问使用MIDI.js播放MIDI文件时出现错误的速度

EN

        MIDI.loadPlugin({
            soundFontUrl: "./soundfont/",
            onsuccess: function(){
                console.log('loaded');
                MIDI.Player.loadFile("data:audio/midi;base64,"+song, function(){
                    console.log('here');
                    MIDI.Player.start();
                }
                );
            },
        });