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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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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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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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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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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What are the characteristics of a smartphone speaker?
What are the characteristics of a smartphone speaker? Whether it is linear or non-linear?
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How to acquire data from an analog input device and feed it back as analog output in real time?
We have a Measurement Computing USB-1616HS-4 card which has 16 Single ended analog inputs and 4 Single ended analog outputs. The cards are capable of 1 million samples/s per channel.
One of our ...
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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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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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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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Can discrete wavelet transform for denoising purposes be implemented in real time? [closed]
I have been researching effective algorithms for denoising biomedical signals (non-stationary) that can be implemented in real time either using FPGA or DSP. I can across many suggestions for ...
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Real time signal processing use cases for eigenvalues of symmetric matrices
I realize that this might be somewhat of an unusual and specific question.
I know that the eigenvalues of symmetric matrices are used in a number of ways in scientific computing, such as for finding ...
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Are there any recursive online max/min filters for time-series
Are there any online recursive filters that can approximate local, time-varying minimum and maximum values of a time series?
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Real-time audio processing FIR vs IIR
My project consists in filtering an audio signal from the microphone, in order to remove noise, and find the time distance between two peeks with the highest precision possible.
I understood that an ...
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How does Overlap-Add work for IIR filter?
So let's say I'm trying to implement something like an LPC vocoder. I analyse a speech signal by breaking it up in small chunks and determining their LPC coefficients, which are by design, the ...
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Signals in real world?especially natural signals?
Do all the signals in real world ,that are of interest in engineering(for measurements or processing)are only continous/analog or there any other alternatives also?
For example birds make voice,...
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How to find if the signals are in sync or out of sync with each other?
Considering these are two signals over time, black and red.Following are some of the properties
Every Second a new data point is added over time . There is no control on the generation of the ...
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realtime software 90 degree phase shift a sinusoidal signal
I would post this to stack overflow but it seems to me more like a signals and systems problem, which EE's thrive on.
I need a realtime system implemented in software that can generate a sinusoid ...
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Real time numerical differentiation of signals
I am trying to implement a PID controller in Python and I am having some problems with real time numerical differentiation of my my discrete signal.
I am using the following method:
$$d{\frac{x_n}{...
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Summing RMS Values
I'm trying to calculate the RMS of a signal whilst only having access to the current RMS values of the waveforms making it up. This is because I need to calculate the total RMS so I can use it to ...
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Synchronising audio in realtime without knowledge of original signal
Was doubting whether this is the right SE forum to ask my (elaborate) question, so don’t hesitate to let me know if it’s not. Also, if anyone knows of a better way to title the question, feel free to ...
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Detect playback position in swept sine sweep
I am wondering what the most precise method is to detect the playback sample position of a sine sweep? The real playback sample position is unknown and an DSP with constraint computing capabilities ...
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How to detect real time sound onsets?
I'm a Software Engineer Undergraduate. I'm trying to detect drum strokes(beats) in real-time in python. I used amplitude threshold-based onset detect (beat detect) algorithm but it takes other noises ...
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Initial Clock synchronization between multiple smart phones (android OS) connected over Wifi?
I want to synchronize the initial clock of multiple smartphone devices (Android-based) for real-time VoIP communication. Basically, a MANET has been formed and I want to synchronize the clocks up to <...
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How to Synchronize multiple real time audio streams before mixing them?
I have been working on a VoIP solution in which I have to mix multiple audio streams coming from various sources. I have been facing muffled sound after the mixing of streams. I have implemented ASW ...
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FFT algorithm for real-time analysis
In a project, I have real-time voice audio being delivered in buffers of around 128 samples at a time. I want to calculate the autocovariance of the signal and use it to control an AR filter.
To do ...
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Is the whole data needed for the fast fourier transform with an ongoing signal?
I sample an signal with around 840k values a second, to check the spectrum around <400kHz. But i can't save the whole data as it is just to much for my microcontroller. I know that for the ...
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How do audiobook players manage to quickly speedup/slowdown playback speed without using more memory?
Many audiobook player apps on Android have a reading speed slider which lets us choose the reading speed e.g. 0.5x 0.75x 1.00x 1.25x 1.50x. This is time-stretching ...
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