Audio device. More...

#include <WaAudioDev.h>

Inheritance diagram for WaAudioDev:

Public Member Functions
virtual WadAPI	GetAPI ()=0
	return API enum
virtual int	Init ()=0
	initialize the OS API and discover all devices
virtual int	GetNumDevices (int *pNumDev)=0
	Get the count of devices discovered.
virtual int	GetDevInfo (int devId, WadDevInfo *pInfo)=0
	Get device information.
virtual int	GetDefaultInDevId (int *pId)=0
	Get the default input device.
virtual int	GetDefaultOutDevId (int *pId)=0
	Get the default output device.
void	SetMeteringEnable (bool enable)
	Enable/disable metering.
bool	GetInPeak (float *pPeakVal)
	Get input peak value.
bool	GetOutPeak (float *pPeakVal)
	Get output peak value.
float	GetLastInPeak ()
	Get peak value of last input buffer processed.
float	GetLastOutPeak ()
	Get peak value of last output buffer processed.
void	ResetMetering ()
	Reset peak metering values.
virtual int	SetVol (int devId, bool isOutput, float vol)
	Set volume.
virtual int	GetVol (int devId, bool isOutput, float *pVol)
	Get volume.
virtual int	GetBufTime (bool isOutput, int *pBufTimeMsec)
	Get buffer time.
virtual int	GetClosestFormat (bool isOutput, WadStreamFormat *pFormat)
	Get closest stream format after an unsupported format error.
WaAudioDev *	GetDevice ()
	Get the device.
virtual char *	GetErrorText ()
	Get the error text after error status is returned.
bool	IsInitialized ()
	Return T/F if Init() has been called and devices are discovered.
bool	IsOpen ()
	Return T/F if device is open for streaming.
bool	IsInOpen ()
	return T/F if device is open for input streaming
bool	IsOutOpen ()
	return T/F if device is open for output streaming
virtual bool	IsRunning ()=0
	Test if stream I/O thread is running.
void	SetErrorText (char *text)
	Set the error text.
Static Public Member Functions
static float	PeakToDb (float peak, float minDb, float maxDb)
	Convert peak sample value to dB.
static int	CalcPeakInt16 (short *buf, unsigned int numSamps)
	Calculate maximum absolute value of short buffer.
static float	CalcPeakFloat32 (float *buf, unsigned int numSamps)
	Calculate maximum absolute value of float buffer.
static WaAudioDev *	WadMake (int options)
	Make audio device.
Protected Member Functions
void	ProcInPeakInt16 (short *buf, unsigned int numSamps)
	do input meter processing on 16-bit integer samples
void	ProcInPeakFloat32 (float *buf, unsigned int numSamps)
	do input meter processing on 32-bit float samples
void	ProcOutPeakInt16 (short *buf, unsigned int numSamps)
	do output meter processing on 16-bit integer samples
void	ProcOutPeakFloat32 (float *buf, unsigned int numSamps)
	do output meter processing on 32-bit float samples
void	SetIsInitialized (bool isInitialized)
	set initialized flag
Protected Attributes
float	inPeak
	running input peak value
float	lastInPeak
	last input buffer peak value
float	outPeak
	running ouput peak value
float	lastOutPeak
	last output buffer peak value
bool	inPeakIsValid
	is inPeak valid, i.e. any samples processed?
bool	outPeakIsValid
	is outPeak value, i.e any samples processed?
WadParam	param
	parameters used to open the device
bool	isInitialized
	Init() has completed, devices have been discovered.
bool	isMeteringEnabled
	metering is enabled/disabled
bool	isOpen
	successful Open sets this, Close resets
char	errorText [WAD_MAX_ERROR_TEXT]
	error text used by device and connected ports

Detailed Description

Audio device.

Virtual base class for cross-platform audio devices. This can be implemented for each OS audio device API, e.g. Windows MME. This is intended for telecom use, not pro audio, hence there is no support for 24-bit or 32-bit integer sample formats or surround multichannel formats.

Creating the object doesn't do anything. Init() initializes the OS API and discovers audio devices. Use the WaAudioDevPort methods to open input and output devices for streaming. A single WaAudioDev object can have at most one input and one output stream. If you want more audio streams you need to create more instances of WaAudioDev.

If you want to rescan devices due to notification of a device change, you must create a new WaAudioDev object. You will probably want to remember any existing active device names, close open streams, and attempt to reopen using the saved device names to find the new device indices.

The audio device interface provides support for device volume control and signal level metering.

Member Function Documentation

float WaAudioDev::CalcPeakFloat32	(	float *	buf,
		unsigned int	numSamps
	)		`[static]`

Calculate maximum absolute value of float buffer.

Parameters:

[in]	buf	buffer of float samples
[in]	numSamps	number of samples

int WaAudioDev::CalcPeakInt16	(	short *	buf,
		unsigned int	numSamps
	)		`[static]`

Calculate maximum absolute value of short buffer.

Parameters:

[in]	buf	buffer of short samples
[in]	numSamps	number of samples

virtual WadAPI WaAudioDev::GetAPI ( ) [pure virtual]

return API enum

Return enum specifying the low level API in use.

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

int WaAudioDev::GetBufTime	(	bool	isOutput,
		int *	pBufTimeMsec
	)		`[virtual]`

Get buffer time.

Parameters:

[in]	isOutput	true if get output buffer time, else get input buffer time
[out]	pBufTimeMsec	pointer to buffer time in milliseconds

Return total buffer times in msec for the currently open devices. This is useful in case we want to increase the buffering because we're getting dropouts.

Reimplemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

int WaAudioDev::GetClosestFormat	(	bool	isOutput,
		WadStreamFormat *	pFormat
	)		`[virtual]`

Get closest stream format after an unsupported format error.

Parameters:

[in]	isOutput	true if get output format, else get input format
[out]	pFormat	pointer to closest format

After an unsupported format error, calling this will return the closest supported format. The caller can then set up appropriate sample rate and sample format and channel format conversions and try to reopen the device.

Reimplemented in WadWASAPI.

virtual int WaAudioDev::GetDefaultInDevId ( int * pId ) [pure virtual]

Get the default input device.

Parameters:

[out] pId pointer to default input device ID

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

virtual int WaAudioDev::GetDefaultOutDevId ( int * pId ) [pure virtual]

Get the default output device.

Parameters:

[out] pId pointer to default output device ID

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

WaAudioDev * WaAudioDev::GetDevice ( ) [virtual]

Get the device.

Returns pointer to the actual WaAudioDev at the end of the processing chain. Hence if you have a WaAudioDevPort pointer and you want to do an operation like get device name or change volume, you can first get the WaAudioDev pointer and call methods on that.

Implements WaAudioDevPort.

virtual int WaAudioDev::GetDevInfo	(	int	devId,
		WadDevInfo *	pInfo
	)		`[pure virtual]`

Get device information.

Parameters:

[in]	devId	the device ID, 0 to numDev-1
[out]	pInfo	pointer to device info

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

char * WaAudioDev::GetErrorText ( ) [virtual]

Get the error text after error status is returned.

When an error occurs using a device or device port the code will often store a descriptive error message. Call this to retrieve the error text after an error. Note that device ports store their errors in the WaAudioDev at the end of the processing chain. You should use or copy the error text before calling additional methods, closing, or deleting port or device.

bool WaAudioDev::GetInPeak ( float * pPeakVal )

Get input peak value.

Parameters:

[out] pPeakVal pointer to peak value

Returns true if any samples processed since last poll. All peak values are represented as float samples where 1.0 is maximum.

float WaAudioDev::GetLastInPeak ( )

Get peak value of last input buffer processed.

This is for internal use (autogain).

float WaAudioDev::GetLastOutPeak ( )

Get peak value of last output buffer processed.

This is for internal use.

virtual int WaAudioDev::GetNumDevices ( int * pNumDev ) [pure virtual]

Get the count of devices discovered.

Parameters:

[out] pNumDev pointer to number of devices

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

bool WaAudioDev::GetOutPeak ( float * pPeakVal )

Get output peak value.

Parameters:

[out] pPeakVal pointer to peak value

Returns true if any samples processed since last poll. All peak values are represented as float samples where 1.0 is maximum.

int WaAudioDev::GetVol	(	int	devId,
		bool	isOutput,
		float *	pVol
	)		`[virtual]`

Get volume.

Parameters:

[in]	devId	device ID
[in]	isOutput	true if get output volume, else get input volume
[out]	vol	pointer to volume, 0.0 (min) to 1.0 (max)

Get volume of device. Any discovered device can be specified and the device does not need to be open for streaming.

Reimplemented in WadMme, WadWASAPI, and WadMacHAL.

virtual int WaAudioDev::Init ( ) [pure virtual]

initialize the OS API and discover all devices

Initialize, which means do device discovery. The idea is that the devices are enumerated at Init time, and from then on only this device set can be used. Any dynamic changes to the device set can be caught via messages and then this WaAudioDev object must be recreated to discover the new devices updating the device table.

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

virtual bool WaAudioDev::IsRunning ( ) [pure virtual]

Test if stream I/O thread is running.

Implement this to return false if the I/O thread has exited perhaps because a callback has returned false. This is a non-blocking alternative to Wait(). But why can't we just use IsOpen()? Ah, because the thread terminating doesn't automatically close the device, that's why.

Implemented in WadMme, WadWASAPI, WadFile, and WadMacHAL.

float WaAudioDev::PeakToDb	(	float	peak,
		float	minDb,
		float	maxDb
	)		`[static]`

Convert peak sample value to dB.

Parameters:

[in]	peak	peak value, 1.0 is maximum
[in]	minDb	minimum dB value to return
[in]	maxDb	maximum dB value to return

Helper function to convert peak values to dBFS (full scale) and restrict range. A peak of 1.0 maps to 0 dB.

void WaAudioDev::ResetMetering ( )

Reset peak metering values.

Implementations should reset metering in Close or Open.

void WaAudioDev::SetErrorText ( char * text )

Set the error text.

Parameters:

[in] text error text

Set the error text. This method is public so that ports can set error text. Ports report error text by storing text in device.

void WaAudioDev::SetMeteringEnable ( bool enable )

Enable/disable metering.

Parameters:

[in] enable enable flag

int WaAudioDev::SetVol	(	int	devId,
		bool	isOutput,
		float	vol
	)		`[virtual]`

Set volume.

Parameters:

[in]	devId	device ID
[in]	isOutput	true if set output volume, else set input volume
[in]	vol	volume, 0.0 (min) to 1.0 (max)

Set volume of device. Any discovered device can be specified and the device does not need to be open for streaming.

Reimplemented in WadMme, WadWASAPI, and WadMacHAL.

WaAudioDev * WaAudioDev::WadMake ( int options ) [static]

Make audio device.

Parameters:

[in] options option flags

Make an audio device for the OS platform. The options argument allows some control. Note that this only creates the WaAudioDev object, the caller must call Init() after creating the object.

The documentation for this class was generated from the following files:

WaAudioDev.h
WaAudioDev.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation