MpodAndroid Class Reference

Audio output driver for Android OS. More...

#include <MpodAndroid.h>

Inheritance diagram for MpodAndroid:

Collaboration diagram for MpodAndroid:

Protected Types
enum	State {   DRIVER_IDLE, DRIVER_INIT, DRIVER_STARTING, DRIVER_PLAYING,   DRIVER_STOPPING, DRIVER_STOPPED }

Protected Member Functions
UtlBoolean	initAudioTrack ()
	Allocates and configures AudioTrack used for PCM output. More...

Static Protected Member Functions
static void	audioCallback (int event, void *user, void *info)
	Callback function called by Android to request more data. More...

Protected Attributes
MpAndroidAudioBindingInterface::StreamType	mStreamType
	Android type of the output stream. More...
OsAtomicLightUInt	mState
	Internal class state. More...
MpAndroidAudioTrack *	mpAudioTrack
	Pointer to audio track used for playback. More...
Mutex	mLock
Condition	mWaitCbkCond
MpFrameTime	mCurFrameTime
	The current frame time for this device. More...
OsNotification *	mpNotifier
	Event signaled when windows is ready to receive a new buffer. 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
	MpodAndroid (const MpodAndroid &rMpodAndroid)
	Copy constructor (not implemented for this class) More...
MpodAndroid &	operator= (const MpodAndroid &rhs)
	Assignment operator (not implemented for this class) More...

Creators
	MpodAndroid (MpAndroidAudioBindingInterface::StreamType streamType)
	Default constructor. More...
virtual	~MpodAndroid ()
	Destructor. More...

Manipulators
virtual OsStatus	enableDevice (unsigned samplesPerFrame, unsigned samplesPerSec, MpFrameTime currentFrameTime, OsCallback &frameTicker)
virtual OsStatus	disableDevice ()
	Uninitialize device driver. More...
virtual OsStatus	pushFrame (unsigned int numSamples, const MpAudioSample *samples, MpFrameTime frameTime)
	Send data to output device. More...

Variables to push audio data to callback.
MpAudioSample *	mpSampleBuffer
	Buffer which pushBuffer should copy to. More...
int	mSampleBufferIndex
	Index of the first sample not yet pushed to device. More...

Additional Inherited Members
Public Member Functions inherited from MpOutputDeviceDriver
	MpOutputDeviceDriver (const UtlString &name)
	Default constructor. More...
virtual	~MpOutputDeviceDriver ()
	Destructor. 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...
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

Audio output driver for Android OS.

See also

MpOutputDeviceDriver

Member Enumeration Documentation

enum State

protected

Enumerator
DRIVER_IDLE	MpodAndroid is being initialized or initialization failed.
DRIVER_INIT	MpodAndroid has been successfully initialized and is not playing.
DRIVER_STARTING	MpodAndroid is starting playing.
DRIVER_PLAYING	MpodAndroid is playing.
DRIVER_STOPPING	MpodAndroid is stopping.
DRIVER_STOPPED	MpodAndroid is stopped: the AudioTrack will be stopped.

Constructor & Destructor Documentation

MpodAndroid ( MpAndroidAudioBindingInterface::StreamType  streamType )

explicit

Default constructor.

Note

Device name is not supported under Android for now.

~MpodAndroid ( )

virtual

Destructor.

MpodAndroid ( const MpodAndroid &  rMpodAndroid )

private

Copy constructor (not implemented for this class)

Member Function Documentation

OsStatus enableDevice ( unsigned  samplesPerFrame, unsigned  samplesPerSec, MpFrameTime  currentFrameTime, OsCallback &  frameTicker  )

virtual

Implements MpOutputDeviceDriver.

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.

UtlBoolean initAudioTrack ( )

protected

Allocates and configures AudioTrack used for PCM output.

void audioCallback ( int  event, void *  user, void *  info  )

staticprotected

Callback function called by Android to request more data.

MpodAndroid& operator= ( const MpodAndroid &  rhs )

private

Assignment operator (not implemented for this class)

Member Data Documentation

MpAndroidAudioBindingInterface::StreamType mStreamType

protected

Android type of the output stream.

OsAtomicLightUInt mState

protected

Internal class state.

MpAndroidAudioTrack* mpAudioTrack

protected

Pointer to audio track used for playback.

Mutex mLock

protected

Mutex to control concurrent access to this object from audio callback and application API

Condition mWaitCbkCond

protected

condition enabling interface to wait for audio callback completion after a change is requested

MpFrameTime mCurFrameTime

protected

The current frame time for this device.

OsNotification* mpNotifier

protected

Event signaled when windows is ready to receive a new buffer.

MpAudioSample* mpSampleBuffer

protected

Buffer which pushBuffer should copy to.

int mSampleBufferIndex

protected

Index of the first sample not yet pushed to device.