understanding PDC problems and solutions

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fx23
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understanding PDC problems and solutions

Post by fx23 » Sun Mar 06, 2011 3:27 pm

(I was asked to put a sticky about PDC, in order to help a bit some users understanding and adapt to the pb.)

As some do already know, Live is provided since V5 with an Automatic Plugin Delay Compensation System

All VSTs introduces more or less process latency. this system tracks latency introduced by the VSTs and shift/delay all other audio tracks so that all the stuff keep in sync in terms of audio content. however, it won't compensate for the 'associated to this audio' controls curves. this means that modulations, automations and global clock timing info will not be proportionally shifted of same amount of time, they will remain to their absolute on grid original position, while audio has been delayed from that same reference grid. So a new offset/drift appears beetween the curves and audio results, affecting sound. the more there are VSTs latencies and PDC process increase, the more resulting audio will shift from the original synced on timing grid curves/clocks.

Now you might not have noticed it or felt drastic pb with it because in some cases it's not perceptible: in scenario A) user uses very few or very low latency VSTs and works in traditional linear way in arrange.
He recs a first automation. Result is ok even if slightly out of 'real' sync grid, because the user has adapted itself to the low latency while recing. for exemple, he will gate each beat, but as audio is slightly begind 1.1, 1.2, 1.3 ect, he will have reced by ears compensating, and the resulting will be wrote and applyed at 1.1.+ latency, 1.2.+ latency ect. So in fact it IS out of grid, but as it's offseted of same amount of audio latency, booth remain in sync and coherent in terms of audio results. the user can go on and rec more automations based on same way, result will sound coherent at the end.(but out or real sync reference)
but.. if the user decides later to add/rem a big latency VST in front of those automated devices, the VST will shift audio but not all the previously reced curves, so the relativity of curves compared to audio is out of original wanted sync results. there are no real solutions to compensate the pb, exect go in and shift all curves.

in scenario B) User works with high latency VSTs in session mode. As working in session, he can't rec automations/modulations to clips :? . So the modulations are made by drawing on the absolute sync grid. if he uses a simple live device and draw a modulation,ie gating each beat, audio result will be coherent with drawn CV. But as previously,if he places a big latency VST before the device, the results in audio will appear anterior than it's apparent drawn position, and is out of sync. he has then no other solution than disbling snap, select the curve and slightly shift the start playing point in order to manually compensate, or directly draw with the offset, wich is not very handy..

To summ-up that means that if you've drawn/reced some sets of critical timmed modulation/ automations, ie an FX strong applied to a note Attack event, then you should avoid altering the chain with big latency VSTs (add or remove). if you add/rem a new big latency VST BEFORE the prevous controlled devices, the already drawn/reced automated curves will be out of sync. As well if you use a native live device after the VST, it's curves will be out of sync. Same goes for timing information of synced FX such as Autopan, beat reapeat, or any midi clocked VST (ie camel Space). Hope you understood.if want a repeatable test showing the pb, you can find one here:
http://rapidshare.com/files/443477011/P ... roject.rar

So, Ableton are aware of the pb from a long time and are working on it. It's not a real 'bug' but a lack of feature assiociated with PDC concept. By waiting you might want to try to understand under lines of this pb to find the best way to work around it. here are my few tips:

_ Try to avoid big latency VST placed at some place in the chain where some devices after it will need/had critical timing automations or timing clock info.
_ If still need a high latency VST flolowed by automated devices, consider render the insert point as Audio, then keep
activated only the rest of the chain that is after the bypassed then VST. this will remove all latencies and offsets.
_ so If need a high latency Vst, try to place it at the end of the chain.
_ If you often draw Lfo/gating type modulations, worth consider using/modulating Auto-Pan instead, wich has a build-in 'offset' setting that will allow you to manually roll and adapt to introduced latency later, otherwise if using volume or other automations you would have no other fixing choice than go back in eack curve, select them and shift them manually. few other live native devices have an ofset feature. use the offset if the chain has introduced new latency to re-align device reference clock.
it can provide a real easier 'maintenance' of the liveset-sync if you are deeply and often affected by the problem.
_ prevent for using any big latency VST in front of other VST that rely on synced clocks (ie CamalSpace).
_ globally avoid drasticlly alter chains latencies over time. (add/rem devices).
_ more generally avoid as much as possible latency inducing process with live by waiting all is compensated.

Hope it can helps some. Don't worry if you worked without never noticing it, if your ears were Ok with audio, then that means
audio is OK :!: . if you have doubts relating some timing offsets artefacts, you are now able to analyse where the pb might have come from and might find some workarounds.
Hope it helps
Last edited by fx23 on Fri Mar 16, 2012 9:15 pm, edited 2 times in total.

jbone1313
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Re: understanding PDC problems and solutions

Post by jbone1313 » Sun Mar 06, 2011 4:27 pm

Great info. Thanks for this. I really hope Ableton addresses this asap.

Klinke
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Re: understanding PDC problems and solutions

Post by Klinke » Mon Mar 07, 2011 9:33 pm

jbone1313 wrote: Thanks for this. I really hope Ableton addresses this asap.
+1...each.
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William
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Re: understanding PDC problems and solutions

Post by William » Mon Mar 07, 2011 10:23 pm

jbone1313 wrote:Great info. Thanks for this. I really hope Ableton addresses this asap.
+1 on both accounts
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LakesideWiseman
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Re: understanding PDC problems and solutions

Post by LakesideWiseman » Mon Nov 14, 2011 11:37 pm

Amazing Post. Very informative.

PDC is a silent killer to alot of my effects chains. So much time spent recreating effects chains because of it.

Thanks.

RD444
Posts: 265
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Re: understanding PDC problems and solutions

Post by RD444 » Tue Mar 06, 2012 10:07 am

great post

I'm still digesting it

Do you think live will ever fix this?

They don't seem to bothered to fix 'obviously going wrong' stuff.
"Plugin Delay compensation -PDC WARNING - Ableton Live 9 does not sequence all information correctly in time"
The bigger the project the more out of time it will be.

1.A.M.
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Re: understanding PDC problems and solutions

Post by 1.A.M. » Tue Mar 06, 2012 10:20 am

Maybe a little off topic, but for me the best "workaround" so far is composing the tracks/song in Live and exporting "dry" rendered tracks to audio and loading them afterwards in studio one for applying effects and mixing/mastering. IMO studio one is having a better PDC support and i can fully enjoy 64 bit VST3's . Hope it helps.
Still Live remains for me the most awesome tool for composing and sound mangling.
Cheers

RD444
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Re: understanding PDC problems and solutions

Post by RD444 » Fri Mar 16, 2012 5:49 pm

cheers for the info

when i found out LIVE did this I felt a bit like it wasn't a professional tool, more like a piece of cr*p

probably why they don't call it a "sequencer" because it doesn't "sequence" properly.

Some of these posts go back years.............
Ableton Live wrote:zzzzzzzzzzzzzzzzzzzzzzzzzzzzzZZZZZZZZZ £££ $$$ $$ zzzzzzzzzz ZZ Z
"Plugin Delay compensation -PDC WARNING - Ableton Live 9 does not sequence all information correctly in time"
The bigger the project the more out of time it will be.

MarkHenry
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Re: understanding PDC problems and solutions

Post by MarkHenry » Tue Mar 20, 2012 9:22 am

Very helpful information provided. Thanks for sharing this nice and useful detail.

TTOZ
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Re: understanding PDC problems and solutions

Post by TTOZ » Tue May 01, 2012 7:08 am

I don't think I can cope with this.

I thought logic was bad (if effect with big latency goes on any bus, visual timing of playhead is completely out, makes audio editing impossible)

Solution? Don't use latency devices on busses, only on tracks and instr.

Ok, can cope.

But this live one is really bad.. I still haven't authorized my suite yet, don't know if i am going to now.


I just presume pdc meant that *everything* kept in sync. I mean logic might look out of sync with playhead but at least plays back correctly.

I guess that's why studio one and cubase are such cpu hogs, because pdc is implemented absolutely flawlessly in every way, which takes many resources i am sure, as well as the ultra low latency mixing engines (mind you from what i tested so far, live is very inefficient on mac also)

:(

i just wish there was news this was even close to being fixed.
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RD444
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Re: understanding PDC problems and solutions

Post by RD444 » Tue May 01, 2012 7:20 am

It's never going to be fixed.

Save your money.

BORROW a copy of live off a friend.
"Plugin Delay compensation -PDC WARNING - Ableton Live 9 does not sequence all information correctly in time"
The bigger the project the more out of time it will be.

TTOZ
Posts: 98
Joined: Fri Oct 09, 2009 5:05 am

Re: understanding PDC problems and solutions

Post by TTOZ » Tue May 01, 2012 7:43 am

It gets worse. you DO realise that placing a latent plugin ANYWHERE in live's mixer, ANYWHERE, even if it has nothing to do with another track, will still throw the automation out?

It gets even worse:( The visual playhead bug also affects live. For example throw a linear eq anywhere in the mixer. Playhead is now out of sync with audio.

So the only way to work with live is to use only effects that introduce zero latency. There is no other way.

It's impossible. You can't automate with snapped automation and you can't edit audio properly cause the playhead out of sync.

How can pdc in live be of ANY use.?

Please explain.

Thanks.
I am bitwig, pick me, pick me, i now hAs midi export!

TTOZ
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Re: understanding PDC problems and solutions

Post by TTOZ » Tue May 01, 2012 7:44 am

RD444 wrote:It's never going to be fixed.

Save your money.

BORROW a copy of live off a friend.

too late for that i bought the upgrade from lite.
I am bitwig, pick me, pick me, i now hAs midi export!

simpli.cissimus
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Re: understanding PDC problems and solutions

Post by simpli.cissimus » Tue May 01, 2012 11:47 pm

TTOZ wrote:
I guess that's why studio one and cubase are such cpu hogs, because pdc is implemented absolutely flawlessly in every way, which takes many resources i am sure, as well as the ultra low latency mixing engines (mind you from what i tested so far, live is very inefficient on mac also)
I'm not sure what kind of PC you use, but I can tell you that on my Intel-Quadcore,
Studio One uses half of CPU then Ableton Live does and PDC works flawless
wherever and whenever I insert a effect into a chain.

I tested this with the exact same set-up of VST instruments and effects in both DAW's.

Even old Cubase 3 runs with less CPU then Live, with this test.

That is confirmed by many others too and it's the first time I read a comment like yours.

-----------
And to all keeping to complain: That thing isn't something you can't fix.
You can always Rewire Live into a DAW, and use the working features you like from Live.

I got pissed off by that too and was frustrated investing so much into one thing
that was buggy from first day and never got right. I got over it, searched a solution and found mine.
Now I'm happier then before and maybe have never switched to a better solution if I were satisfied from the start.
Should say thanks...somehow...LOL....!

On the other hand I won't give up the few real awesome things Live still has for me...
No! I'll never use the Push-App Live 9 !!!

TTOZ
Posts: 98
Joined: Fri Oct 09, 2009 5:05 am

Re: understanding PDC problems and solutions

Post by TTOZ » Wed May 02, 2012 12:38 am

Not on pc here on mac.. Studio one runs much better on windows, it's a known fact...

Live is kind of similar on both platforms...

I did say in my previous post was on mac.. and studio one, cubase and live are all known to perform much worse than logic or dp.

if i rewire it into logic i lose use of vst in live and i use logic in 64 bit mode anyway..

live was to do my dance, loop based stuff in, but not to be able to use a single plugin that even has 1 ms of delay without throwing the sample accuracy out, i am no longer interested.

i mean you can use it, but if the display and sound is not sample accurate to me and i mean sample accurate, then i am not happy. To each their own.

considering so many plugins have latency, this is not some small problem.

i guess most people don't notice if they use a compressor or convo reverb here and there but if you start using plugins with big latency like linear phase eq etc then live is impossible to use. insert a fab filter pro eq on linear mode, press play in live and see for yourself. what a nightmare :(
I am bitwig, pick me, pick me, i now hAs midi export!

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