New wavform drifts in and out of sync

Bug #996897 reported by KWhat on 2012-05-09
This bug affects 5 people
Affects Status Importance Assigned to Milestone
Daniel Schürmann
Daniel Schürmann

Bug Description

Playing 2 tracks, 1 is at pitch 0.0 the other at 2.26. The track at 2.26 seems to fall in and out of sync with the first track even though the BPM matches. Its not by a alot, maybe 10 or so milliseconds but its inconsistent so you cant correct for it.

Running at 48000 and 1.33 ms latency. Let me know if you need more info.

Related branches

KWhat (alex.barker) wrote :

It is really obvious when you set the zoom to like 25%

Thomas Vincent (vrince) wrote :

Do you mean track playback fall in and out of sync ? Can you hear it ?

Or do you mean that only the visual is out of sync ?
Cause if so for the moment we use 2 OpenGl surfaces, one for each waveform, and rendering them separately forces us to wait for vertical sync timer witch is set to 16ms (60Hz) by almost all drivers. So if the play position have changed during this time you will have a 16ms of delay (visually) between the two waveform. This is definitely something we will work on for the next release.

Of course this can we more than 16ms if you machine is not able to handle 60fps ...

Thomas Vincent (vrince) wrote :

I should have written: Of course it can be more than 16ms if your machine is not able to handle 60fps ...

KWhat (alex.barker) wrote :

Originally I thought I heard it but it may have been me trying to correct for the beat markers wondering. Here is a screen shot of what i am seeing.

RJ Skerry-Ryan (rryan) on 2012-05-11
Changed in mixxx:
milestone: none → 1.11.0
importance: Undecided → High
tags: added: waveform
Daniel Schürmann (daschuer) wrote :

This bug is caused due to the different time source for rendering and sound.
I have a solution for this in
A dedicated visualplayPosition class syncs the render time to the sound time.
But there is still an issue to bring the waveform in time to screen.
So I am afraid we must postpone this issue to 1.11.1

Changed in mixxx:
assignee: nobody → Daniel Schürmann (daschuer)
status: New → In Progress
Changed in mixxx:
milestone: 1.11.0 → none
Owen Williams (ywwg) wrote :

is this fixed?

RJ Skerry-Ryan (rryan) wrote :

It doesn't happen for me anymore on OS X.

KWhat (alex.barker) wrote :

Its prefect on Linux now.

Changed in mixxx:
milestone: none → 1.12.0
status: In Progress → Fix Committed
RJ Skerry-Ryan (rryan) on 2015-12-30
Changed in mixxx:
status: Fix Committed → Fix Released
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