New wavform drifts in and out of sync

Bug #996897 reported by KWhat
22
This bug affects 5 people
Affects Status Importance Assigned to Milestone
Mixxx
Fix Released
High
Daniel Schürmann
1.11
Won't Fix
High
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.

Tags: waveform

Related branches

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KWhat (alex.barker) wrote :

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

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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 ...

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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 ...

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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)
Changed in mixxx:
milestone: none → 1.11.0
importance: Undecided → High
tags: added: waveform
Revision history for this message
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
lp:~daschuer/mixxx/daschuers_trunk
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
Revision history for this message
Owen Williams (ywwg) wrote :

is this fixed?

Revision history for this message
RJ Skerry-Ryan (rryan) wrote :

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

Revision history for this message
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)
Changed in mixxx:
status: Fix Committed → Fix Released
Revision history for this message
Swiftb0y (swiftb0y) wrote :

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6418

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