Sync: Tempo dip when silence a sync track

[mixxxbot]

Reported by: daschuer
Date: 2021-08-06T07:07:56Z
Status: New
Importance: Medium
Launchpad Issue: lp1939103
Tags: regression, sync

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This was found during the review of #4156 which aims to fix the issue:

Instead of a jump, we now have the tempo dip stretched over some seconds.
This can be reproduced the best with two 440 Hz tracks and:

Playing two tracks with sync enabled the second one silenced by the line fader
Nudge the second track
Bring the second track in
Silence the first track.
Now the nudging is reverted gradually. (Without this branch it was reverted immediately)
This can be noted by listening the silenced track in headphone
When you bring the track in, the phase adjustment is gone.

[mixxxbot]

Commented by: daschuer
Date: 2021-08-06T07:08:41Z

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when I remove

    if (isMaster(mode)) {
        m_pBpmControl->resetSyncAdjustment();

from void SyncControl::setSyncMode(SyncMode mode) the issue is gone.

Unfortunately the issue is then shifted to the sync enable case because the leader adjustment is not reset when playing as single leader. The code is in place, but somehow bypassed. Hopefully you know already how to fix it right from the main code.

[mixxxbot]

Commented by: ronso0
Date: 2021-09-28T11:21:27Z

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is/was there a PR fixing this?

[mixxxbot]

Commented by: ywwg
Date: 2021-10-08T02:06:37Z

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This is fixed by #4363

[mixxxbot]

Commented by: ywwg
Date: 2021-10-08T02:07:11Z

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(I think)