solarlexus

A few questions regarding jit.fft & external dev...

1. In the Jitter API on the Twiki, there appears to be only one example of using other jitter objects while creating jitter externals (QT-movie.)

I did some digging and found the thread (Jitter-Dev: using jitter gl objects in c) helpful because it explains how to load other jitter objects. However, I am having trouble with the basics I guess-I just want to send a matrix into my external, run a one dim FFT, and send out a matrix containing the result. An example showing the use of any other standard jitter MOP object within an external would be sufficient i think...can anyone point me in the right direction?

2. Facing the issues in [item 1] I decided to create an external using the Altivec Framework on my MBP - 2.4GHz / 4 GB ram - worked fine but I got to thinking maybe the memory is better allocated in jit.fft for MAX or some machines can't run Altivec so it's better for cross platforms to use jit.fft?

3. I have read "The Scientist and Engineer's Guide to Digital Signal Processing" (great reference btw - bare-bones pseudo-code examples are helpful in understanding the algorithms.) So, my question here is, is jit.fft "optimized" in some way? Does jit.fft do anything special performance wise? I am guessing it uses the parallel utility if applicable/available.

4. So obviously i am trying to do some audio analysis I am not a computer scientist by any means but wondering about alternative approaches to non-real time signal analysis. I am trying to get a better understanding of phase relationships and transients by using overlapped windowed frames->jit.fft->scanwrap->one-huge matrix for viewing in a jit.pwindow - suffice to say - works ok but what if I had a separate application running (an engine of sorts) that would do all of the data processing in the background and return a file when the job is done?) This is possibly a utilized method? Anyone have any advice on processing large amounts of data in a non-cluster environment? (I do understand the trade-offs b/t spectrum frame size & overlapping & and the resultant amount of gigaflops.) Is it possible to make a max/msp/jitter application that runs in the background for this type of implementation?

This is my first post so apologies for all of the chr$. Any advice or direction would be greatly appreciated. s. lexus.

I did some digging and found the thread (Jitter-Dev: using jitter gl objects in c) helpful because it explains how to load other jitter objects.  However, I am having trouble with the basics I guess-I just want to send a matrix into my external, run a one dim FFT, and send out a matrix containing the result.  An example showing the use of any other standard jitter MOP object within an external would be sufficient i think...can anyone point me in the right direction?

3. I have read "The Scientist and Engineer's Guide to Digital Signal Processing" (great reference btw - bare-bones pseudo-code examples are helpful in understanding the algorithms.)  So, my question here is, is jit.fft "optimized" in some way? Does jit.fft do anything special performance wise?  I am guessing it uses the parallel utility if applicable/available.

4. So obviously i am trying to do some audio analysis   I am not a computer scientist by any means but wondering about alternative approaches to non-real time signal analysis.  I am trying to get a better understanding of phase relationships and transients by using overlapped windowed frames->jit.fft->scanwrap->one-huge matrix for viewing in a jit.pwindow - suffice  to say - works ok but what if I had a separate application running (an engine of sorts) that would do all of the data processing in the background and return a file when the job is done?)  This is possibly a utilized method? Anyone have any advice on processing large amounts of data in a non-cluster environment? (I do understand the trade-offs b/t spectrum frame size & overlapping & and the resultant amount of gigaflops.) Is it possible to make a max/msp/jitter application that runs in the background for this type of implementation?

This is my first post so apologies for all of the chr$. Any advice or direction would be greatly appreciated. s. lexus.


jit-fftexternalti-vec

Well, for the sake of the forum I will reply to my own post:

I ended up pursuing the straight-up Altivec route and the performance is astonishing.

Does anyone know if Altivec only works on Mac and if so, is there an alternative SIMD "framework" for Windows?

jit.fft+extern/alti-vec