Thread: Reworking FFT code
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Old 07-16-2012, 06:19 PM   #24
knc1
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Quote:
Originally Posted by twobob View Post
In the interim I am looking at this. http://www.lartmaker.nl/projects/fft-arm/

I'm Happy with the smallest size - we just want some results.

the code is 11 years old. I'm hoping maths hasn't moved on too much in that time.
That code spends a significant amount of its time generating the look-up tables when doing such a small fft sample.

Extract the code to generate the lookup tables, write them (the tables) to disk.
Then just mmap them in when needed since they are constant data.

If that helps, then let me know, I will lookup the objcopy magic-foo to turn the binary tables into an elf-object that you can link into the code section of the program.
Bad idea, seems that bin2c is the currently recommended way.

****** Viral Warning *******
That code carries the GPL virus. The other code I suggested is BSD licensed.
Last edited by knc1; 07-16-2012 at 06:45 PM.
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