MIDI BUG causing latency
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CopyRightJustice
- Posts: 130
- Joined: Mon Aug 08, 2005 6:18 pm
Hi folks,
just a short statement on a complicated issue.
Indeed the general behavior of Live is that the overall latency is compensated only when a tracks' monitor switch is set to "Off".
This is the same for Audio and MIDI tracks.
As Chris J already mentioned only the chance to set the monitor switch to "Off" also in a MIDI track is different to Live 4.
All other behavior should be the same.
The initial question was, why only when set to "Off"?
What Live does when it compensates Audio/MIDI input is to move these data
forward in time (because the incoming audio/MIDI data comes with a delay relative to the audio output of Live).
When recording data into a file we can do this easily and silently after finishing the recording. Because it is simply a file.
But if we want to hear the input signal and also want to compensate, we cannot move it forward because
we want to hear the signal immediately and therefore we are already to late.
Therefore to move the incoming data forward it time would mean to delay all other data.
(Similar to a negative track delay when PDC is enabled)
Unfortunately delaying all other tracks would mean we delay the output of Live we use as time references.
Nice version of a vicious circle.
Firstly I hoped this statement would be clear enough but I fear it is not. Furthermore
some issues perplexed me a bit and I want to investigate more.
I will provide a more detailed statement in some days trying to explain our points concerning
latency in this case.
thanks and regards,
Alex
just a short statement on a complicated issue.
Indeed the general behavior of Live is that the overall latency is compensated only when a tracks' monitor switch is set to "Off".
This is the same for Audio and MIDI tracks.
As Chris J already mentioned only the chance to set the monitor switch to "Off" also in a MIDI track is different to Live 4.
All other behavior should be the same.
The initial question was, why only when set to "Off"?
What Live does when it compensates Audio/MIDI input is to move these data
forward in time (because the incoming audio/MIDI data comes with a delay relative to the audio output of Live).
When recording data into a file we can do this easily and silently after finishing the recording. Because it is simply a file.
But if we want to hear the input signal and also want to compensate, we cannot move it forward because
we want to hear the signal immediately and therefore we are already to late.
Therefore to move the incoming data forward it time would mean to delay all other data.
(Similar to a negative track delay when PDC is enabled)
Unfortunately delaying all other tracks would mean we delay the output of Live we use as time references.
Nice version of a vicious circle.
Firstly I hoped this statement would be clear enough but I fear it is not. Furthermore
some issues perplexed me a bit and I want to investigate more.
I will provide a more detailed statement in some days trying to explain our points concerning
latency in this case.
thanks and regards,
Alex
Had a play around at a friends & verified this behaviour.
Now I may be wrong, because it's a long time since I have used the software in question (& I recently gave my copy away) but in the old cubase vst couldn't you set a midi delay, & go into negative values or something like that? I think it effected the actual recording of the note on/offs also ( used for synchronising external gear) I may be wrong, it's late & i'm knackered, but wouldn't a utility/function such as this possibly eliminate this problem? similar to how one may now manually set a negative delay value for audio one could set a negative delay value for the incoming midi notes, obviously there one need to be some way to calculate what this offset is (probably related to soundcard latency?).
Now I may be wrong, because it's a long time since I have used the software in question (& I recently gave my copy away) but in the old cubase vst couldn't you set a midi delay, & go into negative values or something like that? I think it effected the actual recording of the note on/offs also ( used for synchronising external gear) I may be wrong, it's late & i'm knackered, but wouldn't a utility/function such as this possibly eliminate this problem? similar to how one may now manually set a negative delay value for audio one could set a negative delay value for the incoming midi notes, obviously there one need to be some way to calculate what this offset is (probably related to soundcard latency?).
ok so played around a bit more, set up two tracks 2 record at the same time - one with monitoring set to either in or auto & the other to none.
The latency settings in audio preferences were 13+13 = 26, so I added a negative value of -26 & the two sets of midi notes line up perfectly now.
Is this what needs to be done each time midi is recorded in order for it to be perfectly in time, or can it be safely left like this & what other effects could this possibly have, re: audio midi sync problems or anything of that nature?
The latency settings in audio preferences were 13+13 = 26, so I added a negative value of -26 & the two sets of midi notes line up perfectly now.
Is this what needs to be done each time midi is recorded in order for it to be perfectly in time, or can it be safely left like this & what other effects could this possibly have, re: audio midi sync problems or anything of that nature?
First of all thanks Alex for your comments. I have to admit I didn't understand them and will wait patiently for your update.
diverdee, that's an interesting discovery you made here, I tried and you're right. But of course the audio latency compensation is gone when you do that.
I'll leave it up to Ableton to scratch their heads, and hope they'll find a solution.
diverdee, that's an interesting discovery you made here, I tried and you're right. But of course the audio latency compensation is gone when you do that.
I'll leave it up to Ableton to scratch their heads, and hope they'll find a solution.
Quad 6600 Intel, AsusP5Q, 2Gb ram, XP sp3, Evolution MK361c & UC33e, Line6 UX8
So, Abe,
This sounds like the classic latency issue.
Why are you trying to compensate for latency for monitoring during recording?!? Don't do that!
During recording, what we really want is a zero-latency path from input to output. All of us computer-audio types know about this and expect that we will have problems if we try to record through a piece of software with the latency set to a high value. (In my experience, I am good with 10 or 12 mS of latency, but drummers typically need to be down in the 4 mS range to be comfortable). If the CPU is not up to it, we need to resort to zero-latency solutions in the hardware. This is *our* problem - I think you're asking for trouble trying to fix it in software.
The best thing you can do for us is to make your software efficient, so that we can run it at low-latency on our overworked CPUs.
Now, if you are going to do latency compensation for playback, all you have to do (for audio recording) is shift the recorded track back in time by the amount of the latency of the In + Out as it was set during the recording. And for MIDI, you really only need to shift it by about half (Input delay is about 1 mS for MIDI, then there is the processing time for the virtual instrument and the output audio buffer delay).
After recording a track, the Latency compensation should be correct and the tracks should line up correctly. This should be independent of the monitoring settings. I would actually be very upset if (when listening to a clip being played back) I flipped the monitor switch from off to auto and the timing changed.
(FYI, I have not upgraded to Live 5 yet)
To summarize -
for recording, do not compensate.
for playback, always compensate.
This sounds like the classic latency issue.
Why are you trying to compensate for latency for monitoring during recording?!? Don't do that!
During recording, what we really want is a zero-latency path from input to output. All of us computer-audio types know about this and expect that we will have problems if we try to record through a piece of software with the latency set to a high value. (In my experience, I am good with 10 or 12 mS of latency, but drummers typically need to be down in the 4 mS range to be comfortable). If the CPU is not up to it, we need to resort to zero-latency solutions in the hardware. This is *our* problem - I think you're asking for trouble trying to fix it in software.
The best thing you can do for us is to make your software efficient, so that we can run it at low-latency on our overworked CPUs.
Now, if you are going to do latency compensation for playback, all you have to do (for audio recording) is shift the recorded track back in time by the amount of the latency of the In + Out as it was set during the recording. And for MIDI, you really only need to shift it by about half (Input delay is about 1 mS for MIDI, then there is the processing time for the virtual instrument and the output audio buffer delay).
After recording a track, the Latency compensation should be correct and the tracks should line up correctly. This should be independent of the monitoring settings. I would actually be very upset if (when listening to a clip being played back) I flipped the monitor switch from off to auto and the timing changed.
(FYI, I have not upgraded to Live 5 yet)
To summarize -
for recording, do not compensate.
for playback, always compensate.
if my tests are correct in Live 4 midi recording is as late as when monitor is set to AUTO or IN in live5.monarkeys wrote: After recording a track, the Latency compensation should be correct and the tracks should line up correctly. This should be independent of the monitoring settings. I would actually be very upset if (when listening to a clip being played back) I flipped the monitor switch from off to auto and the timing changed.
(FYI, I have not upgraded to Live 5 yet)
ie. only when setting to off in live 5 can you get exactly what you play, in live 4 you have to move your start marker (probably by the amount of latency compensation) once your recording is done to get what you played.
Quad 6600 Intel, AsusP5Q, 2Gb ram, XP sp3, Evolution MK361c & UC33e, Line6 UX8
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CopyRightJustice
- Posts: 130
- Joined: Mon Aug 08, 2005 6:18 pm
serious bug!
I confirm the same problem... 
also in this situation:
http://www.ableton.com/forum/viewtopic. ... highlight=
please fix it Ableton! this is a serious bug!!!
how can one let his inspiration flow when has to fear that something is out of sync?
I fear that Live's lost some immediacy when switching from version 4 to 5.
The whole workflow seems to be more sluggish...
also in this situation:
http://www.ableton.com/forum/viewtopic. ... highlight=
please fix it Ableton! this is a serious bug!!!
how can one let his inspiration flow when has to fear that something is out of sync?
I fear that Live's lost some immediacy when switching from version 4 to 5.
The whole workflow seems to be more sluggish...
confirmed here too (halfway down page 2):
http://www.ableton.com/forum/viewtopic. ... 9&start=15
Yep...Cat's outta the bag now. There's definately problem unless you always switch monitoring OFF. This goes for sending midi to external instruments too. Until I noticed this thread, I didn't know midi input to VST instruments is affected too.
I initially thought it was strange when the recorded files from my midi clock synced drum machine were dead on the beat with monitor OFF. I was thinking to myself, "How could Ableton know the exact negative midi delay my drum machine requires?" I was fine in Live 4 to compensate for midi clock delays by myself in preferences. Now I have keep flipping to prefs to compensate for either -52ms clock delay or -.5 delay depending on what postion I choose to switch the monitoring too.
I have been telling people to keep monitoring OFF but not knowing on a deeper level why it has to be done. I thought there was a technical reason it had to be this way and was normal. But then I remembered, Live 4 didn't behave like this. I've been thinking about this issue ALOT this week trying to get recordings to line up.
One of the reasons I stopped using Logic is because the midi clock stuff was messed up because of their overcompensating and they never fixed it after repeated bug reports. I think these problems spring up when they try to compensate for hardware automatically rather than letting the user apply the negative delay themselves. I trust Ableton is on top of this one though.
We just simply want the recording to be where where we played it along the timeline regardless of the monitor setting. The same amount late or whatever and just let us reduce our buffer size, keep it consistent. We don't need recording monitoring compensation (made up term) or anything complicated like that.
I'm sure there are plenty of people having this problem that don't know they're having the problem. They probably don't realize their timing is changing back & forth inconsistently depending on the monitor setting.
Alex, glad you're looking into this. Hope you guys come out with a fix soon. This one's really important!
http://www.ableton.com/forum/viewtopic. ... 9&start=15
Yep...Cat's outta the bag now. There's definately problem unless you always switch monitoring OFF. This goes for sending midi to external instruments too. Until I noticed this thread, I didn't know midi input to VST instruments is affected too.
I initially thought it was strange when the recorded files from my midi clock synced drum machine were dead on the beat with monitor OFF. I was thinking to myself, "How could Ableton know the exact negative midi delay my drum machine requires?" I was fine in Live 4 to compensate for midi clock delays by myself in preferences. Now I have keep flipping to prefs to compensate for either -52ms clock delay or -.5 delay depending on what postion I choose to switch the monitoring too.
I have been telling people to keep monitoring OFF but not knowing on a deeper level why it has to be done. I thought there was a technical reason it had to be this way and was normal. But then I remembered, Live 4 didn't behave like this. I've been thinking about this issue ALOT this week trying to get recordings to line up.
One of the reasons I stopped using Logic is because the midi clock stuff was messed up because of their overcompensating and they never fixed it after repeated bug reports. I think these problems spring up when they try to compensate for hardware automatically rather than letting the user apply the negative delay themselves. I trust Ableton is on top of this one though.
We just simply want the recording to be where where we played it along the timeline regardless of the monitor setting. The same amount late or whatever and just let us reduce our buffer size, keep it consistent. We don't need recording monitoring compensation (made up term) or anything complicated like that.
I'm sure there are plenty of people having this problem that don't know they're having the problem. They probably don't realize their timing is changing back & forth inconsistently depending on the monitor setting.
Alex, glad you're looking into this. Hope you guys come out with a fix soon. This one's really important!
I think I'm coming to the conclusion that the timing recorded in the AUTO and ON positions is the same as it was in Live 4 just like you say (now that I reread this comment and experimented some more). So it's just a matter of getting the buffer down as far as you can to get things snappy enough for the right feel. Then shift the file manually by the overall latency amount displayed in prefs after it's recorded. Then the audio plays back exactly where you played it originally. This is how it was in Live 4, right?Alex wrote: This is the same for Audio and MIDI tracks.
As Chris J already mentioned only the chance to set the monitor switch to "Off" also in a MIDI track is different to Live 4.
All other behavior should be the same.
So monitoring OFF is like a bonus. An option to have the recording line up automatically the first time around that was not available in Live 4?
So delaying the output of Live (by the latency amount)...effectively doubling the overall latency! Yikes!Alex wrote: The initial question was, why only when set to "Off"?
What Live does when it compensates Audio/MIDI input is to move these data
forward in time
But if we want to hear the input signal and also want to compensate, we cannot move it forward because
we want to hear the signal immediately and therefore we are already to late.
Therefore to move the incoming data forward it time would mean to delay all other data.
(Similar to a negative track delay when PDC is enabled)
Unfortunately delaying all other tracks would mean we delay the output of Live we use as time references.
Ok so let's say progressing to the next step, that you want the recording to line up whether track monitoring is on or off. I don't think you would have to delay the output of Live to get the monitored tracks to line up too. It's just a matter of automatically shifting the individual clip's startpoint to the right against the audio/midi file after the recording right? A repetitive task we would do manually anyway, moving the startpoint to the right by the latency amount. It doesn't matter what is displayed in the clip DURING the recording.
My head's spinning now. Maybe some of this made sense or was useful.
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nobbystylus
- Posts: 1067
- Joined: Sat Feb 21, 2004 4:32 pm
- Location: london
yes.. this does mean that live looping, while using software monitoring (either in/auto) is useless... meaning the idea i had of a Mic going straight into my echo indigo i/o on my laptop and recording loops for immediate playback (not tinkering around with start points and shite like that.. i wanna hit play as soon as the loop is recorded) is impossible.. for now..
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