async void GetBeatPos_Callback(int Channel, double beatPosition, IntPtr User)
{
var curpos = Bass.ChannelBytes2Seconds(Channel, Bass.ChannelGetPosition(Channel));
await Task.Delay(TimeSpan.FromSeconds(beatPosition - curpos));
BeatPosition = Bass.ChannelBytes2Seconds(Channel, Bass.ChannelGetPosition(Channel)) / BassFx.TempoGetRateRatio(Channel);
}