Found a fix for Mcompare glitches when in particular routing situation in Reaper

[ericzang]

Reaper 5.12 x64 Win7
Melda 9.16 VST2

MCompare _when in Sync mode_ and playing a file produces glitches for me when it fulfills these 3 conditions:

On a normal track (MCompare is on my "submaster" track - all tracks go through this before reaching the Master),
Receiving midi messages (even if the submaster track is not armed, midi messages may still go through the track),
and the Mcompare option Sample Accurate Event Processing is On (inside Settings).

No glitches when Mcompare is on the Master track. (I assume because midi messages are not sent through the Master).
No glitches when Sample Accurate Event Processing is Off.
No glitches when MIDI messages are blocked before reaching MCompare. Can block messages by using Reaper's IO routing for MCompare and selecting MIDI Input Disabled.

Happy to finally find a solution for this! I suppose turning off Sample Accurate Event Processing will be no problem with MCompare.

While using MCompare, midi messages may be produced in the project by plugins, such as audio to midi triggers for drum replacement/layering in my case. Apparently these midi messages continue through all above layers of parent tracks, except for the real Master track.

[MeldaProduction]

Hmmm, interesting, thank you for the info! For the recorrd what exact computer and playback settings do you have?

[ericzang]

CPU: i7 960, 6gb ram
ASIO buffer 1024, at 44k
Interface: RME Digiface/Hammerfall (PCIe)

do you need other info?

[MeldaProduction]

Hmmm, that doesn't sound like a bad computer... Btw does that do that even in an empty project? (I mean just MCompare)

[ericzang]

Yes it happens in an otherwise empty project. Here's a minimal Reaper project to test with.
http://ericzang.com/tmp/MCompare_midi_glitches.RPP

Add an audio file to File 1 of MCompare in the Sub-Master track. Have midi generated in track 2 to create glitches (may simply play a midi keyboard) . You don't need any audio in track 2 to test with. Glitches only happen when the MCompare File is activated.

MCompare Sync for File 1 is On.
Settings - Sample Accurate Event Processing is On.
While generating MIDI, turn Off one of the above to stop glitches.

I'm happy with simply turning off the Sample Accurate option.

Thanks!

[DarkStar]

Can't see any glitches here.

I loaded your project and recorded the MIDI output of the track onto new tracks, first with Sample Accurate processing On, then Off. I transposed the recorded MIDI up/down so I could compare all three.



PS I had to turn off RecArm on the first track (or turn on "Monitor track media when recording).

[ericzang]

Thanks for checking it out. Sorry, I don't quite understand the additional testing you made. With my test project, for me, all that needs to be done is load a file into MCompare's File 1 and then start play on Reaper's transport. Glitches will be heard when the midi data is played.

Thinking about your post, perhaps you are looking for glitches in the midi data? The glitches I'm referring to are audio playback click sounds (a bit like when ASIO buffer is too small) only heard on the file in MCompare with the above conditions.

[DarkStar]

Ah, OK, I misunderstood - will try later.

[MeldaProduction]

Aaaaaaaaaaaaaaaaha! Found and fixed! Please wait for an update.

[ericzang]

Wow, excellent!

[Nspace]

Reaper 5.12 x64 Win7
Melda 9.16 VST2
MCompare _when in Sync mode_ and playing a file produces glitches for me when it fulfills these 3 conditions:
On a normal track (MCompare is on my "submaster" track - all tracks go through this before reaching the Master),
Receiving midi messages (even if the submaster track is not armed, midi messages may still go through the track),
and the Mcompare option Sample Accurate Event Processing is On (inside Settings).

No glitches when Mcompare is on the Master track. (I assume because midi messages are not sent through the Master).
No glitches when Sample Accurate Event Processing is Off.
No glitches when MIDI messages are blocked before reaching MCompare. Can block messages by using Reaper's IO routing for MCompare and selecting MIDI Input Disabled.
Happy to finally find a solution for this! I suppose turning off Sample Accurate Event Processing will be no problem with MCompare.
While using MCompare, midi messages may be produced in the project by plugins, such as audio to midi triggers for drum replacement/layering in my case. Apparently these midi messages continue through all above layers of parent tracks, except for the real Master track.

Interesting.
Sounds like we are witnessing developers getting aware of ugly effects from unattended MIDI:
MTotalBundle 9.17 changes
Fix: MCompare could glitch in sample accurate mode in sync when incoming MIDI.

Plus, also yesterday, Ableton released their Live 9.6.1b1 beta including this Release Note; (Improvements and feature changes)
"Improved CPU spikes caused by external MIDI input on OSX."

Could MIDItest help? (users) https://www.soundlib.com/studio/