Plugin tempo only changes to match DAW tempo after DAW play button pressed.

[mikej01]

macOS sequoia 15.5
Reaper 7.42
VMPC2000XL v0.9.0 release candidate 0, Preview v0.9.0.3.

Plugin tempo only changes to match DAW tempo after DAW play button pressed. I notice other plugins (eg MPC Beats) immediately reflect the current DAW tempo.

[izzyreal]

@mikej01 I might wanna reopen this. I just noticed that with the fix as it is currently implemented, there's no way to see what the original tempo is of any sequence.

What is the advantage of syncronizing the tempo to the DAW while not playing?

[mikej01]

I don't have much of a compelling argument, other than to say for me it's more a matter of convention for the plugin to reflect the DAW tempo, than anything else. I suppose I expect the plugin to play at the tempo displayed, rather than to suddenly jump to the DAW tempo?

Is the original sequence tempo important when used as a plugin? To be honest that was not something I considered.

Personally, the current behaviour (always following DAW tempo) is what I would be expecting, purely based on how some other plugins behave. For plugin use, perhaps this be configured an option under vmpc settings in the future, if people do actually need both options? I.e. an option to follow host tempo, or not, or something like that?

I suppose this would be somewhat analogous to how the option is there for the vmpc to be the main midi clock, or to follow via the options in the midi/sync screen?

I did actually spend a few minutes to see if I could get Reaper to follow the vmpc (in standalone mode) midi clock via a virtual midi port with the IAC driver a while back, out of curiosity. I didn't manage to get it working though, perhaps due to incorrect configuration. I haven't looked into it in any further and I haven't yet looked at the code to see if this should actually work - as it did occur to me that perhaps this sort of midi clock functionality is not yet fully implemented.

Cheers!

[izzyreal]

Is the original sequence tempo important when used as a plugin?

Yes, especially when working with unchopped loops and other samples that require a specific tempo. Having no access to the original tempo feels a bit off.

For plugin use, perhaps this be configured an option under vmpc settings in the future, if people do actually need both options?

I just ran into this issue when working on the musical position synchronization and I wanted to load a beat that uses such tempo-dependent samples. See izzyreal/mpc#264 (comment) for progress on that btw, and the tempo-dependent samples are primarily the bass guitar and a short ride loop.

Making it configurable is an option. I'll give it some thought.

I suppose this would be somewhat analogous to how the option is there for the vmpc to be the main midi clock, or to follow via the options in the midi/sync screen?

Yes, good point. I'll check the behaviour on the real MPC2000XL. If I recall correctly, indeed it changes to the tempo provided by the clock also when not playing. If yes, then that behaviour should probably be the default in VMPC2000XL.

as it did occur to me that perhaps this sort of midi clock functionality is not yet fully implemented.

Your intuition is correct. The implementation only processes START, CONTINUE and STOP messages, and not the TIMING ones:

void MidiInput::handleMidiClock(ShortMessage* msg)
{   
    auto mce = std::make_shared<MidiClockEvent>(msg->getStatus());
    auto syncScreen = mpc.screens->get<SyncScreen>("sync");
                
    if (syncScreen->in == index && syncScreen->getModeIn() != 0)
    {           
        switch (mce->getStatus())
        {       
        case ShortMessage::START:
            sequencer->playFromStart();
            break;
        case ShortMessage::CONTINUE:
            sequencer->play();
            break;
        case ShortMessage::STOP:
            sequencer->stop();
            break;
        case ShortMessage::TIMING_CLOCK:
            break;
        }       
    }           
}               

I've raised an issue for it here: izzyreal/mpc#266

[mikej01]

Yes, especially when working with unchopped loops and other samples that require a specific tempo. Having no access to the original tempo feels a bit off.

Fair point. I suppose it could also be a an issue with one shots too of course, depending on tempo and sample length.

By way of discussion - would people not set sequence/sample name to reflect bpm, rather than rely on sequence tempo as such? Is it usual to rely on sequence tempo for that? (As mentioned previously I'm more a DAW user and haven't used the MPC hardware).

In the case of showing the original sequence tempo - I you see the sequence tempo, yet it's going to play back at (and subsequently display) the DAW tempo anyway. I'm just not sure this would be the desired/expected behaviour, DAW wise.

I just ran into this issue when working on the musical position synchronization and I wanted to load a beat that uses such tempo-dependent samples. See izzyreal/mpc#264 (comment) for progress on that btw, and the tempo-dependent samples are primarily the bass guitar and a short ride loop.

Wow, that's amazing progress!

Your intuition is correct. The implementation only processes START, CONTINUE and STOP messages, and not the TIMING ones:

Ah, thanks for explaining that and showing the relevant code - much appreciated. I feel bad now for not getting around to checking the code myself for that :).

• I don't recall that I managed to get START working. I'll try and have another try at it later. I suspect a config issue with the virtual midi cabling and Reaper.