Questions tagged [overlap-add]

Efficient way to evaluate the discrete convolution of a very long signal with a finite impulse response (FIR) filter. The concept is to divide the problem into multiple convolutions of the impulse response of FIR filter with short segments of the very long signal.

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Overlap Add - which length to use?

I am doing realtime audio. Let's say I have a signal $x(n)$ which is passed in blocks of 512 (siobuffer) to the program filter/FFT method. Within this block I want to convolve the signal with the ...
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2answers
51 views

Overlapping in real time fourier transform?

I have an algorithm and I need to record audio and perform short time Fourier transform to obtain which frequency is the most common. I am using a Hanning window to try and reduce spectral leakage as ...
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Overlap-Add for 2-dimensional windows

I understand how overlap-add works for 1-dimensional signals, but I need to do something similar in 2 dimensions. The paper at this link covers the 1D case pretty well (see p29): http://edoc.mpg.de/...
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144 views

Overlap/add time-domain audio frames: How does normalization/scaling work with overlap greater than 50%?

I am attempting to overlap-add time-domain audio frames in a real-time context (with a continuous stream of data coming-in). Each frames consist of 1024 samples and have been previously "Hann" ...
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0answers
57 views

Can Reassigned-STFT be an invertible transform? Algorithm for “Signal => Reassigned-STFT => masking => Reassigned-ISTFT => Output signal”

It is well known in DSP that this is a successful method to modify audio signals: Signal => STFT => masking => ISTFT => Output signal For example, ...
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75 views

Perform overlap add with available FFT size smaller than filter coefficients

I would like to process 12 to 20 seconds of incoming audio at a sample rate of 44100. I must process this audio in real time in an STM embedded kit (perhaps also an Android Smartphone). I'm trying to ...
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2answers
280 views

Linear Convolution in DSP and Hann window

My understanding is that when dealing with discrete finite sequences, convolution done thru FFT is circular. To obtain linear convolution, one would pad the input with zeros up some appropriate length....
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1answer
157 views

Spectral Subtraction python implementation error

I am trying to implement Spectral subtraction in python. I am new to DSP. I used this article as reference and below code is what I can come up with. Of course I did not get the expected output. I ...
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2answers
69 views

How to detect a long signal inside an even longer one?

I'm trying to detect a long pattern inside a long recorded audio. In order to do so I am implementing a matched filter in time by performing a FIR filtering using the coefficients of my pattern ...