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Diffstat (limited to 'pd/portaudio/include/portaudio.h')
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diff --git a/pd/portaudio/include/portaudio.h b/pd/portaudio/include/portaudio.h new file mode 100644 index 00000000..64fa17a2 --- /dev/null +++ b/pd/portaudio/include/portaudio.h @@ -0,0 +1,1134 @@ + +#ifndef PORTAUDIO_H +#define PORTAUDIO_H +/* + * $Id: portaudio.h,v 1.1 2007-08-18 23:49:33 millerpuckette Exp $ + * PortAudio Portable Real-Time Audio Library + * PortAudio API Header File + * Latest version available at: http://www.portaudio.com/ + * + * Copyright (c) 1999-2002 Ross Bencina and Phil Burk + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files + * (the "Software"), to deal in the Software without restriction, + * including without limitation the rights to use, copy, modify, merge, + * publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, + * subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF + * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +/* + * The text above constitutes the entire PortAudio license; however, + * the PortAudio community also makes the following non-binding requests: + * + * Any person wishing to distribute modifications to the Software is + * requested to send the modifications to the original developer so that + * they can be incorporated into the canonical version. It is also + * requested that these non-binding requests be included along with the + * license above. + */ + +/** @file + @brief The PortAudio API. +*/ + + +#ifdef __cplusplus +extern "C" +{ +#endif /* __cplusplus */ + + +/** Retrieve the release number of the currently running PortAudio build, + eg 1900. +*/ +int Pa_GetVersion( void ); + + +/** Retrieve a textual description of the current PortAudio build, + eg "PortAudio V19-devel 13 October 2002". +*/ +const char* Pa_GetVersionText( void ); + + +/** Error codes returned by PortAudio functions. + Note that with the exception of paNoError, all PaErrorCodes are negative. +*/ + +typedef int PaError; +typedef enum PaErrorCode +{ + paNoError = 0, + + paNotInitialized = -10000, + paUnanticipatedHostError, + paInvalidChannelCount, + paInvalidSampleRate, + paInvalidDevice, + paInvalidFlag, + paSampleFormatNotSupported, + paBadIODeviceCombination, + paInsufficientMemory, + paBufferTooBig, + paBufferTooSmall, + paNullCallback, + paBadStreamPtr, + paTimedOut, + paInternalError, + paDeviceUnavailable, + paIncompatibleHostApiSpecificStreamInfo, + paStreamIsStopped, + paStreamIsNotStopped, + paInputOverflowed, + paOutputUnderflowed, + paHostApiNotFound, + paInvalidHostApi, + paCanNotReadFromACallbackStream, /**< @todo review error code name */ + paCanNotWriteToACallbackStream, /**< @todo review error code name */ + paCanNotReadFromAnOutputOnlyStream, /**< @todo review error code name */ + paCanNotWriteToAnInputOnlyStream, /**< @todo review error code name */ + paIncompatibleStreamHostApi, + paBadBufferPtr +} PaErrorCode; + + +/** Translate the supplied PortAudio error code into a human readable + message. +*/ +const char *Pa_GetErrorText( PaError errorCode ); + + +/** Library initialization function - call this before using PortAudio. + This function initialises internal data structures and prepares underlying + host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(), + and Pa_GetErrorText(), this function MUST be called before using any other + PortAudio API functions. + + If Pa_Initialize() is called multiple times, each successful + call must be matched with a corresponding call to Pa_Terminate(). + Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not + required to be fully nested. + + Note that if Pa_Initialize() returns an error code, Pa_Terminate() should + NOT be called. + + @return paNoError if successful, otherwise an error code indicating the cause + of failure. + + @see Pa_Terminate +*/ +PaError Pa_Initialize( void ); + + +/** Library termination function - call this when finished using PortAudio. + This function deallocates all resources allocated by PortAudio since it was + initializied by a call to Pa_Initialize(). In cases where Pa_Initialise() has + been called multiple times, each call must be matched with a corresponding call + to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically + close any PortAudio streams that are still open. + + Pa_Terminate() MUST be called before exiting a program which uses PortAudio. + Failure to do so may result in serious resource leaks, such as audio devices + not being available until the next reboot. + + @return paNoError if successful, otherwise an error code indicating the cause + of failure. + + @see Pa_Initialize +*/ +PaError Pa_Terminate( void ); + + + +/** The type used to refer to audio devices. Values of this type usually + range from 0 to (Pa_GetDeviceCount()-1), and may also take on the PaNoDevice + and paUseHostApiSpecificDeviceSpecification values. + + @see Pa_GetDeviceCount, paNoDevice, paUseHostApiSpecificDeviceSpecification +*/ +typedef int PaDeviceIndex; + + +/** A special PaDeviceIndex value indicating that no device is available, + or should be used. + + @see PaDeviceIndex +*/ +#define paNoDevice ((PaDeviceIndex)-1) + + +/** A special PaDeviceIndex value indicating that the device(s) to be used + are specified in the host api specific stream info structure. + + @see PaDeviceIndex +*/ +#define paUseHostApiSpecificDeviceSpecification ((PaDeviceIndex)-2) + + +/* Host API enumeration mechanism */ + +/** The type used to enumerate to host APIs at runtime. Values of this type + range from 0 to (Pa_GetHostApiCount()-1). + + @see Pa_GetHostApiCount +*/ +typedef int PaHostApiIndex; + + +/** Retrieve the number of available host APIs. Even if a host API is + available it may have no devices available. + + @return A non-negative value indicating the number of available host APIs + or, a PaErrorCode (which are always negative) if PortAudio is not initialized + or an error is encountered. + + @see PaHostApiIndex +*/ +PaHostApiIndex Pa_GetHostApiCount( void ); + + +/** Retrieve the index of the default host API. The default host API will be + the lowest common denominator host API on the current platform and is + unlikely to provide the best performance. + + @return A non-negative value ranging from 0 to (Pa_GetHostApiCount()-1) + indicating the default host API index or, a PaErrorCode (which are always + negative) if PortAudio is not initialized or an error is encountered. +*/ +PaHostApiIndex Pa_GetDefaultHostApi( void ); + + +/** Unchanging unique identifiers for each supported host API. This type + is used in the PaHostApiInfo structure. The values are guaranteed to be + unique and to never change, thus allowing code to be written that + conditionally uses host API specific extensions. + + New type ids will be allocated when support for a host API reaches + "public alpha" status, prior to that developers should use the + paInDevelopment type id. + + @see PaHostApiInfo +*/ +typedef enum PaHostApiTypeId +{ + paInDevelopment=0, /* use while developing support for a new host API */ + paDirectSound=1, + paMME=2, + paASIO=3, + paSoundManager=4, + paCoreAudio=5, + paOSS=7, + paALSA=8, + paAL=9, + paBeOS=10, + paWDMKS=11, + paJACK=12, + paWASAPI=13, + paAudioScienceHPI=14 +} PaHostApiTypeId; + + +/** A structure containing information about a particular host API. */ + +typedef struct PaHostApiInfo +{ + /** this is struct version 1 */ + int structVersion; + /** The well known unique identifier of this host API @see PaHostApiTypeId */ + PaHostApiTypeId type; + /** A textual description of the host API for display on user interfaces. */ + const char *name; + + /** The number of devices belonging to this host API. This field may be + used in conjunction with Pa_HostApiDeviceIndexToDeviceIndex() to enumerate + all devices for this host API. + @see Pa_HostApiDeviceIndexToDeviceIndex + */ + int deviceCount; + + /** The default input device for this host API. The value will be a + device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice + if no default input device is available. + */ + PaDeviceIndex defaultInputDevice; + + /** The default output device for this host API. The value will be a + device index ranging from 0 to (Pa_GetDeviceCount()-1), or paNoDevice + if no default output device is available. + */ + PaDeviceIndex defaultOutputDevice; + +} PaHostApiInfo; + + +/** Retrieve a pointer to a structure containing information about a specific + host Api. + + @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) + + @return A pointer to an immutable PaHostApiInfo structure describing + a specific host API. If the hostApi parameter is out of range or an error + is encountered, the function returns NULL. + + The returned structure is owned by the PortAudio implementation and must not + be manipulated or freed. The pointer is only guaranteed to be valid between + calls to Pa_Initialize() and Pa_Terminate(). +*/ +const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi ); + + +/** Convert a static host API unique identifier, into a runtime + host API index. + + @param type A unique host API identifier belonging to the PaHostApiTypeId + enumeration. + + @return A valid PaHostApiIndex ranging from 0 to (Pa_GetHostApiCount()-1) or, + a PaErrorCode (which are always negative) if PortAudio is not initialized + or an error is encountered. + + The paHostApiNotFound error code indicates that the host API specified by the + type parameter is not available. + + @see PaHostApiTypeId +*/ +PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type ); + + +/** Convert a host-API-specific device index to standard PortAudio device index. + This function may be used in conjunction with the deviceCount field of + PaHostApiInfo to enumerate all devices for the specified host API. + + @param hostApi A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) + + @param hostApiDeviceIndex A valid per-host device index in the range + 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) + + @return A non-negative PaDeviceIndex ranging from 0 to (Pa_GetDeviceCount()-1) + or, a PaErrorCode (which are always negative) if PortAudio is not initialized + or an error is encountered. + + A paInvalidHostApi error code indicates that the host API index specified by + the hostApi parameter is out of range. + + A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter + is out of range. + + @see PaHostApiInfo +*/ +PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi, + int hostApiDeviceIndex ); + + + +/** Structure used to return information about a host error condition. +*/ +typedef struct PaHostErrorInfo{ + PaHostApiTypeId hostApiType; /**< the host API which returned the error code */ + long errorCode; /**< the error code returned */ + const char *errorText; /**< a textual description of the error if available, otherwise a zero-length string */ +}PaHostErrorInfo; + + +/** Return information about the last host error encountered. The error + information returned by Pa_GetLastHostErrorInfo() will never be modified + asyncronously by errors occurring in other PortAudio owned threads + (such as the thread that manages the stream callback.) + + This function is provided as a last resort, primarily to enhance debugging + by providing clients with access to all available error information. + + @return A pointer to an immutable structure constaining information about + the host error. The values in this structure will only be valid if a + PortAudio function has previously returned the paUnanticipatedHostError + error code. +*/ +const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void ); + + + +/* Device enumeration and capabilities */ + +/** Retrieve the number of available devices. The number of available devices + may be zero. + + @return A non-negative value indicating the number of available devices or, + a PaErrorCode (which are always negative) if PortAudio is not initialized + or an error is encountered. +*/ +PaDeviceIndex Pa_GetDeviceCount( void ); + + +/** Retrieve the index of the default input device. The result can be + used in the inputDevice parameter to Pa_OpenStream(). + + @return The default input device index for the default host API, or paNoDevice + if no default input device is available or an error was encountered. +*/ +PaDeviceIndex Pa_GetDefaultInputDevice( void ); + + +/** Retrieve the index of the default output device. The result can be + used in the outputDevice parameter to Pa_OpenStream(). + + @return The default output device index for the defualt host API, or paNoDevice + if no default output device is available or an error was encountered. + + @note + On the PC, the user can specify a default device by + setting an environment variable. For example, to use device #1. +<pre> + set PA_RECOMMENDED_OUTPUT_DEVICE=1 +</pre> + The user should first determine the available device ids by using + the supplied application "pa_devs". +*/ +PaDeviceIndex Pa_GetDefaultOutputDevice( void ); + + +/** The type used to represent monotonic time in seconds that can be used + for syncronisation. The type is used for the outTime argument to the + PaStreamCallback and as the result of Pa_GetStreamTime(). + + @see PaStreamCallback, Pa_GetStreamTime +*/ +typedef double PaTime; + + +/** A type used to specify one or more sample formats. Each value indicates + a possible format for sound data passed to and from the stream callback, + Pa_ReadStream and Pa_WriteStream. + + The standard formats paFloat32, paInt16, paInt32, paInt24, paInt8 + and aUInt8 are usually implemented by all implementations. + + The floating point representation (paFloat32) uses +1.0 and -1.0 as the + maximum and minimum respectively. + + paUInt8 is an unsigned 8 bit format where 128 is considered "ground" + + The paNonInterleaved flag indicates that a multichannel buffer is passed + as a set of non-interleaved pointers. + + @see Pa_OpenStream, Pa_OpenDefaultStream, PaDeviceInfo + @see paFloat32, paInt16, paInt32, paInt24, paInt8 + @see paUInt8, paCustomFormat, paNonInterleaved +*/ +typedef unsigned long PaSampleFormat; + + +#define paFloat32 ((PaSampleFormat) 0x00000001) /**< @see PaSampleFormat */ +#define paInt32 ((PaSampleFormat) 0x00000002) /**< @see PaSampleFormat */ +#define paInt24 ((PaSampleFormat) 0x00000004) /**< Packed 24 bit format. @see PaSampleFormat */ +#define paInt16 ((PaSampleFormat) 0x00000008) /**< @see PaSampleFormat */ +#define paInt8 ((PaSampleFormat) 0x00000010) /**< @see PaSampleFormat */ +#define paUInt8 ((PaSampleFormat) 0x00000020) /**< @see PaSampleFormat */ +#define paCustomFormat ((PaSampleFormat) 0x00010000)/**< @see PaSampleFormat */ + +#define paNonInterleaved ((PaSampleFormat) 0x80000000) + +/** A structure providing information and capabilities of PortAudio devices. + Devices may support input, output or both input and output. +*/ +typedef struct PaDeviceInfo +{ + int structVersion; /* this is struct version 2 */ + const char *name; + PaHostApiIndex hostApi; /* note this is a host API index, not a type id*/ + + int maxInputChannels; + int maxOutputChannels; + + /* Default latency values for interactive performance. */ + PaTime defaultLowInputLatency; + PaTime defaultLowOutputLatency; + /* Default latency values for robust non-interactive applications (eg. playing sound files). */ + PaTime defaultHighInputLatency; + PaTime defaultHighOutputLatency; + + double defaultSampleRate; +} PaDeviceInfo; + + +/** Retrieve a pointer to a PaDeviceInfo structure containing information + about the specified device. + @return A pointer to an immutable PaDeviceInfo structure. If the device + parameter is out of range the function returns NULL. + + @param device A valid device index in the range 0 to (Pa_GetDeviceCount()-1) + + @note PortAudio manages the memory referenced by the returned pointer, + the client must not manipulate or free the memory. The pointer is only + guaranteed to be valid between calls to Pa_Initialize() and Pa_Terminate(). + + @see PaDeviceInfo, PaDeviceIndex +*/ +const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device ); + + +/** Parameters for one direction (input or output) of a stream. +*/ +typedef struct PaStreamParameters +{ + /** A valid device index in the range 0 to (Pa_GetDeviceCount()-1) + specifying the device to be used or the special constant + paUseHostApiSpecificDeviceSpecification which indicates that the actual + device(s) to use are specified in hostApiSpecificStreamInfo. + This field must not be set to paNoDevice. + */ + PaDeviceIndex device; + + /** The number of channels of sound to be delivered to the + stream callback or accessed by Pa_ReadStream() or Pa_WriteStream(). + It can range from 1 to the value of maxInputChannels in the + PaDeviceInfo record for the device specified by the device parameter. + */ + int channelCount; + + /** The sample format of the buffer provided to the stream callback, + a_ReadStream() or Pa_WriteStream(). It may be any of the formats described + by the PaSampleFormat enumeration. + */ + PaSampleFormat sampleFormat; + + /** The desired latency in seconds. Where practical, implementations should + configure their latency based on these parameters, otherwise they may + choose the closest viable latency instead. Unless the suggested latency + is greater than the absolute upper limit for the device implementations + should round the suggestedLatency up to the next practial value - ie to + provide an equal or higher latency than suggestedLatency wherever possibe. + Actual latency values for an open stream may be retrieved using the + inputLatency and outputLatency fields of the PaStreamInfo structure + returned by Pa_GetStreamInfo(). + @see default*Latency in PaDeviceInfo, *Latency in PaStreamInfo + */ + PaTime suggestedLatency; + + /** An optional pointer to a host api specific data structure + containing additional information for device setup and/or stream processing. + hostApiSpecificStreamInfo is never required for correct operation, + if not used it should be set to NULL. + */ + void *hostApiSpecificStreamInfo; + +} PaStreamParameters; + + +/** Return code for Pa_IsFormatSupported indicating success. */ +#define paFormatIsSupported (0) + +/** Determine whether it would be possible to open a stream with the specified + parameters. + + @param inputParameters A structure that describes the input parameters used to + open a stream. The suggestedLatency field is ignored. See PaStreamParameters + for a description of these parameters. inputParameters must be NULL for + output-only streams. + + @param outputParameters A structure that describes the output parameters used + to open a stream. The suggestedLatency field is ignored. See PaStreamParameters + for a description of these parameters. outputParameters must be NULL for + input-only streams. + + @param sampleRate The required sampleRate. For full-duplex streams it is the + sample rate for both input and output + + @return Returns 0 if the format is supported, and an error code indicating why + the format is not supported otherwise. The constant paFormatIsSupported is + provided to compare with the return value for success. + + @see paFormatIsSupported, PaStreamParameters +*/ +PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate ); + + + +/* Streaming types and functions */ + + +/** + A single PaStream can provide multiple channels of real-time + streaming audio input and output to a client application. A stream + provides access to audio hardware represented by one or more + PaDevices. Depending on the underlying Host API, it may be possible + to open multiple streams using the same device, however this behavior + is implementation defined. Portable applications should assume that + a PaDevice may be simultaneously used by at most one PaStream. + + Pointers to PaStream objects are passed between PortAudio functions that + operate on streams. + + @see Pa_OpenStream, Pa_OpenDefaultStream, Pa_OpenDefaultStream, Pa_CloseStream, + Pa_StartStream, Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive, + Pa_GetStreamTime, Pa_GetStreamCpuLoad + +*/ +typedef void PaStream; + + +/** Can be passed as the framesPerBuffer parameter to Pa_OpenStream() + or Pa_OpenDefaultStream() to indicate that the stream callback will + accept buffers of any size. +*/ +#define paFramesPerBufferUnspecified (0) + + +/** Flags used to control the behavior of a stream. They are passed as + parameters to Pa_OpenStream or Pa_OpenDefaultStream. Multiple flags may be + ORed together. + + @see Pa_OpenStream, Pa_OpenDefaultStream + @see paNoFlag, paClipOff, paDitherOff, paNeverDropInput, + paPrimeOutputBuffersUsingStreamCallback, paPlatformSpecificFlags +*/ +typedef unsigned long PaStreamFlags; + +/** @see PaStreamFlags */ +#define paNoFlag ((PaStreamFlags) 0) + +/** Disable default clipping of out of range samples. + @see PaStreamFlags +*/ +#define paClipOff ((PaStreamFlags) 0x00000001) + +/** Disable default dithering. + @see PaStreamFlags +*/ +#define paDitherOff ((PaStreamFlags) 0x00000002) + +/** Flag requests that where possible a full duplex stream will not discard + overflowed input samples without calling the stream callback. This flag is + only valid for full duplex callback streams and only when used in combination + with the paFramesPerBufferUnspecified (0) framesPerBuffer parameter. Using + this flag incorrectly results in a paInvalidFlag error being returned from + Pa_OpenStream and Pa_OpenDefaultStream. + + @see PaStreamFlags, paFramesPerBufferUnspecified +*/ +#define paNeverDropInput ((PaStreamFlags) 0x00000004) + +/** Call the stream callback to fill initial output buffers, rather than the + default behavior of priming the buffers with zeros (silence). This flag has + no effect for input-only and blocking read/write streams. + + @see PaStreamFlags +*/ +#define paPrimeOutputBuffersUsingStreamCallback ((PaStreamFlags) 0x00000008) + +/** A mask specifying the platform specific bits. + @see PaStreamFlags +*/ +#define paPlatformSpecificFlags ((PaStreamFlags)0xFFFF0000) + +/** + Timing information for the buffers passed to the stream callback. +*/ +typedef struct PaStreamCallbackTimeInfo{ + PaTime inputBufferAdcTime; + PaTime currentTime; + PaTime outputBufferDacTime; +} PaStreamCallbackTimeInfo; + + +/** + Flag bit constants for the statusFlags to PaStreamCallback. + + @see paInputUnderflow, paInputOverflow, paOutputUnderflow, paOutputOverflow, + paPrimingOutput +*/ +typedef unsigned long PaStreamCallbackFlags; + +/** In a stream opened with paFramesPerBufferUnspecified, indicates that + input data is all silence (zeros) because no real data is available. In a + stream opened without paFramesPerBufferUnspecified, it indicates that one or + more zero samples have been inserted into the input buffer to compensate + for an input underflow. + @see PaStreamCallbackFlags +*/ +#define paInputUnderflow ((PaStreamCallbackFlags) 0x00000001) + +/** In a stream opened with paFramesPerBufferUnspecified, indicates that data + prior to the first sample of the input buffer was discarded due to an + overflow, possibly because the stream callback is using too much CPU time. + Otherwise indicates that data prior to one or more samples in the + input buffer was discarded. + @see PaStreamCallbackFlags +*/ +#define paInputOverflow ((PaStreamCallbackFlags) 0x00000002) + +/** Indicates that output data (or a gap) was inserted, possibly because the + stream callback is using too much CPU time. + @see PaStreamCallbackFlags +*/ +#define paOutputUnderflow ((PaStreamCallbackFlags) 0x00000004) + +/** Indicates that output data will be discarded because no room is available. + @see PaStreamCallbackFlags +*/ +#define paOutputOverflow ((PaStreamCallbackFlags) 0x00000008) + +/** Some of all of the output data will be used to prime the stream, input + data may be zero. + @see PaStreamCallbackFlags +*/ +#define paPrimingOutput ((PaStreamCallbackFlags) 0x00000010) + +/** + Allowable return values for the PaStreamCallback. + @see PaStreamCallback +*/ +typedef enum PaStreamCallbackResult +{ + paContinue=0, + paComplete=1, + paAbort=2 +} PaStreamCallbackResult; + + +/** + Functions of type PaStreamCallback are implemented by PortAudio clients. + They consume, process or generate audio in response to requests from an + active PortAudio stream. + + @param input and @param output are arrays of interleaved samples, + the format, packing and number of channels used by the buffers are + determined by parameters to Pa_OpenStream(). + + @param frameCount The number of sample frames to be processed by + the stream callback. + + @param timeInfo The time in seconds when the first sample of the input + buffer was received at the audio input, the time in seconds when the first + sample of the output buffer will begin being played at the audio output, and + the time in seconds when the stream callback was called. + See also Pa_GetStreamTime() + + @param statusFlags Flags indicating whether input and/or output buffers + have been inserted or will be dropped to overcome underflow or overflow + conditions. + + @param userData The value of a user supplied pointer passed to + Pa_OpenStream() intended for storing synthesis data etc. + + @return + The stream callback should return one of the values in the + PaStreamCallbackResult enumeration. To ensure that the callback continues + to be called, it should return paContinue (0). Either paComplete or paAbort + can be returned to finish stream processing, after either of these values is + returned the callback will not be called again. If paAbort is returned the + stream will finish as soon as possible. If paComplete is returned, the stream + will continue until all buffers generated by the callback have been played. + This may be useful in applications such as soundfile players where a specific + duration of output is required. However, it is not necessary to utilise this + mechanism as Pa_StopStream(), Pa_AbortStream() or Pa_CloseStream() can also + be used to stop the stream. The callback must always fill the entire output + buffer irrespective of its return value. + + @see Pa_OpenStream, Pa_OpenDefaultStream + + @note With the exception of Pa_GetStreamCpuLoad() it is not permissable to call + PortAudio API functions from within the stream callback. +*/ +typedef int PaStreamCallback( + const void *input, void *output, + unsigned long frameCount, + const PaStreamCallbackTimeInfo* timeInfo, + PaStreamCallbackFlags statusFlags, + void *userData ); + + +/** Opens a stream for either input, output or both. + + @param stream The address of a PaStream pointer which will receive + a pointer to the newly opened stream. + + @param inputParameters A structure that describes the input parameters used by + the opened stream. See PaStreamParameters for a description of these parameters. + inputParameters must be NULL for output-only streams. + + @param outputParameters A structure that describes the output parameters used by + the opened stream. See PaStreamParameters for a description of these parameters. + outputParameters must be NULL for input-only streams. + + @param sampleRate The desired sampleRate. For full-duplex streams it is the + sample rate for both input and output + + @param framesPerBuffer The number of frames passed to the stream callback + function, or the preferred block granularity for a blocking read/write stream. + The special value paFramesPerBufferUnspecified (0) may be used to request that + the stream callback will recieve an optimal (and possibly varying) number of + frames based on host requirements and the requested latency settings. + Note: With some host APIs, the use of non-zero framesPerBuffer for a callback + stream may introduce an additional layer of buffering which could introduce + additional latency. PortAudio guarantees that the additional latency + will be kept to the theoretical minimum however, it is strongly recommended + that a non-zero framesPerBuffer value only be used when your algorithm + requires a fixed number of frames per stream callback. + + @param streamFlags Flags which modify the behaviour of the streaming process. + This parameter may contain a combination of flags ORed together. Some flags may + only be relevant to certain buffer formats. + + @param streamCallback A pointer to a client supplied function that is responsible + for processing and filling input and output buffers. If this parameter is NULL + the stream will be opened in 'blocking read/write' mode. In blocking mode, + the client can receive sample data using Pa_ReadStream and write sample data + using Pa_WriteStream, the number of samples that may be read or written + without blocking is returned by Pa_GetStreamReadAvailable and + Pa_GetStreamWriteAvailable respectively. + + @param userData A client supplied pointer which is passed to the stream callback + function. It could for example, contain a pointer to instance data necessary + for processing the audio buffers. This parameter is ignored if streamCallback + is NULL. + + @return + Upon success Pa_OpenStream() returns paNoError and places a pointer to a + valid PaStream in the stream argument. The stream is inactive (stopped). + If a call to Pa_OpenStream() fails, a non-zero error code is returned (see + PaError for possible error codes) and the value of stream is invalid. + + @see PaStreamParameters, PaStreamCallback, Pa_ReadStream, Pa_WriteStream, + Pa_GetStreamReadAvailable, Pa_GetStreamWriteAvailable +*/ +PaError Pa_OpenStream( PaStream** stream, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamFlags streamFlags, + PaStreamCallback *streamCallback, + void *userData ); + + +/** A simplified version of Pa_OpenStream() that opens the default input + and/or output devices. + + @param stream The address of a PaStream pointer which will receive + a pointer to the newly opened stream. + + @param numInputChannels The number of channels of sound that will be supplied + to the stream callback or returned by Pa_ReadStream. It can range from 1 to + the value of maxInputChannels in the PaDeviceInfo record for the default input + device. If 0 the stream is opened as an output-only stream. + + @param numOutputChannels The number of channels of sound to be delivered to the + stream callback or passed to Pa_WriteStream. It can range from 1 to the value + of maxOutputChannels in the PaDeviceInfo record for the default output dvice. + If 0 the stream is opened as an output-only stream. + + @param sampleFormat The sample format of both the input and output buffers + provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. + sampleFormat may be any of the formats described by the PaSampleFormat + enumeration. + + @param sampleRate Same as Pa_OpenStream parameter of the same name. + @param framesPerBuffer Same as Pa_OpenStream parameter of the same name. + @param streamCallback Same as Pa_OpenStream parameter of the same name. + @param userData Same as Pa_OpenStream parameter of the same name. + + @return As for Pa_OpenStream + + @see Pa_OpenStream, PaStreamCallback +*/ +PaError Pa_OpenDefaultStream( PaStream** stream, + int numInputChannels, + int numOutputChannels, + PaSampleFormat sampleFormat, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamCallback *streamCallback, + void *userData ); + + +/** Closes an audio stream. If the audio stream is active it + discards any pending buffers as if Pa_AbortStream() had been called. +*/ +PaError Pa_CloseStream( PaStream *stream ); + + +/** Functions of type PaStreamFinishedCallback are implemented by PortAudio + clients. They can be registered with a stream using the Pa_SetStreamFinishedCallback + function. Once registered they are called when the stream becomes inactive + (ie once a call to Pa_StopStream() will not block). + A stream will become inactive after the stream callback returns non-zero, + or when Pa_StopStream or Pa_AbortStream is called. For a stream providing audio + output, if the stream callback returns paComplete, or Pa_StopStream is called, + the stream finished callback will not be called until all generated sample data + has been played. + + @param userData The userData parameter supplied to Pa_OpenStream() + + @see Pa_SetStreamFinishedCallback +*/ +typedef void PaStreamFinishedCallback( void *userData ); + + +/** Register a stream finished callback function which will be called when the + stream becomes inactive. See the description of PaStreamFinishedCallback for + further details about when the callback will be called. + + @param stream a pointer to a PaStream that is in the stopped state - if the + stream is not stopped, the stream's finished callback will remain unchanged + and an error code will be returned. + + @param streamFinishedCallback a pointer to a function with the same signature + as PaStreamFinishedCallback, that will be called when the stream becomes + inactive. Passing NULL for this parameter will un-register a previously + registered stream finished callback function. + + @return on success returns paNoError, otherwise an error code indicating the cause + of the error. + + @see PaStreamFinishedCallback +*/ +PaError Pa_SetStreamFinishedCallback( PaStream *stream, PaStreamFinishedCallback* streamFinishedCallback ); + + +/** Commences audio processing. +*/ +PaError Pa_StartStream( PaStream *stream ); + + +/** Terminates audio processing. It waits until all pending + audio buffers have been played before it returns. +*/ +PaError Pa_StopStream( PaStream *stream ); + + +/** Terminates audio processing immediately without waiting for pending + buffers to complete. +*/ +PaError Pa_AbortStream( PaStream *stream ); + + +/** Determine whether the stream is stopped. + A stream is considered to be stopped prior to a successful call to + Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. + If a stream callback returns a value other than paContinue the stream is NOT + considered to be stopped. + + @return Returns one (1) when the stream is stopped, zero (0) when + the stream is running or, a PaErrorCode (which are always negative) if + PortAudio is not initialized or an error is encountered. + + @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamActive +*/ +PaError Pa_IsStreamStopped( PaStream *stream ); + + +/** Determine whether the stream is active. + A stream is active after a successful call to Pa_StartStream(), until it + becomes inactive either as a result of a call to Pa_StopStream() or + Pa_AbortStream(), or as a result of a return value other than paContinue from + the stream callback. In the latter case, the stream is considered inactive + after the last buffer has finished playing. + + @return Returns one (1) when the stream is active (ie playing or recording + audio), zero (0) when not playing or, a PaErrorCode (which are always negative) + if PortAudio is not initialized or an error is encountered. + + @see Pa_StopStream, Pa_AbortStream, Pa_IsStreamStopped +*/ +PaError Pa_IsStreamActive( PaStream *stream ); + + + +/** A structure containing unchanging information about an open stream. + @see Pa_GetStreamInfo +*/ + +typedef struct PaStreamInfo +{ + /** this is struct version 1 */ + int structVersion; + + /** The input latency of the stream in seconds. This value provides the most + accurate estimate of input latency available to the implementation. It may + differ significantly from the suggestedLatency value passed to Pa_OpenStream(). + The value of this field will be zero (0.) for output-only streams. + @see PaTime + */ + PaTime inputLatency; + + /** The output latency of the stream in seconds. This value provides the most + accurate estimate of output latency available to the implementation. It may + differ significantly from the suggestedLatency value passed to Pa_OpenStream(). + The value of this field will be zero (0.) for input-only streams. + @see PaTime + */ + PaTime outputLatency; + + /** The sample rate of the stream in Hertz (samples per second). In cases + where the hardware sample rate is inaccurate and PortAudio is aware of it, + the value of this field may be different from the sampleRate parameter + passed to Pa_OpenStream(). If information about the actual hardware sample + rate is not available, this field will have the same value as the sampleRate + parameter passed to Pa_OpenStream(). + */ + double sampleRate; + +} PaStreamInfo; + + +/** Retrieve a pointer to a PaStreamInfo structure containing information + about the specified stream. + @return A pointer to an immutable PaStreamInfo structure. If the stream + parameter invalid, or an error is encountered, the function returns NULL. + + @param stream A pointer to an open stream previously created with Pa_OpenStream. + + @note PortAudio manages the memory referenced by the returned pointer, + the client must not manipulate or free the memory. The pointer is only + guaranteed to be valid until the specified stream is closed. + + @see PaStreamInfo +*/ +const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream ); + + +/** Determine the current time for the stream according to the same clock used + to generate buffer timestamps. This time may be used for syncronising other + events to the audio stream, for example synchronizing audio to MIDI. + + @return The stream's current time in seconds, or 0 if an error occurred. + + @see PaTime, PaStreamCallback +*/ +PaTime Pa_GetStreamTime( PaStream *stream ); + + +/** Retrieve CPU usage information for the specified stream. + The "CPU Load" is a fraction of total CPU time consumed by a callback stream's + audio processing routines including, but not limited to the client supplied + stream callback. This function does not work with blocking read/write streams. + + This function may be called from the stream callback function or the + application. + + @return + A floating point value, typically between 0.0 and 1.0, where 1.0 indicates + that the stream callback is consuming the maximum number of CPU cycles possible + to maintain real-time operation. A value of 0.5 would imply that PortAudio and + the stream callback was consuming roughly 50% of the available CPU time. The + return value may exceed 1.0. A value of 0.0 will always be returned for a + blocking read/write stream, or if an error occurrs. +*/ +double Pa_GetStreamCpuLoad( PaStream* stream ); + + +/** Read samples from an input stream. The function doesn't return until + the entire buffer has been filled - this may involve waiting for the operating + system to supply the data. + + @param stream A pointer to an open stream previously created with Pa_OpenStream. + + @param buffer A pointer to a buffer of sample frames. The buffer contains + samples in the format specified by the inputParameters->sampleFormat field + used to open the stream, and the number of channels specified by + inputParameters->numChannels. If non-interleaved samples were requested, + buffer is a pointer to the first element of an array of non-interleaved + buffer pointers, one for each channel. + + @param frames The number of frames to be read into buffer. This parameter + is not constrained to a specific range, however high performance applications + will want to match this parameter to the framesPerBuffer parameter used + when opening the stream. + + @return On success PaNoError will be returned, or PaInputOverflowed if input + data was discarded by PortAudio after the previous call and before this call. +*/ +PaError Pa_ReadStream( PaStream* stream, + void *buffer, + unsigned long frames ); + + +/** Write samples to an output stream. This function doesn't return until the + entire buffer has been consumed - this may involve waiting for the operating + system to consume the data. + + @param stream A pointer to an open stream previously created with Pa_OpenStream. + + @param buffer A pointer to a buffer of sample frames. The buffer contains + samples in the format specified by the outputParameters->sampleFormat field + used to open the stream, and the number of channels specified by + outputParameters->numChannels. If non-interleaved samples were requested, + buffer is a pointer to the first element of an array of non-interleaved + buffer pointers, one for each channel. + + @param frames The number of frames to be written from buffer. This parameter + is not constrained to a specific range, however high performance applications + will want to match this parameter to the framesPerBuffer parameter used + when opening the stream. + + @return On success PaNoError will be returned, or paOutputUnderflowed if + additional output data was inserted after the previous call and before this + call. +*/ +PaError Pa_WriteStream( PaStream* stream, + const void *buffer, + unsigned long frames ); + + +/** Retrieve the number of frames that can be read from the stream without + waiting. + + @return Returns a non-negative value representing the maximum number of frames + that can be read from the stream without blocking or busy waiting or, a + PaErrorCode (which are always negative) if PortAudio is not initialized or an + error is encountered. +*/ +signed long Pa_GetStreamReadAvailable( PaStream* stream ); + + +/** Retrieve the number of frames that can be written to the stream without + waiting. + + @return Returns a non-negative value representing the maximum number of frames + that can be written to the stream without blocking or busy waiting or, a + PaErrorCode (which are always negative) if PortAudio is not initialized or an + error is encountered. +*/ +signed long Pa_GetStreamWriteAvailable( PaStream* stream ); + + +/* Miscellaneous utilities */ + + +/** Retrieve the size of a given sample format in bytes. + + @return The size in bytes of a single sample in the specified format, + or paSampleFormatNotSupported if the format is not supported. +*/ +PaError Pa_GetSampleSize( PaSampleFormat format ); + + +/** Put the caller to sleep for at least 'msec' milliseconds. This function is + provided only as a convenience for authors of portable code (such as the tests + and examples in the PortAudio distribution.) + + The function may sleep longer than requested so don't rely on this for accurate + musical timing. +*/ +void Pa_Sleep( long msec ); + + + +#ifdef __cplusplus +} +#endif /* __cplusplus */ +#endif /* PORTAUDIO_H */ |