Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Martin Braun (CEL)
On Thu, Oct 17, 2013 at 05:17:45PM +0200, Sylvain Munaut wrote: > Hi, > > > You're right, but in this case the input was already real and the > > "channel" doesn't modify the phase. So it's OK--the 'correct' thing > > would be to do a real FFT. > > Huh ? Erm, yep :) My apology. I was assuming yo

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Sylvain Munaut
Hi, > You're right, but in this case the input was already real and the > "channel" doesn't modify the phase. So it's OK--the 'correct' thing > would be to do a real FFT. Huh ? To make sure I actually ran a quick python test before posting : In [13]: ifft([x.real for x in fft([1,2,3,4])]) Out[1

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Marcus D. Leech
On 10/17/2013 10:52 AM, Martin Braun (CEL) wrote: On Thu, Oct 17, 2013 at 04:44:00PM +0200, Sylvain Munaut wrote: http://img844.imageshack.us/img844/5910/s2i3.png I'm not convinced by the way you handle the complex part of the FFT result ... You can't just drop it, it's needed for the reconstr

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Martin Braun (CEL)
On Thu, Oct 17, 2013 at 04:44:00PM +0200, Sylvain Munaut wrote: > > http://img844.imageshack.us/img844/5910/s2i3.png > > I'm not convinced by the way you handle the complex part of the FFT result ... > > You can't just drop it, it's needed for the reconstruction ... You're right, but in this cas

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Sylvain Munaut
> http://img844.imageshack.us/img844/5910/s2i3.png I'm not convinced by the way you handle the complex part of the FFT result ... You can't just drop it, it's needed for the reconstruction ... Cheers, Sylvain ___ Discuss-gnuradio mailing list Di

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Martin Braun (CEL)
On Thu, Oct 17, 2013 at 11:13:14AM -0300, Gui Ritter wrote: > I'm new to Pastebin, and I couldn't find an option to upload images, so I used > ImageShack instead. That's fine :) Have you tried a boxcar window? MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL)

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Gui Ritter
I'm new to Pastebin, and I couldn't find an option to upload images, so I used ImageShack instead. http://img844.imageshack.us/img844/5910/s2i3.png ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https

Re: [Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-17 Thread Martin Braun (CEL)
On Wed, Oct 16, 2013 at 07:01:31PM -0300, Gui Ritter wrote: > Sorry, forgot the attachment. GR 3.7 won't open this. Can you pastebin a screenshot? MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Buil

[Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-16 Thread Gui Ritter
Sorry, forgot the attachment. fft test.grc Description: Binary data ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gn

[Discuss-gnuradio] Retrieving audio after FFT and IFFT

2013-10-16 Thread Gui Ritter
Hi everyone. I'm trying to pass an audio file through FFT and IFFT, and the resulting audio is being distorted. I searched about it and I only found this link: http://lists.gnu.org/archive/html/discuss-gnuradio/2012-10/msg00111.html I did as suggested and divided the signal by the FFT size after t