Page 2 of 2
Re: Help with green FFT
Posted: Thu Dec 31, 2015 3:34 pm
by Youlean
I made some progress. Here is the test example.
Now tell me how do you want to put out FFT for use in streams. Do you want mem out, or better mem address?
One thing is not clear to me yet. Let's say that we have audio that is 10240 sample long and I want to get 1024 window FFT, if I want to get stream FFT should I compute FFT on every sample which leads to 10240 computations, or every 1024 sample which leads to 10 computations?
BTW happy new year to everyone!
Re: DLL Stream FFT (Finally some progress)
Posted: Sun Feb 07, 2016 11:34 pm
by RJHollins
Found this thread ...
In researching a project idea, I'm understanding that FFT may be the ticket to capture a 'snapshot' of an audio source frequency response.
I'm just wading into this this and searching the forum for possible examples.
Wondering if this example has developed further ?
Re: DLL Stream FFT (Finally some progress)
Posted: Sun Feb 07, 2016 11:41 pm
by Youlean
Yes, I had made: stream -> FFT -> iFFT-> stream in dll, but I had problem with FFT overlap, I couldn't get it working properly, so I was getting glitches, then I paused development as it was just fun project...
BTW CPU usage was 10 times less than stream FFT in Flowstone...
Re: DLL Stream FFT (Finally some progress)
Posted: Mon Feb 08, 2016 2:53 am
by martinvicanek
Very interesting, Youlean! I have to catch up on this when I am at my computer again.
Re: Help with green FFT
Posted: Mon Feb 08, 2016 4:51 pm
by martinvicanek
Youlean wrote:I made some progress. Here is the test example.
Now tell me how do you want to put out FFT for use in streams. Do you want mem out, or better mem address?
One thing is not clear to me yet. Let's say that we have audio that is 10240 sample long and I want to get 1024 window FFT, if I want to get stream FFT should I compute FFT on every sample which leads to 10240 computations, or every 1024 sample which leads to 10 computations?
BTW happy new year to everyone!
You would typically process (adjacent, often overlapping) blocks of 1024 samples - or whatever FFT size.
I would be interested to see if mem could be passed without the notorious crashes in this case?
Re: DLL Stream FFT (Finally some progress)
Posted: Mon Feb 08, 2016 7:06 pm
by Youlean
Thanks. I dont know how to do overlap... That is the problem... Can you make asm code that will take adress from array and to have one input to select position from array, and to have output that will display value from that position?