Tempo Changes causing unexpected results

Matt Mayfield · 08-05-2017, 08:15 AM

Hi all,

I've been struggling with tempos and time signatures causing unexpected changes in projects.

Over the past year I've experimented with pretty much every combination of timebases, setting MIDI items to "ignore project tempo" or not, and everything else I can think of. Nothing has resulted in behavior that works consistently as I expect.

The latest issue that has me baffled is demonstrated in 90 seconds in this video:

https://youtu.be/XmsJ859xdYo

- Issue is also reproducible in REAPER 5.50rc13
- See "Full Project No Extra Tracks or Audio.RPP" in attachment

- After making the above video, I tried cropping the project to just the problem area for upload
- Cropping resulted in other issues:
-> 4/4 (instead of correct 6/8) time signature at beginning
-> Looped MIDI regions offset incorrectly
- After fixing these issues manually in the cropped project, the original issue is NOT reproducible (?!)
-> Tempo change behaves as I expect in the cropped project
-> See "MIDI Audio Sync Example cropped can't reproduce issue.RPP" in attachment

REAPER is such a great DAW in so many ways that I can't imagine giving it up at this point, but tempos and MIDI/Audio sync have been a source of such pain and frustration that I could really use some help from experts or developers here.

I'd expect the behavior to at least be consistent between the two projects, and I believe it should always act like it does on the cropped one.

This seems like a bug to me, or possibly several. If not and this is working as intended, I'd like to understand why this would be considered correct behavior, and how to work around it to achieve the results I need.

Thanks,

Matt

juliansader · 08-05-2017, 01:32 PM

No, you are not missing something: REAPER's tempo envelope is indeed terribly buggy.

Setting the timesig marker to "Allow partial measures" should help to avoid bugs like these.

If "Allow partial measures" is UNchecked, timesig markers are forced to jump to the next measure start when the number of beats are changed.

However, timesig markers (like everything else in REAPER's tempo envelope) are finicky and buggy, and they will sometimes jump around for no good reason, even when Timebase for tempo envelope = Beats and no changes are made in the number of beats, so it seems safer to always set all timesig markers to allow partial measures.

Changing the tempo envelope by dragging points or line segments in the master track is somehow also safer than changing tempos by clicking on the marker.

vanhaze · 08-05-2017, 02:08 PM

Hate to say but (anyways for me and i am guessing for others) the "allow partial measure" functionality is totally buggy and problaby won't help OP any further.

In general, i myself and with me problaby many other film composers, working in Reaper or lurking to Reaper, would wish for a way better, logical, less buggy implementation of Reaper's time signature/tempo functionality.

I can fully understand OP's frustration.
My 2 cents to Cockos: please forget the AI development abit and focus on this.
Then again, Cockos is just doing it's own thang and i totally respect that.

Klangfarben · 08-05-2017, 03:42 PM

I agree with Vanhaze. Trying to do something simple like remeter a cue in Reaper is nearly impossible unless you just delete all your meters and time signatures and start over.

The problem is Reaper even when in bars/beats is not acting like it is in bars/beats.

For example, if I have a bar that is 6/4 and I need to change to 5/4, in any other sequencer it isn't trying to move everything. The first beat of the next bar simply becomes beat 4 of the current bar. And then if later on I add a beat back, again everything doesn't move. It simply stays where it is and I can re-meter accordingly. Same thing if I change a 6/4 bar to a 7/4 bar. Everything that was in beat 1 on the next measure now happens on beat 2. In Reaper you have now unleashed holy hell.

I honestly don't understand how or why Reaper is trying to change everything when I simply want to do something simple like re-meter a cue. I don't think it was ever properly dealt with as most people not working in film just don't have a lot of tempo/meter changes whereas on the film side you have constant tempo and meter changes throughout.

dea-man · 08-05-2017, 05:28 PM

This is my only true pet peeve about Reaper.

It must be really, really hard to fix.

Matt Mayfield · 08-06-2017, 09:56 AM

Thanks for the replies.

I'm not sure exactly how Reaper internally represents position, but in general it seems to expose a lot of its internal logic in the UI (in things like manually setting timebase).

If I could choose the next development sprint or push for Reaper, it would be to overhaul its tempo and positioning system. This would really make it the ultimate DAW in my opinion. What I'd like to see includes:

Code:

I. Beats, not measures, become the master unit of beat-based positioning
	A. Changing a time signature should never move any items relative to each other, regardless of timebase
	B. Changing a time signature should never insert or remove time, regardless of timebase
	C. Time signature changes should simply "remap" which beats belong to which measures
	D. One "beat" by this definition would be:
		1. A quarter note in 3/4, 4/4, etc. time
		2. Three eighth notes in 3/8, 6/8, etc. time
II. When cutting or inserting time:
	A. Looped MIDI items should behave consistently
		- i.e currently the offset sometimes changes unpredictably and notes change position
	B. No tracks should EVER go out of sync from each other after a cut or insert
III. When changing tempo in the middle of a project:
	A. Audio and MIDI items need to remain in sync
	B. Nothing should move beat-wise
	C. Nothing after the following tempo change (after the edited one) should be affected at all
		- Exception: "time" timebase items

Probably more stuff too. If the developers decide to make this a priority, I would be VERY happy to do a lot of detailed beta testing and bug reporting, and to provide projects that reproduce issues.

Matt

studio1602 · 08-07-2017, 05:12 AM

Quote:

Originally Posted by juliansader

Setting the timesig marker to "Allow partial measures" should help to avoid bugs like these.

Where is the setting for this in 5.40? According to the manual, it should be at Preferences > Editing Behavior > Envelope Display, but I do not see it on that page, and a search in Preferences finds nothing.

Oh, and +1 for fixing the tempo bugs.

juliansader · 08-07-2017, 05:42 AM

Quote:

Originally Posted by studio1602

Where is the setting for this in 5.40? According to the manual, it should be at Preferences > Editing Behavior > Envelope Display, but I do not see it on that page, and a search in Preferences finds nothing.

It is a (small, inconspicuous) setting in the dialog box when you create or edit a time signature.

(I should probably create a script that changes all time sigs in a project to allow partial measures, so that users don't have to edit each timesig one by one.)

For some discussions about other bugs and idiosyncracies solved by allowing partial measures, see:

* Bug inserting or deleting bars over a tempo change

* BUG: Adding meter change adds an extra bar

* Inserting new point into tempo envelope creates weird new timesigs

studio1602 · 08-07-2017, 07:55 AM

It is indeed inconspicuous! I've looked at that edit dialog hundreds of times and not noticed it. Thanks!

Matt Mayfield · 08-07-2017, 11:39 AM

Quote:

Originally Posted by juliansader

It is a (small, inconspicuous) setting in the dialog box when you create or edit a time signature.

(I should probably create a script that changes all time sigs in a project to allow partial measures, so that users don't have to edit each timesig one by one.)

For some discussions about other bugs and idiosyncracies solved by allowing partial measures, see:

* Bug inserting or deleting bars over a tempo change

* BUG: Adding meter change adds an extra bar

* Inserting new point into tempo envelope creates weird new timesigs

Wow, that actually allows me to work around the original issue I was seeing. Thank you very much!

The weird thing is, when I check that box for the following tempo change, it doesn't become a partial measure (with a *) and yet the issue doesn't happen.

This seems to suggest some additional layers of complexity around how Reaper deals with time signatures and tempo internally and how it "reshuffles" things when changing tempos/time sigs earlier in a project.

I don't have a clear logical analysis, but instinctively this feels to me like the tempo/beat-vs-time code in Reaper must have started in one direction, then evolved organically in another direction, and so built up a lot of workarounds leading to inconsistent behavior.

foxAsteria · 08-07-2017, 12:09 PM

I will cry tears of joy the day the devs fix this bloody nightmare of an issue.

I'm only using playrate for tempo changes anymore, because I can't bear to sort out one more MIDI item fiasco. By far my biggest caveat with Reaper...

Robert Johnson III · 08-08-2017, 04:30 AM

Quote:

Originally Posted by vanhaze

My 2 cents to Cockos: please forget the AI development abit and focus on this.

Could not agree more!

Matt Mayfield · 08-08-2017, 08:50 AM

Well I mean they're close to done with the AIs as seen in the Pre-Release forum, so it probably doesn't make sense to drop it right now. But after that's done I'd really like to see some attention focused this direction. There are many-year-old threads complaining bitterly about this, and it's time.

In my imagination I guess it would be a change to some pretty deep underlying stuff, so I suspect those changes would break the current file format and have to go into REAPER 6.0. That's my outsider's best-guess impression, anyway.