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0
votes
2answers
44 views

Downsampling PCM Audio

I'm looking everywhere for solutions for audio downsampling. However for one reason or another they are incomplete, sometimes buggy, and sometimes are in a programming language I cannot understand. ...
0
votes
0answers
16 views

Big sharp spikes with maximal negativity

I am wondering if anyone knows how can I detect a big sharp spikes with maximal negativity as shown in the figure below in the red box. Many thanks.
0
votes
1answer
54 views

Convert Triangle Wave to Sine Wave

I have this triangle wave as input: and I want to derive a sine wave out of it. How do I go about it? PS: I am doing this in Lua, so any piece of code close to that language would be appreciated.
0
votes
1answer
39 views

Given two waves, 441 Hz and 700 Hz, how many samples long is each wave's period if the sample-rate is 48 kHz?

The title says it all. I have two waves, Master and Slave. Master is at 441 Hz and Slave at 700 Hz. The sample-rate is 48 kHz. I want to know how to calculate the period of each wave in terms of ...
0
votes
0answers
34 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
0
votes
1answer
28 views

Does Wav format supports writing complex values

I have a sine tone, doing some math, and finally gets an harmonically accumulated sine tone in complex numbers. I do want to preserve the phase information of imaginary part on the other end, which ...
0
votes
1answer
35 views

Wav file scale factor

I seek a scaled audio file format for my dsp output. I'd like to produce "scaled wav files", when I've done my pre processing. Eg. if the amplitude is 15.5 (of whatever unit), you should be able to ...
0
votes
1answer
43 views

Instantaneous phase calculation problems

I am currently struggling with a problem when calculating the instantaneous phase of a wavefield using a 1D Hilbert transformation. The scheme is as follows. 1D Hilbert transformation of wave field ...
0
votes
2answers
34 views

Spectral Content of two waveforms

I have found this interesting question here: Which of these two waveforms has a richer spectral content, and why? Intuitively speaking, I think that the first one is richer, but I cant really ...
-1
votes
1answer
31 views

Power of a square wave signal

I have a signal with half-amplitude $A$ and period $T$ and I want to calculate the average power of the signal. I think I remember the power of a signal $x(t)$ to be ...
1
vote
1answer
111 views

Is it theoretically possible to perfectly quantize a continuous signal?

So, I'm completely new to digital signal processing, but while reading a piece this morning about quantization it got me daydreaming: could a machine ever be fast enough to sample the position and ...
0
votes
1answer
63 views

Basics of waveform, how to define the zero point

Audio is a sequence of waveforms which have peaks, troughs, 0, just like below. How to define the x axis (y = 0) in the picture, how to choose the 0 point in the waveform since there are so many ...
1
vote
1answer
61 views

Structure of function that describes sine signal

I need to create a vector of sine signal. So I'm trying to figure out what the structure of the function that describe sine signal ? For example the function $\sin 2x$ meets the requirements? If ...
0
votes
2answers
126 views

Band Limited Table Look Up Oscillator C++

I would like to create a Band Limited Table Lookup Oscillator that functions much like the sin() function in C++ works where i would inout a phase value and receive ...
0
votes
1answer
77 views

Wave Correlation?

I have an image processing application that is different than anything that I've done before, and am looking for suggestions on how to approach. Here is a basic description of the problem: Given a ...
2
votes
2answers
125 views

Need help with FFT results

I am playing around with FFT and cant seem to get the expected results. I have a sound clip that i recorded from a mic placed on an analogue clock. So it has a sound every second. ...
0
votes
1answer
253 views

How to obtain the Sound Pressure Level from .wav file based on these given parameters?

I have a wav file recorded from a hydrophone. I am not quite familiar with signal processing so I really need some advice from you. I have gathered the information which looks useful and related. ...
1
vote
2answers
136 views

Bandpass filter on noisy sinusoid that predicts turning points

Is there an application where it is required to predict turning-points of a signal that is like a sinusoid with constant frequency, variable amplitude and some noise (Gaussian additive noise)? The ...
0
votes
1answer
134 views

Modelling propagation of sound wave by particle simulation

How might one model the propagation of a sound wave through a 3D environment with obstacles in it? My initial thought would be to use freely moving particles that repel one another; with sufficiently ...
3
votes
2answers
402 views

Audio Signal Separation - Identifying Interest points

I asked this question here: Audio Separation of .wav signal but it wasn't clear, so, here is my second attempt: First off, assume that I have a .wav file containing a sentence as follows: "My name ...
3
votes
1answer
122 views

remove spatial sinusoid noise from 2d image

Given a 2D image where each row of pixels is shifted by some amount horizontally in a sinusoid fashion, is it possible to recover the original image? Imagine a camera that can capture one row at a ...
1
vote
1answer
87 views

Isolating Bat Species without prior training base

I am attempting a project and I have been given Bat calls (in .wav) which are not ultra-sound navigation calls and I'm looking to isolate the different species of bats and monitor their activity. ...
0
votes
2answers
440 views

Audio Watermarking in MATLAB - How to choose frames to embed in?

Hello I am working on audio watermarking in MATLAB and am trying to choose specific frames of the audio signal where the watermark will be embedded. Through research, I have read that the best way to ...
1
vote
1answer
284 views

Audio Watermarking - What is typically embedded?

Just starting research in audio watermarking and have read many papers regarding audio watermarking but I am still a little confused on what exactly gets embedded into the signal. For example, one ...
2
votes
1answer
2k views

What do I do with the result of an FFT?

So I am working on a project using digital signal processing, which I am not familiar with at all, and a lot of this is all new to me. I am using SciPy\NumPy to play around with code to understand the ...
0
votes
1answer
112 views

In a periodic square wave, how to change in a particular condition?

The periodic square wave, $$x(t) = 1, |t| < T_1 \\ x(t) = 0, T_1 < |t| < T/2$$ What I wonder is .. (1) If $T_1$ is constant and $T \to \infty$, is x(t) a constant function? (2) If $T_1$ is ...
3
votes
1answer
306 views

How to make pop-free, crisp two-beep ringtone?

I hope this ultra-noob question is not entirely out of place here. I'm trying to make a super simple ringtone: 0.5s silence + 1s "pure tone" + 0.5s silence + 1s "pure tone" + 0.5s silence. By "pure ...
0
votes
4answers
942 views

How to generate a good Sinus audio signal of specific SampleRate, DataBits and Chunnels in a time frame

I encountered a problem when I tried to generate by a program an sinus audio signal. My parameters are Sample Rate: 44100 Hz Data Bits: 16 bits Channels: 2 I need to create a WAV file ...
1
vote
1answer
2k views

time in Sine Wave equation

According to Wikipedia, The sine wave or sinusoid is a mathematical function that describes a smooth repetitive oscillation. The formula for the Sine wave is, A = Amplitude of the Wave ω = ...
8
votes
1answer
200 views

Recognizing data clustered into shapes

I am working on a project in Python to detect and classify some bird song, and I have found myself in a position where I need to convert a wave file into frequency vs. time data. This hasn't been too ...
4
votes
2answers
120 views

Understanding values saved in WAVE file

The values that one can find in a wave file, e.g. 0.0036 0.0026 0.0174 0.0050 0.0026 0.0108 0.0154 -0.0114 -0.0006 0.0115 ...
9
votes
3answers
1k views

Determining Frequency and Period of a wave

I'm gathering temperature data from a refrigerator. The data looks like a wave. I would like to determine the period and frequency of the wave (so that I can measure if modifications to the ...
4
votes
1answer
548 views

Why does a wave continuously decreasing in frequency start increasing its frequency past the half of its length?

I'm trying to programmatically generate a wave (sine or square) with a continuously decreasing frequency. To do so, I simply multiply the starting frequency for a decreasing value, that linearly goes ...
3
votes
1answer
125 views

Procedural wave generation, frequency shift issue

sorry for the long post but I want to try and get all the details in here in hopes it will help. I've been working on building a procedural audio system for use in XNA projects. First this is general ...
3
votes
1answer
105 views

Problem reading and rendering Spectrum

I'm now processing PCM codes extracted from .wav file and want render the spectrum myself. First I try to read a spectrum on my foobar2000 player as below. My problem with this spectrum is: what do ...
4
votes
2answers
349 views

WAV encoding problem

When processing wav files, I encounter this problem: the what I extract PCM from a 8-bit encoded .wav file, I got a sequence of integers. However, when verifying my implementation with ...
3
votes
1answer
406 views

Mathematics / Signal theory behind billiard ball 'wave pendulum' effect

This YouTube video shows a very interesting effect. What is the underlying science? I have recently started studying Fourier theory and DSP, and and trying to understand what is going on in terms of ...