Old 09-03-2019, 01:42 PM   #1
explodingPSYCH
Human being with feelings
 
Join Date: Sep 2015
Posts: 205
Default MIDI Recording NOT Sample Accurate

REPRODUCING BUG:

Run an I/O audio test, set "Output Manual Offset" and/or "Input Manual Offset" until audio is sample accurate.

Then run the same test using MIDI. MIDI appears ahead of it's beat. When midi is set to sample accurate, Audio will no longer be sample accurate.

EXPECTATION:

I would expect that once audio is sample accurate that MIDI would also be sample accurate, or that there would be another setting to offset recorded MIDI data.

See this post for further information:

https://forum.cockos.com/showthread....90#post2076590
explodingPSYCH is offline   Reply With Quote
Old 09-03-2019, 10:42 PM   #2
EvilDragon
Human being with feelings
 
EvilDragon's Avatar
 
Join Date: Jun 2009
Location: Croatia
Posts: 23,621
Default

MIDI doesn't work this way, it doesn't adhere to the sample rate grid because it works in ticks (by default 960 PPQ), so things are rounded to the closest sample.
EvilDragon is offline   Reply With Quote
Old 11-07-2019, 01:11 PM   #3
explodingPSYCH
Human being with feelings
 
Join Date: Sep 2015
Posts: 205
Default

(Sorry for the late response).

That's a good point. I also understand MIDI to work based on PPQ. However, something about the Manual Offsets seems to be effecting MIDI.

Specifically recorded MIDI in Reaper does not seem to reflect accurately what is played. It seems to always be ahead. Manual Offsets seems to move where the MIDI falls, but unfortunately I cannot get the MIDI to be accurate with the same settings needed to get the audio accurate.

Here's a video I made on the issue.:

https://youtu.be/8qDoXord_DY

I play a beat on my keyboard to a click three times. The first time is no offset. The second time I set input and output offset to 100, the third time I set both to 800.

The MIDI moves ahead of the grid each time I increase the offset values.

Here's a relevant post:

https://forum.cockos.com/showthread....90#post2076590

I'm hoping it can be resolved soon, as I use a lot of MIDI and would like to have access to an accurate representation of my performances.
explodingPSYCH is offline   Reply With Quote
Old 11-07-2019, 03:02 PM   #4
mschnell
Human being with feelings
 
mschnell's Avatar
 
Join Date: Jun 2013
Location: Krefeld, Germany
Posts: 8,153
Default

Quote:
Originally Posted by EvilDragon View Post
MIDI doesn't work this way, it doesn't adhere to the sample rate grid because it works in ticks (by default 960 PPQ), so things are rounded to the closest sample.
Is this what Reaper stores in the rpp file ?

I understand that the Midi timing is different in different stages of a possible Midi stream.

e.g.:

- Within reaper it's timed with a resolution of samples (i.e. the "offset" the realtime Midi API provides is in count of samples since the block start)
- in Midi files the resolution (supposedly) is 960 PPQ.
- in USB the timing is sloppy, depending on the USB transfer blocks.
- in a plain old Midi cable it's 3 characters per message) * 11 (bits per character) / 31.25 (Baudrate) in mSec.

-Michael

Last edited by mschnell; 11-23-2019 at 02:34 PM.
mschnell is offline   Reply With Quote
Old 11-23-2019, 05:28 AM   #5
KosmicEarth
Human being with feelings
 
Join Date: Nov 2019
Posts: 2
Default Due Diligence before I buy in to the next decade of Reaper :)

Due Diligence before I buy -
Hi First post from UK music maker....
Been diving into Reaper last week & loving it. (BTW The TUTS are awesome - Love the NY accent, very happy memories of my time there from the golden period of 1981 in Central park listening to Simon Garfuncle live

I am about to plunge into the Galaxy known as Reaper after a break of 20yrs away from home studio recording. I was brought here from multiple forum posts Including this AWESOME post - https://forum.cockos.com/showthread.php?t=52382 and by many others highly recommending Reapers multiple VST stability regarding CPU issues like crashes, clicks, etc. on large track recordings.

However Just catching up on this particular thread can you please confirm my Midi Sync to Audio will be hassle free? You see I have x12 External midi driven "Real World" machines (Everything from Multiple M1R's to Old CasioFZ1 samplers, etc) that I wish to combine as I construct my EDM with the very best of the VST world (Kontakt. Dune3,Omni 2.5, Serum, Uhe Repro 1, etc) I know things have moved on but I never want to face the same issues I had with Sonar (And dare I say it the ISIS I/O card !). I am also about to buy a Pro Audio card (Something like the zero latency MOTU M4 but open to suggestions by the pro's here! )to bring me into the "Star Trek" Era : - ) Thanks in advance. (Brain HQ is Acer Nitro, i7, Win764, 8GB Ram, Nvidia GeForce GTX 4GB,SSD, etc. also I have several spare machines for driving other VST's via ethernet & copperlan) Thanks in advance.
KosmicEarth is offline   Reply With Quote
Old 11-23-2019, 02:36 PM   #6
mschnell
Human being with feelings
 
mschnell's Avatar
 
Join Date: Jun 2013
Location: Krefeld, Germany
Posts: 8,153
Default

If USB is involved, Midi timing sometimes is not very accurate. That is because USB is defined the way it ism, and because of certain OS issues. The DAW can't help with that.

There are rumors that non-USB Midi devices (e.g. Thunderbold and PCI) might be more hassle free, if you use devices with plain old 5-pin Midi sockets.

-Michael
mschnell is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 10:44 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.