PDC -- what is it? why has it never bothered me?

[mholloway]

for being one of the major talking points about Live's failures, and considering that I've written and produced two entire albums in Live 8 alone, I'm kinda surprised that I actually have no clue or experience (that I'm aware of) regarding the much maligned "Plugin Delay Compensation." When does this cause a problem? I use upwards of 30 plugin instruments per session, all third party, plus numerous 3rd party effects... and I've never had a delay / latency issue with any of them, that I'm aware of...

..I've heard it's specifically something to do with autmoation of plug-in parameters, yes? If so, which ones? What is a typical scenario in which this problem arises (and thereby could explain why so many people are angry about it...)? I just feel like I ought to know...

thanks,
-M

[UltimateOutsider]

I had the same question a week or two ago. Check out this linked post. There are links to two other threads that get into the specifics.

If I remember right, you need to be using plugins that introduce notable latency and have things chained in a certain manner on tracks coming in from external hardware instruments that also have automation.

I've never encountered the issues either, even on projects with many live external instruments going, and it's likely because my plugin choices are pretty vanilla.

[beatmunga]

16.5 Device Delay Compensation
Live automatically compensates for delays caused by Live and plug-in instruments and
effects, including those on the return tracks. These delays can arise from the time taken by
devices to process an input signal and output a result. The compensation algorithm keeps
Live’s tracks in sync while minimizing delay between the player’s actions and the audible
result.

CHAPTER 16. WORKING WITH INSTRUMENTS AND EFFECTS 229
Note: there are a few situations in which Live cannot compensate for plug-in delay:
• Automation is not delay compensated. As a result, when using automation on tracks
that contain devices that cause delays, the automation may sound early.
• Tempo-synced effects and other devices that get timing information from Live’s internal
clock may sound out of sync if they are placed in a device chain after devices which
cause delay.
Device delay compensation is on by default and does not normally have to be adjusted
in any way. However, Live Sets that were created with Live 4 or earlier will open without
device delay compensation. To manually turn latency compensation on (or off), use the
Delay Compensation option in the Options menu.
Unusually high individual track delays or reported latencies from plug-ins may cause noticeable
sluggishness in the software. If you are having latency-related difculties while
recording and playing back instruments, you may want to try turning off device delay compensation,
however this is not normally recommended. You may also nd that adjusting the
individual track delays is useful in these cases, but please note that the Track Delay controls
are unavailable when device delay compensation is deactivated.
Note that device delay compensation can, depending on the number of tracks and devices
in use, increase the CPU load.

[Tone Deft]

sending sends to sends also seems to have this problem.

a list of uncompensated Live devices:
viewtopic.php?f=1&t=177073


this issue never frustrated me because my automation doesn't change in a mix. I have one tune with a send feeding on itself with active automation changes, it got weird one day, I think it's this problem. I haven't taken the time to poke around and see what's up.

[merges]

(X-posted from another thread)

Here is a very silly but straightforward example of the plugin-delay-automation issue. As others have indicated, it's truly insidious in that the "errors" accumulate and depending on how many tweaks you make/how much automation you have, can render your project fit only for the trash heap. Again, this will not happen to *everyone* but to many, especially those working with precision.

My analog is to Illustrator. Not everyone needs to tweak down to the millimeter, but it would be ludicrous for Adobe to say that alignment just kind of starts drifting when you use filters and brush strokes, and you'll just have to deal with it. Like graphics software, Live is built around digital precision.

In the following example, I was using the Mac standard audio on my newish MacBook Pro with Intel godknowswhat fast processors and blabity bla. 48Khz, 128 sample buffer. I used FabFilter plugins (regular offenders—but it *should not matter* whose plugins they are; Live should adjust) in this example.

This is a silly example. I have a reverse kick/bass sound with a high cut filter on top of it. I want the high cut to be at a low frequency for the duration of the sound, and to pop up to a high frequency after the sound stops. The result should be silence. I drew the automation to be precisely at the right time. The resulting resampled audio shows exactly what we'd expect: silence.

Then I threw in two more plugins and rendered the audio. The filter rise happens at the same precise time, but the rendered audio shows sound. What gives? The audio signal has drifted forward in time. The filter rise now happens BEFORE the reverse kick/bass sound "finishes" playing. What?! How far did it drift? I have no clue about how far, until I render the audio. (Or listen, and hear things out of whack.)

Edit: The plugins I added are EQs; they aren't verbs and delays adding residual echoes to the sound.



Again, this is a silly example and a simple one to demonstrate the problem. It can get a lot more hairy in a complex project. And in my mind, this just isn't professional grade handling of audio. Music and sound is about time, it's about a certain reliable precision. Just as Photoshop isn't paint, it's pixels.

Edit: if you're having trouble imagining a realistic situation whEre this might occur... say you've automated a filter cutoff on a synth. Then you decide to change the sound by throwing on a saturator and eq before the filter. Suddenly your automation is out of sync with the notes of the synth. Ouch.

(Edited for clarity.)

[beatmunga]

I've never used an emoticon in all of my internet life merges but if there was one available here with clapping hands I would be tempted to do the unthinkable.

Great post. Let the deniers/apologists look silly countering it.

[puzzlefactory]

Out of interest. To everyone who is dissatisfied with Lives PDC. What did you all do before PDC existed?

[Akshara]

Out of interest. To everyone who is dissatisfied with Lives PDC. What did you all do before PDC existed?

Used hardware with relatively few plugins. That was almost a decade ago. It was only a few years after the release of VST 2.0 (1999) when full PDC support was released in Cubase SX2 and Sonar 3 (2003), then a couple of years later in Logic 7 and Live 5 (2005). It was while running Sonar 3 Producer that I started taking plugins more seriously, and shifting away from hardware.

Before that, there wasn't a need for PDC, as it was all MTC/SMPTE sync between hardware sequencing with something like an MC-50 and a program like Motu Performer, and direct monitoring of outboard synths through analog and digital consoles, and the DAW was just a glorified digital tape machine, like a DA-88 or ADAT, that allowed for better audio editing, with all effects processing happening either outboard or within the console.

And never did the console automation just move to a different location from adding an outboard delay or by calling up a console compressor, nor did the tempo sync drift more than a frame or two before syncing up again. If either of those ever did happen, then something was either physically broken or setup incorrectly.

As an aside, I didn't encounter serious PDC issues with tempo synced effects and automation in Live until version 8.

[Sarrova-Q]

Out of interest. To everyone who is dissatisfied with Lives PDC. What did you all do before PDC existed?

Record on tape and edit the tape
Without PDC you have to bounce everything to audio and then manually align your tracks for perfect sync which costs a lot of time.
But exactly that is one of the things a DAW on a modern computer should be able to do for you.
I think it's important to look forward instead of looking back no?
I mean, you could also ask what users did before there was usb or timestretching or automation or ...
The fact is these tools and functions exist and modern DAW's should be able to handle them perfectly.

Personally, I think good PDC is the one main feature Live is still missing. Especially now you can record automation inside clips.
I understand Live is different from other DAW's (more LIVE oriented - hence the name :p) but some opted for a "live" and a "producers" modus.
This seems like a good idea to me, because it would let you switch between perfect PDC (but with delay compensation) and less perfect sync but the ability to drop in effects without interrupting the audio (needed for live situations). This would also mean the end of the "ableton sound engine" debate which is only there because of the sync / phasing issues you get when PDC is not perfectly aligning the audio.

[puzzlefactory]

Without PDC you have to bounce everything to audio and then manually align your tracks for perfect sync which costs a lot of time.
But exactly that is one of the things a DAW on a modern computer should be able to do for you.
I think it's important to look forward instead of looking back no?
The fact is these tools and functions exist and modern DAW's should be able to handle them perfectly.

I disagree.

It seems to me that people nowadays just seem to refuse to have to workaround a problem and refuse to commit to audio. Like you said you have to bounce stuff down and manually fix the timing issues, it's something people have been doing for years (i know i certainly have had to do it). But we're talking about Live here, manipulating audio and getting it in time is easy, it just takes a couple of clicks with the warp markers.

Music technology has never worked properly (at a prosummer level) it's all about working round the limitations. People talk about this software not being professional because of it's pitfalls but what is much more relevant to your work is whether your attitude is professional. If a professional is faced with a situation where the only solution is to bounce stuff down, he's not going to moan about it or tell the client that it can't be done because he doesn't want to commit to audio and the software should do it automatically. No, he'll bounce it down save it as a new project in case he wants to come back to it later and get on with the job.

At the end of the day, Live is a relatively cheap piece of software (in terms of music technology). If you want something that works flawlessly then go by a Pro-Tools HD rig.

Don't get me wrong, i'm all for improvement and for looking forward rather than back. If Lives PDC doesn't work ideally then of course it should be worked on and improved. But the way some people talk about it here, it's as if because of it, no one can do any work what so ever.

Maybe i'm old school (as i learnt in an era where you had to find your own solutions to problems and internet forums didn't exist), but i would much rather find a way of working within an applications limitations rather than complain about it on a website.

[beatmunga]

Here we go. The 'bitch' word again.

Amazing how much time 'people nowadays' seem to have to bitch about what they perceive as bitching.

[puzzlefactory]

Here we go. The 'bitch' word again.

Amazing how much time 'people nowadays' seem to have to bitch about what they perceive as bitching.

Terribly sorry to offend your sensibilities, i have edited my post appropriately. Hopefully now it will be easier to focus on the content of the post rather than the language.

[Sarrova-Q]

It seems to me that people nowadays just seem to refuse to have to workaround a problem and refuse to commit to audio. Like you said you have to bounce stuff down and manually fix the timing issues, it's something people have been doing for years (i know i certainly have had to do it). But we're talking about Live here, manipulating audio and getting it in time is easy, it just takes a couple of clicks with the warp markers.

Music technology has never worked properly (at a prosummer level) it's all about working round the limitations. People talk about this software not being professional because of it's pitfalls but what is much more relevant to your work is whether your attitude is professional. If a professional is faced with a situation where the only solution is to bounce stuff down, he's not going to bitch and moan about it or tell the client that it can't be done because he doesn't want to commit to audio and the software should do it automatically. No, he'll bounce it down save it as a new project in case he wants to come back to it later and get on with the job.

At the end of the day, Live is a relatively cheap piece of software (in terms of music technology). If you want something that works flawlessly then go by a Pro-Tools HD rig.

Don't get me wrong, i'm all for improvement and for looking forward rather than back. If Lives PDC doesn't work ideally then of course it should be worked on and improved. But the way some people talk about it here, it's as if because of it, no one can do any work what so ever.

Maybe i'm old school (as i learnt in an era where you had to find your own solutions to problems and internet forums didn't exist), but i would much rather find a way of working within an applications limitations rather than bitch about it on a website.

Yeah I understand with what you're saying, but if nobody complains, it will never get fixed or looked at.
Please understand, I absolutely love live and I do agree that you sometimes have to work around some issues or adjust your workflow a bit.
There's never going to be a DAW that works perfectly for every single users need.
But I do think PDC is a relative big issue because other DAWs seem to be able to handle timing much better.
Also, if you use a lot of timed automation (i do) in complex sets, it's not always possible to bounce to audio over and over again.
The automation of your plugin will be out of time even after you bounce so that's unacceptable.
Yes, I made some great music with Live and I did manage to work around some issues but I think now is the time for good PDC and automation sync.
I think there's a lot of complaining just because users love ableton so much, and because they don't want another DAW to work in.

[beatmunga]

Here we go. The 'bitch' word again.

Amazing how much time 'people nowadays' seem to have to bitch about what they perceive as bitching.

Terribly sorry to offend your sensibilities, i have edited my post appropriately. Hopefully now it will be easier to focus on the content of the post rather than the language.

Fair enough, and thank you.

Like you said you have to bounce stuff down and manually fix the timing issues, it's something people have been doing for years (i know i certainly have had to do it)...

...People talk about this software not being professional because of it's pitfalls but what is much more relevant to your work is whether your attitude is professional. If a professional is faced with a situation where the only solution is to bounce stuff down, he's not going to moan about it or tell the client that it can't be done because he doesn't want to commit to audio and the software should do it automatically. No, he'll bounce it down save it as a new project in case he wants to come back to it later and get on with the job...

...Maybe i'm old school (as i learnt in an era where you had to find your own solutions to problems and internet forums didn't exist)

I'm not sure how you used to do things exactly puzzlefactory but even when I was using a computer just to record MIDI information and send it back out to a load of hardware 10-20 years ago, my MIDI controller messages for things like filter sweeps (automation is just MIDI after all) used to happen where I put them and not audibly before.

Latency was not really an issue in the old days because analog audio needs no number crunching and MIDI was such beautifully simple digital data that a toaster could cope with it almost instantly.

In their quest to do something admittedly very clever, it could look like Ableton have unfortunately thrown the baby out with the bathwater with regards to tightness and accuracy.

[djadonis206]

Commit to audio and move on...i really dont understand why this is hard for some people