IPB

Welcome Guest ( Log In | Register )

Sparse Fast Fourier Transform, The faster-than-fast Fourier transform
16 Hz
post Feb 10 2012, 19:55
Post #1





Group: Members
Posts: 6
Joined: 27-November 09
From: Argentina
Member No.: 75344



Hello.
I don't know if this topic was already mentioned here (I wasn't able to find it).

Somebody here could find it interesting:

MIT news article: The faster-than-fast Fourier transform

sFFT web page: sFFT: Sparse Fast Fourier Transform

Best regards.

Omar
Go to the top of the page
+Quote Post
 
Start new topic
Replies
m45t3r
post Sep 23 2012, 00:25
Post #2





Group: Members
Posts: 22
Joined: 14-January 12
Member No.: 96431



QUOTE (saratoga @ Sep 22 2012, 13:30) *
QUOTE (quackalist @ Sep 22 2012, 11:59) *
I'm just wondering if any power savings are expected to be significant in typical consumer uses...phones, tablets etc or in more general scientific and engineering computation?


Probably not. The FFT isn't really the bottleneck in anything consumers do that I can think of. Yes, video and audio codecs often use them, but they're usually only a small part of the entire codec time, and for these applications approximations to the FFT are already available. I didn't look at the math but my guess is that something like this becomes more useful for very large FFT sizes or for more then 1 or 2 dimensional transforms.

Science, engineering and maybe telcom applications might be a completely different story though.

Well, on Rockbox at least the FFT part of decoding can take up to 50% of CPU time (http://www.rockbox.org/wiki/FasterMDCT). It's true that audio decoding is not really that much CPU intensive, but video encoding/decoding probably is another mater.
Go to the top of the page
+Quote Post
saratoga
post Sep 23 2012, 00:30
Post #3





Group: Members
Posts: 5119
Joined: 2-September 02
Member No.: 3264



QUOTE (m45t3r @ Sep 22 2012, 19:25) *
Well, on Rockbox at least the FFT part of decoding can take up to 50% of CPU time (http://www.rockbox.org/wiki/FasterMDCT).


Well it did until stripwax, mt and I rewrote it using a modern, efficient split radix FFT. Now its quite a bit faster.

QUOTE (m45t3r @ Sep 22 2012, 19:25) *
It's true that audio decoding is not really that much CPU intensive, but video encoding/decoding probably is another mater.


Sure, but the DCT is usually only a pretty small portion of that. And of course you can already use approximations if you want (though usually people don't since its not very slow to begin with).
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 27th November 2014 - 18:36