Signal Processing

Questions tagged [real-time]

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

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39 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 ...
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0answers
28 views

Block Processing to Plot Phase in Real Time

I am trying to modify an LTFAT demo script that records and plays back streaming audio simultaneously. The objective is to read in the block to a vector, and take the DFT of the block samples, and ...
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3answers
99 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 ...
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2answers
150 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}{...
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51 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 ...
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1answer
32 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 ...
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1answer
37 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 ...
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2answers
68 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 ...
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17 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 <...
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34 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 ...
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0answers
95 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 ...
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39 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 ...
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0answers
97 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 ...
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1answer
23 views

Implementing echo on adsp 21262 [closed]

I'm working on an echo implementation on the board adsp 21262. I've added a buffer to have more samples to work with. I end up then with 4 buffers of size 2048 each. The problem is that I need to ...
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1answer
425 views

How to find correlation/cross-correlation of two signals in real time?

Considering there are two signals and the signals are real time in nature. Visibly when one signal does up the other signal does down and vice versa. Sometimes both the signals moved towards the same ...
2
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1answer
292 views

Are there DC removal techniques that do not introduce a filtering transient?

I have an application in which I need to remove DC components from a sampled signal in real time (basically the same constraints of ECG, but it has nothing to do with the brain). My measured signal in ...
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1answer
194 views

Implementing real-time signal processing filters

I’m currently working on my capstone for school, and I’m looking for some guidance/tips when it comes to real-time filtering. The nature of the project is to monitor breathing patterns, send the ...
3
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1answer
149 views

FFT of a $N$-length real sequence via FFT of a N/2-length complex sequence

I would like to optimise FFT algorithm by only using a FFT of size $N/2$ to transform a real sequence of length $N$. There are already many questions and many excellent answers on the matter (here for ...
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2answers
99 views

What fps can be considered as a hardline for real-time performance? Is there any academic paper that describes this?

I am trying to design a deep learning based inferencing solution for security applications. My deployed program achieves an FPS of 15fps for classification. Can it be considered real-time?
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1answer
40 views

Question on Levinson's proposed discrete form of Wiener filter

The whole foundation of Levinson's discrete version of Wiener filter is based on the assumption of stationarity of a time series, and aims to predict a value based on the past observed values. Now, if ...
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2answers
58 views

How can I calculate what a recording would sound like if it was played through my speakers and mic?

I am trying to isolate the sound of someone speaking while music plays back in a noisy environment. I have multiple speakers and a microphone in my system. I am able to play back just music and ...
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1answer
102 views

Perform overlap add with available FFT size smaller than filter coefficients

I would like to process 12 to 20 seconds of incoming audio at a sample rate of 44100. I must process this audio in real time in an STM embedded kit (perhaps also an Android Smartphone). I'm trying to ...
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1answer
75 views

How can i record 1 MHz signal and do a real-time processing in a PC? [closed]

I have a 1 MHz signal from transducer that needs to be analyzed in real-time condition, so the sampling needs to be more than 2 MHz. It consists of digital filtering, turn into spectogram and feed ...
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1answer
52 views

What are some efficient algorithms for real-time calculation of eigenvalues?

I need to calculate eigenvalues of a square matrix for a real-time implementation using microcontrollers or dSPACE. Obviously, I can find the eigenvalues of a 2by2 matrix analytically. I am wondering ...
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1answer
2k views

Matlab code for wigner ville distribution [closed]

I wanna to have a wigner ville distribution spec.and need code in matlab
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1answer
204 views

Real-time modulated IIR filter

I've been learning to implement an IIR filter for a synthesizer project. It is now more or less stable when the parameters are constant, but ultimately I want the parameters to be arbitrarily ...
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0answers
53 views

DSP Hardware recommendation or is it even needed?

I'm new in embedded programming. Trying to choose a dsp, they seem very feature rich for my planned usage. I want to analyze 18 signals (simultaneously or near simultaneously) real time. I want to do ...
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2answers
1k views

Do all real-time filters introduce phase lag, or can there be such a thing as “lag-less” or “zero lag” real time filters?

Do all real-time filters introduce phase lag? I once heard of "lagless filters", but I don't think they can be used real-time (ie: on live data streaming in for a control system, for example, ...
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0answers
169 views

Real-time implementation of cascaded all-pass filters from given transfer function

I am working on real-time implementation of spring reverb based on scientific paper called Parametric Spring Reverberation Effect by Välimäki, Vesa; Parker, Julian; Abel, Jonathan S. One block of ...
3
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1answer
692 views

Real-time wavelet decomposition and reconstruction for ECG feature extraction

I need to locate R-peaks in an ECG signal. I'm using wavelets to extract QRS complexes: First, I decompose the signal using a maximal overlap discrete wavelet transform with the Symlet 4 wavelet. This ...
3
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1answer
127 views

Finding good feedback coefficients for basic reverb

I'm currently working on some reverb algorithm code for the Gamebody Advance to get a bit of that ambient feeling for the music instead of having plain dull sound. A few challanging restrictions are ...
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0answers
30 views

Efficient format for 2D signal?

I'm trying to solve the following problem. I got a "low frequency" input 2D signal over a square region. I'll collect a few samples, somewhere around 10-30 maybe, the exact sample count will be ...
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1answer
49 views

Buffering block and filter length in real-time processing

I have a signal sampled at 256 Hz, which I want to filter with a 50 taps long FIR filter in real time. Would it be a problem, if my data block size is only 32 samples? And should I then concatenate 3 ...
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3answers
3k views

what is the difference between buffering and queuing?

I've some problems with definition of queuing and buffering so what is the difference between buffering and queuing ?
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1answer
1k views

How to find Leq for a WAV audio file like an SPL Meter would?

Given an audio file (WAV), I need to find the $\rm L_{A_{eq}}$ (continuous A-weighted equivalent sound pressure level) of the audio file. For this purpose, I am following this workflow: Get a frame ...
3
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2answers
434 views

Two real time signals convolving

This might be a stupid question but is it possible to convolve two real-time signals together? I know that generally for running convolution you have the IR and the block of the real time signal and ...
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0answers
74 views

Pose-invariant face detection and recognition

I would like to detect faces and later apply recognition algorithms to surveillance videos. Ideally, the application should run in real-time (or near real-time) and transfer the data first to an ...
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0answers
87 views

Dot or point pattern recognition for Braille Paper

we are very new to image processing field. We are gonna do a study about braille to text conversion, by the way braille is a method of writing for blind. !(https://fryemuseum.org/images/...
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3answers
458 views

IIR biquad real-time filter just output noises

I've implemented a IIR filter but it outputs only noise (like FM radio out of tuning) and I can't see what's wrong. This is the processing function: ...
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1answer
766 views

Guitar pitch detection [duplicate]

I try to develop a guitar game in android platform. And I need to do the real-time pitch detection of guitar chord. I will get the input from the microphone, and then analyze the input (the input ...
0
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1answer
131 views

Matching guitar signal with tablature, near real-time algorithms?

I'm looking for candidate algorithms that might work for a use-case comparable to Rocksmith's analysis system. To compare a clean electric guitar signal with a tablature reference. A higher latency ...
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75 views

Which is faster: image segmentation or line detection?

Some papers use image segmentation techniques and others use edge detection. I need to know which one is faster. update: I need to do semantic segmentation for outdoor sense and the data is optical ...
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1answer
87 views

Rollercoaster: determining subject position from inertial data?

I have inertial data (accelerometer, gyroscope, magnetometer) from phones of human subjects riding a single rollercoaster repeatedly. The ride has temporal variance (ex. sometimes getting from A to B ...
0
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1answer
65 views

Does it make sense to recompute Parks-Mccellan on a per sample basis?

I'm thinking of using Parks-Mccellan for my equalization needs, but since I require that the filter be variable (gain, Q etc.) then does it make sense to recompute Parks-Mccellan on a per sample basis?...
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0answers
120 views

Fast greyscale image segmentation on 16x16 image

I have a 8-bit greyscale 16x16 image where I want to extract coherent shapes with a more or less consistent pixel arrangement if possible (like: a rectangle, staircase, line). Currently, I'm doing ...
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1answer
462 views

Determining the covariance of point clouds in real-time

So basically I have a set of multidimensional data that I need to determine the covariance of between dimensions in real-time. Each point that comes in is a vector. I have gotten the mean and variance ...
2
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2answers
552 views

detect and distinguish driving maneuvers via smartphone sensors

I want to do some driving style analysis via smartphone. Therefore, I programmed an app that records a 2D acceleration (when accelerating/braking and turning left/right). The app calibrates itself in ...
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103 views

Sample-By-Sample Linear Prediction

As I understand it and have it currently implemented, linear prediction [via Burg's method or the autocorrelation method] is a block algorithm. Hence, there will be latency involved because one must ...
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2answers
813 views

Play IQ data in the soundcard

I have short-wave digital receiver that send RP packets with IQ components over network depend of the RF frequency and passband. I need to work with the telephone passband (0.3 - 3.4 kHz). The task is:...
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2answers
8k views

Can deep neural networks achieve real-time video analysis?

Recently, convolutional neural network based, deep architectures (DNN) such as AlexNet and VGGnet have been very successful in image classification challenges (e.g. ImageNet) and action recognition/...

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