I am trying to create a graphical spectrum analyzer in python. I am currently reading 1024 bytes of a 16 bit dual channel 44,100 Hz sample rate audio stream and averaging the amplitude of the 2 channels together. So now I have an array of 256 signed shorts. I now want to preform a fft on that array, using a module like numpy, and use ...
My question has to do with the physical meaning of the results of doing the spectral analysis of a signal, or, put another way, of interpreting what comes out of throwing a signal into an FFT of a math package. Specifically: (i) take a signal, a time-varying voltage v(t) (ii) throw it into an FFT -- you get back a sequence of re...
I have a program that plots the spectrum analysis (Amp/Freq) of a signal, which is preety much the DFT converted to polar. However, this is not exactly the sort of graph that, say, winamp (right at the top-left corner), or effectively any other audio software plots. I am not really sure what is this sort of graph called (if it has a dist...
I have a Flex3 app I wrote and I'm streaming audio over RTMP from a Red5 server. I'd love to be able to use SoundMixer.computeSpectrum(), but the spectrum data is all zeros. In one location, Adobe writes that SoundMixer.computeSpectrum() does not work with RTMP data: "For media loaded from RTMP sources, you cannot use the BitmapData.dra...
Hi For my current project in C++ / Qt I need a library (LGPL is preferred) which can calculate a spectrogram from a signal ( basically an array of doubles ). I already use Qwt for the GUI part. Any suggestions? Thanks. ...
i've come across this ActionScript sample, which demonstrates drawing of the color spectrum, one line at a time via a loop, using waveforms. however, the waveform location of each RGB channel create a color spectrum that is missing colors (pure yellow, cyan and magenta) and therefore the spectrum is incomplete. how can i remedy this pr...
I am just trying to understand what the values sent back from computeSpectrum(bytes,true,0) mean. I have values ranging from 0 to 1 for each float i read from the byte array but does each value represent a range of Hz Thanks! ...
I'm racking my brain in order to solve a knotty problem (at least for me). While playing an audio file (using Java) I want the signal amplitude to be displayed against time. I mean I'd like to implement a small panel showing a sort of oscilloscope (spectrum analyzer). The audio signal should be viewed in the time domain (vertical axis ...
I'm looking for a C or C++ API that will give me real-time spectrum analysis of a waveform on Windows. I'm not entirely sure how large a sample window it should need to determine frequency content, but the smaller the better. For example, if it can work with a 0.5 second long sample and determine frequency content to the Hz, that would...
Hi folks, I am looking for a library that can accept a chunk of audio data and return the average amplitude over time within a given frequency band. I've already asked this question over at comp.dsp, but it's clear to me that acquiring the know-how to build this on my own using a basic FFT library is going to require more time and energ...
Does exist any program that detects the bitrate of an mp3? I'm not talking about the effective bitrate that the file has been encoded with, but the real bitrate that can be calculated only by frequency spectrum analysis. For example, to explain more clearly what i mean for the two kinds of bitrates: if i have an mp3 encoded in 128kbps w...
I've tried looking up how I might go about this for a while now, and maybe I am using the wrong terminology in my searches or it's way too advanced for me. I basically want to be able to analyze audio files in real-time. I know hardly anything about audio processing so I should probably start small and work my way up. Eventually I'd like...