code indicating the cause cannam@89: of failure. cannam@89: cannam@89: @see Pa_Terminate cannam@89: */ cannam@89: PaError Pa_Initialize( void ); cannam@89: cannam@89: cannam@89: /** Library termination function - call this when finished using PortAudio. cannam@89: This function deallocates all resources allocated by PortAudio since it was cannam@89: initialized by a call to Pa_Initialize(). In cases where Pa_Initialise() has cannam@89: been called multiple times, each call must be matched with a corresponding call cannam@89: to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically cannam@89: close any PortAudio streams that are still open. cannam@89: cannam@89: Pa_Terminate() MUST be called before exiting a program which uses PortAudio. cannam@89: Failure to do so may result in serious resource leaks, such as audio devices cannam@89: not being available until the next reboot. cannam@89: cannam@89: @return paNoError if successful, otherwise an error code indicating the cause cannam@89: of failure. cannam@89: cannam@89: @see Pa_Initialize cannam@89: */ cannam@89: PaError Pa_Terminate( void ); cannam@89: cannam@89: cannam@89: cannam@89: /** The type used to refer to audio devices. Values of this type usually cannam@89: range from 0 to (Pa_GetDeviceCount()-1), and may also take on the PaNoDevice cannam@89: and paUseHostApiSpecificDeviceSpecification values. cannam@89: cannam@89: @see Pa_GetDeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification cannam@89: */ cannam@89: typedef int PaDeviceIndex; cannam@89: cannam@89: cannam@89: /** A special PaDeviceIndex value indicating that no device is available, cannam@89: or should be used. cannam@89: cannam@89: @see PaDeviceIndex cannam@89: */ cannam@89: #define paNoDevice ((PaDeviceIndex)-1) cannam@89: cannam@89: cannam@89: /** A special PaDeviceIndex value indicating that the device(s) to be used cannam@89: are specified in the host api specific stream info structure. cannam@89: cannam@89: @see PaDeviceIndex cannam@89: */ cannam@89: #define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2) cannam@89: cannam@89: cannam@89: /* Host API enumeration mechanism */ cannam@89: cannam@89: /** The type used to enumerate to host APIs at runtime. Values of this type cannam@89: range from 0 to (Pa_GetHostApiCount()-1). cannam@89: cannam@89: @see Pa_GetHostApiCount cannam@89: */ cannam@89: typedef int PaHostApiIndex; cannam@89: cannam@89: cannam@89: /** Retrieve the number of available host APIs. Even if a host API is cannam@89: available it may have no devices available. cannam@89: cannam@89: @return A non-negative value indicating the number of available host APIs cannam@89: or, a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@89: or an error is encountered. cannam@89: cannam@89: @see PaHostApiIndex cannam@89: */ cannam@89: PaHostApiIndex Pa_GetHostApiCount( void ); cannam@89: cannam@89: cannam@89: /** Retrieve the index of the default host API. The default host API will be cannam@89: the lowest common denominator host API on the current platform and is cannam@89: unlikely to provide the best performance. cannam@89: cannam@89: @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1) cannam@89: indicating the default host API index or, a PaErrorCode (which are always cannam@89: negative) if PortAudio is not initialized or an error is encountered. cannam@89: */ cannam@89: PaHostApiIndex Pa_GetDefaultHostApi( void ); cannam@89: cannam@89: cannam@89: /** Unchanging unique identifiers for each supported host API. This type cannam@89: is used in the PaHostApiInfo structure. The values are guaranteed to be cannam@89: unique and to never change, thus allowing code to be written that cannam@89: conditionally uses host API specific extensions. cannam@89: cannam@89: New type ids will be allocated when support for a host API reaches cannam@89: "public alpha" status, prior to that developers should use the cannam@89: paInDevelopment type id. cannam@89: cannam@89: @see PaHostApiInfo cannam@89: */ cannam@89: typedef enum PaHostApiTypeId cannam@89: { cannam@89: paInDevelopment=0, /* use while developing support for a new host API */ cannam@89: paDirectSound=1, cannam@89: paMME=2, cannam@89: paASIO=3, cannam@89: paSoundManager=4, cannam@89: paCoreAudio=5, cannam@89: paOSS=7, cannam@89: paALSA=8, cannam@89: paAL=9, cannam@89: paBeOS=10, cannam@89: paWDMKS=11, cannam@89: paJACK=12, cannam@89: paWASAPI=13, cannam@89: paAudioScienceHPI=14 cannam@89: } PaHostApiTypeId; cannam@89: cannam@89: cannam@89: /** A structure containing information about a particular host API. */ cannam@89: cannam@89: typedef struct PaHostApiInfo cannam@89: { cannam@89: /** this is struct version 1 */ cannam@89: int structVersion; cannam@89: /** The well known unique identifier of this host API @see PaHostApiTypeId */ cannam@89: PaHostApiTypeId type; cannam@89: /** A textual description of the host API for display on user interfaces. */ cannam@89: const char *name; cannam@89: cannam@89: /** The number of devices belonging to this host API. This field may be cannam@89: used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate cannam@89: all devices for this host API. cannam@89: @see Pa_HostApiDeviceIndexToDeviceIndex cannam@89: */ cannam@89: int deviceCount; cannam@89: cannam@89: /** The default input device for this host API. The value will be a cannam@89: device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice cannam@89: if no default input device is available. cannam@89: */ cannam@89: PaDeviceIndex defaultInputDevice; cannam@89: cannam@89: /** The default output device for this host API. The value will be a cannam@89: device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice cannam@89: if no default output device is available. cannam@89: */ cannam@89: PaDeviceIndex defaultOutputDevice; cannam@89: cannam@89: } PaHostApiInfo; cannam@89: cannam@89: cannam@89: /** Retrieve a pointer to a structure containing information about a specific cannam@89: host Api. cannam@89: cannam@89: @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) cannam@89: cannam@89: @return A pointer to an immutable PaHostApiInfo structure describing cannam@89: a specific host API. If the hostApi parameter is out of range or an error cannam@89: is encountered, the function returns NULL. cannam@89: cannam@89: The returned structure is owned by the PortAudio implementation and must not cannam@89: be manipulated or freed. The pointer is only guaranteed to be valid between cannam@89: calls to Pa_Initialize() and Pa_Terminate(). cannam@89: */ cannam@89: const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi ); cannam@89: cannam@89: cannam@89: /** Convert a static host API unique identifier, into a runtime cannam@89: host API index. cannam@89: cannam@89: @param type A unique host API identifier belonging to the PaHostApiTypeId cannam@89: enumeration. cannam@89: cannam@89: @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or, cannam@89: a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@89: or an error is encountered. cannam@89: cannam@89: The paHostApiNotFound error code indicates that the host API specified by the cannam@89: type parameter is not available. cannam@89: cannam@89: @see PaHostApiTypeId cannam@89: */ cannam@89: PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type ); cannam@89: cannam@89: cannam@89: /** Convert a host-API-specific device index to standard PortAudio device index. cannam@89: This function may be used in conjunction with the deviceCount field of cannam@89: PaHostApiInfo to enumerate all devices for the specified host API. cannam@89: cannam@89: @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) cannam@89: cannam@89: @param hostApiDeviceIndex A valid per-host device index in the range cannam@89: 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) cannam@89: cannam@89: @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1) cannam@89: or, a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@89: or an error is encountered. cannam@89: cannam@89: A paInvalidHostApi error code indicates that the host API index specified by cannam@89: the hostApi parameter is out of range. cannam@89: cannam@89: A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter cannam@89: is out of range. cannam@89: cannam@89: @see PaHostApiInfo cannam@89: */ cannam@89: PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi, cannam@89: int hostApiDeviceIndex ); cannam@89: cannam@89: cannam@89: cannam@89: /** Structure used to return information about a host error condition. cannam@89: */ cannam@89: typedef struct PaHostErrorInfo{ cannam@89: PaHostApiTypeId hostApiType; /**< the host API which returned the error code */ cannam@89: long errorCode; /**< the error code returned */ cannam@89: const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */ cannam@89: }PaHostErrorInfo; cannam@89: cannam@89: cannam@89: /** Return information about the last host error encountered. The error cannam@89: information returned by Pa_GetLastHostErrorInfo() will never be modified cannam@89: asynchronously by errors occurring in other PortAudio owned threads cannam@89: (such as the thread that manages the stream callback.) cannam@89: cannam@89: This function is provided as a last resort, primarily to enhance debugging cannam@89: by providing clients with access to all available error information. cannam@89: cannam@89: @return A pointer to an immutable structure constraining information about cannam@89: the host error. The values in this structure will only be valid if a cannam@89: PortAudio function has previously returned the paUnanticipatedHostError cannam@89: error code. cannam@89: */ cannam@89: const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void ); cannam@89: cannam@89: cannam@89: cannam@89: /* Device enumeration and capabilities */ cannam@89: cannam@89: /** Retrieve the number of available devices. The number of available devices cannam@89: may be zero. cannam@89: cannam@89: @return A non-negative value indicating the number of available devices or, cannam@89: a PaErrorCode (which are always negative) if PortAudio is not initialized cannam@89: or an error is encountered. cannam@89: */ cannam@89: PaDeviceIndex Pa_GetDeviceCount( void ); cannam@89: cannam@89: cannam@89: /** Retrieve the index of the default input device. The result can be cannam@89: used in the inputDevice parameter to Pa_OpenStream(). cannam@89: cannam@89: @return The default input device index for the default host API, or paNoDevice cannam@89: if no default input device is available or an error was encountered. cannam@89: */ cannam@89: PaDeviceIndex Pa_GetDefaultInputDevice( void ); cannam@89: cannam@89: cannam@89: /** Retrieve the index of the default output device. The result can be cannam@89: used in the outputDevice parameter to Pa_OpenStream(). cannam@89: cannam@89: @return The default output device index for the default host API, or paNoDevice cannam@89: if no default output device is available or an error was encountered. cannam@89: cannam@89: @note cannam@89: On the PC, the user can specify a default device by cannam@89: setting an environment variable. For example, to use device #1. cannam@89: 
cannam@89:  set PA_RECOMMENDED_OUTPUT_DEVICE=1
cannam@89:
cannam@89: The user should first determine the available device ids by using cannam@89: the supplied application "pa_devs". cannam@89: */ cannam@89: PaDeviceIndex Pa_GetDefaultOutputDevice( void ); cannam@89: cannam@89: cannam@89: /** The type used to represent monotonic time in seconds. PaTime is cannam@89: used for the fields of the PaStreamCallbackTimeInfo argument to the cannam@89: PaStreamCallback and as the result of Pa_GetStreamTime(). cannam@89: cannam@89: PaTime values have unspecified origin. cannam@89: cannam@89: @see PaStreamCallback, PaStreamCallbackTimeInfo, Pa_GetStreamTime cannam@89: */ cannam@89: typedef double PaTime; cannam@89: cannam@89: cannam@89: /** A type used to specify one or more sample formats. Each value indicates cannam@89: a possible format for sound data passed to and from the stream callback, cannam@89: Pa_ReadStream and Pa_WriteStream. cannam@89: cannam@89: The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8 cannam@89: and aUInt8 are usually implemented by all implementations. cannam@89: cannam@89: The floating point representation (paFloat32) uses +1.0 and -1.0 as the cannam@89: maximum and minimum respectively. cannam@89: cannam@89: paUInt8 is an unsigned 8 bit format where 128 is considered "ground" cannam@89: cannam@89: The paNonInterleaved flag indicates that audio data is passed as an array cannam@89: of pointers to separate buffers, one buffer for each channel. Usually, cannam@89: when this flag is not used, audio data is passed as a single buffer with cannam@89: all channels interleaved. cannam@89: cannam@89: @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo cannam@89: @see paFloat32, paInt16, paInt32, paInt24, paInt8 cannam@89: @see paUInt8, paCustomFormat, paNonInterleaved cannam@89: */ cannam@89: typedef unsigned long PaSampleFormat; cannam@89: cannam@89: cannam@89: #define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */ cannam@89: #define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */ cannam@89: #define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */ cannam@89: #define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */ cannam@89: #define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */ cannam@89: #define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */ cannam@89: #define paCustomFormat ((PaSampleFormat) 0x00010000) /**< @see PaSampleFormat */ cannam@89: cannam@89: #define paNonInterleaved ((PaSampleFormat) 0x80000000) /**< @see PaSampleFormat */ cannam@89: cannam@89: /** A structure providing information and capabilities of PortAudio devices. cannam@89: Devices may support input, output or both input and output. cannam@89: */ cannam@89: typedef struct PaDeviceInfo cannam@89: { cannam@89: int structVersion; /* this is struct version 2 */ cannam@89: const char *name; cannam@89: PaHostApiIndex hostApi; /**< note this is a host API index, not a type id*/ cannam@89: cannam@89: int maxInputChannels; cannam@89: int maxOutputChannels; cannam@89: cannam@89: /** Default latency values for interactive performance. */ cannam@89: PaTime defaultLowInputLatency; cannam@89: PaTime defaultLowOutputLatency; cannam@89: /** Default latency values for robust non-interactive applications (eg. playing sound files). */ cannam@89: PaTime defaultHighInputLatency; cannam@89: PaTime defaultHighOutputLatency; cannam@89: cannam@89: double defaultSampleRate; cannam@89: } PaDeviceInfo; cannam@89: cannam@89: cannam@89: /** Retrieve a pointer to a PaDeviceInfo structure containing information cannam@89: about the specified device. cannam@89: @return A pointer to an immutable PaDeviceInfo structure. If the device cannam@89: parameter is out of range the function returns NULL. cannam@89: cannam@89: @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1) cannam@89: cannam@89: @note PortAudio manages the memory referenced by the returned pointer, cannam@89: the client must not manipulate or free the memory. The pointer is only cannam@89: guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate(). cannam@89: cannam@89: @see PaDeviceInfo, PaDeviceIndex cannam@89: */ cannam@89: const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device ); cannam@89: cannam@89: cannam@89: /** Parameters for one direction (input or output) of a stream. cannam@89: */ cannam@89: typedef struct PaStreamParameters cannam@89: { cannam@89: /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1) cannam@89: specifying the device to be used or the special constant cannam@89: paUseHostApiSpecificDeviceSpecification which indicates that the actual cannam@89: device(s) to use are specified in hostApiSpecificStreamInfo. cannam@89: This field must not be set to paNoDevice. cannam@89: */ cannam@89: PaDeviceIndex device; cannam@89: cannam@89: /** The number of channels of sound to be delivered to the cannam@89: stream callback or accessed by Pa_ReadStream() or Pa_WriteStream(). cannam@89: It can range from 1 to the value of maxInputChannels in the cannam@89: PaDeviceInfo record for the device specified by the device parameter. cannam@89: */ cannam@89: int channelCount; cannam@89: cannam@89: /** The sample format of the buffer provided to the stream callback, cannam@89: a_ReadStream() or Pa_WriteStream(). It may be any of the formats described cannam@89: by the PaSampleFormat enumeration. cannam@89: */ cannam@89: PaSampleFormat sampleFormat; cannam@89: cannam@89: /** The desired latency in seconds. Where practical, implementations should cannam@89: configure their latency based on these parameters, otherwise they may cannam@89: choose the closest viable latency instead. Unless the suggested latency cannam@89: is greater than the absolute upper limit for the device implementations cannam@89: should round the suggestedLatency up to the next practical value - ie to cannam@89: provide an equal or higher latency than suggestedLatency wherever possible. cannam@89: Actual latency values for an open stream may be retrieved using the cannam@89: inputLatency and outputLatency fields of the PaStreamInfo structure cannam@89: returned by Pa_GetStreamInfo(). cannam@89: @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo cannam@89: */ cannam@89: PaTime suggestedLatency; cannam@89: cannam@89: /** An optional pointer to a host api specific data structure cannam@89: containing additional information for device setup and/or stream processing. cannam@89: hostApiSpecificStreamInfo is never required for correct operation, cannam@89: if not used it should be set to NULL. cannam@89: */ cannam@89: void *hostApiSpecificStreamInfo; cannam@89: cannam@89: } PaStreamParameters; cannam@89: cannam@89: cannam@89: /** Return code for Pa_IsFormatSupported indicating success. */ cannam@89: #define paFormatIsSupported (0) cannam@89: cannam@89: /** Determine whether it would be possible to open a stream with the specified cannam@89: parameters. cannam@89: cannam@89: @param inputParameters A structure that describes the input parameters used to cannam@89: open a stream. The suggestedLatency field is ignored. See PaStreamParameters cannam@89: for a description of these parameters. inputParameters must be NULL for cannam@89: output-only streams. cannam@89: cannam@89: @param outputParameters A structure that describes the output parameters used cannam@89: to open a stream. The suggestedLatency field is ignored. See PaStreamParameters cannam@89: for a description of these parameters. outputParameters must be NULL for cannam@89: input-only streams. cannam@89: cannam@89: @param sampleRate The required sampleRate. For full-duplex streams it is the cannam@89: sample rate for both input and output cannam@89: cannam@89: @return Returns 0 if the format is supported, and an error code indicating why cannam@89: the format is not supported otherwise. The constant paFormatIsSupported is cannam@89: provided to compare with the return value for success. cannam@89: cannam@89: @see paFormatIsSupported, PaStreamParameters cannam@89: */ cannam@89: PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters, cannam@89: const PaStreamParameters *outputParameters, cannam@89: double sampleRate ); cannam@89: cannam@89: cannam@89: cannam@89: /* Streaming types and functions */ cannam@89: cannam@89: cannam@89: /** cannam@89: A single PaStream can provide multiple channels of real-time cannam@89: streaming audio input and output to a client application. A stream cannam@89: provides access to audio hardware represented by one or more cannam@89: PaDevices. Depending on the underlying Host API, it may be possible cannam@89: to open multiple streams using the same device, however this behavior cannam@89: is implementation defined. Portable applications should assume that cannam@89: a PaDevice may be simultaneously used by at most one PaStream. cannam@89: cannam@89: Pointers to PaStream objects are passed between PortAudio functions that cannam@89: operate on streams. cannam@89: cannam@89: @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream, cannam@89: Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive, cannam@89: Pa_GetStreamTime, Pa_GetStreamCpuLoad cannam@89: cannam@89: */ cannam@89: typedef void PaStream; cannam@89: cannam@89: cannam@89: /** Can be passed as the framesPerBuffer parameter to Pa_OpenStream() cannam@89: or Pa_OpenDefaultStream() to indicate that the stream callback will cannam@89: accept buffers of any size. cannam@89: */ cannam@89: #define paFramesPerBufferUnspecified (0) cannam@89: cannam@89: cannam@89: /** Flags used to control the behavior of a stream. They are passed as cannam@89: parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be cannam@89: ORed together. cannam@89: cannam@89: @see Pa_OpenStream, Pa_OpenDefaultStream cannam@89: @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput, cannam@89: paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags cannam@89: */ cannam@89: typedef unsigned long PaStreamFlags; cannam@89: cannam@89: /** @see PaStreamFlags */ cannam@89: #define paNoFlag ((PaStreamFlags) 0) cannam@89: cannam@89: /** Disable default clipping of out of range samples. cannam@89: @see PaStreamFlags cannam@89: */ cannam@89: #define paClipOff ((PaStreamFlags) 0x00000001) cannam@89: cannam@89: /** Disable default dithering. cannam@89: @see PaStreamFlags cannam@89: */ cannam@89: #define paDitherOff ((PaStreamFlags) 0x00000002) cannam@89: cannam@89: /** Flag requests that where possible a full duplex stream will not discard cannam@89: overflowed input samples without calling the stream callback. This flag is cannam@89: only valid for full duplex callback streams and only when used in combination cannam@89: with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using cannam@89: this flag incorrectly results in a paInvalidFlag error being returned from cannam@89: Pa_OpenStream and Pa_OpenDefaultStream. cannam@89: cannam@89: @see PaStreamFlags, paFramesPerBufferUnspecified cannam@89: */ cannam@89: #define paNeverDropInput ((PaStreamFlags) 0x00000004) cannam@89: cannam@89: /** Call the stream callback to fill initial output buffers, rather than the cannam@89: default behavior of priming the buffers with zeros (silence). This flag has cannam@89: no effect for input-only and blocking read/write streams. cannam@89: cannam@89: @see PaStreamFlags cannam@89: */ cannam@89: #define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008) cannam@89: cannam@89: /** A mask specifying the platform specific bits. cannam@89: @see PaStreamFlags cannam@89: */ cannam@89: #define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000) cannam@89: cannam@89: /** cannam@89: Timing information for the buffers passed to the stream callback. cannam@89: cannam@89: Time values are expressed in seconds and are synchronised with the time base used by Pa_GetStreamTime() for the associated stream. cannam@89: cannam@89: @see PaStreamCallback, Pa_GetStreamTime cannam@89: */ cannam@89: typedef struct PaStreamCallbackTimeInfo{ cannam@89: PaTime inputBufferAdcTime; /**< The time when the first sample of the input buffer was captured at the ADC input */ cannam@89: PaTime currentTime; /**< The time when the stream callback was invoked */ cannam@89: PaTime outputBufferDacTime; /**< The time when the first sample of the output buffer will output the DAC */ cannam@89: } PaStreamCallbackTimeInfo; cannam@89: cannam@89: cannam@89: /** cannam@89: Flag bit constants for the statusFlags to PaStreamCallback. cannam@89: cannam@89: @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow, cannam@89: paPrimingOutput cannam@89: */ cannam@89: typedef unsigned long PaStreamCallbackFlags; cannam@89: cannam@89: /** In a stream opened with paFramesPerBufferUnspecified, indicates that cannam@89: input data is all silence (zeros) because no real data is available. In a cannam@89: stream opened without paFramesPerBufferUnspecified, it indicates that one or cannam@89: more zero samples have been inserted into the input buffer to compensate cannam@89: for an input underflow. cannam@89: @see PaStreamCallbackFlags cannam@89: */ cannam@89: #define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001) cannam@89: cannam@89: /** In a stream opened with paFramesPerBufferUnspecified, indicates that data cannam@89: prior to the first sample of the input buffer was discarded due to an cannam@89: overflow, possibly because the stream callback is using too much CPU time. cannam@89: Otherwise indicates that data prior to one or more samples in the cannam@89: input buffer was discarded. cannam@89: @see PaStreamCallbackFlags cannam@89: */ cannam@89: #define paInputOverflow ((PaStreamCallbackFlags) 0x00000002) cannam@89: cannam@89: /** Indicates that output data (or a gap) was inserted, possibly because the cannam@89: stream callback is using too much CPU time. cannam@89: @see PaStreamCallbackFlags cannam@89: */ cannam@89: #define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004) cannam@89: cannam@89: /** Indicates that output data will be discarded because no room is available. cannam@89: @see PaStreamCallbackFlags cannam@89: */ cannam@89: #define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008) cannam@89: cannam@89: /** Some of all of the output data will be used to prime the stream, input cannam@89: data may be zero. cannam@89: @see PaStreamCallbackFlags cannam@89: */ cannam@89: #define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010) cannam@89: cannam@89: /** cannam@89: Allowable return values for the PaStreamCallback. cannam@89: @see PaStreamCallback cannam@89: */ cannam@89: typedef enum PaStreamCallbackResult cannam@89: { cannam@89: paContinue=0, /**< Signal that the stream should continue invoking the callback and processing audio. */ cannam@89: paComplete=1, /**< Signal that the stream should stop invoking the callback and finish once all output samples have played. */ cannam@89: paAbort=2 /**< Signal that the stream should stop invoking the callback and finish as soon as possible. */ cannam@89: } PaStreamCallbackResult; cannam@89: cannam@89: cannam@89: /** cannam@89: Functions of type PaStreamCallback are implemented by PortAudio clients. cannam@89: They consume, process or generate audio in response to requests from an cannam@89: active PortAudio stream. cannam@89: cannam@89: When a stream is running, PortAudio calls the stream callback periodically. cannam@89: The callback function is responsible for processing buffers of audio samples cannam@89: passed via the input and output parameters. cannam@89: cannam@89: The PortAudio stream callback runs at very high or real-time priority. cannam@89: It is required to consistently meet its time deadlines. Do not allocate cannam@89: memory, access the file system, call library functions or call other functions cannam@89: from the stream callback that may block or take an unpredictable amount of cannam@89: time to complete. cannam@89: cannam@89: In order for a stream to maintain glitch-free operation the callback cannam@89: must consume and return audio data faster than it is recorded and/or cannam@89: played. PortAudio anticipates that each callback invocation may execute for cannam@89: a duration approaching the duration of frameCount audio frames at the stream cannam@89: sample rate. It is reasonable to expect to be able to utilise 70% or more of cannam@89: the available CPU time in the PortAudio callback. However, due to buffer size cannam@89: adaption and other factors, not all host APIs are able to guarantee audio cannam@89: stability under heavy CPU load with arbitrary fixed callback buffer sizes. cannam@89: When high callback CPU utilisation is required the most robust behavior cannam@89: can be achieved by using paFramesPerBufferUnspecified as the cannam@89: Pa_OpenStream() framesPerBuffer parameter. cannam@89: cannam@89: @param input and @param output are either arrays of interleaved samples or; cannam@89: if non-interleaved samples were requested using the paNonInterleaved sample cannam@89: format flag, an array of buffer pointers, one non-interleaved buffer for cannam@89: each channel. cannam@89: cannam@89: The format, packing and number of channels used by the buffers are cannam@89: determined by parameters to Pa_OpenStream(). cannam@89: cannam@89: @param frameCount The number of sample frames to be processed by cannam@89: the stream callback. cannam@89: cannam@89: @param timeInfo Timestamps indicating the ADC capture time of the first sample cannam@89: in the input buffer, the DAC output time of the first sample in the output buffer cannam@89: and the time the callback was invoked. cannam@89: See PaStreamCallbackTimeInfo and Pa_GetStreamTime() cannam@89: cannam@89: @param statusFlags Flags indicating whether input and/or output buffers cannam@89: have been inserted or will be dropped to overcome underflow or overflow cannam@89: conditions. cannam@89: cannam@89: @param userData The value of a user supplied pointer passed to cannam@89: Pa_OpenStream() intended for storing synthesis data etc. cannam@89: cannam@89: @return cannam@89: The stream callback should return one of the values in the cannam@89: ::PaStreamCallbackResult enumeration. To ensure that the callback continues cannam@89: to be called, it should return paContinue (0). Either paComplete or paAbort cannam@89: can be returned to finish stream processing, after either of these values is cannam@89: returned the callback will not be called again. If paAbort is returned the cannam@89: stream will finish as soon as possible. If paComplete is returned, the stream cannam@89: will continue until all buffers generated by the callback have been played. cannam@89: This may be useful in applications such as soundfile players where a specific cannam@89: duration of output is required. However, it is not necessary to utilize this cannam@89: mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also cannam@89: be used to stop the stream. The callback must always fill the entire output cannam@89: buffer irrespective of its return value. cannam@89: cannam@89: @see Pa_OpenStream, Pa_OpenDefaultStream cannam@89: cannam@89: @note With the exception of Pa_GetStreamCpuLoad() it is not permissible to call cannam@89: PortAudio API functions from within the stream callback. cannam@89: */ cannam@89: typedef int PaStreamCallback( cannam@89: const void *input, void *output, cannam@89: unsigned long frameCount, cannam@89: const PaStreamCallbackTimeInfo* timeInfo, cannam@89: PaStreamCallbackFlags statusFlags, cannam@89: void *userData ); cannam@89: cannam@89: cannam@89: /** Opens a stream for either input, output or both. cannam@89: cannam@89: @param stream The address of a PaStream pointer which will receive cannam@89: a pointer to the newly opened stream. cannam@89: cannam@89: @param inputParameters A structure that describes the input parameters used by cannam@89: the opened stream. See PaStreamParameters for a description of these parameters. cannam@89: inputParameters must be NULL for output-only streams. cannam@89: cannam@89: @param outputParameters A structure that describes the output parameters used by cannam@89: the opened stream. See PaStreamParameters for a description of these parameters. cannam@89: outputParameters must be NULL for input-only streams. cannam@89: cannam@89: @param sampleRate The desired sampleRate. For full-duplex streams it is the cannam@89: sample rate for both input and output cannam@89: cannam@89: @param framesPerBuffer The number of frames passed to the stream callback cannam@89: function, or the preferred block granularity for a blocking read/write stream. cannam@89: The special value paFramesPerBufferUnspecified (0) may be used to request that cannam@89: the stream callback will receive an optimal (and possibly varying) number of cannam@89: frames based on host requirements and the requested latency settings. cannam@89: Note: With some host APIs, the use of non-zero framesPerBuffer for a callback cannam@89: stream may introduce an additional layer of buffering which could introduce cannam@89: additional latency. PortAudio guarantees that the additional latency cannam@89: will be kept to the theoretical minimum however, it is strongly recommended cannam@89: that a non-zero framesPerBuffer value only be used when your algorithm cannam@89: requires a fixed number of frames per stream callback. cannam@89: cannam@89: @param streamFlags Flags which modify the behavior of the streaming process. cannam@89: This parameter may contain a combination of flags ORed together. Some flags may cannam@89: only be relevant to certain buffer formats. cannam@89: cannam@89: @param streamCallback A pointer to a client supplied function that is responsible cannam@89: for processing and filling input and output buffers. If this parameter is NULL cannam@89: the stream will be opened in 'blocking read/write' mode. In blocking mode, cannam@89: the client can receive sample data using Pa_ReadStream and write sample data cannam@89: using Pa_WriteStream, the number of samples that may be read or written cannam@89: without blocking is returned by Pa_GetStreamReadAvailable and cannam@89: Pa_GetStreamWriteAvailable respectively. cannam@89: cannam@89: @param userData A client supplied pointer which is passed to the stream callback cannam@89: function. It could for example, contain a pointer to instance data necessary cannam@89: for processing the audio buffers. This parameter is ignored if streamCallback cannam@89: is NULL. cannam@89: cannam@89: @return cannam@89: Upon success Pa_OpenStream() returns paNoError and places a pointer to a cannam@89: valid PaStream in the stream argument. The stream is inactive (stopped). cannam@89: If a call to Pa_OpenStream() fails, a non-zero error code is returned (see cannam@89: PaError for possible error codes) and the value of stream is invalid. cannam@89: cannam@89: @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream, cannam@89: Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable cannam@89: */ cannam@89: PaError Pa_OpenStream( PaStream** stream, cannam@89: const PaStreamParameters *inputParameters, cannam@89: const PaStreamParameters *outputParameters, cannam@89: double sampleRate, cannam@89: unsigned long framesPerBuffer, cannam@89: PaStreamFlags streamFlags, cannam@89: PaStreamCallback *streamCallback, cannam@89: void *userData ); cannam@89: cannam@89: cannam@89: /** A simplified version of Pa_OpenStream() that opens the default input cannam@89: and/or output devices. cannam@89: cannam@89: @param stream The address of a PaStream pointer which will receive cannam@89: a pointer to the newly opened stream. cannam@89: cannam@89: @param numInputChannels The number of channels of sound that will be supplied cannam@89: to the stream callback or returned by Pa_ReadStream. It can range from 1 to cannam@89: the value of maxInputChannels in the PaDeviceInfo record for the default input cannam@89: device. If 0 the stream is opened as an output-only stream. cannam@89: cannam@89: @param numOutputChannels The number of channels of sound to be delivered to the cannam@89: stream callback or passed to Pa_WriteStream. It can range from 1 to the value cannam@89: of maxOutputChannels in the PaDeviceInfo record for the default output device. cannam@89: If 0 the stream is opened as an output-only stream. cannam@89: cannam@89: @param sampleFormat The sample format of both the input and output buffers cannam@89: provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. cannam@89: sampleFormat may be any of the formats described by the PaSampleFormat cannam@89: enumeration. cannam@89: cannam@89: @param sampleRate Same as Pa_OpenStream parameter of the same name. cannam@89: @param framesPerBuffer Same as Pa_OpenStream parameter of the same name. cannam@89: @param streamCallback Same as Pa_OpenStream parameter of the same name. cannam@89: @param userData Same as Pa_OpenStream parameter of the same name. cannam@89: cannam@89: @return As for Pa_OpenStream cannam@89: cannam@89: @see Pa_OpenStream, PaStreamCallback cannam@89: */ cannam@89: PaError Pa_OpenDefaultStream( PaStream** stream, cannam@89: int numInputChannels, cannam@89: int numOutputChannels, cannam@89: PaSampleFormat sampleFormat, cannam@89: double sampleRate, cannam@89: unsigned long framesPerBuffer, cannam@89: PaStreamCallback *streamCallback, cannam@89: void *userData ); cannam@89: cannam@89: cannam@89: /** Closes an audio stream. If the audio stream is active it cannam@89: discards any pending buffers as if Pa_AbortStream() had been called. cannam@89: */ cannam@89: PaError Pa_CloseStream( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Functions of type PaStreamFinishedCallback are implemented by PortAudio cannam@89: clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback cannam@89: function. Once registered they are called when the stream becomes inactive cannam@89: (ie once a call to Pa_StopStream() will not block). cannam@89: A stream will become inactive after the stream callback returns non-zero, cannam@89: or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio cannam@89: output, if the stream callback returns paComplete, or Pa_StopStream is called, cannam@89: the stream finished callback will not be called until all generated sample data cannam@89: has been played. cannam@89: cannam@89: @param userData The userData parameter supplied to Pa_OpenStream() cannam@89: cannam@89: @see Pa_SetStreamFinishedCallback cannam@89: */ cannam@89: typedef void PaStreamFinishedCallback( void *userData ); cannam@89: cannam@89: cannam@89: /** Register a stream finished callback function which will be called when the cannam@89: stream becomes inactive. See the description of PaStreamFinishedCallback for cannam@89: further details about when the callback will be called. cannam@89: cannam@89: @param stream a pointer to a PaStream that is in the stopped state - if the cannam@89: stream is not stopped, the stream's finished callback will remain unchanged cannam@89: and an error code will be returned. cannam@89: cannam@89: @param streamFinishedCallback a pointer to a function with the same signature cannam@89: as PaStreamFinishedCallback, that will be called when the stream becomes cannam@89: inactive. Passing NULL for this parameter will un-register a previously cannam@89: registered stream finished callback function. cannam@89: cannam@89: @return on success returns paNoError, otherwise an error code indicating the cause cannam@89: of the error. cannam@89: cannam@89: @see PaStreamFinishedCallback cannam@89: */ cannam@89: PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback ); cannam@89: cannam@89: cannam@89: /** Commences audio processing. cannam@89: */ cannam@89: PaError Pa_StartStream( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Terminates audio processing. It waits until all pending cannam@89: audio buffers have been played before it returns. cannam@89: */ cannam@89: PaError Pa_StopStream( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Terminates audio processing immediately without waiting for pending cannam@89: buffers to complete. cannam@89: */ cannam@89: PaError Pa_AbortStream( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Determine whether the stream is stopped. cannam@89: A stream is considered to be stopped prior to a successful call to cannam@89: Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. cannam@89: If a stream callback returns a value other than paContinue the stream is NOT cannam@89: considered to be stopped. cannam@89: cannam@89: @return Returns one (1) when the stream is stopped, zero (0) when cannam@89: the stream is running or, a PaErrorCode (which are always negative) if cannam@89: PortAudio is not initialized or an error is encountered. cannam@89: cannam@89: @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive cannam@89: */ cannam@89: PaError Pa_IsStreamStopped( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Determine whether the stream is active. cannam@89: A stream is active after a successful call to Pa_StartStream(), until it cannam@89: becomes inactive either as a result of a call to Pa_StopStream() or cannam@89: Pa_AbortStream(), or as a result of a return value other than paContinue from cannam@89: the stream callback. In the latter case, the stream is considered inactive cannam@89: after the last buffer has finished playing. cannam@89: cannam@89: @return Returns one (1) when the stream is active (ie playing or recording cannam@89: audio), zero (0) when not playing or, a PaErrorCode (which are always negative) cannam@89: if PortAudio is not initialized or an error is encountered. cannam@89: cannam@89: @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped cannam@89: */ cannam@89: PaError Pa_IsStreamActive( PaStream *stream ); cannam@89: cannam@89: cannam@89: cannam@89: /** A structure containing unchanging information about an open stream. cannam@89: @see Pa_GetStreamInfo cannam@89: */ cannam@89: cannam@89: typedef struct PaStreamInfo cannam@89: { cannam@89: /** this is struct version 1 */ cannam@89: int structVersion; cannam@89: cannam@89: /** The input latency of the stream in seconds. This value provides the most cannam@89: accurate estimate of input latency available to the implementation. It may cannam@89: differ significantly from the suggestedLatency value passed to Pa_OpenStream(). cannam@89: The value of this field will be zero (0.) for output-only streams. cannam@89: @see PaTime cannam@89: */ cannam@89: PaTime inputLatency; cannam@89: cannam@89: /** The output latency of the stream in seconds. This value provides the most cannam@89: accurate estimate of output latency available to the implementation. It may cannam@89: differ significantly from the suggestedLatency value passed to Pa_OpenStream(). cannam@89: The value of this field will be zero (0.) for input-only streams. cannam@89: @see PaTime cannam@89: */ cannam@89: PaTime outputLatency; cannam@89: cannam@89: /** The sample rate of the stream in Hertz (samples per second). In cases cannam@89: where the hardware sample rate is inaccurate and PortAudio is aware of it, cannam@89: the value of this field may be different from the sampleRate parameter cannam@89: passed to Pa_OpenStream(). If information about the actual hardware sample cannam@89: rate is not available, this field will have the same value as the sampleRate cannam@89: parameter passed to Pa_OpenStream(). cannam@89: */ cannam@89: double sampleRate; cannam@89: cannam@89: } PaStreamInfo; cannam@89: cannam@89: cannam@89: /** Retrieve a pointer to a PaStreamInfo structure containing information cannam@89: about the specified stream. cannam@89: @return A pointer to an immutable PaStreamInfo structure. If the stream cannam@89: parameter invalid, or an error is encountered, the function returns NULL. cannam@89: cannam@89: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@89: cannam@89: @note PortAudio manages the memory referenced by the returned pointer, cannam@89: the client must not manipulate or free the memory. The pointer is only cannam@89: guaranteed to be valid until the specified stream is closed. cannam@89: cannam@89: @see PaStreamInfo cannam@89: */ cannam@89: const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Returns the current time in seconds for a stream according to the same clock used cannam@89: to generate callback PaStreamCallbackTimeInfo timestamps. The time values are cannam@89: monotonically increasing and have unspecified origin. cannam@89: cannam@89: Pa_GetStreamTime returns valid time values for the entire life of the stream, cannam@89: from when the stream is opened until it is closed. Starting and stopping the stream cannam@89: does not affect the passage of time returned by Pa_GetStreamTime. cannam@89: cannam@89: This time may be used for synchronizing other events to the audio stream, for cannam@89: example synchronizing audio to MIDI. cannam@89: cannam@89: @return The stream's current time in seconds, or 0 if an error occurred. cannam@89: cannam@89: @see PaTime, PaStreamCallback, PaStreamCallbackTimeInfo cannam@89: */ cannam@89: PaTime Pa_GetStreamTime( PaStream *stream ); cannam@89: cannam@89: cannam@89: /** Retrieve CPU usage information for the specified stream. cannam@89: The "CPU Load" is a fraction of total CPU time consumed by a callback stream's cannam@89: audio processing routines including, but not limited to the client supplied cannam@89: stream callback. This function does not work with blocking read/write streams. cannam@89: cannam@89: This function may be called from the stream callback function or the cannam@89: application. cannam@89: cannam@89: @return cannam@89: A floating point value, typically between 0.0 and 1.0, where 1.0 indicates cannam@89: that the stream callback is consuming the maximum number of CPU cycles possible cannam@89: to maintain real-time operation. A value of 0.5 would imply that PortAudio and cannam@89: the stream callback was consuming roughly 50% of the available CPU time. The cannam@89: return value may exceed 1.0. A value of 0.0 will always be returned for a cannam@89: blocking read/write stream, or if an error occurs. cannam@89: */ cannam@89: double Pa_GetStreamCpuLoad( PaStream* stream ); cannam@89: cannam@89: cannam@89: /** Read samples from an input stream. The function doesn't return until cannam@89: the entire buffer has been filled - this may involve waiting for the operating cannam@89: system to supply the data. cannam@89: cannam@89: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@89: cannam@89: @param buffer A pointer to a buffer of sample frames. The buffer contains cannam@89: samples in the format specified by the inputParameters->sampleFormat field cannam@89: used to open the stream, and the number of channels specified by cannam@89: inputParameters->numChannels. If non-interleaved samples were requested using cannam@89: the paNonInterleaved sample format flag, buffer is a pointer to the first element cannam@89: of an array of buffer pointers, one non-interleaved buffer for each channel. cannam@89: cannam@89: @param frames The number of frames to be read into buffer. This parameter cannam@89: is not constrained to a specific range, however high performance applications cannam@89: will want to match this parameter to the framesPerBuffer parameter used cannam@89: when opening the stream. cannam@89: cannam@89: @return On success PaNoError will be returned, or PaInputOverflowed if input cannam@89: data was discarded by PortAudio after the previous call and before this call. cannam@89: */ cannam@89: PaError Pa_ReadStream( PaStream* stream, cannam@89: void *buffer, cannam@89: unsigned long frames ); cannam@89: cannam@89: cannam@89: /** Write samples to an output stream. This function doesn't return until the cannam@89: entire buffer has been consumed - this may involve waiting for the operating cannam@89: system to consume the data. cannam@89: cannam@89: @param stream A pointer to an open stream previously created with Pa_OpenStream. cannam@89: cannam@89: @param buffer A pointer to a buffer of sample frames. The buffer contains cannam@89: samples in the format specified by the outputParameters->sampleFormat field cannam@89: used to open the stream, and the number of channels specified by cannam@89: outputParameters->numChannels. If non-interleaved samples were requested using cannam@89: the paNonInterleaved sample format flag, buffer is a pointer to the first element cannam@89: of an array of buffer pointers, one non-interleaved buffer for each channel. cannam@89: cannam@89: @param frames The number of frames to be written from buffer. This parameter cannam@89: is not constrained to a specific range, however high performance applications cannam@89: will want to match this parameter to the framesPerBuffer parameter used cannam@89: when opening the stream. cannam@89: cannam@89: @return On success PaNoError will be returned, or paOutputUnderflowed if cannam@89: additional output data was inserted after the previous call and before this cannam@89: call. cannam@89: */ cannam@89: PaError Pa_WriteStream( PaStream* stream, cannam@89: const void *buffer, cannam@89: unsigned long frames ); cannam@89: cannam@89: cannam@89: /** Retrieve the number of frames that can be read from the stream without cannam@89: waiting. cannam@89: cannam@89: @return Returns a non-negative value representing the maximum number of frames cannam@89: that can be read from the stream without blocking or busy waiting or, a cannam@89: PaErrorCode (which are always negative) if PortAudio is not initialized or an cannam@89: error is encountered. cannam@89: */ cannam@89: signed long Pa_GetStreamReadAvailable( PaStream* stream ); cannam@89: cannam@89: cannam@89: /** Retrieve the number of frames that can be written to the stream without cannam@89: waiting. cannam@89: cannam@89: @return Returns a non-negative value representing the maximum number of frames cannam@89: that can be written to the stream without blocking or busy waiting or, a cannam@89: PaErrorCode (which are always negative) if PortAudio is not initialized or an cannam@89: error is encountered. cannam@89: */ cannam@89: signed long Pa_GetStreamWriteAvailable( PaStream* stream ); cannam@89: cannam@89: cannam@89: /* Miscellaneous utilities */ cannam@89: cannam@89: cannam@89: /** Retrieve the size of a given sample format in bytes. cannam@89: cannam@89: @return The size in bytes of a single sample in the specified format, cannam@89: or paSampleFormatNotSupported if the format is not supported. cannam@89: */ cannam@89: PaError Pa_GetSampleSize( PaSampleFormat format ); cannam@89: cannam@89: cannam@89: /** Put the caller to sleep for at least 'msec' milliseconds. This function is cannam@89: provided only as a convenience for authors of portable code (such as the tests cannam@89: and examples in the PortAudio distribution.) cannam@89: cannam@89: The function may sleep longer than requested so don't rely on this for accurate cannam@89: musical timing. cannam@89: */ cannam@89: void Pa_Sleep( long msec ); cannam@89: cannam@89: cannam@89: cannam@89: #ifdef __cplusplus cannam@89: } cannam@89: #endif /* __cplusplus */ cannam@89: #endif /* PORTAUDIO_H */