Digital scale peak meter (IEC 60268-18)

[juha_p]

Hello!

I'm making a peak meter for windows based on this example where the peak-meter values obtained from the methods in the IAudioMeterInformation interface are floating-point numbers in the normalized range from 0.0 to 1.0. I think the peak values are not linear (y=L(x)) based so ATM I think it as voltage range 0 - 1V and using dBV scaling (label positions (below -3) are set using audacity normalizing function):


Does it look OK at below -3 (-3-0dBV is fixed, though dBV)?

EDIT: These are the values now:

Code: Select all

	  
   dB              returned peak value
 -96.32          0.000015276
 -80	            0.0001
 -70	            0.000316228
 -60	            0.001                 
 -50	            0.003162278
 -40	            0.01
 -35	            0.017782794
 -30	            0.031622777
 -25	            0.056234133
 -20	            0.1
 -15	            0.177827941
 -10	            0.316227766
 -5	            0.562341325
 -3	            0.707945784
 -1	            0.891250938
  0	            1.0000 

(right column values are from GetChannelsPeakValues())


Anyway, now I would like to change to digital scale as like showing in this image:


Is there some ready to use formula for to calculate the bar positions for that type scaling?

[camsr]

It would be easy enough to floor() the result, after conversion to decibel of course.

[tomicious]

Hi, may be this can help? http://www.musicdsp.org/archive.php?classid=0#94

[juha_p]

Hi, may be this can help? <span class="skimlinks-unlinked">http://www.musicdsp.org/archive.php?classid=0#94</span>

Thanks, I'll play with that.