Questions tagged [real-time]
real-time refers to processing done with a strict set of time constraints in a deterministic manner.
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Isn't the MFCC feature good for real time applications?
I am interested in the audio classification problem. You can think of the problem as ML, but my question is from a signal processing perspective. I am questioning the classification performance of ...
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Loss of Resolution When Shifting Up With FFT / Phase Vocoder Pitch Shifter (Compared to Shifting Down)
I am working on a project writing a realtime FFT / phase vocoder based pitch shifting algorithm in C++. In development, I notice that shifting down has much better audible pitch tracking and ...
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What is the name for amplitude variation over time with angle measurement called?
I am trying to create a method in my real-time algorithm to measure the variation in time based on a simple technique to avoid a huge overhead in the processing on the hardware.
The first method I am ...
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Help with real-time TD-PSOLA - sounds very very bad
So I have a pretty robust and fast pitch tracker I've been working on based on this thesis. I want to use it for real-time pitch shifting. However, one of the simplest algorithms for formant-...
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Some questions about realtime filter
the sample rate of signal is 1khz,which filter method can i take to realize a 3-5ms delay.
I would like to ask if there is a way to pass the signal through a low-pass filter and then adjust it through ...
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Some questions about realtime filter in control system
Can I use filtfilt function in realtime filter. filtfilt first filters a piece of data forward and then filters it backward. I ...
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Algorithms for real time multi-pitch guitar detection
I've been looking for info on this topic for a while and I came across several algorithms that may be suitable for this purpose.
Specifically I'm interested in getting a frequency representation like ...
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Initial conditions of backward filter for forward-backward filtering on chunked real data in python
I have to apply a downsampling filter on a realtime data stream (signal) and I want to do it in python. The data is sampled at 16 kHz and loaded in a loop in chunks of 1 second. I have to downsample ...
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Real-time convolution with Gaussian noise
I have a brain activity simulator that is capable of receiving various stimuli. Both generated signals and input stimulus are causal: a single sample is created every time step. I use a sinusoidal ...
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How to detect the end of a period of a repeating pattern in some time series signal
I have an incoming stream of time-series data which looks like in the below figure :-
I want to detect the end of each cycle in real-time (marked with red arrows) using C language. What would be the ...
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672
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Wigner-Ville Distribution (WVD) vs STFT for Spectral Analysis
What are the Pros and Cons of using Wigner-Ville Distribution for spectral analysis of a signal vs taking the STFT. When is it appropriate to use one over the other and is WVD used in real-time ...
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Are there ways to reduce the smearing of zero-padding interpolated data?
Are there ways to reduce the smearing / spectral leakage of zero-padding interpolated data?
I learned that, given a small collection of samples, one can increase the frequency resolution of an FFT ...
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On-the-fly computation of a variable cutoff frequency polyphase resampling filter
I'm creating a polyphonic audio sample player and I want to let the user play each voice faster or slower using resampling by a rational factor (classical interpolate by L / decimate by M scenario), ...
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Realtime DSP algorithms by NI aquisition by PC host
Is it possible to implement realtime DSP algorithms on PC using a NI PC acquisition card like NI PCI-4461?
In A New FXLMS Algorithm with Off-line and On-line Secondary-Path Modeling Scheme for Active ...
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153
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Real time processing in matlab
I have to extract a particular frequency range from an audio signal. For that I am using an FIR filter of order 50 and it is written in MATLAB as below:
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what are the advantages of higher-order Generalized Morse Wavelets?
What are the advantages of the higher-order Generalized Morse Wavelets in comparison with the first-order ones?
Are they also more computationally expensive?
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Is online Continuous Wavelet Transform possible?
I have recently created a real-time STFT with 50% overlap.
I wanted to know if this window-based is possible for scalogram, especially continuous wavelet transform. I haven't found anyone ...
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Does Fast Continuous Wavelet Transform (fCWT) have theory-supported novelty or just simply a computation optimization?
A recent publication, The fast Continuous Wavelet Transform (fCWT), enables real-time, wide-band, and high-quality, wavelet-based time–frequency analysis on non-stationary noisy signals.
I'm a ...
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Is it possible to update wavelet packet from fixed-sized window of data without repeating the whole process?
Assume that a scalogram is generated from performing wavelet packet in a fixed size window of data. Then, is it possible to update the scalogram with the incoming and outgoing data points without ...
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Accessing first few elements of a circular buffer in real time Python
I've made a circular buffer of size 10,000 in which I'm getting real time input from the mic. Now I want to access first 1920 samples every time and do the post processing but I'm only able to access ...
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What ADC precision and sampling rate for record sound?
What ADC precision and sampling rate would you choose and why if You wish to record sound that has frequency components are 200 to 2000 Hz. And the signal-to-noise ratio of your microphone is 50 dB?
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Questionable results of on-line butterworth bandpass filtering using scipy.signal.lfilter
I have a data_stream that I'm attempting to filter using two on-line butterworth bandpass filters to extract two frequency bands of interest. The original ...
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Is there a discrete signal which isn't discrete in time?
Is there a discrete signal which isn't discrete in time (rather, discrete in at least one other thing which isn't time)?
If so please share a typical example.
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Detecting background noise from audio time-freq domain analysis
I have a requirement to detect/reduce sidetalk/background noise in real-time audio. I am stuck in how can I detect this from audio time-frequency domain analysis. I am already getting the time-freq ...
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How to implement Auto Gain Control (AGC) before and after mixng realtime audio for a conference?
I mix audio(16bit,16khz, little-endian, mono,frame-duration:60ms) packets after dividing the short values by participant count so it never gets clipped. but before that, I need to apply a certain gain ...
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GNU RadioTagged Stream: How to clip the stream as "packet length" tag long
I am currently trying to develop a GNU Radio block which takes a tagged stream as an input.
The tags keeps the length of the packets. But the distance between the tags and the packet length are not ...
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Calculating numerator and denominator polynomials of a transfer function
I was reading this passage in a Doctoral Thesis about Adaptive cancellation.
Using MATLAB, if i were to write a simple code, it would look something like this.
...
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Why is voice clipping happening after Dynamic Range Compressor (MATLAB) when applied in real time on chunks of data?
I have been working on real-time audio signals on smartphones (iOS and Android) and my goal is to make voice amplitude stable in a certain range even if a person is talking closer to the mic of the ...
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Non-Uniformly Partitioned Convolution Implementation
I've succeded in implementing the uniformly partitioned convolution algorithm and now I'm looking to implement the non-uniformly partitioned version. I've had no luck with running parallel threads on ...
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Real Time Partitioned Convolution Not Working
EDIT: Scroll down for actual working code.
I'm working on implementing a real-time convolvution reverb JACK client on C and I've been trying to follow a number of sources (including Gardner and Wefers ...
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96
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xcorr MATLAB is not giving accurate result in case of noisy signals
I've a signal $x(n)$. I've generated its delayed copy named $x1(n)$ and applied xcorr function of MATLAB to find out the delay. It gives accurate delay.
Now I ...
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225
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How to remove or smooth the comb filter effect in real time audio signal mixing?
I have been working on a project where I have to mix multiple audio signals of the same source coming from different slave smartphones on one master smartphone in a distributed way. Now I have aligned ...
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78
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Timeshifting in streaming based audio processing
I am currently running into a larger problem whilst programming an audio processing software.
My target is time-shifting signals in frequency domain, then transform them back to time domain and ...
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98
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FFT requirements of real time signal from sensors
I have an electrical current sensor which generates measurements every second. I want to calculate the FFT of this signal. Since my real-time values are received every second, I think that the fastest ...
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understanding FIR SRRC filter with memory implementation in C
I translated the Matlab QPSK receiver/transmitter into real-time C code that I have running on a PlutoSDR platform. QPSK receiver/transmitter
I wrote the square root raised cosine filter for the TX ...
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Low-pass filter + HRTF cascade audio artifacts
I am implementing a 3D audio application. I have correctly implemented a set of HRTF to perform binaural simulation and interpolation.
To achieve this, I converted the HRTF into minimum-phase ones, ...
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Electric Bass with RJ45 Digital Output
I'm working on a project bass guitar with individual outputs per string using Nu pickups from Cycfi Research: https://www.cycfi.com/
The common sense approach is to simply take their circular ...
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48
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Phase-vocoder normalization for different speed factors
Question in short: How can I normalize audio from a block-based phase-vocoder system without knowing the global minimum and maximum during runtime?
Longer version:
Hey! I am very new to DSP and need ...
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Dynamic filter in real time audio
Following my previous question: Removing cracking in real time audio, I'm trying to implement a dynamic filter in real time audio.
What I want to do is to create a filter where I can change the cut-...
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Removing cracking in real time audio filtering
I am getting back to DSP applications after a while and I've written a real time audio player in Python.
Basically I'm reading chunks of data from a .wav file (I am doing this to simulate a real time ...
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125
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Echo removal from a chunk of PCM signal
I have implemented a paper regarding echo detection in real-time using MFCC coefficients. Now, I want to remove the echo from the mixed signal. Let me explain it as:
There are two signals, NearEnd ...
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How to ampfify/reduce certain frequencies in time data
currently I am trying to filter time data so that certain containing frequencies are getting amplified/reduced. I am dealing with a system which has a certain characteristic that I would like to get ...
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Applying zero-phase filtering in the frequency domain - also works in real-time?
In my application a filtering in the frequency space is desired. I designed two high-pass filters: $h_1$ Butterworth IIR filter, and $h_2$ FIR. I designed them using Python's ...
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What are the wavelet packet functions and how are they different from the wavelet and scaling functions?
I understand that in the decomposition process, wavelet and scaling functions are used to split the signal to approximation and detail coefficients.
Most of the time I saw the wavelet and scaling ...
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Apply "non-causal" filter buffer-wise, a.k.a "soft real-time filtering"
I am dealing with digital filtering of signals, both offline and in real-time. Typical filtering purposes are highpass filter or bandpass filter.
So far I worked on prerecorded signals (e.g. ...
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How to filter, in real-time, a quasi periodic signal
I have a signal affected by a rather complex quasi-periodic noise.
I must filter this signal in real-time to remove this noise.
The noise is not really "high frequency" and its main ...
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Sampling the Wave Equation for String Vibration
I am having a difficult time understanding the basic principles when sampling the function describing the vibration of a string. Mainly I am confused on given a sampling rate how many samples to take ...
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Confusion understanding digital signal processor?
I am reading wikipedia article about digital signal processor and as shown in end of attached snapshot
." Most general-purpose microprocessors can also execute digital signal processing ...
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Why should wavelet re-synthesis produce an output when the main component is suppressed and what does this mean for denoising?
I understand that aliasing occurs in DWPT if the wavelet used is of low order since the "filters" are not perfect and the combination of down sampling and overlapping between bands causes ...
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How well can discrete wavelet packet transform reduce noises that are similar to the input signal in the same frequency band?
If I had 50Hz noise coming from power line, and signals in the same frequency range (EEG for example 0.1Hz to 100Hz). If my sampling frequency is 30kHz but I downsample my signal to 937kHz and use the ...
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