VuoAudio.cc File Reference

Description

VuoAudio implementation.

Copyright

Copyright © 2012–2018 Kosada Incorporated. This code may be modified and distributed under the terms of the MIT License. For more information, see http://vuo.org/license.

Classes
struct	_VuoAudio_internal
	Private data for a VuoAudio instance. More...

Typedefs
typedef std::map< void *, std::queue< VuoList_VuoAudioSamples > >	pendingOutputType
	For each unique audio source (identified by void *), a queue of buffers to output. More...
typedef std::map< void *, std::map< VuoInteger, VuoReal > >	lastOutputSampleType
	For each unique audio source (identified by void *), the last sample value that was output on each channel. More...
typedef struct _VuoAudio_internal *	VuoAudio_internal
	Private data for a VuoAudio instance. More...

Functions
static void	__attribute__ ((constructor)) VuoAudio_init()
	Ensure we're listening for the system's device notifications. More...
VuoList_VuoAudioInputDevice	VuoAudio_getInputDevices (void)
	Returns a list of the available audio input devices. More...
VuoList_VuoAudioOutputDevice	VuoAudio_getOutputDevices (void)
	Returns a list of the available audio output devices. More...
int	VuoAudio_receivedEvent (void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames, double streamTime, RtAudioStreamStatus status, void *userData)
	RtAudio calls this function when a new sample buffer is ready or needed. More...
VuoAudioIn	VuoAudioIn_getShared (VuoAudioInputDevice aid)
	Returns the reference-counted object for the specified audio input device. More...
VuoAudioOut	VuoAudioOut_getShared (VuoAudioOutputDevice aod)
	Returns the reference-counted object for the specified audio output device. More...
void	VuoAudioIn_addTrigger (VuoAudioIn ai, VuoOutputTrigger(receivedChannels, VuoList_VuoAudioSamples))
	Sets up the audio input device to call the trigger functions when it receives an event. More...
void	VuoAudioOut_addTrigger (VuoAudioOut ao, VuoOutputTrigger(requestedChannels, VuoReal))
	Sets up the audio output device to call the trigger functions when it receives an event. More...
void	VuoAudioIn_removeTrigger (VuoAudioIn ai, VuoOutputTrigger(receivedChannels, VuoList_VuoAudioSamples))
	Stops the audio input device from calling trigger functions when it receives an event. More...
void	VuoAudioOut_removeTrigger (VuoAudioOut ao, VuoOutputTrigger(requestedChannels, VuoReal))
	Stops the audio output device from calling trigger functions when it receives an event. More...
void	VuoAudioOut_sendChannels (VuoAudioOut ao, VuoList_VuoAudioSamples channels, void *id)
	Enqueues channels for eventual playback. More...
	VUOKEYEDPOOL (unsigned int, VuoAudio_internal)
static void	VuoAudio_destroy (VuoAudio_internal ai)
VuoAudio_internal	VuoAudio_make (unsigned int deviceId)
	VUOKEYEDPOOL_DEFINE (unsigned int, VuoAudio_internal, VuoAudio_make)

Variables
const VuoInteger	VuoAudio_queueSize = 8
	The number of buffers that must be enqueued before starting playback. More...

---

Class Documentation

_VuoAudio_internal

struct _VuoAudio_internal

Class Members
VuoAudioInputDevice	inputDevice	The device's id must be nonnegative, and channelCount must be set.
VuoTriggerSet< VuoList_VuoAudioSamples >	inputTriggers	Trigger methods to call when an audio buffer is received.
lastOutputSampleType	lastOutputSample	The last sample value sent on each channel (to smoothly move back to 0 DC when there's a dropout). Not present means no buffer was sent to the channel during the last frame.
VuoAudioOutputDevice	outputDevice	The device's id must be nonnegative, and channelCount must be set.
VuoTriggerSet< VuoReal >	outputTriggers	Trigger methods to call when an audio buffer is needed.
pendingOutputType	pendingOutput	Sample buffers waiting to be output.
dispatch_queue_t	pendingOutputQueue	Serializes access to the following set of buffers.
VuoReal	priorStreamTime	The time at which the prior VuoAudio_receivedEvent() happened, to track stream overflows.
RtAudio *	rta	RtAudio's device pointer.

Typedef Documentation

lastOutputSampleType

typedef std::map<void *, std::map<VuoInteger, VuoReal> > lastOutputSampleType

For each unique audio source (identified by void *), the last sample value that was output on each channel.

pendingOutputType

typedef std::map<void *, std::queue<VuoList_VuoAudioSamples> > pendingOutputType

For each unique audio source (identified by void *), a queue of buffers to output.

VuoAudio_internal

typedef struct _VuoAudio_internal * VuoAudio_internal

Private data for a VuoAudio instance.

Function Documentation

__attribute__()

static void __attribute__ ( (constructor)  )

static

Ensure we're listening for the system's device notifications.

https://b33p.net/kosada/node/12551 http://lists.apple.com/archives/Coreaudio-api/2010/Aug//msg00304.html

VuoAudio_destroy()

static void VuoAudio_destroy ( VuoAudio_internal  ai )

static

Todo:

https://b33p.net/kosada/node/4724

VuoAudio_getInputDevices()

VuoList_VuoAudioInputDevice VuoAudio_getInputDevices

(

void

)

Returns a list of the available audio input devices.

VuoAudio_getOutputDevices()

VuoList_VuoAudioOutputDevice VuoAudio_getOutputDevices

(

void

)

Returns a list of the available audio output devices.

VuoAudio_make()

VuoAudio_internal VuoAudio_make

(

unsigned int

deviceId

)

Todo:

https://b33p.net/kosada/node/4724

VuoAudio_receivedEvent()

int VuoAudio_receivedEvent	(	void *	outputBuffer,
		void *	inputBuffer,
		unsigned int	nBufferFrames,
		double	streamTime,
		RtAudioStreamStatus	status,
		void *	userData
	)

RtAudio calls this function when a new sample buffer is ready or needed.

Todo:

handle differing sample rates

Todo:

Should we clamp here (or after all buffers for this channel have been summed), or does CoreAudio handle that for us?

VuoAudioIn_addTrigger()

void VuoAudioIn_addTrigger	(	VuoAudioIn	ai,
		VuoOutputTrigger(receivedChannels, VuoList_VuoAudioSamples)
	)

Sets up the audio input device to call the trigger functions when it receives an event.

This function may be called from any thread.

VuoAudioIn_getShared()

VuoAudioIn VuoAudioIn_getShared

(

VuoAudioInputDevice

aid

)

Returns the reference-counted object for the specified audio input device.

Todo:

https://b33p.net/kosada/node/4724

VuoAudioIn_removeTrigger()

void VuoAudioIn_removeTrigger	(	VuoAudioIn	ai,
		VuoOutputTrigger(receivedChannels, VuoList_VuoAudioSamples)
	)

Stops the audio input device from calling trigger functions when it receives an event.

This function may be called from any thread.

VuoAudioOut_addTrigger()

void VuoAudioOut_addTrigger	(	VuoAudioOut	ao,
		VuoOutputTrigger(requestedChannels, VuoReal)
	)

Sets up the audio output device to call the trigger functions when it receives an event.

This function may be called from any thread.

VuoAudioOut_getShared()

VuoAudioOut VuoAudioOut_getShared

(

VuoAudioOutputDevice

aod

)

Returns the reference-counted object for the specified audio output device.

Todo:

https://b33p.net/kosada/node/4724

VuoAudioOut_removeTrigger()

void VuoAudioOut_removeTrigger	(	VuoAudioOut	ao,
		VuoOutputTrigger(requestedChannels, VuoReal)
	)

Stops the audio output device from calling trigger functions when it receives an event.

This function may be called from any thread.

VuoAudioOut_sendChannels()

void VuoAudioOut_sendChannels	(	VuoAudioOut	ao,
		VuoList_VuoAudioSamples	channels,
		void *	id
	)

Enqueues channels for eventual playback.

id should be a unique identifier for the audio stream (e.g., a pointer to the node's instance data).

When multiple sources are simultaneously sending to the same audio device, each is buffered independently — each unique id gets its own queue, and at output time a single buffer from each source's queue is mixed to form the final output stream.

VUOKEYEDPOOL()

VUOKEYEDPOOL	(	unsigned	int,
		VuoAudio_internal
	)

Todo:

https://b33p.net/kosada/node/4724

VUOKEYEDPOOL_DEFINE()

VUOKEYEDPOOL_DEFINE	(	unsigned	int,
		VuoAudio_internal	,
		VuoAudio_make
	)

Todo:

https://b33p.net/kosada/node/4724

Variable Documentation

VuoAudio_queueSize

const VuoInteger VuoAudio_queueSize = 8

The number of buffers that must be enqueued before starting playback.