MIDI timing in Reaper

[schwa]

A few words about MIDI timing in Reaper, specifically timing for MIDI coming in to or going out of Reaper.

To be clear, this is entirely about MIDI hardware timing. Internally within Reaper, there should never be any issue with MIDI timing.



When recording and playing MIDI you care about three kinds of timing: jitter, audio sync, and latency.

Jitter is how consistent or inconsistent the timing between notes is. If you have a quantized MIDI beat, you want it to actually play quantized instead of hits being randomly early or late.

There are systemic limitations on how low jitter can be with any hardware. A couple of good articles about MIDI timing and Windows:
http://www.soundonsound.com/sos/dec0...etech_1207.htm (e-sub)
http://www.tim-carter.com/music-prod...di-latency.php

The summary is that there is a minimum MIDI jitter on Windows in the 1 ms range, with the additional problem that each device must make a decision about what kind of timestamps to use, and mismatched timestamp assumptions can cause terrible jitter in the 50 ms range.

Reaper 3 adds a per-device MIDI timestamp setting, with the default choice of ignoring the device's timestamps and letting Reaper timestamp everything. In loopback tests, either using the default setting, or ensuring that Reaper's setting matches the hardware device, should reduce jitter to the 1.5 ms range, which is about as good as it gets on Windows.

(Any piece of hardware or software that handles the MIDI data along the way may cause additional jitter, so keeping the signal path short is important.)

Audio sync is making sure that MIDI and audio events that occur at the same time get heard at the same time. When not in low-latency output mode, Reaper syncs audio and MIDI during playback or recording, but specific devices may add additional latency that Reaper doesn't know about, which will throw the MIDI out of sync. You can adjust for additional latency per-device in Reaper's MIDI output settings.

Keeping MIDI and audio in sync allows creative processing of MIDI and audio together, like triggering a synth with an audio gate, or using audio volume to modulate a cutoff filter.

Latency is how long it takes for a MIDI note played on hardware to get recorded by Reaper, or a MIDI note output by Reaper to get played on hardware. Because Reaper does not yet have a direct MIDI-thru mode, there will always be some MIDI latency and when not in low-latency mode, the latency depends on the audio hardware buffer size. This latency makes it difficult to route MIDI through Reaper for live playing. We intend to add a MIDI-thru mode that will disable MIDI/audio sync completely but allow MIDI to pass through Reaper with very low latency, but for now, MIDI takes time to pass through Reaper.

So: for minimum jitter in Reaper, make sure the device is not set to low-latency mode in Reaper's preferences. For minimum latency, make sure that the hardware device is set to low-latency mode. And remember that jitter is worse than latency, because it's much harder to correct once recorded.

(Thanks very much to user beatbybit for running a number of controlled hardware measurement tests.)

[stupeT]

OK and thank you.

How about that tricky MIDI-interface which once came from Emagic? I am still using it. 8 ports, I guess its called ATM-8 (Advanced time management) or something. The trick of that device (as far as I remember):

To keep latency low it will accept MIDI events before they should actually be fired. But it keeps the timestamp in mind. So it is (thereotically) able to fire on all ports (and channels) at the SAME time and overcoming latency of some kind (i.e. caused by the serial transportation protocol for the 16 channels per port or the windows jitter you mentioned).

Will it's driver take care anyway? Will it be configurable to take full advantage of it?

[schwa]

Reaper always streams the MIDI events to the device at the start of the audio block during which they are meant to be played, in other words, there is a slight amount of send-ahead. In most cases that doesn't do much for latency though, if the device needs additional time to process the MIDI events, that's additional latency.

[Lawrence]

Originally Posted by schwa

Latency is how long it takes for a MIDI note played on hardware to get recorded by Reaper, or a MIDI note played by Reaper to get played by hardware. Because Reaper always syncs audio and MIDI, there will always be high MIDI latency and the latency depends on the audio hardware buffer size.

Latency should affect the realtime timing of audio that is dependent on the system - like VSTi's - but should have nothing to do with midi passing through the system... like midi passing through the daw triggering a hardware synth. That midi signal should *not* be delayed by the system latency/buffer size.

That seems very wrong to me, as someone who regularly plays/records midi with hardware synths in the daw at max buffers with no delay. It's one of the reasons people use hardware synths, to avoid latency, now you're saying with Reaper even that signal is dependent on the audio buffers?

That simply can't be a good thing.

[schwa]

As I wrote in the original post:

Originally Posted by schwa

This latency makes it difficult to route MIDI through Reaper for live playing. We intend to add a "MIDI thru" mode that will disable MIDI/audio sync but allow MIDI to pass through Reaper with very low latency, but for now, MIDI takes a long time to pass through Reaper.

Reaper's current low-latency MIDI output mode will decrease the "long time" but not all the way to zero. For now, if you want no MIDI latency while playing live, the MIDI signal from your controller to the hardware synth has to go around Reaper, by routing the MIDI cables either physically or virtually (using MIDI-OX or similar).

When we add MIDI thru, everyone will be happy.

[Lawrence]

Originally Posted by schwa

As I wrote in the original post:



Reaper's current low-latency MIDI output mode will decrease the "long time" but not all the way to zero. For now, if you want no MIDI latency while playing live, the MIDI signal from your controller to the hardware synth has to go around Reaper, by routing the MIDI cables either physically or virtually (using MIDI-OX or similar).

When we add MIDI thru, everyone will be happy.

Cool schwa. Is that a 3.0 fix?

My comments above were just me shaking my head as to how that could be overlooked. It's really obvious that the devs are audio guys, not midi guys, as some really, really basic midi stuff got overlooked early on.

Midi thru is about as basic as it gets no?

[stupeT]

Originally Posted by schwa

Reaper always streams the MIDI events to the device at the start of the audio block during which they are meant to be played, in other words, there is a slight amount of send-ahead. In most cases that doesn't do much for latency though, if the device needs additional time to process the MIDI events, that's additional latency.

Sounds like a perfect solution. Slightly ahead is exactly what that thingie needs.

[Justin]

Originally Posted by Lawrence

My comments above were just me shaking my head as to how that could be overlooked. It's really obvious that the devs are audio guys, not midi guys, as some really, really basic midi stuff got overlooked early on.

Midi thru is about as basic as it gets no?

Well, it has its uses, however it also will have its limitations -- in a low latency MIDI thru mode, you will not be able to do many of the MIDI processing things you can do now with plug-ins. We valued extreme flexibility over a single special purpose mode that is easily accomplished using other software/hardware, which I don't think can be boiled down to an audio/midi mindset difference.

[Lawrence]

Originally Posted by Justin

Well, it has its uses, however it also will have its limitations -- in a low latency MIDI thru mode, you will not be able to do many of the MIDI processing things you can do now with plug-ins. We valued extreme flexibility over a single special purpose mode that is easily accomplished using other software/hardware, which I don't think can be boiled down to an audio/midi mindset difference.

No offense intended Justin - and great and sincere respect to you - but I have no idea what that means. What is the extreme midi flexibility you're talking about with Reaper?

Your comment above suggests that other hosts that have a real midi thru are somehow hampered with midi FX processing? I don't see that in practice at all. I apply midi plugins to realtime streams and the result (the output to hardware) isn't held hostage to the audio buffer latency.

My comment was actually part compliment. It's obvious you guys are audio guys and it shows.

I know it's considered heresy to disagree with the devs but I don't get this one.

[schwa]

With MIDI thru you would not be able to do things like

Originally Posted by schwa

Keeping MIDI and audio in sync allows creative processing of MIDI and audio together, like triggering a synth with an audio gate, or using audio volume to modulate a cutoff filter.

But whatever. Nobody's saying we shouldn't have a MIDI thru mode.

[Evan]

Will the very informative first post, (and similar posts) find a way in the Reaper manual, or some sort of accessible online help? It's a shame to see threads like these get lost over time.

[Oxytoxine]

thanks schwa, excellent summary on the topic!

FWIW, from my experience reaper is in the same "jitter league" as samplitude and cubase when recording sequenced HW synths (but me ignoramus thought that this has to do with clock issues of the interface).

[Lawrence]

Originally Posted by schwa

With MIDI thru you would not be able to do things like



But whatever. Nobody's saying we shouldn't have a MIDI thru mode.

Of course not and I wasn't suggesting that was the case. I certainly disagree with the above conclusion about what can't be done while midi thru is also active.

I don't see midi thru as some exclusive mode like you do but just another mult of the incoming midi signal.

But I'll stfu and go away...

Thanks for the info schaw. I didn't mean to be confrontational.

[tony_man]

Many thanks for the good explanation Schwa..

the MIDI does appear to be tighter on my system..
IE Recording the audio of a midi click track sent from Reaper
(reaper MIDI->Device->Audio->Reaper) is to within 3 MS.


I think you guys may have cracked it...I hope it stays there like that.

oh to have MIDI pass thru (0 Latency)..


Excellent job.. I am enjoying reaper more and more.

[Jae.Thomas]

Originally Posted by Lawrence

It's really obvious that the Majority of users did not need this, as some uneeded standard midi stuff got ignored early on.

fixed for accuracy.

[Lawrence]

Originally Posted by Jason Brian Merrill

fixed for accuracy.

??............... ahhh never mind. I would ask that you not quote me after you change what I say though. You can't "fix" my opinion for accuracy nor can I yours?

Please don't do that. If you do, put it down as your opinion (what it is) and not me supposedly quoting your opinion.

If we all started re-quoting each others opinions "for accuracy" what a mess we'd have huh?

Thanks Jason.

[_Devin]

Originally Posted by Lawrence

You can't "fix" my opinion for accuracy nor can I yours?

I am firmly of the opinion that the world is flat, rests on 4 pillars made of god's own granite, and is the unmoving center of the universe, and I ask that none of you violate my right to an opinion by suggesting otherwise. Thx.

[Lawrence]

Originally Posted by _Devin

I am firmly of the opinion that the world is flat, rests on 4 pillars made of god's own granite, and is the unmoving center of the universe, and I ask that none of you violate my right to an opinion by suggesting otherwise. Thx.

That's so far out of the context of my request to Jason it's quite silly.

[jbone1313]

Where do you set "low-latency mode"? Or is "low-latency mode" synonymous with a low buffer size on your audio device?

[Jae.Thomas]

Originally Posted by Lawrence

??............... ahhh never mind. I would ask that you not quote me after you change what I say though. You can't "fix" my opinion for accuracy nor can I yours?

Please don't do that. If you do, put it down as your opinion (what it is) and not me supposedly quoting your opinion.

If we all started re-quoting each others opinions "for accuracy" what a mess we'd have huh?

Thanks Jason.

its not an opinion. you stated as fact, and i corrected you.

what i quoted is EXACTLY what happened, not your version


i wont change your quotes anymore however.

[stupeT]

Originally Posted by Jason Brian Merrill

its not an opinion. you stated as fact, and i corrected you.

what i quoted is EXACTLY what happened, not your version


i will continue to change your quotes however.

That is not fair.

[Jae.Thomas]

Originally Posted by stupeT

I'm a gay fish

you are?

[DarkStar]

Originally Posted by Jason Brian Merrill

its not an opinion. you stated as fact, and i corrected you.

what i quoted is EXACTLY what happened, not your version


i wont change your quotes anymore however.

Nope, I must disagree.

Quoting people is fine, and removing non-pertinent parts of the quote is also OK.

Changing the quote to say something quite different is not the right way to do things.

IMO, of course.

[Jae.Thomas]

Originally Posted by DarkStar

Nope, I must disagree.

Quoting people is fine, and removing non-pertinent parts of the quote is also OK.

Changing the quote to say something quite different is not the right way to do things.

IMO, of course.

i dont disagree that its wrong to do that

and im sorry.

it was a creative way to explain what REALLY happened.

[moliere]

Originally Posted by Jason Brian Merrill

it was a creative way to explain what REALLY happened.

Its also a very widely accepted way of making a light hearted point in web forums, so people just need to chill out a bit.

[Jae.Thomas]

Originally Posted by moliere

Its also a very widely accepted way of making a light hearted point in web forums, so people just need to chill out a bit.

+1.........................

[brainwreck]

Originally Posted by Lawrence

Of course not and I wasn't suggesting that was the case. I certainly disagree with the above conclusion about what can't be done while midi thru is also active.

I don't see midi thru as some exclusive mode like you do but just another mult of the incoming midi signal.

But I'll stfu and go away...

Thanks for the info schaw. I didn't mean to be confrontational.

yea, i'm not too smart on the midi stuff, but couldn't 'midi thru' be a separate stream than the midi that needs to sync with audio? i mean, why couldn't reaper pass a midi thru stream without being set to a midi thru mode?

[airon]

Let's heard the forum combat kids out in to their own play pen. Relax and stay on topic lads.

On topic, I've sent every midi citizen I know to this thread for the information you folks provided. I also agree this information should be part of the manual. Most folks will assume that's where they'll find out about accurate Reaper and midi devices can be. This will help to reassure them, i.e. remove doubt and uncertainty(which I call fear and ignorance) about this subject.

[_Devin]

Originally Posted by airon

Let's herd the forum combat kids out in to their own play pen.

fixed for accuracy

[Lawrence]

Originally Posted by Jason Brian Merrill

its not an opinion. you stated as fact, and i corrected you.

what i quoted is EXACTLY what happened, not your version


i wont change your quotes anymore however.

Thanks. My point was that this is *your* opinion about what happened. Unless you took a poll of all of the users of Reaper and the majority told you they didn't need those particular midi features... how else would you know that exactly? You state this as fact as if you asked them.

Opinions abound... we all have them and we often disagree. The opinion part being what you think most people need.

As far as the quotes go... forget my request. I'll just make it a personal habit to "correct for accuracy" all of the bullshit I read here.

So be my guest... have at it. Correct me for accuracy whenever you like... I'm gonna have fun doing the same to people here. Relax and chill right?

[Dstruct]

Is there a way to find out if the driver is using QPC?

[schwa]

Originally Posted by Dstruct

Is there a way to find out if the driver is using QPC?

Both of the articles in the first post refer to a "MIDITime Utility" which is meant to check your driver against both timers until it perceives a difference. However I don't see an actual link to the utility on either page.

[17hex]

Schwa and justin

THANK YOU. It's posts like this one and attention like you are giving this topic that give me NO hesitation in recommending Reaper to all of the musicians, producers and "sound guys" I know (many of whom have quite happily taken my advice). Also thank you for the "ReaControlMIDI" in v3beta. I have pull-down lists in Reaper of the patches on my SQR and DX7 (and other MIDI gear) now. Awesome. Oh yeah and inline MIDI editing.. and.. I could go on and on.. ask any of my friends ;-)

Anyway, as for the MIDI through thing, maybe I could suggest a hybrid approach to MIDI through? that's to say, sort of like how you added FX settings to individual takes (which is FANTASTIC), maybe you could have a "ReaFXMIDI" section that could be inserted inline in the MIDI through path. This would give you the opportunity to use a MIDI Arpeggiator or MIDI delay or whatever VST MIDI fx if you wanted, but still use the MIDI through. Obviously both of those plugins would do well to have "host BPM Sync", but that is quite a different thing than ASIO buffer sync... Maybe this is already what you had in mind and I just misunderstood.

I (ReaFXMIDI or not) will be VERY happy when Reaper gets MIDI through. Thank you again.

[Dstruct]

Originally Posted by schwa

Both of the articles in the first post refer to a "MIDITime Utility" which is meant to check your driver against both timers until it perceives a difference. However I don't see an actual link to the utility on either page.

Ok, I found the Link.


Now the problem:

Please tell MIDITime which MIDI ports you are using for the loopback test.

Output #1: Microsoft GS Wavetable SW Synth
Output #2: HDSP9632 Midi

Choose output (1 to 2): 2


Input #1: HDSP9632 Midi

Choose input (1 to 1): 1


MIDITime will now send an exciting melody through your loopback cable,
consisting solely of Middle C. (Aren't you glad you aren't the cable?)
This will probably take just a few minutes, but in rare cases it may take
up to an hour. You can use your machine normally during this time, but
if another program tries to open the MIDI port we're using, you may
get an error from that program, and if it sends MIDI data to the port,
MIDITime will get confused.
......

Your interface takes about 0 ms to process
each note.

For best results in Nuendo or Cubase, you will need to set the 'Use
System Timestamp' option under Devices | Device Setup | DirectMusic.
If your MIDI interface doesn't provide its own DirectMusic driver, you
will *have* to use the emulated port that Windows creates; the
Windows MIDI port will give you incorrect timing.


By the way, after 60 seconds, your clocks had drifted apart by
983 microseconds. A man with one watch knows what time it is; a man
with two watches is never sure.

QPC frequency: 2666810000
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: 0 ms (TGT), 0 ms (QPC)
Round trip: -1 ms (TGT), 0 ms (QPC)
Result: QPC.

---------
TGT start: 8354911 QPC start: 22278388223920
TGT sent: 8415411 QPC sent: 22439727609110
TGT in bounds: 0 QPC in bounds: 1
TGT delta: -1 QPC delta: 0
TGT avg: -0.08333 QPC avg: 0
Slow responses: 0 QPC frequency: 2666810000
Run: 60 Drift: -983
Device: HDSP9632 Midi
Driver: 050a
CPU speed: 2666
CPU type: Intel(R) Core(TM)2 CPU 6700 @ 2.66GHz

As far as I know, the RME HDSP WDM driver 3.077 doesn't have DirectMusic MIDI support. This means I need to use the emulated MIDI ports. But REAPER doesn't list them


What to do?

[schwa]

That's a saucy bit of program, isn't it.

I believe the app is simply telling you to use QPC timestamps. Apparently in Cubase you can only use QPC timestamps with DM or emulated DM ports, but in Reaper you can use QPC with the normal Windows MIDI port.

[Dstruct]

Ok, thanks!

[Lawrence]

True. Cubase / Nuendo has had a long history of midi timing problems for some users that has only recently started to die down. The system timestamp thing didn't necessarily fix it for everyone and the complaints were still coming in.

I personally didn't have any issues after doing the ignore port filter thing but some users have.

It's a pretty well documented historical issue/problem with that daw. Good to hear that Reaper won't have that problem.

Cool.

[Shan]

Originally Posted by schwa

A few words about MIDI timing in Reaper, specifically timing for MIDI coming in to or going out of Reaper...

Thanks for the overview! This sort of thing is definitely of value to be put in the wiki or manual.

Shane

[Jae.Thomas]

what about this situation in reaper:

(i never seemed to have a problem with this in reaper but i have with other programs, but im wondering how it will be affected)

you have an audio/vsti mix running

you are across the room with headphones on at your electronic drumkit

you hit the snare

the information gets read by the brain, sent to the pc through midi, into the audio interface, delayed a bit, gets processed into the vsti, causing a bit more delay, you HEAR it...

now, you would try to get latency down as far as possible

but is reaper "what you hear is what you get" when it comes to midi?

like, will it show up aligned with audio correctly?

[jbone1313]

Originally Posted by Jason Brian Merrill

what about this situation in reaper:

(i never seemed to have a problem with this in reaper but i have with other programs, but im wondering how it will be affected)

you have an audio/vsti mix running

you are across the room with headphones on at your electronic drumkit

you hit the snare

the information gets read by the brain, sent to the pc through midi, into the audio interface, delayed a bit, gets processed into the vsti, causing a bit more delay, you HEAR it...

now, you would try to get latency down as far as possible

but is reaper "what you hear is what you get" when it comes to midi?

like, will it show up aligned with audio correctly?

Jitter notwithstanding, I *think* Reaper is what you play is what you get. (That's what I prefer.) Ableton is what you hear is what you get.

See also: http://forum.ableton.com/viewtopic.p...+delay#p834240