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AudioTools

  

Modulate

  

modulates one audio recording using another

 

Calling Sequence

Parameters

Description

Examples

Calling Sequence

Modulate(audArray, maskArray)

Parameters

audArray

-

Array, Vector, or Matrix containing the audio to be modulated

maskArray

-

Array, Vector, or Matrix specifying the modulation mask

Description

• 

The Modulate command uses one audio recording to modulate another.

• 

The audArray parameter specifies the audio to be modulated, and must be a dense, rectangular, one or two dimensional Array, Vector, or Matrix with datatype=float[8].

• 

The maskArray parameter specifies the modulation mask, and must be a dense rectangular Array, Vector, or Matrix with datatype=float[8], and the same dimensions as audArray.

• 

The Modulate operation consists of multiplying each sample in the audArray by the corresponding sample in the maskArray, and writing the result to the output. Notice that this operation is commutative; the data and mask can be interchanged and will still give the same result.

  

Samples with a value of 1.0 in the maskArray will cause the corresponding audArray sample to be copied verbatim into the output. Samples of value 0.0 in the mask will result in 0.0 in the output, regardless of the value of the corresponding audio sample. Samples of value -1.0 in the mask will invert the value of the corresponding audio sample.

• 

For example, consider a mask M that gradually transitions from 1.0 on the left to 0.0 on the right. Using the Modulate command with this mask and audio data A produces audio data that starts out sounding like A and fades to silence. Modulating audio B with the inverse of M, namely 1M, will produce audio data that starts out silent and intensifies to full volume.

  

Combining these two audio objects by simple addition, A+B, yields audio data that fades from A to B.

Examples

audiofilecatkerneloptsdatadir,/audio/stereo.wav:

withAudioTools:

audAudioTools:-Readaudiofile

aud:= 1..19962 x 1..2 ArrayData Type: float8Storage: rectangularOrder: C_order

(1)

dimsrtable_dimsaud

dims:=1..19962,1..2

(2)

leftauddims1,1

left:= 1 .. 19962 ArrayData Type: float8Storage: rectangularOrder: C_order

(3)

rightauddims1,2

right:= 1 .. 19962 ArrayData Type: float8Storage: rectangularOrder: C_order

(4)

weirdModulateleft,right

weird:= 1 .. 19962 ArrayData Type: float8Storage: rectangularOrder: C_order

(5)

See Also

Array

AudioTools

AudioTools[Convolution]

AudioTools[Scale]

Matrix

Vector

 


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