Questions tagged [lpc]
The lpc tag has no usage guidance.
44
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Formant bandwidths
I have some intuition about bandwidths from these videos (1 and 2) explaining how the frequency response corresponds to the Z-surface.
The only thing I could find on the internet about calculating the ...
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2
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1
answer
135
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How were the coefficients for polynomial linear predictive coding derived?
FLAC uses linear predictive coding (LPC) as one of its central compression steps. While it allows for arbitrary LPC coefficients in the "FIR Linear prediction" subframe compression type, ...
1
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1
answer
86
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What is the "chirped response FIR filter"?
In Pitch synchronous split-band LPC (PS-SBLPC) vocoder the authors describe an algorithm to identify pitch cycle boundaries. In "Pitch cycle detection" section, this sentence describes ...
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Strange result in simple LPC simulation of a sinus
I'm trying to understand how Matlab LPC function works. So I made a little example script : I generate a real cosinus, calculate the LPC coefficients of this signal and then I try to predict the ...
- 57
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3
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405
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Formant analysis LPC (Matlab)
I wanted to do formant analysis using MATLAB and did everything according to the following tutorial:
https://de.mathworks.com/help/signal/ug/formant-estimation-with-lpc-coefficients.html
I have speech ...
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1
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137
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LPC Formant Estimation: Why resample?
The Burg algorithm implemented in PRAAT for formant estimation also works via LPC. First the sound is resampled to a sampling frequency of twice the value of maximum formant. Then a pre-emphasis is ...
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1
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2
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334
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Conceptually confused by LPC for speech: Do we synthesize by the inverse filter (FIR)?
I've been following the process of using LPC to analyse the speech and then synthesize the speech by swapping out coefficients over time. I'm purely concerned with pitched vowels at this point.
...
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561
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Zero-padding vs. nonzero-padding in computation of auto-correlation with FFT
Isn't the usual zero-padding in the computation of the auto-correlation function with FFT just one of many possible extrapolations of the original signal?
If I have a measured signal which has good ...
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1
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348
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AR Modeling: Why residual is white noise?
I was going through AR modeling.
The AR model of a covariance stationary process can be expressed as:
$$x[n]=\sum\limits_{i=1}^{p} \alpha_i x[n-i] + \epsilon[n]$$
where $p$ is the model order and $...
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1
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3k
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Linear Predictive Coding example in MATLAB
I have some data that is highly correlated and I wanted to see if I could try and encode it using linear predictive coding (LPC). Here is how I've been understanding the process:
Encoding
Generate ...
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1
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209
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Understanding linear predictive coding in MATLAB
I want to test my understanding of linear prediction by running it on some test data in MATLAB. The way I understand it is if I have some data that is correlated, I can encode the signal with linear ...
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1
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940
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Linear Predictive coding vs AR modeling
I'm looking for a suitable explanation of the circumstances in which the LPC error polynomial for a discrete time process x[n] is replaceable with an error polynomial categorized under the AR model? I ...
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2
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What Is the Definition of Linear Predictive Coefficients When the Optimal Value Aren't Unique?
Linear predictive coefficients of signal y are defined as the best $k$ coefficients $a_i, i = 1, \ldots, k$, that will approximate $y_n$ by $-\sum_{i=1}^k{a_iy_{n-i}}$. (Best approximation is that ...
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1
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243
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How to prove Line Spectral Pair coefficient properties?
I am trying to understand the definition of LSP coefficients from http://www.dspcsp.com/pdf/lsp.pdf.
We take the polynomial $a(x)$ of degree $M$ from the denominator of the LPC system function, and ...
- 151
2
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1
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176
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Linear Prediction task
$$x[n] = \big(A_1 r_1^n\cos(\omega_1 n) + A_2 r_2^n \cos(\omega_2 n) + A_3 \sin(\omega_3*n) \big)u[n],$$
where $\qquad \omega_1 \ne \omega_2 \ne \omega_3, \qquad |r_1|,|r_2|<1 $
I need an ...
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1
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505
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taking FFT from DCT
There is a speech signal, $y[n]$, in the time-domain.
To take it to the frequency-domain, DCT has been got from $y[n]$ (w = dct(y) in MATLAB).
After it, I applied ...
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1
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2k
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Why is LPCC and LPC used in speech recognition
I am currently trying to understand why LPCC and LPC is being used in speech recognition and why?
LPC as I understand is model similar to source filter model, modelling speech production,
and LPC ...
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2
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867
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How do I go from LPC coefficients to a filter polynomial?
I've recently begun experimenting with LPC, and while I understand that it works, I'm still slightly lost on why it works.
Specifically, I understand that LPC involves finding coefficients $a_1, a_2, ...
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3
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2k
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Understanding LPC for Formant Estimation
I went through the Matlab tutorial on Formant Estimation using LPC Coefficients. Though I vaguely understand the details, it's not entirely clear why we need to do this. From http://person2.sol.lu.se/...
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Linear prediction (LPC) of Sine wave samples around maximas
I think I missed class when this was explained ...
Anyway as part of a bigger project I have to implement a LPC to predict 2-3 future values of a sinusoidal process. I wrote a small Matlab m-file to ...
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1
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166
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How to build a simple model for voice-controlled system?
I want to build a speaker independent voice-controlled system. If I ask 10 people to say one unique word(for example"hello"), and record their voice and do LPC(linear predicting coding) upon them, I ...
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3
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9k
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What is the need for prediction filter in PCM and DPCM?
The DPCM works by the difference between actual samples and predicted samples.
If we already have the actual samples, we can quantize it and encode it later.
But why we use prediction filter?
And ...
6
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523
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Matching LPC frequency response to raw sample data frequency response
Background:
The intention is feature/formant extraction from speech input.
I have used an FFT on raw samples in the past and have done simple peak picking from a weighted average of frequencies over ...
2
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233
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how to detect number of syllables in a batch of audio recordings?
I have a corpus of short speech samples from Kiswahili speakers, and I want to detect the number of syllables in each audio recording. How should I approach this task?
Background: I asked a ...
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426
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hamming window for LPC
I am working on a library for generating LPC for speech synthesis. I am currently using a hamming window for the spectral analysis which goes in 200ms blocks over the signal, and does the a-to-k ...
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2
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294
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pre-emphasis with scaling?
I am working on speech synthesis with LPC and I originally implemented a pre-emphasis filter:
...
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1
answer
924
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Division by zero in Levinson–Durbin recursion?
I am doing a LPC analysis of a speech signal using the autocorrelation method. To calculate the LPCs I am using the Levinson–Durbin recursion. In my literature the error is initialized with the first ...
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0
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122
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What is actually transmitted following LPC of a speech frame?
For each frame, what's sent over to the receiver for decoding? The coefficients , pitch in some bits, voiced/unvoiced classification in another bit?
Another broad question to develop intuition about ...
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2
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335
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Improving the separation of a signal into source and filter
I am implementing a voice morphing system, but I am having difficulties getting a good quality output signal. The method I am using is LPC analysis and synthesis. In theory, the LPC process should ...
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1
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204
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LPC produces unexpected residual
I have written a vocal pitch shifting algorithm which uses LPC to separate the signal into its spectral envelope (predicted by the coefficients) and the pitch information (the residual error).
My ...
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2
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278
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Preprocessing signal before LPC
I have a signal that contains the speaking of three vowels. The signal is contaminated with dc offset and an interference at 60 Hz. I want to perform LPC for the synthesis of the spoken vowels. Do I ...
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1
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513
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autocorrelation A to K conversion for LPC speech analysis?
I am building an LPC analysis tool for speech synthesis and did the following to generate my a0 through a10:
...
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2
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551
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pitch extraction for speech
I am building an LPC analysis tool, and am at the point of needing to do pitch period analysis. I was initially interested in using the Gold & Rabiner algorithm for this, and got a hold of a ...
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2
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613
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Separating excitation from filtering for sound sythesis
From my days at college I rememeber that LPC splits a signal into a series of slowly changing filter coefficents and an audio-rate residual error signal, such that the original signal gets reproduced ...
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379
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Definition of LPCC
would you please tell me what does LPCC exactly do?How can we calculate the coefficients of LPCC?
I need to know clearly what is it so i can implement it.
I dont know if i am asking this question ...
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298
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Getting LPC coefficient by HTK
How can i get lpc coefficient by htk?
I know that there is a binary code "HCopy" which is ganna help with that... but my question is how can i read a wav file in htk?
and i guess i need activeperl to ...
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Gentle request for explanation on LPC and LPCC coefficients :)
If I understand what LPC does, I think. It predicts the next sample by taking into account previous $p$ samples. I don't understand why it is useful in DPS and speech recognition.
I also came across ...
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355
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Remove the extra peaks by lag
Suppose that we have some peaks of a signal and we know the time lag between dominant peaks. How is it possible to remove the extra peaks by applying time lag ?
Lets say it in MATLAB
...
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What is the "pitch marker" in the LP-PSOLA algorithm?
The LP-PSOLAR algorithm uses a the Linear Prediciton Coding (LPC) to calculate an error vector from a signal. This error vector is used to calculate the pitch markers. What do these pitch markers ...
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1
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1k
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Derivation of Yule-Walker Equation for LPC
I have derived the Yule-Walker equation as shown below.
\begin{align}
\hat s(n) &= -\sum_{k=1} ^ p a_k s(n-k)\\
e(n) &= s(n) - \hat s(n) = s(n) + \sum_{k=1}^pa_k s(n-k)
\end{align}
In order ...
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1
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194
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Format location from LPC magnitude
I am confusing when I find the lpc roots magnitude, f1=0.9313, f2=0.9308, f3=0.91 and f4=0.95 but when I look at LPC envelope the f1 is higher than f4 in term of magnitude in dB.
Could anybody explain ...
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543
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Remove spurious peaks of Hilbert transform
I want to eliminate spurious peaks of Hilbert transform for finding glottal closure in the linear prediction (LP) residual. I have the following 4 steps:
Down-sample.
Hilbert Transform.
Identify ...
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1k
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DFT, cepstrum, LPC for feature extraction
I am a newbie in speech processing and experimenting to get a feel. I have extracted some speech segments using a window function and I want to find distance between a pair of segments. First, I took ...
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2
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950
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Matching an LPC Magnitude Spectrum to FFT Magnitude Spectrum
I'm trying to get an LPC magnitude spectrum to match to an FFT magnitude spectrum. Basically I want the peak height in the LPC Spectrum to match the peak height in the FFT Spectrum.
Thanks to ...
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