I have a dream of external delay compensation.

Fibes · Post by **Fibes** » Tue Oct 03, 2006 1:10 pm

C'mon already.

monkey man · Post by **monkey man** » Wed Oct 04, 2006 7:44 am

Hey, Fibes

A thought I had the other day:

E-ADC plug gets inserted in mixer slot.
Its only 3 parameter fields are:
1) Input selection from the return
2) Output selection as the send
3) Manual compensation setting, just in case of trouble, and for possible fine-tuning.

DP compares a (sent) blip or the incoming and outgoing audio and measures the I/O delay.
From here in, it's normal ADC measures all the way.
I believe this would then only involve a "virtual, non-destructive" track-shift.
Who knows, maybe I've missed something, but shouldn't it be this simple?

Monkey

Fibes · Post by **Fibes** » Wed Oct 04, 2006 8:21 am

I DON'T want to start a platform war but Nuendo can do it.

It's native.

And very easy to ping.

auptown · Post by **auptown** » Wed Oct 04, 2006 9:20 am

Well, I think I can write this plug-in. I did a similar algorithm in the Digital Audio Toolbox for the Latency measurement (my company is TerraSonde, although now Sencore sells these things).

So that I understand, can someone describe the full details of the setup, and what is not happening now that should be? I think this is related to using external outboard gear to process tracks, but I am not sure if that fully covers it.

Eleventh Hour Sound · Thu Oct 05, 2006 11:32 am

I sometimes use a second computer as a MIDI sound module running BFD drums and it would be nice to use "automatic external delay compensation" to compensate for any latency introduced. Right now, I do it manually using the MIDI shift plug in to advance a track so it will play in time....

jeronimo · Post by **jeronimo** » Thu Oct 05, 2006 7:03 pm

That would be awsome to have on DP.
Cubase SX 3 and Nuendo 3 have it.
Maybe someone that owns SX3 or N3 could help auptown to write this plug!
C'mon guys!!

Fibes · Post by **Fibes** » Thu Oct 05, 2006 9:10 pm

Bows down and prays...

mcevilley · Post by **mcevilley** » Thu Oct 05, 2006 9:17 pm

auptown wrote:Well, I think I can write this plug-in. I did a similar algorithm in the Digital Audio Toolbox for the Latency measurement (my company is TerraSonde, although now Sencore sells these things).

So that I understand, can someone describe the full details of the setup, and what is not happening now that should be? I think this is related to using external outboard gear to process tracks, but I am not sure if that fully covers it.

Sounds great! Yeah, I think he's just talking about being able to use outboard processing or modules without any noticeable delay. Maybe Fibes could elaborate? C'mon Fibes, auptown is offering...

monkey man · Post by **monkey man** » Fri Oct 06, 2006 8:21 am

auptown wrote:So that I understand, can someone describe the full details of the setup, and what is not happening now that should be? I think this is related to using external outboard gear to process tracks, but I am not sure if that fully covers it.

Hey, auptown

What have I missed? Have you read this?
Did anyone read my post? No comment so far...

monkey man wrote:Hey, Fibes
A thought I had the other day:

E-ADC plug gets inserted in mixer slot.
Its only 3 parameter fields are:
1) Input selection from the return
2) Output selection as the send
3) Manual compensation setting, just in case of trouble, and for possible fine-tuning.

DP compares a (sent) blip or the incoming and outgoing audio and measures the I/O delay.
From here in, it's normal ADC measures all the way.
I believe this would then only involve a "virtual, non-destructive" track-shift.
Who knows, maybe I've missed something, but shouldn't it be this simple?
Monkey

1) Input selection from the return = Output from your 'verb, comp etc.
2) Output selection as the send = DP channel insert "sends" to 'verb, comp etc. input.

DP compares a (sent) blip or the incoming and outgoing audio = Stopped (not playing) "blip calibrate" option, or DP realtime calibration where the app intelligently compares incoming with outgoing (confident

) audio on the mixer channel.

mcevilley wrote:Sounds great! Yeah, I think he's just talking about being able to use outboard processing or modules without any noticeable delay. Maybe Fibes could elaborate? C'mon Fibes, auptown is offering...

External delay = Introduced processing lag
Compensation = Well, compensation, ie. track-shift.
I hope this is what Fibes is talking about. Dunno what else it could be.

All I've done here is explain what I've already written.
Some sort of response or comment would help, as typing to myself aint as gratifying as talking (to myself).

Cheers
M

auptown · Post by **auptown** » Fri Oct 06, 2006 12:00 pm

Hey there Monkey Man,

Sorry if you felt ignored!

I did read your post and in my programmer mode was just trying to make sure that I had the full grasp of the problem before I started codin' codin' codin'. I myself posted a question about an aspect of this situation a while back, at the time I thought (incorrectly) that the buffers were part of the delay problem. I was corrected, and now I believe that the only delays com from the external equipment itself.

Might be a bit dicier in the case of external VIs, since I'm not sure quite how to pass a blip through them to figure out their delay. But there must be a way...

Meantime I'm going to try to build this beast. I just started working in the plugin arena, I have previously worked in actual DSP coding. But I have built a few plugs and although I am fumbling around quite a lot I think I can get them to do my bidding now.

Thanks for the idea, and I will keep you posted as to my progress.

Cheers

Eleventh Hour Sound · Fri Oct 06, 2006 12:26 pm

My application would be for eliminating delay on tracks that were originally MIDI being sent to any combination of internal and external sound modules and computers. For example, When I record the MIDI data from Roland eDrums, and then on playback send the MIDI track to several destinationsL a Roland TD-12 (very little latency) BFD running internally in DP (No latency because of DP's built in delay compensation) or BFD running on another computer (lots of latency) I have to duplicate the MIDI track and use the MIDI shift plug in to set the right offset for the tracks sending MIDI to the external devices...

auptown · Post by **auptown** » Fri Oct 06, 2006 12:35 pm

RecordingArts, this is certainly possible as well. In this case, would you have some audio somewhere that is aligned correctly, ie not delayed? That would give me the 2 signals that I need to compare, in order to compute the offset and clean up.

Eleventh Hour Sound · Post by **Eleventh Hour Sound** » Fri Oct 06, 2006 1:57 pm

Could you use MIDI data as your reference point?

If you wanted internal audio as a reference, I guess we could use audio coming from BFD running as an AudioUnits plug in. External audio could come from the Roland TD-12 since it's pretty low latency.

Thanks,
Vincent

acro · Post by **acro** » Sat Oct 07, 2006 4:39 am

Thank you auptown for the gracious offer!

I'd been dreaming of the same feature for quite a long time myself; after all, delay compensation/alignment have been part of hardware like the O2R, DA-88, or the Oxford desk... so we're talking about >10 years that DP hasn't caught up (no intent of starting a flame war here). The audio delay or automatic SMPTE negative offsets on all these devices worked quite nicely, too.

The overall "reference" would depend on the setup, in that the instantiation with the max. latency determines the overall amount of compensation.

In theory, MIDI latency compensation is an entirely different story. However, setting up a dummy instantiation of this hypothetical plugin in an audio aux track (ex. named "MIDI delay compensation" in your "start as new template" file...) should take care of the problem quite nicely.

auptown · Post by **auptown** » Sat Oct 07, 2006 6:44 am

Well, I'm happy to have somthing useful to provide as I figure out how work in this new software programming environment. I have a number of the issues solved already, and I have a plan sketched out, and so far I haven't found anything that would prevent this from working.

Looks like I won't have any problems finding beta testers!