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dbamp - convert from absolute amplitude to decibels (dB)


Synopsis

decibels = dbamp(ampval)


Description

dbamp returns a corresponding decibel value for an absolute amplitude value. The 16-bit (0-32768) absolute amplitude range is approximately matched by a 1-90 decibel range (0 dB returns "-inf").

NOTE: With the exception of boost, The RTcmix conversion functions follow a pattern. The command is divided into two halves, the one closest to the argument represent the format of the argument, and the one closest to the assignment represents the format to be returned. For example, "cpspch" is divided into "cps" and "pch". The argument is in oct.pc form ("pch") and the return value will be in cps ("cps").

The various format specifiers are:

   amp = absolute amplitude (16-bit, 0-32768)
   cps = cycles per second (Hz)
   db = decibels
   midi = midi note # (60 is middle C)
   oct = linear octaves (8.5 is halfway between octave 8.00 [middle C] and 9.00)
   pch = octave.pitch-class (oct.pc; 8.00 is middle C, 8.02 is D, 8.12 = 9.00 = C above middle C)
   let = note-letter specification ("C4" is middle C, "C#4" is C-sharp above middle C,
      "Gb5" is G-flat the octave above middle C octave. [see pitch-reps for more info])


Arguments

ampval
Any positive number, floating point or integer, representing a 16-bit amplitude value


Examples

   dbval = dbamp(20000)

See Also

dbamp, boost, cpsmidi, cpslet, cpsoct, cpspch, midipch, octcps, octlet, octmidi, octpch, pchcps, pchlet, pchmidi, pchoct