Rodolfo Cangiotti

I am trying to generate random pitch grains which are randomly spatialized using the Ambisonics technique. In order to obtain this, briefly I have created a subpatch for the poly~ object including the sound generation unit (a simple FM synthesizer) and the spatialization unit (a kind of decomposition of the objects uploaded by ICST). It seems to works properly except for the fact that the CPU utilization increases massively (considering that each grain is also sent to a basical reverberation circuit) and doesn't allow a real time computation. Actually, I conceived this patch to be used just to render a sound sample for a musical composition (in other words, I don't properly need a real time processing), so I turn to you to ask if it is possible to render the output of a patch in Max not in real time; it could be a solution to not create clicks, silences or other artifacts in the resulting sound sample.

Waiting for your replies, I thank you in advance.

Hello all,
I am trying to generate random pitch grains which are randomly spatialized using the Ambisonics technique. In order to obtain this, briefly I have created a subpatch for the poly~ object including the sound generation unit (a simple FM synthesizer) and the spatialization unit (a kind of decomposition of the objects uploaded by ICST). It seems to works properly except for the fact that the CPU utilization increases massively (considering that each grain is also sent to a basical reverberation circuit) and doesn't allow a real time computation. Actually, I conceived this patch to be used just to render a sound sample for a musical composition (in other words, I don't properly need a real time processing), so I turn to you to ask if it is possible to render the output of a patch in Max not in real time; it could be a solution to not create clicks, silences or other artifacts in the resulting sound sample.
Waiting for your replies, I thank you in advance.


offline-rendering

There is a "non-realtime" audio driver, which should do what you want. If you need the scheduler to be synchronous to the non-realtime audio system, you have to make sure that "Scheduler in Audio Interrupt" is checked.

Thanks for reply. If it is possible, I'd like to ask you for more in depth information about non-realtime audio driver on Max: first of all, what is the "Passive Mode"? Then, what do you properly mean with the term? Do you refer to the control signal engine?

I actually don't know what "Passive Mode" is. I asked about it on this forum but never got a reply. (I might try again someday...) – however, I usually keep it unchecked and I get what I want.

The scheduler is the subsystem of Max taking care that high-priority and timed messages (typically, and with some exceptions, MIDI data and messages – not audio – coming from objects with a notion of time such as metro, delay, transport, or snapshot~) are evaluated at the proper time. The possible temporal relationships between data with different priorities (low priority, high priority and audio) are probably the most complex thing to grasp in Max. There's a great article by Joshua about it: 

https://cycling74.com/articles/event-priority-in-max-scheduler-vs-queue/

Anyway, long story short: in the usual, realtime operating mode of Max the scheduler runs in real-world time. But if you decouple the audio time from the real-world time (through the non-realtime audio driver), then you will probably want the scheduler to run at audio time (so that [metro 1000] fires once for each second of audio) rather than real-world time. For this, you need to have both Overdrive and Scheduler in Audio Interrupt checked.

The scheduler is the subsystem of Max taking care that high-priority and timed messages (typically, and with some exceptions, MIDI data and messages – not audio – coming from objects with a notion of time such as metro, delay, transport, or snapshot~) are evaluated at the proper time. The possible temporal relationships between data with different priorities (low priority, high priority and audio) are probably the most complex thing to grasp in Max. There's a great article by Joshua about it: https://cycling74.com/articles/event-priority-in-max-scheduler-vs-queue/

It is a really clear explaination. Thank you so much once again.

Offline Rendering