Container for device specific output CoreAudio driver. More...

#include <MpodCoreAudio.h>

Inheritance diagram for MpodCoreAudio:

Collaboration diagram for MpodCoreAudio:

Public Member Functions
Creators
	MpodCoreAudio (const UtlString &name)
	Default constructor. More...

	~MpodCoreAudio ()
	Destructor. More...

Manipulators
OsStatus	enableDevice (unsigned samplesPerFrame, unsigned samplesPerSec, MpFrameTime currentFrameTime)
	Initialize device driver and state. More...

OsStatus	disableDevice ()
	Uninitialize device driver. More...

OsStatus	pushFrame (unsigned int numSamples, const MpAudioSample *samples, MpFrameTime frameTime)
	Send data to output device. More...

OsStatus	setTickerNotification (OsNotification *pFrameTicker)

Public Member Functions inherited from MpOutputDeviceDriver
	MpOutputDeviceDriver (const UtlString &name)
	Default constructor. More...

virtual	~MpOutputDeviceDriver ()
	Destructor. More...

virtual OsStatus	enableDevice (unsigned samplesPerFrame, unsigned samplesPerSec, MpFrameTime currentFrameTime, OsCallback &frameTicker)=0
	Initialize device driver and state. More...

MpFrameTime	getFramePeriod () const
	Calculate the number of milliseconds that a frame occupies in time. More...

unsigned	getSamplesPerFrame () const
	Get number of samples in a frame. More...

unsigned	getSamplesPerSec () const
	Get number of samples per second. More...

const UtlString &	getDeviceName () const
	Get device name. More...

virtual OsStatus	canEnable ()
	Check if this device can connect. More...

virtual UtlBoolean	isEnabled () const
	Inquire if this driver is enabled. More...

Protected Member Functions
OsStatus	signalForNextFrame ()
	Signaling for next frame if notificator used do nothing otherwise. More...

void	skipFrame ()
	Adding frame time to `mCurrentFrameTime`. More...

bool	setAudioUnitFormat (const AudioStreamBasicDescription &ds)

bool	initResempler (const AudioStreamBasicDescription &ds)

bool	setBuffers ()

Static Protected Member Functions
static void	propertyListener (void *inRefCon, AudioUnit ci, AudioUnitPropertyID inID, AudioUnitScope inScope, AudioUnitElement inElement)

static OSStatus	renderProc (void inRefCon, AudioUnitRenderActionFlags inActionFlags, const AudioTimeStamp inTimeStamp, UInt32 inBusNumber, UInt32 inNumFrames, AudioBufferList ioData)

static OSStatus	ACproc (AudioConverterRef inAudioConverter, UInt32 ioDataPackets, AudioBufferList ioData, AudioStreamPacketDescription *inUserData, void inUData)

Protected Attributes
AudioUnit	mOutputUnit
	AudioUnit output handle. More...

AudioConverterRef	mConverter
	Sample rate converter. More...

CoreAudioHardware	mDevice
	CoreAudio hardware device handle. More...

double	mOutputSampleRate
	Device smaple rate. More...

MpAudioSample *	mAudioFrame
	Wave buffer for silence. More...

MpAudioSample *	mAudioFrameData
	Second wave buffer for actual data. More...

OsNotification *	pNotificator
	Notificator used for signaling next frame. More...

MpFrameTime	mCurrentFrameTime
	The current frame time for this device. More...

Protected Attributes inherited from MpOutputDeviceDriver
OsAtomicLightBool	mIsEnabled
	Whether this device driver is enabled or not. More...

OsAtomicLightUInt	mSamplesPerFrame
	number of samples. More...

OsAtomicLightUInt	mSamplesPerSec
	of samples per second. More...

OsCallback *	mpTickerNotification
	is ready to accept more data. See enableDevice() for details. More...

Private Member Functions
	MpodCoreAudio (const MpodCoreAudio &rMpOutputDeviceDriver)
	Copy constructor (not implemented for this class) More...

MpodCoreAudio &	operator= (const MpodCoreAudio &rhs)
	Assignment operator (not implemented for this class) More...

Additional Inherited Members
Static Public Member Functions inherited from MpOutputDeviceDriver
static MpFrameTime	getFramePeriod (unsigned samplesPerFrame, unsigned samplesPerSec)
	Calculate the number of milliseconds that a frame occupies in time. More...

Detailed Description

Container for device specific output CoreAudio driver.

Constructor & Destructor Documentation

MpodCoreAudio ( const UtlString & name )

Default constructor.

Parameters

name	- (in) unique device driver name (e.g. "/dev/dsp", "YAMAHA AC-XG WDM Audio", etc.).
nInputBuffers	- (in) Maximum number of frames in internal buffer.

~MpodCoreAudio ( )

Destructor.

MpodCoreAudio ( const MpodCoreAudio & rMpOutputDeviceDriver )

private

Copy constructor (not implemented for this class)

Member Function Documentation

OsStatus enableDevice	(	unsigned	samplesPerFrame,
		unsigned	samplesPerSec,
		MpFrameTime	currentFrameTime
	)

Initialize device driver and state.

This method enables the device driver.

this SHOULD NOT be used to mute/unmute a device. Disabling and enabling a device results in state and buffer queues being cleared.

Parameters

[in]	samplesPerFrame	- the number of samples in a frame of media
[in]	samplesPerSec	- sample rate for media frame in samples per second
[in]	currentFrameTime	- time in milliseconds for beginning of frame relative to the MpOutputDeviceManager reference time
[in]	frameTicker	- notification to signal when device become ready. Device driver MUST signal this notification as soon as it become ready to receive next portion of data to play back. Note, it is a callback which in turn calls pushFrame() method of this device driver. Also notification may be used to signal begin of frame interval for one or several flowgraphs, so it should be as uniform as possible, i.e. it should not burst or hold over, driver should signal this notification after equal intervals of time.

Returns: OS_INVALID_STATE if device already enabled.

This method is supposed to be used from MpAudioOutputConnection only. If you want enable device, use MpOutputDeviceManager or MpAudioOutputConnection methods.

OsStatus disableDevice ( )

virtual

Uninitialize device driver.

This method disables the device driver and should release any platform device resources so that the device might be used else where.

this SHOULD NOT be used to mute/unmute a device. Disabling and enabling a device results in state and buffer queues being cleared.

This method is supposed to be used from MpAudioOutputConnection only. If you want disable device, use MpOutputDeviceManager or MpAudioOutputConnection methods.

Implements MpOutputDeviceDriver.

OsStatus pushFrame	(	unsigned int	numSamples,
		const MpAudioSample *	samples,
		MpFrameTime	frameTime
	)

virtual

Send data to output device.

This method is called from a callback which is called when we fire ticker notification. See enableDevice() for details.

Parameters

[in]	numSamples	- Number of samples in `samples` array.
[in]	samples	- Array of samples to push to device.
[in]	frameTime	- Time of pushed frame. Device may consider does it want it or not internally. If frame come too late driver should return OS_SUCCESS and throw out it silently. Common problem is when MediaTask queue is jammed - no frames are processed for some time and then they are processed bursty. Using given frameTime driver may keep its internal queue short. It is guaranteed that frame time would increase monotonically.

Returns: OS_LIMIT_REACHED if mixer buffer is full, i.e. frame come too early.; OS_FAILED for other errors.; OS_SUCCESS if frame sent correctly.

See also: enableDevice() for documentation when this is being called.

Implements MpOutputDeviceDriver.

OsStatus setTickerNotification ( OsNotification * pFrameTicker )

OsStatus signalForNextFrame ( )

protected

Signaling for next frame if notificator used do nothing otherwise.

void skipFrame ( )

protected

Adding frame time to mCurrentFrameTime.

bool setAudioUnitFormat ( const AudioStreamBasicDescription & ds )

protected

bool initResempler ( const AudioStreamBasicDescription & ds )

protected

bool setBuffers ( )

protected

void propertyListener	(	void *	inRefCon,
		AudioUnit	ci,
		AudioUnitPropertyID	inID,
		AudioUnitScope	inScope,
		AudioUnitElement	inElement
	)

staticprotected

OSStatus renderProc	(	void *	inRefCon,
		AudioUnitRenderActionFlags *	inActionFlags,
		const AudioTimeStamp *	inTimeStamp,
		UInt32	inBusNumber,
		UInt32	inNumFrames,
		AudioBufferList *	ioData
	)

staticprotected

OSStatus ACproc	(	AudioConverterRef	inAudioConverter,
		UInt32 *	ioDataPackets,
		AudioBufferList *	ioData,
		AudioStreamPacketDescription **	inUserData,
		void *	inUData
	)

staticprotected

MpodCoreAudio& operator= ( const MpodCoreAudio & rhs )

private

Assignment operator (not implemented for this class)

Member Data Documentation

AudioUnit mOutputUnit

protected

AudioUnit output handle.

AudioConverterRef mConverter

protected

Sample rate converter.

CoreAudioHardware mDevice

protected

CoreAudio hardware device handle.

double mOutputSampleRate

protected

Device smaple rate.

MpAudioSample* mAudioFrame

protected

Wave buffer for silence.

MpAudioSample* mAudioFrameData

protected

Second wave buffer for actual data.

OsNotification* pNotificator

protected

Notificator used for signaling next frame.

MpFrameTime mCurrentFrameTime

protected

The current frame time for this device.

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation