Gearslutz.com - View Single Post - Digidesigns answer to auto delay compensation

JFernandez · 18th October 2002

Hi Folks,

First of all, I'd also like to thank you for all your feedback, - we do take it seriously. I can promise you that we know how valuable automatic delay compensation is, and as some of you already know, adding it to Pro Tools has been Digi’s goal for a while. While this is very high on the long list of stuff we’d like to add, it hasn’t happened yet because we have had to focus on transitioning our entire product line to OSX. As the Mac is still a favorite platform for many, this transition was not an option for us, and it has been no small task either - it will have taken the team over two years of coding by the time it is complete! I’m happy to say that although 6.0 doesn’t include as many new features as some of our previous software releases, we were able to add a bunch of other things, including some you specifically asked for, such as addition of Trim Scrub with Pro Control and Control|24, and TDM Plug-In instantiation on-the-fly. And now that Pro Tools’ OSX support is almost done, we’ll be able to return our focus to even more new features, including auto delay compensation.

Some folks have questioned whether auto delay compensation hasn’t been done because it isn’t doable. I can say for sure that the TDM architecture is capable of supporting auto delay compensation, but it is a lot of work to do, and quite a bit more to do it right . It isn’t just a case of advancing tracks behind the scenes; many other things have to be taken into account too:

First of all, Pro Tools’ mixer architecture is completely dynamic, so users can configure it almost any way they wish. With auto delay compensation, this flexibility means that the implementation must manage the wide variety of configurations with their associated accumulating delays. For example, when routing a channel to a sub-group as well as a main output (such as when setting up a compressed drum sub group), the two arrival times at the main output might be different. This is just one "sub group" in the whole mix that has to be considered. Managing this essentially requires that Pro Tools considers all routing paths and then determines the compensation required for each track accordingly.
Many Pro Tools users have other devices synchronized with Pro Tools - all of which must be managed correctly. Other timeline elements should to be considered as well, such as ensuring markers, sync points, automation playlists, etc. reference the relative audio position correctly.
Finally, all plug-ins need to broadcast the amount of delay, and do so accurately, so that Pro Tools can compensate for all inserts.
So while all of this is certainly achievable, implementing and testing it to ensure all scenarios are correctly accounted for will take a while, as I am sure you can imagine.
It’s important for the many folks reading this who are new to this topic that we clarify that the delays we are talking about here are not an issue in many of the common mixing scenarios, and with many of the plug ins. Most of the Digidesign and third party plug-ins have a few samples of delay, so if you are using mono tracks there isn’t an audible issue here (e.g. 4 samples at 44.1 kHz is 90 microseconds of delay). Using plug-ins with longer delays may have a noticeable affect, such as affecting the musical groove of a track, but in those cases, Pro Tools does allow you to manually compensate for delays. I think most of you are aware of the options here, but in case not, I’ll quickly summarize them:

TimeAdjuster Plug-In - The track delay indicators in the Mix window display the total delay for the track. The TimeAdjuster Plug-In can be used to match the delay value for tracks that need to remain phase coherent.

Audio Playlist Nudging - Audio playlists can be advanced by nudging in sample increments to compensate for the amount of insert delay on the track.

As you know, we don’t pre-announce releases more than several months before they ship so that we avoid causing disappointment if there are unavoidable release delays or changes of content. So while I can say we will be adding auto delay compensation to Pro Tools future release, I don’t have a release time frame to share with you right now, (although we’re obviously already thinking hard about it!)
Thanks again for your feedback,

Wendy Abowd
Director, Pro Tools Product Line
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IP

18th October 2002	#1
JFernandez Gear nut Joined: Jun 2002 Location: Chicago IL Posts: 118 Thread Starter	Digidesigns answer to auto delay compensation Hi Folks, First of all, I'd also like to thank you for all your feedback, - we do take it seriously. I can promise you that we know how valuable automatic delay compensation is, and as some of you already know, adding it to Pro Tools has been Digi’s goal for a while. While this is very high on the long list of stuff we’d like to add, it hasn’t happened yet because we have had to focus on transitioning our entire product line to OSX. As the Mac is still a favorite platform for many, this transition was not an option for us, and it has been no small task either - it will have taken the team over two years of coding by the time it is complete! I’m happy to say that although 6.0 doesn’t include as many new features as some of our previous software releases, we were able to add a bunch of other things, including some you specifically asked for, such as addition of Trim Scrub with Pro Control and Control\|24, and TDM Plug-In instantiation on-the-fly. And now that Pro Tools’ OSX support is almost done, we’ll be able to return our focus to even more new features, including auto delay compensation. Some folks have questioned whether auto delay compensation hasn’t been done because it isn’t doable. I can say for sure that the TDM architecture is capable of supporting auto delay compensation, but it is a lot of work to do, and quite a bit more to do it right . It isn’t just a case of advancing tracks behind the scenes; many other things have to be taken into account too: First of all, Pro Tools’ mixer architecture is completely dynamic, so users can configure it almost any way they wish. With auto delay compensation, this flexibility means that the implementation must manage the wide variety of configurations with their associated accumulating delays. For example, when routing a channel to a sub-group as well as a main output (such as when setting up a compressed drum sub group), the two arrival times at the main output might be different. This is just one "sub group" in the whole mix that has to be considered. Managing this essentially requires that Pro Tools considers all routing paths and then determines the compensation required for each track accordingly. Many Pro Tools users have other devices synchronized with Pro Tools - all of which must be managed correctly. Other timeline elements should to be considered as well, such as ensuring markers, sync points, automation playlists, etc. reference the relative audio position correctly. Finally, all plug-ins need to broadcast the amount of delay, and do so accurately, so that Pro Tools can compensate for all inserts. So while all of this is certainly achievable, implementing and testing it to ensure all scenarios are correctly accounted for will take a while, as I am sure you can imagine. It’s important for the many folks reading this who are new to this topic that we clarify that the delays we are talking about here are not an issue in many of the common mixing scenarios, and with many of the plug ins. Most of the Digidesign and third party plug-ins have a few samples of delay, so if you are using mono tracks there isn’t an audible issue here (e.g. 4 samples at 44.1 kHz is 90 microseconds of delay). Using plug-ins with longer delays may have a noticeable affect, such as affecting the musical groove of a track, but in those cases, Pro Tools does allow you to manually compensate for delays. I think most of you are aware of the options here, but in case not, I’ll quickly summarize them: TimeAdjuster Plug-In - The track delay indicators in the Mix window display the total delay for the track. The TimeAdjuster Plug-In can be used to match the delay value for tracks that need to remain phase coherent. Audio Playlist Nudging - Audio playlists can be advanced by nudging in sample increments to compensate for the amount of insert delay on the track. As you know, we don’t pre-announce releases more than several months before they ship so that we avoid causing disappointment if there are unavoidable release delays or changes of content. So while I can say we will be adding auto delay compensation to Pro Tools future release, I don’t have a release time frame to share with you right now, (although we’re obviously already thinking hard about it!) Thanks again for your feedback, Wendy Abowd Director, Pro Tools Product Line -------------------------------------------------------------------------------- IP