#include <pa_hostapi.h>

Data Fields
PaUtilPrivatePaFrontHostApiInfo	privatePaFrontInfo

PaHostApiInfo	info

PaDeviceInfo **	deviceInfos

void(*	Terminate )(struct PaUtilHostApiRepresentation *hostApi)

PaError(*	OpenStream )(struct PaUtilHostApiRepresentation hostApi, PaStream stream, const PaStreamParameters inputParameters, const PaStreamParameters outputParameters, double sampleRate, unsigned long framesPerCallback, PaStreamFlags streamFlags, PaStreamCallback streamCallback, void *userData)

PaError(*	IsFormatSupported )(struct PaUtilHostApiRepresentation hostApi, const PaStreamParameters inputParameters, const PaStreamParameters *outputParameters, double sampleRate)

Detailed Description

A structure representing the interface to a host API. Contains both concrete data and pointers to functions which implement the interface.

Field Documentation

◆ deviceInfos

PaDeviceInfo** PaUtilHostApiRepresentation::deviceInfos

Referenced by IsFormatSupported(), OpenStream(), Pa_GetDeviceInfo(), PaAsio_GetAvailableBufferSizes(), PaAsio_GetInputChannelName(), PaAsio_GetOutputChannelName(), PaAsio_ShowControlPanel(), PaAudioIO_Initialize(), PaMacCore_GetBufferSizeRange(), and PaMacCore_GetChannelName().

◆ info

PaHostApiInfo PaUtilHostApiRepresentation::info

The host api implementation should populate the info field. In the case of info.defaultInputDevice and info.defaultOutputDevice the values stored should be 0 based indices within the host api's own device index range (0 to deviceCount). These values will be converted to global device indices by pa_front after PaUtilHostApiInitializer() returns.

Referenced by Pa_GetDefaultInputDevice(), Pa_GetDefaultOutputDevice(), Pa_GetHostApiInfo(), PaAsio_Initialize(), PaAudioIO_Initialize(), PaJack_Initialize(), PaMacCore_Initialize(), PaOSS_Initialize(), PaPulseAudio_Initialize(), PaPulseAudio_StartStreamCb(), PaSkeleton_Initialize(), PaSndio_Initialize(), PaUtil_DeviceIndexToHostApiDeviceIndex(), PaWasapi_Initialize(), PaWinDs_Initialize(), PaWinMme_Initialize(), and PaWinWdm_Initialize().

◆ IsFormatSupported

PaError(* PaUtilHostApiRepresentation::IsFormatSupported) (struct PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *inputParameters, const PaStreamParameters *outputParameters, double sampleRate)

Referenced by Pa_IsFormatSupported(), PaAudioIO_Initialize(), and PaMacCore_Initialize().

◆ OpenStream

PaError(* PaUtilHostApiRepresentation::OpenStream) (struct PaUtilHostApiRepresentation *hostApi, PaStream **stream, const PaStreamParameters *inputParameters, const PaStreamParameters *outputParameters, double sampleRate, unsigned long framesPerCallback, PaStreamFlags streamFlags, PaStreamCallback *streamCallback, void *userData)

The inputParameters and outputParameters pointers should not be saved as they will not remain valid after OpenStream is called.

The following guarantees are made about parameters to (*OpenStream)():

[NOTE: the following list up to *END PA FRONT VALIDATIONS* should be
    kept in sync with the one for ValidateOpenStreamParameters and
    Pa_OpenStream in pa_front.c]

PaHostApiRepresentation *hostApi
    - is valid for this implementation

PaStream** stream
    - is non-null

- at least one of inputParameters & outputParmeters is valid (not NULL)

- if inputParameters & outputParmeters are both valid, that
    inputParameters->device & outputParmeters->device  both use the same host api

PaDeviceIndex inputParameters->device
    - is within range (0 to Pa_CountDevices-1) Or:
    - is paUseHostApiSpecificDeviceSpecification and
        inputParameters->hostApiSpecificStreamInfo is non-NULL and refers
        to a valid host api

int inputParameters->numChannels
    - if inputParameters->device is not paUseHostApiSpecificDeviceSpecification, numInputChannels is > 0
    - upper bound is NOT validated against device capabilities

PaSampleFormat inputParameters->sampleFormat
    - is one of the sample formats defined in portaudio.h

void *inputParameters->hostApiSpecificStreamInfo
    - if supplied its hostApi field matches the input device's host Api

PaDeviceIndex outputParmeters->device
    - is within range (0 to Pa_CountDevices-1)

int outputParmeters->numChannels
    - if inputDevice is valid, numInputChannels is > 0
    - upper bound is NOT validated against device capabilities

PaSampleFormat outputParmeters->sampleFormat
    - is one of the sample formats defined in portaudio.h

void *outputParmeters->hostApiSpecificStreamInfo
    - if supplied its hostApi field matches the output device's host Api

double sampleRate
    - is not an 'absurd' rate (less than 1000. or greater than 384000.)
    - sampleRate is NOT validated against device capabilities

PaStreamFlags streamFlags
    - unused platform neutral flags are zero
    - paNeverDropInput is only used for full-duplex callback streams
        with variable buffer size (paFramesPerBufferUnspecified)

[*END PA FRONT VALIDATIONS*]

The following validations MUST be performed by (*OpenStream)():

- check that input device can support numInputChannels

- check that input device can support inputSampleFormat, or that
    we have the capability to convert from outputSampleFormat to
    a native format

- if inputStreamInfo is supplied, validate its contents,
    or return an error if no inputStreamInfo is expected

- check that output device can support numOutputChannels

- check that output device can support outputSampleFormat, or that
    we have the capability to convert from outputSampleFormat to
    a native format

- if outputStreamInfo is supplied, validate its contents,
    or return an error if no outputStreamInfo is expected

- if a full duplex stream is requested, check that the combination
    of input and output parameters is supported

- check that the device supports sampleRate

- alter sampleRate to a close allowable rate if necessary

- validate inputLatency and outputLatency

- validate any platform specific flags, if flags are supplied they
    must be valid.

Referenced by Pa_OpenStream(), PaAudioIO_Initialize(), and PaMacCore_Initialize().

◆ privatePaFrontInfo

PaUtilPrivatePaFrontHostApiInfo PaUtilHostApiRepresentation::privatePaFrontInfo

Referenced by Pa_HostApiDeviceIndexToDeviceIndex(), and PaUtil_DeviceIndexToHostApiDeviceIndex().

◆ Terminate

void(* PaUtilHostApiRepresentation::Terminate) (struct PaUtilHostApiRepresentation *hostApi)

(*Terminate)() is guaranteed to be called with a valid <hostApi> parameter, which was previously returned from the same implementation's initializer.

Referenced by PaAudioIO_Initialize(), and PaMacCore_Initialize().

The documentation for this struct was generated from the following file:

pa_hostapi.h

Data Fields