Player sometimes plays duplicated when synced with transport

[v-o-y-a-g-e-r00]

To Reproduce

    this.testPlayer?.sync();
    this.testPlayer?.start(2);
    this.testPlayer.onstop = () => {
      console.log("onstop", performance.now())
    }

    Tone.getTransport().schedule((time) => {
      Tone.getTransport().seconds = 2;
    }, 2.9);

Duplicating the launch will be heard as louder playback.
Also, the console will display two stops at the same time (the same or almost the same time values ​​will follow each other)

[baparham]

I am running into the same behavior. All I could determine from trying to instrument the source, player, timeline, etc classes were that the start event seems to get called twice, as if it's matching for one tick, and then matches for another tick or something.

Have you been able to find any clues or workarounds to this issue @v-o-y-a-g-e-r00 ?

[tambien]

I am able to repro this issue, not sure what the cause is yet, but i'll try to solve it.

In the meantime, it seems like you want the Transport to loop between 2 and 2.9, using Transport.loopStart and Transport.loopEnd instead probably works as you'd want.

[baparham]

I'm not sure if my symptoms are caused by the same root cause, but I tried to create a minimal reproducer which showcased the duplicated playing I am seeing. It takes clicking on the Play/Pause/Restart button several times before it reproduces, so it's not super deterministic. Reproduces maybe one in ten attempts.

https://jsfiddle.net/rcs3qmoe/9/

And with some experimentation I have been able to see that this seems to be exacerbated when I am doing these three things, together:

1. shifting the transport.seconds earlier to attempt to "pre-play" audio and account for device latency (e.g. Transport.seconds = setToTheseSeconds - LATENCY_COMPENSATION)
2. when I am scheduling the transport to start playing at a future absolute time (e.g. 50ms in the future) which allows me to synchronize some other things in my app so the audio starts playing exactly when I expect it to (e.g. Transport.start(someTimeInFuture))
3. when I reset the transport.seconds (as in point 1. above) immediately or very soon after calling transport.stop() or transport.pause()

I tried to add some comments in the code to show where these things occur so you can experiment as well