I'm looking at working with a neuroscience team next year. Some of the applications will involve signal processing, image processing, and data-mining. (I do know there will be some MATLAB work, but otherwise, much is left uncharted.) What development experiences have you had in these areas and what techniques, domain-specific terms, met...
Hi have made one source in python for get fundamental frequecys from audio files, i want use this for get tones from DTMF audios ! but how get the low tones from the audio? thks!! ...
I have a real vector time series x of length T and a filter h of length t << T. h is a filter in fourier space, real and symmetric. It is approximately 1/f. I would like to filter x with h to get y. Suppose t == T and FFT's of length T could fit into memory (neither of which are true). To get my filtered x in python, I would do: impor...
There are a lot of audio-resampling libraries available. My favorite in Secret Rabbit Code. Audio resamplers keep the correct frequency of the resampled signals, so a 4KHz sine in the source, will remain a 4KHz sine in the destination. This time, however, I need to resample a sampled IF/RF signal. The sampled signal contains data orig...
How can I convert baseband sampled signal from real-valued samples to complex-valued samples (real,imaginary) and vice-versa. My samples are integers, and I'm looking for a fast (but accurate) conversion algorithms. A C++ sample code (real, not complex ;-) would be more than welcome. Edit: IPP code will be much welcome. Edit: I'm loo...
For example you measure the data coming from some device, it can be a mass of the object moving on the bridge. Because it is moving the mass will give data which will vibrate in some amplitude depending on the mass of the object. Bigger the mass - bigger the vibrations. Are there any methods for filtering such kind of noise from that dat...
Dear all, I would like to do a convolution using a 35 x 35 kernel. Any suggestion? or any method already in opencv i can use? Because now the cvfilter2d can only support until 10 x 10 kernel. ...
Hello, I'm not a DSP expert, but I understand that there are two ways that I can apply a discrete time-domain filter to a discrete time-domain waveform. The first is to convolve them in the time domain, and the second is to take the FFT of both, multiply both complex spectrums, and take IFFT of the result. One key difference in these met...
I just saw this, and it is one of the most amazing things I've ever seen: http://www.youtube.com/watch?v=MDrqBYkco-Y I am not even able to fathom this. What is going on here? ...
My view is that a C implementation cannot satisfy the specification of certain stdio functions (particularly fputc/fgetc) if sizeof(int)==1, since the int needs to be able to hold any possible value of unsigned char or EOF (-1). Is this reasoning correct? (Obviously sizeof(int) cannot be 1 if CHAR_BIT is 8, due to the minimum required r...
Possible Duplicate: Fast fourier transform in c# I am looking for an example of performing a real time FFT (Fast Fourier Transform) of line in or mic audio data in C#. My goal is to determine in real time if a particular note is present in the audio data. Any examples appreciated. ...
I'm currently testing the GStreamer audio framework and it's capabilities. My goal would be to write a basic radio automation system which can handle the scheduling of audio track mixing and stream the result to a media server like Shoutcast. I like to add some post processing to the final mix before sending it to the encoder. Although ...
I am trying to understand how to go about determining the frequency of various sounds captured on the phone via microphone. I am attempting to display a graph plotting the frequency of the note. ...
Hi, I've read some explanations of how autocorrelation can be more efficiently calculated using the fft of a signal, multiplying the real part by the complex conjugate (fourier domain), then using the inverse fft, but I'm having trouble realizing this in matlab because at a detailed level, I don't really know what I'm doing. :o) Any k...
I want to record two voices and compare them whether both are identical.I thing there is a apple sample code for voice recording.I have no idea about comparing two audio files.Please help me out.I am struggling badly for 2 days.what is the right approach for this?Is there any framework apple provides for this purpose or is there any th...
Hi! I want to record sounds from a live playing band. Then I want to make some effects with using a programming language. After this i want to play this sounds also live. Which programming language would be useful? Can I use python? EDIT: I want to play them simultaneously (in sync). The sound effects take the recorded music as input. ...
I want to implement some image-processing algorithms which are intended to run on a beagleboard. These algorithms use convolutions extensively. I'm trying to find a good C implementation for 2D convolution (probably using the Fast Fourier Transform). I also want the algorithm to be able to run on the beagleboard's DSP, because I've heard...
I have to perform a FFT for a .wav file in an iPhone application. I have seen FFT algorithms out there, but how would I go about parsing a WAV file and using in such an algorithm? Should I convert the WAV file to NSData or something else? Has anyone successfully performed a FFT of a WAV file in the iPhone before? I tried to use iPhon...
Here is the scenario: using a spectrum analyzer i have the input values and the output values. the number of samples is 32000 and the sampling rate is 2000 samples/sec, and the input is a sine wave of 50 hz, the input is current and the output is pressure in psi. How do i calculate the frequency response from this data using MATLAB, usi...
I would like to compare to WAV audio files using an FFT. What open source libraries and / or sample code exist for performing such an operation? ...