Beat detection slow for 48 k and 96 k tracks

[Daniel Schürmann]

The beat detection in 2.3 for 48 k tracks and is significant slower that before.
I may case it has raised from 4 to 14 sec.

I did a bisect and the first failing commit is.
https://github.com/mixxxdj/mixxx/pull/2683/commits/4ed2e132693c3c3d286488daf400fb8559b45f27

I did not investigate this further to check the results.
At least the BPM values are different.
It looks like 44.2 k tracks are not affected.

We need to investigate this more.

[Daniel Schürmann (daschuer)]

It looks like this is a symptom of a deeper issue.
With 2.2.4 the analysis of 48 k Tracks is also significant longer than for 44.2k tracks.
However the result is looking reasonable.

In 2.3 the result looks random, before and after the commit of question.

We have also fixed a buffer overflow later in the code.
So maybe we see here a QM bug?

[Cristiano Lacerda (crislacerda)]

If this was working with VAMP the bug is unlikely to be in QM. The plugins call the exact same qm-lib.

In VAMP stepsize for 48khz is also 557 IIRC so that's why it's slower than 44khz which lands nicely in 512. But it should not be slower than VAMP using qm-lib directly.

Maybe it's something related to the downmix helper where the buffer overflow was happening..

I'm going to investigate this

[Cristiano Lacerda (crislacerda)]

Are you sure master is significantly slower than 2.2?

I just tried a couple of 48khz tracks here and they were equally slow on 2.2 and master. Taking a bit mote than 45 seconds as opposed to a bit less than 15 in 44khz for the same tracks.

The results a random before and after that commit because of the buffer overflow that the odd stepsize was causing probably.

But after that was fixed, it appears to me that it's working equally slow than it was before.
Tested current master twice with two 48khz tracks each time, and there is no difference at all from 2.2

[Daniel Schürmann (daschuer)]

Ok, this is no regression, but room for improvements.
Here it is:
https://github.com/mixxxdj/mixxx/pull/2817

[Foss-4 (foss-4)]

Should this be fix committed?

[Daniel Schürmann (daschuer)]

Yes.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9983