使用Web Audio API在iOS上控制增益

Question

I know volume control of an audio tag isn't possible on iOS but I want to bypass that by using Web audio API and modify the value of the gain node. The code is working on desktop but not on iOS, can you see the problem ?

    var soundx = document.getElementById("sound");
    var audiocontext =  window.AudioContext || window.webkitAudioContext;
    var context = new audiocontext;
    var source1 = context.createMediaElementSource(soundx);
    var gain1 = context.createGain();

        soundx.get(0).play();
        gain1.connect(context.destination);
        source1.connect(gain1);
        gain2.gain.value=0.5;
        gain1.gain.value=0.5;

Answer 1

您没有将source1连接到gain节点，并且gain2是未定义的（因此将抛出，并且gain1.gain.value设置将不会发生。