Is it possible to trim a video layer according to sound levels found in its audio spectrum?

Question

Hi There,
I'm interested to know if there is any way via a script or an existing plugin that would allow me to trim down a video layer based on the sound levels in it audio track?  For example, if I wanted to set the in point for a source footage element to where sound started.  Is that possible with scripting?  If not, is there a plugin that analyzes the audio spectrum so that a script could possibly determine that point?
Thanks for your time and help!

Answer 1

This example uses the "Convert Audio to Keyframes" menu command to find the first frame where the selected layer's audio level is above the value specified in variable "threshold" (0.1 in this example). It then sets the selected layer's in point to that frame.
    var threshold = .1;
    function main(){
        var myComp = app.project.activeItem;
        if (myComp == null || ! (myComp instanceof CompItem)){
            alert("No comp active.");
            return;
        if (myComp.selectedLayers.length == 0){
            alert("No layer selected.");
            return;
        if (myComp.selectedLayers.length > 1){
            alert("More that one layer selected.");
            return;
        var myLayer = myComp.selectedLayers[0];
        if (! myLayer.hasAudio){
            alert("Selected layer doesn't have audio.");
            return;
        app.executeCommand(app.findMenuCommandId("Convert Audio to Keyframes"));
        var myAudioLayer = myComp.layer(1);
        var myProp = myAudioLayer.effect("Both Channels")("Slider")
        audioFound = false;
        for (var i = 1; i <= myProp.numKeys; i++){
            if (myProp.keyValue(i) > threshold){
                audioFound = true;
                myLayer.inPoint = myProp.keyTime(i);
                break;
        myAudioLayer.remove();
        if (! audioFound){
            alert("No audio above threshold found.");
            return;
    main();
Dan