Limits for plugin delay compensation/lookahead?

DSP, Plug-in and Host development discussion.
Fender19
KVRist
253 posts since 30 Aug, 2012

Post Wed Apr 24, 2019 9:17 pm

If you have a plugin that uses large FIR filters, FFTs, "lookahead", etc., what is the most latency delay compensation you could expect to be supported by most DAWs (for VST2/3, and AU)?

Some plugins from companies like Izotope have very large PDC of 12,000 samples or more at 44.1kHz. That's a lot but what are the limits - or is that already pushing the limits?

And is that latency compensation limit a total for all plugins - or for each plugin?

Finally, does that amount of PDC typically scale with sample rate or is it a fixed number of max samples (i.e., less PDC time at higher sample rates)?

Xenakios
KVRian
1196 posts since 9 Sep, 2005 from Oulu, Finland

Re: Limits for plugin delay compensation/lookahead?

Post Thu Apr 25, 2019 8:15 am

Reaper supports at least up to 3 seconds. But you will need to test each host you are planning to support or try finding out the limits from their manuals or support channels.

mike_the_ranger
KVRist
148 posts since 16 Feb, 2017

Re: Limits for plugin delay compensation/lookahead?

Post Thu Apr 25, 2019 8:29 am

Good question. I ask myself why there should be a limit anyways. It's only about the host building a buffer of that length and the customer that has to wait for the right position.

Maybe that helps: FabFilter proq in max linear phase mode has more that 65000 samples latency and that's not a problem for pro tools or fl studio.

Fender19
KVRist
253 posts since 30 Aug, 2012

Re: Limits for plugin delay compensation/lookahead?

Post Thu Apr 25, 2019 4:21 pm

Xenakios wrote:
Thu Apr 25, 2019 8:15 am
Reaper supports at least up to 3 seconds. But you will need to test each host you are planning to support or try finding out the limits from their manuals or support channels.
Wow! I thought maybe a couple hundred mS or so. Thanks for the info.

Fender19
KVRist
253 posts since 30 Aug, 2012

Re: Limits for plugin delay compensation/lookahead?

Post Thu Apr 25, 2019 4:22 pm

mike_the_ranger wrote:
Thu Apr 25, 2019 8:29 am
Good question. I ask myself why there should be a limit anyways. It's only about the host building a buffer of that length and the customer that has to wait for the right position.

Maybe that helps: FabFilter proq in max linear phase mode has more that 65000 samples latency and that's not a problem for pro tools or fl studio.
OK, again, way more than I thought. Thank you for the info!

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