<!DOCTYPE html> <embed type="application/x-test" width="200" height="200"></embed> <script> var plugin = document.querySelector("embed"); function startAudio() { plugin.startAudioPlayback(); } function stopAudio() { plugin.stopAudioPlayback(); } function pluginMuted() { return plugin.audioMuted(); } function toggleMuteState(muted) { var Ci = SpecialPowers.Ci; var utils = SpecialPowers.wrap(window).top .QueryInterface(Ci.nsIInterfaceRequestor) .getInterface(Ci.nsIDOMWindowUtils); utils.audioMuted = muted; } </script>