[BUGs] APDC related and a few general ones

[dreammachine_nl]

Hi Jo,
I think I’ve found a few bugs related to the APDC system (on Mulab 8.6.9 32-bit, samplerate 48k, block size 512) and some general bugs. Thank you in advance for putting up with the lengthy read.

Bug #1: Play cursor / time displays out of sync. Not a big issue, because you probably never hit/want a latency of more than 1 second in a setup, but here are the steps to repeat it.

Step 1: See picture below. Build a simple project to simulate a delayed audio path (piano Rack and Pure Delay set to 48k samples). Insert a Latency Generator and set it to 48k (=max) and ‘Report Latency’ checked. In the Composer Area link the piano Rack to a Track and insert a Part with a note at the start postion. Play Part and everything works as expected.

Bug01.PNG

Step 2: Double the delay time of the audio path by copying the Pure Delay (and inserting it in series with the other one). To compensate, also copy the Latency Generator and insert it in series with the other one. Play the same Part again: the total audio latency is now as expected 2 sec, 96k samples (all input/output latency info of the modules is also ok). But the composer play cursor, edit play cursor and transport bar play time displays are not in sync anymore. They appear to handle up to a maximum latency of 48k samples (=system sample rate).


Bug #2: Rack / Mixer Strip level meters out of sync.

Step 1: see picture below. Expand the previous project (with 48k samples latency) with another parallel instrument Rack (preferably with an instrument that can sustain a note, e.g. Basic Rock Organ, so you can reuse it for bug #3).

Bug02.PNG

Just a quick related question before I go on. You wrote elsewhere on the forum:

When playing live MIDI or live from the GUI, APDC will be avoided on that live MIDI as much as possible for an instant play feel. For example, if you have 2 parallel track racks, one with a synth, and one which causes a latency, now you can still play that synth without the latency!

I noticed that this only works when you link the newly created instrument/synt Rack (or actually any playable Mux) to a Track. Is it intended like this? It kind of limits quick jamming with a synth/playable effect when working in the Modular Area.

Step 2: link the Rock Organ Rack to a Track and start live playing. The audio is played without latency (=okay). [Bug 2a:] The Level Meter of the Rock Organ Rack is still delayed (out of sync). Switching the Rack off and on, fixes the problem (or apparently even navigating away from Mulab to another app, or collapsing/expanding the Racks or hiding/showing the Mixing Desk or Browser).

(By the way, of course step 1 & 2 could be excecuted from the Composer Area via ‘add instrument track’ but the problem remains until switching off/on the Rack, navigating away, etc.)

Step 3: now insert another Rack. Re-route the Rock Organ Rack to this Rack.

Bug02b.PNG

[Bug 2b:] The level meter of this newly created rack is also out of sync. Same solutions fix the problem. Inserting multiple Racks and connecting them in series leads to the same problem. Individually switching the Racks off/on fixes the problem of each Rack, but not of the others. Navigating away, etc., fixes all the Racks at once.

Step 4: instead of a Rack now insert an empty Mux module and re-route the Rock Organ Rack to that Mux. Add a Rack inside the Mux and connect it to the audio input.

Bug02c.PNG

[Bug 2c:] The Level Meter of that Rack is out of sync. This time none of the solutions above fix the problem.

Instead of a Rack, we could have added a Mixer Strip inside the Mux module. [Bug 2d:] The Mixer Strip Level Meter is also out of sync. Other visual elements like the Oscilloscope or Spectrum Analyser seem to be working fine.

Finally, when you add a Mixer Strip/Oscilloscope/Freq.Spec.Analyser directly to the audio signal chain in the Project Modular Area, they all work fine/are synced.


Bug #3: is about playable effects and their position in the signal chain. Actually, I just realised this is closely related to the question I posed above about linking a module/Rack to a Track and this might not be a real bug.

Step 1: for this, start from the situation as sketched by picture of bug #2 step 1. Next, link the Rock Organ Rack to a Track and create a Part with a long sustained note (one bar or so) at the start position. Switch the Rock Organ Rack off/on to be sure that the level meter syncs.

Step 2: insert the Note Gater Effect into the the Rock Organ Rack. Set Midi Focus to the Note Gater (drag drop onto virtual keyboard). Press Play and start live playing the Note Gater via the Virtual Keyboard or an external midi device. As far as the audio is concerned, there is no latency, but the Note Event Pad visual (on the front panel of the Note Gater) is not synced.

Step 3: drag dropping the Note Gater onto a Track so that the Track targets it, syncs the Note Event Pad visual.

Alternatively you could of course insert a Note Gater after the Rock Organ Rack in the Project Modular Area. In this case when you set Midi Focus to the Note Gater, it is live playable and the Note Event Pad visual is synced without linking it to a Track first...


These were the APDC related bugs. The following are more general:

Bug #4: drag dropping a MuClip into the Project Modular Area or in a Mux messes up the visual arrangement of the Modules. All modules will be vertically aligned.
I also noticed that drag dropping a MuClip in a Mux without Event Input Module only adds the Sequence Player. Drag dropping it into a Project Modular Area without Event Input creates a Sequence Player and a Rack, but they are not connected.


Bug #5: concerns the tooltip when you route Rack audio in the Project Modular Area. For example:

Step 1: start with a blank Project Modular Area. Create two Racks. Both show ‘No Audio Connection’.

Step 2: connect one Rack to the other in the Project Modular Area with the red audio cable. The connection is correctly shown at the bottom label of that one Rack, but the tooltip (hovering mouse over label) always shows its previous state. For the tooltip to update, you have to click the connection label at the bottom of a Rack and select the connection there.


Bug #6: (again, not sure if this is a bug.) When you create an instrument Track, the keyboard in the Part editor always shows the Note Key Names of the most recently inserted module in the Rack (unless you override all of them by setting the Note Key Names of the Rack itself). But now consider the following scenario:

Step 1: insert an instrument Track (for example the Basic Rock Organ). The keyboard in the Part editor shows the black/white keys when no Note Key Names are set, which is the case with most synth presets.

Step 2: insert for example a Note Gater in that Basic Rock Organ Rack and set the Note Key Name of C4 to ‘On’ (or insert any random module which contains Note Key Names)
Now the keyboard in the Part editor also shows the Note Key name of the Note Gater, which is not preferable, I think. I would like to see the black/white keys of the Rock Organ. I overcome this problem by drag dropping the Rock Organ module itself onto the Track, hereby destroying the Track-Rack link and creating a new direct link between Track and Rock Organ module (now the Part editor shows black/white keys again). Wouldn’t it be better to always show the Note Key Names of the top module within a Rack? If not, would it be possible to make available in the Show Note Key Names of the Rack (which overrides the Note Key Names of the modules inside the Rack) an option like ‘show black/white keys’ or something?

Regards, TDM

[MuTools]

Bug #1: Play cursor / time displays out of sync. Not a big issue, because you probably never hit/want a latency of more than 1 second in a setup, but here are the steps to repeat it.

Indeed currently the maximal visual latency compensation is limited to 1 sec. I did not expect that users would use a process latency of more than 1 sec. If it's really necessary i'm sure i can resolve that practical limit. To avoid confusion: This is only for the visual latency compensation, the music signals themselves (audio, events, modulation) have no limit regarding process latency.

I'll reply on the other issues lateron, step by step.

[MuTools]

Bug #2: Rack / Mixer Strip level meters out of sync.

Step 1: see picture below. Expand the previous project (with 48k samples latency) with another parallel instrument Rack (preferably with an instrument that can sustain a note, e.g. Basic Rock Organ, so you can reuse it for bug #3).
Bug02.PNG

Just a quick related question before I go on. You wrote elsewhere on the forum:

When playing live MIDI or live from the GUI, APDC will be avoided on that live MIDI as much as possible for an instant play feel. For example, if you have 2 parallel track racks, one with a synth, and one which causes a latency, now you can still play that synth without the latency!

I noticed that this only works when you link the newly created instrument/synt Rack (or actually any playable Mux) to a Track. Is it intended like this? It kind of limits quick jamming with a synth/playable effect when working in the Modular Area.

To answer your question: Yes that's intended. Atm i can't immediately remember the tech reason for it, but i've taken note to review this aspect at appropriate time.

Step 2: link the Rock Organ Rack to a Track and start live playing. The audio is played without latency (=okay). [Bug 2a:] The Level Meter of the Rock Organ Rack is still delayed (out of sync). Switching the Rack off and on, fixes the problem (or apparently even navigating away from Mulab to another app, or collapsing/expanding the Racks or hiding/showing the Mixing Desk or Browser).

A bug indeed. Will be fixed.

Step 4: instead of a Rack now insert an empty Mux module and re-route the Rock Organ Rack to that Mux. Add a Rack inside the Mux and connect it to the audio input.
Bug02c.PNG

[Bug 2c:] The Level Meter of that Rack is out of sync. This time none of the solutions above fix the problem.

This will also be fixed by that same bug fix mentioned above.

Bug #3: is about playable effects and their position in the signal chain. Actually, I just realised this is closely related to the question I posed above about linking a module/Rack to a Track and this might not be a real bug.

Step 1: for this, start from the situation as sketched by picture of bug #2 step 1. Next, link the Rock Organ Rack to a Track and create a Part with a long sustained note (one bar or so) at the start position. Switch the Rock Organ Rack off/on to be sure that the level meter syncs.

Step 2: insert the Note Gater Effect into the the Rock Organ Rack. Set Midi Focus to the Note Gater (drag drop onto virtual keyboard). Press Play and start live playing the Note Gater via the Virtual Keyboard or an external midi device. As far as the audio is concerned, there is no latency, but the Note Event Pad visual (on the front panel of the Note Gater) is not synced.

I see. This will be fixed in the next update.

I'll reply on the remaining issues lateron.

[MuTools]

Bug #4: drag dropping a MuClip into the Project Modular Area or in a Mux messes up the visual arrangement of the Modules. All modules will be vertically aligned.
I also noticed that drag dropping a MuClip in a Mux without Event Input Module only adds the Sequence Player. Drag dropping it into a Project Modular Area without Event Input creates a Sequence Player and a Rack, but they are not connected.

Both these issue will be fixed in the next update.

Bug #5: concerns the tooltip when you route Rack audio in the Project Modular Area. For example:
Step 1: start with a blank Project Modular Area. Create two Racks. Both show ‘No Audio Connection’.
Step 2: connect one Rack to the other in the Project Modular Area with the red audio cable. The connection is correctly shown at the bottom label of that one Rack, but the tooltip (hovering mouse over label) always shows its previous state. For the tooltip to update, you have to click the connection label at the bottom of a Rack and select the connection there.

Will be fixed in the next update.

I'll reply on the last issue lateron.

[MuTools]

Bug #6: (again, not sure if this is a bug.) When you create an instrument Track, the keyboard in the Part editor always shows the Note Key Names of the most recently inserted module in the Rack (unless you override all of them by setting the Note Key Names of the Rack itself). But now consider the following scenario:

Step 1: insert an instrument Track (for example the Basic Rock Organ). The keyboard in the Part editor shows the black/white keys when no Note Key Names are set, which is the case with most synth presets.

Step 2: insert for example a Note Gater in that Basic Rock Organ Rack and set the Note Key Name of C4 to ‘On’ (or insert any random module which contains Note Key Names)
Now the keyboard in the Part editor also shows the Note Key name of the Note Gater, which is not preferable, I think. I would like to see the black/white keys of the Rock Organ. I overcome this problem by drag dropping the Rock Organ module itself onto the Track, hereby destroying the Track-Rack link and creating a new direct link between Track and Rock Organ module (now the Part editor shows black/white keys again). Wouldn’t it be better to always show the Note Key Names of the top module within a Rack? If not, would it be possible to make available in the Show Note Key Names of the Rack (which overrides the Note Key Names of the modules inside the Rack) an option like ‘show black/white keys’ or something?

This is a more complex issue and maybe it needs some extra thinking work, but i'll postpone that to a later point in time as i'm too focused on a quite big task these weeks which really needs full attention (forgive me that i stay vague about it atm, it's still much too much in r&d state).
Anyway, as a immediate improvement to the issue you reported i've made sure that the Note Key Names of a rack slot plugin are only taken into account if it's event input is effectively connected, because only then it makes sense. In the example you gave the Note Gater preset is after a synth without an event output and so the Note Gater event input is not connected and so in the next version its Note Key Names won't be taken into account anymore for the rack.

[dreammachine_nl]

Thanks for looking into all of this!

...i'm too focused on a quite big task these weeks which really needs full attention (forgive me that i stay vague about it atm, it's still much too much in r&d state).

Nice you're really building up suspense...

[MuTools]

Nice you're really building up suspense...

That's not my intention. In fact there will first be some other updates/releases before this main thing i'm working on goes public. Just mentioning this so to avoid confusion.