mfb

mfb — Mel scale filterbank for spectral magnitudes.

Description

Applies a Mel scale filterbank to an array containing a series of magnitude bins.

Syntax

kout[] mfb kin[],klow,khigh,ibands

Initialization

ibands -- number of bands in the Mel filter bank. Determines the size of the output array.

Performance

kout[] -- output array containing the MFB with ibands bands. It will be created if it does not exist.

kin[] -- input array containing the input magnitude bins.

klow -- lowest frequency (rounded to the nearest bin centre frequency).

khigh -- highest lowest frequency (rounded to the nearest bin centre frequency).

Examples

Here is an example of the mfb opcode. It uses the file mfb.csd.

Example 508. Example of the mfb opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>
<CsOptions>

</CsOptions>
<CsInstruments>
ksmps = 64
instr 1

 ifftsize init 1024
 ibins init ifftsize/2
 kIn[] init ifftsize
 kcnt init 0
 p3 = filelen("fox.wav")
 asig diskin "fox.wav"
 kIn shiftin asig
 kcnt += ksmps
 if kcnt == ifftsize then
  kFFT[] = rfft(kIn)
  kPows[] = pows(kFFT)
  kMFB[] = log(mfb(kPows,300,8000,32))
  kmfcc[] = dct(kMFB)
  kcnt = 0
  kfb = 0
  while kfb < 32 do
   printf("mfcc[%d] = %.3f \n", kfb+1, kfb, kmfcc[kfb])
   kfb += 1
  od
 endif
               
endin
</CsInstruments>
<CsScore>
i1  0 1
</CsScore>
</CsoundSynthesizer>

See Also

Vectorial opcodes, array opcodes, dct

Credits

Author: Victor Lazzarini
NUI Maynooth
2016

New in version 6.08