asynchronous transmittion
how we can identify the stop and the start bit from a signal? ...
signal-processing
C++ Sound Processing
I'm looking for a library that could be used to manipulate audio files. Essentially what I would like to do is: Load an MP3/WAV file Get a 15 second clip of the file Overlay another MP3/WAV file ontop of it Render as a new MP3/WAV file ...
How to make MFCC algorithm?
I wanna make the Mel-Frequency Cepstrum Algorithm but there are some things that I don't understand. After FTT is done we need to "Map the powers of the spectrum obtained above onto the mel scale, using triangular overlapping windows." I know how to calculate the triangles and I also know how to pass to mel scale. I simply don't know w...
How to compute ifft from fft?
Hello, I've done a fft to get fundamental frequency in real time and to implement high and low pass filters. Now I want to be able to record to a .wav file after I apply a filter. First I'll have to invert the fft and that is my question. What are the steps to do this? I use the FFT defined in this project. Here is the code for it: ...
C# library to do fft and ifft?
Hello, is there a free c# library to do the fast fourier transform and its inverse? ...
When calculating the fast fourier tranform..?
If we get the sound from microphone with two channels, to calculate the frequency spectrum we: calculate the fast fourier transform of all the data input? calculate the fast fourier transform of each left and right channel and then make a average of both? calculate the fast fourier transform of each left and right channel and get the b...
Cross platform audio analysis library
I'm looking for a cross-platform library that allows me to analyze the waveform of a sound file. It needs to be able to at least have the ability to query the amplitude for a given sample, and it would be nice if it could do frequency detection. ...
Entertaining a baby with VB.NET
I would like to write a little application in VB.NET that will detect a baby's cry. How would I get started with such an application? ...
Basic DSP question
I'm new to DSP programming, and I'm wondering how best to carry out the seemingly basic operation of level adujustment. Say I have an 8 bit number that represents the amplitude I want a signal to be in 256 steps. I have a set of 16 bit numbers representing the signal data. What's the best way to go about scaling the signal data based ...
How to make a Simple FIR Filter using Matlab?
How can I make a simple low-pass FIR filter using Matlab (without using the built-in function) ? Problem example: Implement a FIR LPF with cut-off frequency 250Hz it may also be necessary that, sampling freq is given... Solution attempt or what I already know: x = [...] -> input signal A = 1; -> Since this is FIR B = [?????] y = fi...
Any good C/C++ DSP library?
Which DSP library in C/C++ would you recommend? I will need it for real-time embedded systems. It'd be great to have sound signal processing accompany too, but not a mandatory. If you have knowledge of any DSP library, please kindly share. Thank you! ...
MATLAB: filter noisy EKG signal
What is the best filter to use to remove noise from an ECG signal with matlab? ...
Complex numbers: fast cartesian to polar conversion
Hi. I'm looking for a fast way to turn an array of complex numbers into polar representation. E.g, given a complex number X I want to turn it into polar representation like this: Q.phase = atan2 (X.imag / X.real); Q.magniude = sqrt (X.imag * X.imag + X.real * X.real); I need to do this conversion around 400 thousand times pe...
MATLAB: Apply a low-pass or high-pass filter to an array
Hi, is there an easy way to apply a low-pass or high-pass filter to an array in MATLAB? I'm a bit overwhelmed by MATLABs power (or the complexity of mathematics?) and need an easy function or some guidance as I couldn't figure it out from the documentation or searching the web. ...
Which time-frequency coefficients does the Wavelet transform compute?
The Fast Fourier Transform takes O(N log N) operations, while the Fast Wavelet Transform takes O(N). But what, specifically, does the FWT compute? Although they are often compared, it seems like the FFT and FWT are apples and oranges. As I understand it, a more appropriate comparison would be the STFT (FFTs of small chunks over time) ...
Digital Sound Processing in C# (and possibly SilverLight)
Hi, I need to do some basic and non basic DSP programming in C#. At its core, it includes the generation of a sin wave deciding its frequency in Hertz. Then I'd like to Frequency Modulate it and maybe filter it. Can you suggest any library to help me? Ideally this should also work in a SilverLight environment, as my aim is to showcase a...
DSP Algorithms Book
I'm looking for a book similar to "Introduction to Algorithms" by Thomas Cormen geared towards DSP algorithms. Is there anything as thorough as Cormen on the DSP market? EDIT I should say I'm looking for a book that's analogous to The Joy of Cooking. ...
Cross-correlation coefficient
I have two waveforms in the time domain, of which I need to measure the cross-correlation coefficient in MATLAB. I have tried max(abs(xcorr(m,n,'coeff'))) but it doesn't seem to be working properly. Also I need to measure the cross correlation coefficient for different sections of the waveform, e.g. measure the cross correlation coeffic...
.NET Library to Identify Pitches
I'd like to write a simple program(preferably in C#) to which I sing a pitch using a mic and the program identifies to which musical note that pitch corresponds. Thank you very much for your prompt responses. I clarify: I'd like a (preferably .NET) library that would identify the notes I sing. I'd like that such a library: Identifi...
resampling, interpolating matrix
I'm trying to interpolate some data for the purpose of plotting. For instance, given N data points, I'd like to be able to generate a "smooth" plot, made up of 10*N or so interpolated data points. My approach is to generate an N-by-10*N matrix and compute the inner product the original vector and the matrix I generated, yielding a 1-by-...