Search found 162 matches

by Piotr Grochowski
Thu Aug 09, 2018 4:15 pm
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Re: Internals of Equalization

steve wrote:
Thu Aug 09, 2018 2:16 pm
Are you just trying to waste my time?
HELL NO!!!
steve wrote:
Thu Aug 09, 2018 2:16 pm
I did not say anything about Android.
I admit you didn't know that my PC has broken system beyond repair.
by Piotr Grochowski
Thu Aug 09, 2018 1:20 pm
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Re: Internals of Equalization

steve wrote:
Thu Aug 09, 2018 11:56 am
The source code is available, so you are free to experiment if you wish to do so.
Are you sure I can run the source code in Android?
by Piotr Grochowski
Thu Aug 09, 2018 8:14 am
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Re: Internals of Equalization

The choice of Window function is in most cases, a compromise between different properties, such as the frequency resolution, dynamic range, SNR losses, computational efficiency ... More information about window functions on Wikipedia: https://en.wikipedia.org/wiki/Window_function Indeed. But have y...
by Piotr Grochowski
Wed Aug 08, 2018 7:31 pm
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Re: Internals of Equalization

You don't need to be a freakin programmer to read the comments at the top of the file. \class EffectEqualization \brief An Effect that modifies volume in different frequency bands. Performs filtering, using an FFT to do a FIR filter. It lets the user draw an arbitrary envelope (using the same envel...
by Piotr Grochowski
Wed Aug 08, 2018 10:22 am
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Re: Internals of Equalization

I'm not a freakin' programmer.
by Piotr Grochowski
Sat Aug 04, 2018 4:34 pm
Forum: Audio Processing
Topic: Internals of Equalization
Replies: 10
Views: 223

Internals of Equalization

My guess is that Equalization works like this: 1. Do inverse fast fourier transform on the frequency response. 2. Window it with an unknown windowing function. 3. Convolute with every sample. But what windowing function does it use? Here are some examples: 1. Rectangle 2. Triangle 3. Parzen 4. Sine ...
by Piotr Grochowski
Mon Jul 30, 2018 10:38 am
Forum: Audio Processing
Topic: Time scaling curiosity
Replies: 25
Views: 707

Re: Time scaling curiosity

On the subject of time scale/pitch shift, some sample–level procedures can cause an effect that pitch shifts some sounds. For example squaring all samples, for a centered sine wave, produces a quieter, double frequency, non–centered sine wave. However on a combination of 2 sine waves it distorts by ...
by Piotr Grochowski
Thu Jul 12, 2018 4:54 pm
Forum: Audio Processing
Topic: FFT windowing time and frequency resolution
Replies: 8
Views: 162

Re: FFT windowing time and frequency resolution

OK, I think I see what you are saying. Are you asking if window types that give less smearing in the frequency domain, give more smearing in the time domain, and vice verse? The answer is that the window type has little effect on the time resolution. It's the size of the window that has the major e...
by Piotr Grochowski
Thu Jul 12, 2018 3:48 pm
Forum: Audio Processing
Topic: FFT windowing time and frequency resolution
Replies: 8
Views: 162

Re: FFT windowing time and frequency resolution

Note that it talks about lower frequency resolution, but nothing about the higher time resolution. See higher up the same page: Time Smearing and Frequency Smearing Clearly such an issue will be reduced with a window that concentrates itself near the middle more! Let's say that height there is the ...
by Piotr Grochowski
Thu Jul 12, 2018 3:00 pm
Forum: Audio Processing
Topic: FFT windowing time and frequency resolution
Replies: 8
Views: 162

Re: FFT windowing time and frequency resolution

Are you referring to something in the Audacity manual? If so, please add a link to the relevant page of the on-line manual and quote the exact text so that I can find it on the page. Yes. https://manual.audacityteam.org/man/spectrogram_view.html#types "Changing to the Blackman-Harris Window Type ge...