COM Objects > Effects object > Methods > Effects.AutoWahApply method

Remarks

Applies an AutoWah effect to the given portion of sound under editing.

The effect implements the AutoWah by using 4-stage phaser effect which moves a peak in the frequency response up and down the frequency spectrum by amplitude of input signal.

A successful call to this method will fire the SoundEditStarted event followed by a number of SoundEditPerc events and finally by the SoundEditDone event.

For further details about methods related to the use of special effects refer to the Effects COM object.

Syntax

[Visual Basic]

control.Effects.AutoWahApply (

nStartPosition as Long,

nEndPosition as Long,

nAffectedChannel as enumChannelMasks,

fDryMix as Single,

fWetMix as Single,

fFeedback as Single,

fRate as Single,

fRange as Single,

fFrequency as Single

) as enumErrorCodes

[C++]

short control.Effects.AutoWahApply (

long nStartPosition,

long nEndPosition,

short nAffectedChannel,

float fDryMix,

float fWetMix,

float fFeedback,

float fRate,

float fRange,

float fFrequency

);

Parameter

Description

nStartPosition

Start position, expressed in milliseconds, of the affected sound range.

nEndPosition

End position, expressed in milliseconds, of the affected sound range.. If set to -1 the end position will be set to the end of the sound.

nAffectedChannel

Numeric value that determines the combination of affected channels.

Supported values are the following:

Mnemonic constant	Value	Meaning
CHANNEL_MASK_0	1 (0x01)	Channel 0 or left channel
CHANNEL_MASK_1	2 (0x02)	Channel 1 or right channel
CHANNEL_MASK_2	4 (0x04)	Channel 2
CHANNEL_MASK_3	8 (0x08)	Channel 3
CHANNEL_MASK_4	16 (0x10)	Channel 4
CHANNEL_MASK_5	32 (0x20)	Channel 5
CHANNEL_MASK_6	64 (0x40)	Channel 6
CHANNEL_MASK_7	128 (0x80)	Channel 7
CHANNEL_MASK_LEFTS	85 (0x55)	All left channels
CHANNEL_MASK_RIGHTS	170 (0xAA)	All right channels
CHANNEL_MASK_ALL	255 (0xFF)	All available channels

fDryMix

Numeric value representing the Dry (unaffected) signal mix.

Supported values are in the range from -2 to +2.

fWetMix

Numeric value representing the Wet (affected) signal mix.

Supported values are in the range from -2 to +2.

fFeedback

Numeric value representing the output signal to feed back into input.

Supported values are in the range from -1 to +1.

fRate

Numeric value representing the rate of sweep expressed in cycles per second.

Supported values are in the range from 0 to 10.

fRange

Numeric value representing the sweep range expressed in octaves.

Supported values are in the range from 0 to 10.

fFrequency

Numeric value representing the base frequency of sweep range.

Supported values are in the range from 0 to 1000.

The fDryMix is the volume of input signal & the fWetMix is the volume of delayed signal. The fFeedback sets feedback of AutoWah(phaser). The fRate and fRange control how fast and far the frequency notches move. The fRate is the rate of sweep in cycles per second, fRange is the width of sweep in octaves. And the the fFrequency is the base frequency of sweep.

Below some sample:

Effect type	fDryMix	fWetMix	fFeedback	fRate	fRange	fFrequency

Slow Auto Wah	0.500	1.500	0.5	2.0	4.3	50.0
Fast Auto Wah	0.500	1.500	0.5	5.0	5.3	50.0
Hi Fast Auto Wah	0.500	1.500	0.5	5.0	4.3	500.0

Return value

Value	Meaning

Negative value	An error occurred (see the LastError property for further error details)
enumErrorCodes.ERR_NOERROR (0)	The call was successful.