jayrope

I am not really under-equipped regarding CPU power, nevertheless to work efficiently from the start and to prepare root patches for later [poly~] use i wonder:

Does save CPU to downgrade the quality of signal only used to drive displays, LFOs and such?

Given this could be saving, which method would you prefer to use? Would you use [degrade~] at 8-bit/original sample rate (or 44.1KHz)?

Thank you very much for passing on any hints!

Given this could be saving, which method would you prefer to use? Would you use [degrade~] at 8-bit/original sample rate (or 44.1KHz)?
Or rather [downsamp~]? If so, why?

saving-cpu-by-degrading-signal-used-only-for-displays

As far as I am aware using downsamp~ or degrade~ will not save you any CPU cycles at all, because you are adding signal objects you will in fact use more CPU cycles.

I am assuming that the signal coming out of these objects is still represented by 32 bits even though it may sound like it's lower. As a general rule max uses 32-bit to represent all of it's signals. [please correct me if I misunderstand this]

to lower the CPU usage you can lower the sample rate over all or insert the part of the patch you wish to resample into a poly~ object with the appropriate down-sampling arguments.

You will get better savings by not using audio rate connections for things that don't need it. I quite often use non signal rate lfo's for example.

If you are not pushed for power then don't worry about it - REALLY! Just patch away and streamline later if you run into problems.

Actually my question was related to building an LFO module for 6 or more different waveforms, so i'd be very curios, how you achieve to produce lfo waveforms withotu the use of [cycle~], [phasor~] or [triangle~]!

p.s. Alex: She had caught me on Facebook meanwhile! The world is small.

Janek
p.s. Alex: She had caught me on Facebook meanwhile! The world is small.


Well you could use counter to get saw or ramp shapes and experiment with sin to get sine shapes or you could use tables as in the example i've included below. I drew the wave-shapes into tables by hand though you could do it much more accurately using the appropriate maths.

I posted a javascript-based lfo awhile ago:

https://cycling74.com/forums/index.php?t=msg&goto=112728&rid=116&S=783db9e712a948bf43c403d1a3feb4fd#msg_112728

I posted a javascript-based lfo awhile ago:
https://cycling74.com/forums/index.php?t=msg&goto=112728&rid=116&S=783db9e712a948bf43c403d1a3feb4fd#msg_112728

On Nov 26, 2008, at 1:52 PM, jayrope wrote:

> Actually my question was related to building an LFO module for 6 or 

> more different waveforms, so i'd be very curios, how you achieve to 

> produce lfo waveforms withotu the use of [cycle~], [phasor~] or 

If you are really talking about LFOs that don't need to run too fast, 

you might want to take a look at the "Gesture Recorder" example on my 

arbitrary waveshapes of LFO to be played back.

> Actually my question was related to building an LFO module for 6 or  
> more different waveforms, so i'd be very curios, how you achieve to  
> produce lfo waveforms withotu the use of [cycle~], [phasor~] or  
> [triangle~]!

If you are really talking about LFOs that don't need to run too fast,  
you might want to take a look at the "Gesture Recorder" example on my  
Max page: http://www.xfade.com/max  It uses tables to allow for  
arbitrary waveshapes of LFO to be played back.

Chris Muir
cbm@well.com	
http://www.xfade.com

Some time ago I saw a post by Roman in which he ran his signal meter objects through poly~'s and would downsample by a factor of 8-ish.

On today's machines that can be performing much more demanding tasks in MSP, I'm not sure it's that big of a help if you're already maxing out your CPU.

However, now that poly~ can run its separate instances on parallel cpu cores, it could save some cycles to make a poly-loaded level metering patch using other msp objects and then run your own meters out of that using outlets that switch depending on the poly instance no.'s.

regarding the downsampling method i am confused now, since John reports, that downsampling would instead increase the CPU load for it's inherent increase in cords between signal processing objects.

Is there a formula of CPU-load, which is based on the total amount of cords/connections between signal processing objects?

I think i need to understand more in detail, how MSP works, and would be most grateful for hints pointing in the right direction of reading matter (besides the references and tutorials of course)

If you downsample a patch in poly~, you can save some CPU, i believe, but using degrade~ to downsample is merely for auditory purposes, not CPU savings.

Also, speaking of "gesture" recording, there's a decent example of that in Livid Looper 

http://lividinstruments.com/support_downloads.php#looper

using seq~ and pattrstorage (you could use pattrhub, too.)

Basically, I use seq~ to record messages that can be sent to pattrhub or pattrstorage.

Also, speaking of "gesture" recording, there's a decent example of that in Livid Looper http://lividinstruments.com/support_downloads.php#looper
using seq~ and pattrstorage (you could use pattrhub, too.)
Basically, I use seq~ to record messages that can be sent to pattrhub or pattrstorage.

Quote: pnyboer wrote on Thu, 27 November 2008 12:18

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> If you downsample a patch in poly~, you can save some CPU, i believe, but using degrade~ to downsample is merely for auditory purposes, not CPU savings.

That's it. Downsampling a patch in poly~ is kind of a special case in MSP.. normally every msp object is running at the sampling rate set in the DSP settings. Poly~ gives the option of actually running everything within its patch at a downsampled rate, which makes it still useful for control signals or most metering calculations. (or even for aesthetic reasons.. :)

Using downsamp~ or degrade~ performs a downsampling algorithm, but still passes the signal through at the same sampling rate as any other object in the DSP chain. They're analogous to bitcrusher-type plugins used in music production.

Quote: pnyboer wrote on Thu, 27 November 2008 12:18
----------------------------------------------------
> If you downsample a patch in poly~, you can save some CPU, i believe, but using degrade~ to downsample is merely for auditory purposes, not CPU savings.
----------------------------------------------------

Using downsamp~ or degrade~ performs a downsampling algorithm, but still passes the signal through at the same sampling rate as any other object in the DSP chain. They're analogous to bitcrusher-type plugins used in music production.


I tried a combination of a repeating line and cos for a sine wave with no luck,

what is the difference between cos and cos~

I tried a combination of a repeating line and cos for a sine wave with no luck,
what is the difference between cos and cos~


Saving CPU by degrading signal used only for displays