external MIDI instrument timing

[magicd]

Edited for accuracy.


See post for accurate info:

viewtopic.php?f=26&t=62230&start=30#p531139

Dave

[Kurt Cowling]

And... Make sure there are no latency inducing plugins on the Master Fader. This always makes MIDI record late in my experience.

[bayswater]

Also, see this, second post.

viewtopic.php?f=1&t=62235

[dewdman42]

Who is making it it complicated? LPX handles this exact situation very simply with an external inst plugin. Dp does not handle it simply with a plugin but you can get the job done by fiddling with the MIDI time shift plugin,

I understand the difference between inside and outside. The timing for external instruments is subject to delays and MIDI timestamping is not always available but even when it is it does not help in this situation of sending MIDI to a synth and receiving back audio.

[magicd]

LPX handles this exact situation very simply with an external inst plugin. Dp does not handle it simply with a plugin but you can get the job done by fiddling with the MIDI time shift plugin,

You don't need a plug-in to get proper MIDI timing in DP. You just need to do a one time calibration.

Dave

[dewdman42]

Regarding the audio fine tuning, I am going to calibrate my studio for basic audio path correctness using that feature for sure, but I do not feel that is a practical solution for handling external synths, which as you say are inconsistent especially if you have more then one. I don't want to have to recalibrate every time I switch to a different external synth. Also this all applies to using external audio software with IAC and jackosx. There will be up to 10ms of latency there, with a reasonable buffer setting, but totally different then the audio hardware so the audio fine tuning would need to recalibrated for that situation too. And it's reasonable to assume that if I changed the global setting to handle MIDI external devices, the audio playback timing would be off for tracking vocals and other audio tracks that don't involve MIDI, maybe. IMHO the audio fine tuning should be a set once and leave it alone setting that simply compensates for any unaccounted for latency in the basic A/D audio path. The MIDI time shift can be used to compensate for individual tracks being sent to different external gear or to external software within the computer. A dedicated ext inst plugin could be interesting to make it more seamless like the one was provided in 9.1 for FX.

[dewdman42]

And... Make sure there are no latency inducing plugins on the Master Fader. This always makes MIDI record late in my experience.

That's interesting, I think that is most likely related to the thing HC pointed out earlier.

[Robert Randolph]

Regarding the audio fine tuning, I am going to calibrate my studio for basic audio path correctness using that feature for sure, but I do not feel that is a practical solution for handling external synths, which as you say are inconsistent especially if you have more then one. I don't want to have to recalibrate every time I switch to a different external synth. Also this all applies to using external audio software with IAC and jackosx. There will be up to 10ms of latency there, with a reasonable buffer setting, but totally different then the audio hardware so the audio fine tuning would need to recalibrated for that situation too. And it's reasonable to assume that if I changed the global setting to handle MIDI external devices, the audio playback timing would be off for tracking vocals and other audio tracks that don't involve MIDI, maybe. IMHO the audio fine tuning should be a set once and leave it alone setting that simply compensates for any unaccounted for latency in the basic A/D audio path. The MIDI time shift can be used to compensate for individual tracks being sent to different external gear or to external software within the computer. A dedicated ext inst plugin could be interesting to make it more seamless like the one was provided in 9.1 for FX.

So it would appear that the main benefit of the idea of an external synth plug-in is that it would allow you to account for different response times of various equipment, not necessarily MIDI/audio latency inherent to the interface being used.

The fine tuning compensates quite well for the interface latency (both audio and MIDI), but it won't take in to account response times and latency of the hardware instruments themselves.

I don't really have a take on the topic other than clarifying what seems to be being said between the lines. DP's fine tuning works quite well for me when using hardware synths, but I can certainly see the benefit of a dedicated plug-in now.

[dewdman42]

also for the case of using external software instruments within the same computer which will be different then the normal hardware audio D/A-A/D path......ie..... jackOSX or soundflower setups.

basically any situation where the amount of latency between sending the MIDI event and receiving the audio back into DP could be different then a simple hardware audio loopback test.

Another nice thing about an ext inst plugin is that you could put it in a v-rack like any other software instrument. It would receive MIDI there, and return audio, just like any VI does...and the latency dial could be used to configure how much latency it requires to go externally and do that, which will effect PDC in the right way.

In principle this is what the new FX hardware insert plugin does for audio inserts...it provides a seamless way to insert it into a track and have the latency get factored into PDC calculations, etc.

I believe the audio fine tuning does not change how early the MIDI gets sent, like PDC does. Rather the record timing would effect where on the track the incoming audio gets placed when it comes in... you cannot make the audio come in any earlier then it actually does, but you can cause DP to register it on the track at an earlier point on the timeline (globally)....thus compensating for delays. This can solve the problem for sure, but the question is whether this factor will always be consistent in all recording situations.

Like recording vocals...

vs

sending MIDI and recording the resulting audio from different external devices which take more or less time to do it....

vs....

sending MIDI over IAC to another mac program that produces its own unique latency and receiving the audio via soundflower or jack that add 10ms latency....

etc..

[David Polich]

You cannot guarantee MIDI delay compensation for all possible external MIDI instruments across the board. That is because every single piece of MIDI-equipped hardware known to man exhibits different degrees of latency between MIDI received and the tone generator (the part that "makes sound") responding. This is internal to the synth or drum machine or whatever you're triggering. It has zero to do with DP. If you are triggering more than one external MIDI module, how could you adjust for their delayed MIDI response with a global setting? You can't because you have two different modules with different response times.

MIDI itself is a slow protocol. Its basic speed has not been improved on in over 20 years.

[dewdman42]

exactly

in theory you can set the playback offset a bit later...and it will probably be close enough to satisfy many people for most things...basically the plackback of all audio tracks (and I guess instrument output?) will be delayed by that amount, enough that it should kinda line up with what MIDI is sending in true real time. But there are a lot of unique situations that won't match a one size fits all setting for that.

I have been trying to mess around with the audio fine tuning thing this afternoon...I think it might be broken in 9.1 actually, there is another thread about that in the criticism section.

[Robert Randolph]

You cannot guarantee MIDI delay compensation for all possible external MIDI instruments across the board. That is because every single piece of MIDI-equipped hardware known to man exhibits different degrees of latency between MIDI received and the tone generator (the part that "makes sound") responding. This is internal to the synth or drum machine or whatever you're triggering. It has zero to do with DP. If you are triggering more than one external MIDI module, how could you adjust for their delayed MIDI response with a global setting? You can't because you have two different modules with different response times.

MIDI itself is a slow protocol. Its basic speed has not been improved on in over 20 years.

That is the point that he's been making, and why the suggestion of a per-track solution (plug-in) was made.

At this point I can definitely see the use of it, but I've also made it this far without it so...

[dewdman42]

Another thing that's nagging me in the back of my mind, setting the playback offset later to accommodate external synths essentially gives more latency to everything else. That would make VI's less responsive in the same way raising the buffer size would, without the advantages of raising the buffer size. and if you're tracking any vocals or guitars through the Mixer then them too. The advantage would be that while you're actually playing the MIDI part for the external synth, the external sound itself that is being routed back through the mixer would line up with everything else that has been delayed to match it, presuming the global playback offset value is close enough to reasonably match the delay for each external synth.

Conversely if playback offset is zero then VI's will be as responsive as possible, but while you're actually playing the external synth part, the sounds from the synth would be coming back into dp a little late, which might cause you to rush the parts. You'd want to direct monitor ext synth parts while recording them that way so that you don't hear them delayed compared to all the other audio while recording it.

[magicd]

Edited for accuracy.


See post for accurate info:

viewtopic.php?f=26&t=62230&start=30#p531139

Dave

[RROY]

Part of my concern as I stated in the related thread on Audio I/O timing was the huge difference between DP 9.02 and 9.1. An offset of 250 in DP 9.02 got me accurate results, whereas in 9.1 I had to increase the offset to 1250 to get accurate placement. So if you are recording external MIDI devices to audio in DP 9.1 and have not adjusted the offset accordingly those tracks will now be substantially late. And if you go back to 9.02 you will have to change the offset back to what worked before. But why are they different and why was there no notification of this change?