Hi Martin, since you've been so kind to chime in, can I ask you a further effort? Can you please run the easy test that I described in my earlier post?

I tell you what I did step to step in case you can take the time to replicate it:

- Created a new song in DP

- Added Kontakt instrument (internally), added a "New Instrument" in the first Kontakt slot, loaded a Bass Drum sample

- Added a VEPRO Plugin and connencted it to my PC slave VEPRO Server

- Added a Kontakt instance in my PC slave, added a "New Instruments" in the first Kontakt slot, loaded the same Bass Drum sample

- Added a midi track in DP and armed it to the internal Kontakt instance

- Recorded a C3 note 127 velocity every quarter

- Create a duplicate of the midi track and armed it to the VEPRO Kontakt instance.

I'm really curious to see what are your results, because if the ACD would work as advertised, the two tracks had to stay aligned no matter the Plugin buffer number and no matter the DP buffer size settings.

Well, this is not what I experience. My VEPRO midi tracks has latency that varies whenever I change the Plugin buffers numbers (which I usually leave to "2") and/or the DP buffers (Which I usually leave at 256).

I would reeeally appreciate if you could take some time to run this test and give me your results.

Thanks in advance and kudos anyway for this brilliant piece of software that helps me on a day basis to get my workflow more productive. This little issue is just a little annoyance compared to the beauty and the stability of the program.

Arceo

I can confirm that DP does not latency compensate properly. The audiounit does however report the latency changes properly, and all other hosts with ADC pickup on this and adjust the latency accordingly. It might be an issue with DP only expecting a static latency for the plugin - not considering any changes in the latency value during runtime. This is necessary for VEPro, since the latency depends on (a) soundcard buffer size, (b) VEPro numbuffers setting.

@MS said:

I can confirm that DP does not latency compensate properly. 

Err... okay... and the solution is???

I mean, since you did not imply it in your post: can we expect a future VEPRO version that addresses this (already now known!) DP/ADC issue?

TIA

Arceo

We will have to investigate this further, but currently it looks more like a DP issue than a VEP issue.

I can confirm that DP does not delay compensate VEP 5 properly. I would like to roll back to VEP 4. Is there an easy way to do this?

@Another User said:

I can confirm that DP does not delay compensate VEP 5 properly. I would like to roll back to VEP 4. Is there an easy way to do this?

Latency compensation also doesn't work with VEP4 in DP. As I wrote earlier, it looks to be a DP issue.

I don't recall ever having a problem with VEP4 not latency compensating. Hmm this is a huge issue. I hope this gets resolved soon because right now it looks to me that the software doesn't do what it is advertised to do. 

As I wrote earlier, VEP reports latency properly to the sequencer. It does however rely upon the host sequencer being able to adjust the latency compensation of plugins dynamically. It might simply be that DP lacks this feature.

It needs to react to latency changes during playback, when changing buffer settings in the plugin, or changing latency of your soundcard. Most plugins with latency have a fixed latency, which of course is easier to compensate for, perhaps only during plugin instantiation, or a plugin scan.

Does this mean that if we don't touch our DP latency or the VEP latency, then it works?

I'm wondering becuaes it seems to be working okay here...  and I never really change my buffers..

Thanks!

J

just to add..

It's not working 100% here.. but at a low enough buffer, it works decently.. 

At a higher buffer, it's unusable..

~J

Hi Martin,

Thanks for getting involved in this. I understand your explanation of the problem. However, I can't help but feeling that this explanation is the equivalent of saying that the software is incompatible. I wouldn't be so critical if this were a minor inconvenience, however I think most musicians would say that having perfect time is not some added luxury feature, but a requirement. I also wouldn't be so critical if I was forewarned about this issue. 

Thanks for your attention. I hope this gets resolved with haste.

As a P.S. to DP users: this issue can be alleviated (albeit painstakingly) by adding a MIDI time shift plugin to each MIDI track, and shifting the timing earlier by the correct number of samples. For those of you with hundreds of tracks... have fun with that!

Are these other plugins instruments or effects?

We just did an experiment here with the Vienna Suite Convolution Reverb, which reports latency changes to DP in the exact same way as Vienna Ensemble Pro does. Here, latency compensation is updated and works as it should after a stop/play cycle, just as expected. My suspicion therefore remains, that DP doesn't respond to property change events for kAudioUnitProperty_Latency with AU instruments.

Many of us have submitted a tech note to MOTU regarding this. A fellow at MOTU named Lorne said that he will look into it.

So then if we leave the VEP server plugin at zero buffers, it should compensate correctly?

I just did a test where I set the VEP plugin latency to zero buffers, but set the MOTU hardware buffer to 1024. I then recorded the audio output of some snare drum hits coming off my slave-- both dry and running through Altiverb. Everything lined up. Changing the buffer setting to anything other than zero is what causes the problem, as Martin is suggesting.