Questions tagged [real-time]

real-time refers to processing done with a strict set of time constraints in a deterministic manner.

Filter by
Sorted by
Tagged with
0 votes
1 answer
28 views

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?
user avatar
  • 11
0 votes
1 answer
16 views

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 ...
user avatar
-1 votes
1 answer
26 views

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.
user avatar
3 votes
1 answer
124 views

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 ...
user avatar
2 votes
1 answer
42 views

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 ...
user avatar
0 votes
1 answer
88 views

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 ...
user avatar
0 votes
1 answer
96 views

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. ...
user avatar
1 vote
0 answers
66 views

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 ...
user avatar
2 votes
2 answers
130 views

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 ...
user avatar
  • 53
3 votes
2 answers
163 views

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 ...
user avatar
  • 53
0 votes
1 answer
54 views

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 ...
user avatar
0 votes
1 answer
51 views

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 ...
user avatar
0 votes
1 answer
50 views

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 ...
user avatar
0 votes
0 answers
36 views

What are the characteristics of a smartphone speaker?

What are the characteristics of a smartphone speaker? Whether it is linear or non-linear?
user avatar
0 votes
0 answers
23 views

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 ...
user avatar
0 votes
1 answer
52 views

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 ...
user avatar
  • 101
0 votes
0 answers
75 views

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 ...
user avatar
0 votes
0 answers
140 views

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, ...
user avatar
0 votes
2 answers
66 views

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 ...
user avatar
0 votes
0 answers
27 views

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 ...
user avatar
2 votes
1 answer
883 views

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-...
user avatar
0 votes
2 answers
454 views

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 ...
user avatar
1 vote
1 answer
97 views

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 ...
user avatar
0 votes
0 answers
36 views

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 ...
user avatar
0 votes
1 answer
259 views

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 ...
user avatar
1 vote
0 answers
32 views

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 ...
user avatar
  • 61
1 vote
1 answer
475 views

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. ...
user avatar
0 votes
0 answers
109 views

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 ...
user avatar
1 vote
2 answers
82 views

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 ...
user avatar
  • 11
2 votes
3 answers
286 views

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 ...
user avatar
  • 906
1 vote
0 answers
38 views

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 ...
user avatar
  • 61
1 vote
0 answers
17 views

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 ...
user avatar
  • 61
1 vote
2 answers
140 views

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 ...
user avatar
  • 61
0 votes
1 answer
138 views

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 ...
user avatar
1 vote
1 answer
79 views

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?
user avatar
  • 143
1 vote
0 answers
388 views

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 ...
user avatar
  • 11
1 vote
1 answer
252 views

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 ...
user avatar
  • 119
0 votes
2 answers
842 views

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,...
user avatar
  • 906
1 vote
0 answers
89 views

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 ...
user avatar
3 votes
3 answers
493 views

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 ...
user avatar
  • 135
3 votes
2 answers
637 views

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}{...
user avatar
  • 133
0 votes
0 answers
1k views

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 ...
user avatar
3 votes
1 answer
55 views

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 ...
user avatar
  • 131
0 votes
1 answer
75 views

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 ...
user avatar
  • 21
2 votes
2 answers
244 views

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 ...
user avatar
0 votes
1 answer
88 views

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 <...
user avatar
0 votes
0 answers
194 views

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 ...
user avatar
1 vote
0 answers
212 views

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 ...
user avatar
0 votes
0 answers
92 views

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 ...
user avatar
  • 1
2 votes
1 answer
282 views

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 ...
user avatar
  • 231