How to calculate delay time for PDC compensation

not logged in right now · Post by **not logged in right now** » Fri Jul 23, 2004 10:56 am

to the Live geeks:
since L4 hasnt got PDC how do you find out the parameter values for the inserted delay plugin ?

without PDC most of the vst plugins are unusable in Live, so how is possible to compensate with a negative value insert ?

for what i know, the only plugin that does this automatically is the UAD PDC plugin.

any help from the gurus or the Ableton team would be welcome

ryst · Post by **ryst** » Fri Jul 23, 2004 12:31 pm

not logged in right now,

Unusable? Are you referring to input monitoring with vst's or mixdown? The only way to calculate how many samples need to be shifted is to contact each plug-in manufacturer and ask them how much delay is introduced on their respective plug-ins. That's what the major sequencer companies had to do in order to create a PDC feature in their programs. Also, I would like to know why you think most vsts are unusable in LIVE? Most plug-ins during mixdown don't introduce much of a noticable delay. I have spoken to quite a few pro engineers about this overhyped subject and I am being told that it's not an issue that they worry about because the delay is so minor that it's not noticable and the phasing is non-existant. But if it is, they just shift the tracks until everything lines up correctly. If you are referring to monitoring then that's a whole other issue. By the way, are your vst's more "unusable" when they are inserted on each track individually or when you use them on an auxilary?

not logged in right now · Post by **not logged in right now** » Fri Jul 23, 2004 1:42 pm

@ryst MANY THANKS FOR YOUR REPLY !

ryst wrote:not logged in right now,

Unusable? Are you referring to input monitoring with vst's or mixdown? The only way to calculate how many samples need to be shifted is to contact each plug-in manufacturer and ask them how much delay is introduced on their respective plug-ins. That's what the major sequencer companies had to do in order to create a PDC feature in their programs.

-- Really? Doesnt the program "notice" it by itself ?

Also, I would like to know why you think most vsts are unusable in LIVE? Most plug-ins during mixdown don't introduce much of a noticable delay.

-- They do-all of them...try render a track with insert vst applied and compare the waveforms of the original. You will see a huge delay depending on the type of plugin. And applied on drumtracks it is catastrophic.

I have spoken to quite a few pro engineers about this overhyped subject and I am being told that it's not an issue that they worry about because the delay is so minor that it's not noticable and the phasing is non-existant.

But if it is, they just shift the tracks until everything lines up correctly.

-- Me too (i am a pro engineer) That is true, its the only workaround but isnt really a solution..

If you are referring to monitoring then that's a whole other issue. By the way, are your vst's more "unusable" when they are inserted on each track individually or when you use them on an auxilary?

-- No not monitoring, insert on each track, aux is less PD
the only plugins that dont delay are the native Abletons.

-- And i dont wanna ask myself what the vstis do in Live4....

beatmaster · Post by **beatmaster** » Fri Jul 23, 2004 6:32 pm

Most people here (the typical Live user) wont notice any difference anyway. (as also seen in endless Live-sound discussions...)

It is true that once you are used to PDC it is hard to accept the absence of it. Took years to implement this feature in Cubase and Nuendo.
The only efficient workaround is use Ableton only plugs for inserts.

Perhaps Live 5.0 will bring this feature (and the stability of Live 3.0) and rise Live to the professional level of Cubase and Logic.

ryst · Post by **ryst** » Fri Jul 23, 2004 8:46 pm

not logged in right now,

-- Really? Doesnt the program "notice" it by itself ?

Yes, after they have confirmed with the plug-in companies the correct amount of compensation it becomes "automatic" You asked for a work-around so that's really my only suggestion if you really think it's a problem.

They do-all of them...try render a track with insert vst applied and compare the waveforms of the original. You will see a huge delay depending on the type of plugin. And applied on drumtracks it is catastrophic.

I agree with the drumtracks. Especially if you are bussing the signals to 1 or 2 stereo tracks for processing.

-- Me too (i am a pro engineer) That is true, its the only workaround but isnt really a solution..

I know. But I feel very lucky that we even have these tools at our disposal for such a great price. What happened was that one company (I think it was Steinberg, maybe not) put ADC as a feature in their program and then everyone jumped on the bandwagon. It was more or less just to stay competitive. This issue has been talked about and talked about more lately than just a year ago. It's similar to the DAW "sound issue" and even the high sampling rate arguments (some people hear it and some don't...pros and non-pros). It makes me wonder if some of it is just marketing hype? Some people actually have dumped DP because of this one reason alone! It's scary to think that people vote politically like this too.

-- And i dont wanna ask myself what the vstis do in Live4....

Neither do I!!!!!!

It would be nice if someone could develop a plug in that can analize the amout of latency an individual plug in produces from any company and then apply the appropriate amount of compensation for that track. It would seem feasible since the amount of latency a plug in introduces does not vari. It's the same no matter what track you insert it on. hhmmmmm.....Maybe one day.

Good luck, not logged in right now!

bensuthers · Post by **bensuthers** » Sat Jul 24, 2004 2:33 am

why not simply choose a few of your favorite plugins, and do some waveform analysis to determine what size buffer they are using internally.

generate a simple HF click, and play it without warping or looping through a bus/plugin structure. render it out.

view the waveforms side by side, workout the difference in ms or samples or whatever.

apply a delay (maybe save some delay plugin settings that correspond to your favorite compressor, or limiter, or bussing structure) to the non-effected tracks, test it to see if it works and bob is once again your uncle.

this is the procedure I went through when I realised that Logic 4.8.1's busses were buffered, and the built-in compressor used a buffer to generate a look ahead delay.

it worked a treat!