add controls to manipulate the bpm via skin/midi controller

[mixxxbot]

Reported by: index82
Date: 2018-02-13T17:35:16Z
Status: Confirmed
Importance: Wishlist
Launchpad Issue: lp1749252
Tags: bpm, skin, usability

---

like e.g. beats_adjust_faster, beats_adjust_slower ...

Options:

• double BPM
• halve BPM
• 2/3 BPM
• 3/4 BPM
• 4/3 BPM
• 3/2 BPM

[mixxxbot]

Commented by: esbrandt
Date: 2018-02-21T08:07:53Z

---

Could you elaborate a bit more what you are requesting here?

Some skins e.g. Tango and Deere do have controls to edit a beatgrid, and all skins have the ability to Change the BPM by right-clicking a track in the library, or by editing the BPM tab in the track properties editor.

Beatgrid editing controls are also available in the MIDI controller wizard, under the BPM menu.

[mixxxbot]

Commented by: index82
Date: 2018-02-23T21:14:06Z

---

I checked the midi controller wizard now but didn't find the requested controls.
The library contextmenu is usable but not very fast. (find title; right click; hover and move; left click)

Mixxx has

• beats_adjust_faster
• beats_adjust_slower
• beats_translate_curpos
• beats_translate_match_alignment
• beats_translate_earlier
• beats_translate_later

Mixxx hasn't

• beats_set_halve

• beats_set_double

• beats_set_twothirds

• beats_set_threehalves

• beats_set_threefourths

• beats_set_fourthirds
  (I don't know the correct terms.)

  OK, in this case it's a personal wish.
  I don't want these controls as ui elements in the official mixxx skins.
  But it would be good to have the possibility and to fill the small gap of controls. ;)

My idea is to speed up the workflow for preparing tracks/beatgrids. And it makes realy fun to work with.
FYI: clone my repo and test the editdeck (WIP) https://github.com/22degrees/RoundCorners
The "EDIT"-Button in the left upper corner in each deck.

[mixxxbot]

Commented by: mxmilkiib
Date: 2020-08-24T21:08:41Z

---

MIDI control for fixing incorrect BPM detection would be incredibly welcome.

The default skin now doesn't have these options in the main UI body, one has to go back into the media library to use a submenu, which is a bit of a workflow nightmare.

The pads on many controllers now would be perfect for binding such to.

[mixxxbot]

Commented by: ronso0
Date: 2020-08-25T13:52:40Z

---

FYI
in Mixxx 2.3 there's no need to go back to the library anymore: you can open the track context menu by right-clicking on a track property in decks: title, artist, comment (Tango only). There you have a 'Adjust BPM' menu with all options.

You can also double-click on artist/title fileds in the decks to open the Track Properties window. Besides the track metadata, it has a second tab 'BPM' with all BPM options where you can also tap the BPM or enter a value manually.

[ronso0]

This is a kind of a no-brainer:
just add the controls and slots like in DlgTrackInfo to BpmControl
40a7de1 for a starter. I have no intention to work on this, so feel free to adopt that commit.

[mxmilkiib]

This would be very handy/essential for keyboard+mouse free library management.

What is the actual status of what is in the 40a7de1 commit? Before I go yak shaving on implementing this. Is it purely an example with just one of the fractional BPM Adjustments? I guess some mindful copying+pasting and rewordings could fulfil this?

[mxmilkiib]

So, given the actions are already defined in wtrackmenu.cpp, is it sensible to reproduce the = in that commit? Should there be some DRY here? Should that function remain in the wtrackmenu file even though it would be used elsewhere?

If redefining is best, would that require a different w_ name to avoid a collisions, or is the scope different enough?

[ronso0]

What is the actual status of what is in the 40a7de1 commit?

40a7de1 is just a POC, I don't intend to continue that.

In order to extend that example for more scales, this

    connect(m_pBeatsDouble,
            &ControlObject::valueChanged,
            this,
            &BpmControl::slotDoubleBpm,
            Qt::DirectConnection);

would simply use a lambda

    connect(m_pBeatsDouble,
            &ControlObject::valueChanged,
            this,
            [this](value) {
                if (value > 0) {
                    slotScaleBpm(mixxx::Beats::Double);
                }
            });

(and drop void BpmControl::slotDoubleBpm())
Other BPM scale controls would be set up identically, just use different scales.

Does that make sense?

[ronso0]

So, given the actions are already defined in wtrackmenu.cpp, is it sensible to reproduce the = in that commit? Should there be some DRY here? Should that function remain in the wtrackmenu file even though it would be used elsewhere?

IMHO we don't need to care about the actions in WTrackMenu, redundancy is not an issue in that case.

[mxmilkiib]

Does that make sense?

I don't quite understand.

I'm trying to add to the files, but I'm getting this, so I'm a bit lost;

If I right click m_pTranslateBeatsMove and go to the declaration, it goes to :47 in .h

What am I missing here?

[mxmilkiib]

Oh, I think it's just an misconfigured extension.. nm

I just disabled it n went with another clangd extension.

Now I'm getting;

on attempting to cmake .. scratch head thought that was fixed

[mxmilkiib]

Why are there 5 connect() parameters in the original example and only 4 in the lambda example?

[ronso0]

The fifth parameter is the Qt::ConnectionType. If it's omitted it defaults to Qt::AutoConnection. Nothing to worry about for a POC.

[ronso0]

I suggest to open a draft PR where we can discuss code much easier than with screenshots ; )

[mxmilkiib]

I shall, once I've been able to try build 2.5 :)

[mxmilkiib]

Finally, right.

How is the scope meant to get this? And where exactly do I declare Halve as a member of Beats? Cheers!

/home/milk/src/mixxx/src/engine/controls/bpmcontrol.cpp: In constructor ‘BpmControl::BpmControl(const QString&, UserSettingsPointer)’:
/home/milk/src/mixxx/src/engine/controls/bpmcontrol.cpp:101:20: error: ‘value’ has not been declared
  101 |             [this](value) {
      |                    ^~~~~
/home/milk/src/mixxx/src/engine/controls/bpmcontrol.cpp: In lambda function:
/home/milk/src/mixxx/src/engine/controls/bpmcontrol.cpp:102:21: error: ‘value’ was not declared in this scope
  102 |                 if (value > 0) {
      |                     ^~~~~
/home/milk/src/mixxx/src/engine/controls/bpmcontrol.cpp:103:48: error: ‘Halve’ is not a member of ‘mixxx::Beats’
  103 |                     slotScaleBpm(mixxx::Beats::Halve);
      |                                                ^~~~~

[ronso0]

I shall, once I've been able to try build 2.5 :)

Actually you don't need to build it yourself, just commit, push and CI will build for you. Should be sufficient to spot errors and discuss code.

[mxmilkiib]

Some ints and BpmScale::s I think have sorted it..

#12934