Round BPM option

[RJ Skerry-Ryan]

Add an option to round detected BPMs to the preferences.

[Owen Williams (ywwg)]

Should this be an option in the right-click menu, ie a per-track manual selection? I have some tracks that I definitely don't want to round (vinyl captures) and others that should be rounded. Or is the idea that it will only round results from the bpm detector?

[Owen Williams (ywwg)]

On Sat, 2012-01-07 at 16:12 +0100, Juan Pedro Bolívar Puente wrote:

> The current implementation in the round-bpm branch just rounds up on
> track load. This means that the original detected BPM are still stored
> and that it is a global setting that you should disable while it you are
> loading tracks that should not be rounded -- e.g vinyl captures as you
> pointed out.
>
> I can reimplement it any other way you think is better from a user
> interaction POV. I would rather go for some workflow that allows to
> have it by default and disable it for concrete tracks than otherwise.
> What I like about rounding on track load is that you can still see what
> Mixxx detected... Maybe we can have it like that and then disabling it
> on a per-track basis?
>
> Cheers,
>
> JP
>
>

To me, the reason I want to round the BPM is because the bpm detector
always gets it wrong. So I don't understand the value of maintaining
the old, detected bpm but then rounding it when the track is loaded. If
I'm always going to round it because the detected value is wrong, what
use do I have for the wrong value? The implementation as you describe
it doesn't really make sense to me.

Instead, I strongly think Mixxx should *always* round the bpm coming out
of the detector at the time of track *analysis*, not track load. Since
I have never, ever seen the bpm detector choose the right value, I don't
see a need for this to be an option at all -- let's just turn it on all
the time.

If the value is wrong (like on my 127.98 vinyl captures) the user can
tweak the bpm value manually. If we show one value in the library but
then use another value when the track is loaded, it would be very, very
confusing. A Mixxx newbie would see a BPM in the library that's
correct, but when they load the track it changes.

For users with large libraries of un-rounded bpms, we can add a bonus
shortcut for old tracks that have already been analyzed. It should be
easy to add a feature to select tracks in the library, right click, and
select "Round BPM" without going into the properties window.

Owen

[RJ Skerry-Ryan (rryan)]

Here are my thoughts:

1) VAMP support is coming in 1.11 which is a huge step forward for getting beatgrids right automatically. Hopefully this will lessen the urgency of having a rounding feature.

2) Mixxx doesn't have any proper way to indicate the source of analysis data. We don't have a way to differentiate between a BPM value that is
* Read from an ID3 tag
* Typed by a user
* Tapped by a user
* Detected by SoundTouch
* Rounded by this code

Because of #2, I am very wary of any preference option that modifies database entries permanently. Once we have a more general way for a track to have multiple "Analyses" that the user can pick as their default (e.g. you can choose to ignore the Mixxx generated analysis and activate the beatgrid we got from Traktor via the track-info dialog) then I would be happy with making this generate an alternate analysis that is the rounded form of an existing one.

Having a preference option to round on track-load is nice if you assume every single detected BPM is wrong and should be a whole number. I think this will become less useful in 1.11 since our BPM detection will be a lot better. The VAMP branch is already getting VERY positive reviews by people who are using it and it is within a small margin of error from Traktor most of the time.

It would also be nice to have a right-click context menu or maybe an option on the track info dialog that allows the user to manually choose to round the BPM of a track. It would essentially be a quick helper to save the time of typing out the rounded BPM by hand. That would be an easy project for a new contributor that we could leave around in the wishlist.

[RJ Skerry-Ryan (rryan)]

Thanks again for working on this raskolnikov. Our new accurate beatgrid detection code makes a direct fix for this bug unnecessary.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6233