Still can't make it to work
pkj, did you manage to do such trick?
It seems that when my AudioTrackList is exposed to JS like array (by newArray()) then only standard JS array methods and properties are accessible.
When I try to call getTrackById() method I get such error:
http://192.168.23.2/play.html:94: TypeError: 'undefined' is not a function (evaluating 'p.audioTracks.getTrackById("id1")')