Skip to main content
Hey Evgenii
Hey Evgenii
Inspiring
May 16, 2023
Answered

Premiere pro extend script set audio level of clip

  • May 16, 2023
  • 1 reply
  • 1155 views

Hi guys I am trying to descrease/increase level of clip's audio using extendScript, what can be the problem here?

 

function setAudioLevel(volume){
  var activeSequence = app.project.activeSequence;
  var track = activeSequence.audioTracks[0]
  for (var i = 0; i < track.clips.length; i++) {
    var prop = track.clips[i].components[0].properties[1]
        prop.setTimeVarying(false)
    var value = prop.getValue() // returns 0.17782793939114 while interface shows 0.0 
    track.clips[i].components[0].properties[1].setValue(volume)// if volume is -3 it will set to infinity 
    
  }

}

 

    Correct answer Justin Taylor-Hyper Brew

    Found it, there's just an offset of 15 so these formulas after the log10 * 20 for db Conversion, these seem to work well:


    function dbToDec(x) {
  return Math.pow(10, (x - 15) / 20);
}

function decToDb(x) {
  return 20 * Math.log(x) * Math.LOG10E + 15;
}

    1 reply

    Justin Taylor-Hyper Brew
    Community Expert
    Justin Taylor-Hyper BrewCommunity Expert
    Community Expert
    May 22, 2023

    So the values are displayed in dB, but they are stored in float 0.0-1.0 scale. That's why:

     

    negative infinity : 0

    -2 : 0.14125375449657

    -1 : 0.15848931670189

    0 : 0.17782793939114

    1 : 0.19952623546124

    2 : 0.22387212514877

    15 : 1

     

    I'm unsure of the exact conversion, supposed to be Log10 for dB, but looks little different, maybe @Bruce Bullis could chime in.

    Justin Taylor-Hyper Brew
    Community Expert
    Justin Taylor-Hyper BrewCommunity ExpertCorrect answer
    Community Expert
    May 23, 2023

    Found it, there's just an offset of 15 so these formulas after the log10 * 20 for db Conversion, these seem to work well:


    function dbToDec(x) {
  return Math.pow(10, (x - 15) / 20);
}

function decToDb(x) {
  return 20 * Math.log(x) * Math.LOG10E + 15;
}
      Hey Evgenii
      Hey EvgeniiAuthor
      Inspiring
      May 22, 2025
      had an issues  0.17782793939114  showing -7.87740184193808e-8

      this is a little fix
      function decToDb(x) {
var result = 20 * Math.log(x) * Math.LOG10E + 15;

// Round very small values to 0 (handles floating-point precision)
if (Math.abs(result) < 1e-6) {
return 0;
}

// Round to reasonable precision (2 decimal places for dB)
return Math.round(result * 100) / 100;
}
      Terms & ConditionsAccessibility statement
      Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices