Question: linear predictive coding, spectral estimation

Started by Lars Hansen in comp.dsp14 years ago 4 replies

Hi I have a question about LPC-analysis. I have a frame of 256 speech samples which I assume is the output of an IIR-filter and I do...

Hi I have a question about LPC-analysis. I have a frame of 256 speech samples which I assume is the output of an IIR-filter and I do LPC-analysis of the frame to obtain the coefficients of the IIR-filter. I want to do a comparison of the non-parametric power spectrum (by use of FFT) and the model-based power spectrum to see how well they fit, but I am not sure if I have done it right....


Does LPC analysis of noisy speech make any sense?

Started by Jack in comp.dsp13 years ago 7 replies

Hello, I have read some literature about LPC analysis as a tool for estimating the parameters of a source-filter speech model. According to...

Hello, I have read some literature about LPC analysis as a tool for estimating the parameters of a source-filter speech model. According to the model, voiced speech can be modelled as s[k]=u[k]G[z]V[z]R[z] where G is a glottal pulse filter, V is vocal-tract filter and R is a radiation filter. G has 2 poles. V has 10 poles. R has 1 zero that cancels one of the poles of G. Pre-emphasizing...


Encoding residual (LPC on speech signal)

Started by Carlos Moreno in comp.dsp14 years ago 10 replies

Hi, As part of my research project, I'm working on vector-quantization applied to an LPC-like encoding scheme. For each frame of speech...

Hi, As part of my research project, I'm working on vector-quantization applied to an LPC-like encoding scheme. For each frame of speech (I tentatively put a frame length of 128 samples -- at 8kHz sampling rate), I compute the optimal prediction filter (using the autocorrelation method), and then apply that filter to the signal (well, I apply 1-P to the signal, where P(z) is the optima...


fast fixed point lsf / lpc algorithm???

Started by John McDermick in comp.dsp8 years ago 2 replies

Hi, Which fixed point algorithm is the optimal choice in terms of precision (and speed?) for calculating LPC and LSF coefficients? The...

Hi, Which fixed point algorithm is the optimal choice in terms of precision (and speed?) for calculating LPC and LSF coefficients? The algorithm I am working on loads 16bit samples into a frame. The frame is high pass filtered and the filter output ranges between -50000 to 50000. I wanted to keep the output in 16bit and tried to scale the filter output, but that screws up the signal proc...


reading sound samples from text for lpc-10 in c language ???

Started by emperor84 in comp.dsp13 years ago 1 reply

my lpc-10 c program works on an ".au" sound file but my aim is to run the program from a txt file where the sound samples are settled in...

my lpc-10 c program works on an ".au" sound file but my aim is to run the program from a txt file where the sound samples are settled in the begining part of lines like that : 14183 12593 29486 25712 -9985 12288 16384 -5889 -12033 -22273 -30465 -9985 18432 12288 12288 20480 8192 4096 4096 -12033 ............... but i can't solve this problem, the .au file is opened that with ...


Query to number recognition

Started by Learner Jr in comp.dsp5 years ago

Can someone please suggest me what approach will be quick for number recognition ? HMM / LPC etc Further is there any existing implementation in...

Can someone please suggest me what approach will be quick for number recognition ? HMM / LPC etc Further is there any existing implementation in Matlab? Thanks


regarding white noise

Started by venugopal in comp.dsp12 years ago 3 replies

hi, I am new to these group. I want to know why white noise floor is added to the autocorrelation function in the lpc analysis. what is...

hi, I am new to these group. I want to know why white noise floor is added to the autocorrelation function in the lpc analysis. what is the difference between lsp and lsf thanks in advance venugopal


Yule Walker Equations for LPC

Started by naebad in comp.dsp13 years ago 1 reply

for a random signal (AR) y(k)=-a1y(k-1)-a2y(k-2)-...-any(k-n)+e(k) (e(k) is white noise) I am a bit confused - I understood the YW normal ...

for a random signal (AR) y(k)=-a1y(k-1)-a2y(k-2)-...-any(k-n)+e(k) (e(k) is white noise) I am a bit confused - I understood the YW normal equations were of the form Ra = b where R is the correlation matrix a=[a1,a2...an] is the parameter vector and b=[-r(2),-r(3)...-r(n)] However I see many web refs to the above which has the same except b=[sigma^2,0,0...0] where...


Poles of AR estimator

Started by Arthur Herbert in comp.dsp15 years ago 3 replies
LPC

Hi, I am workin on a LPC AR estimator and i need to compute each of its poles. The denominator is a complex coefficients polynom of 120 degrees...

Hi, I am workin on a LPC AR estimator and i need to compute each of its poles. The denominator is a complex coefficients polynom of 120 degrees one. Does anyone knows a way to find the roots of a complex coef. polynomial ? Thx to those who can help


Yule Walker Equations - LPC

Started by Naebad in comp.dsp13 years ago 3 replies

I understood the Yules Walker equations for an AR process was given by...

I understood the Yules Walker equations for an AR process was given by this Ra=b ie http://www.mathworks.com/access/helpdesk/help/toolbox/dspblks/levinsondurbin .html where R is the autocorrelation matrix, a=[a1,a2....an] is the parameters and b is a vector made up of correlations ie b=[R(1),R(2)....R(n+1)]. However, I have seen the following where b is different and is b=[sigma...


Linear predictive coefficient computation

Started by RAMU in comp.dsp13 years ago 2 replies

To find the Linear predictive coefficents all are using auto correlation with levinson durbin equation. I want to know is there any alternative...

To find the Linear predictive coefficents all are using auto correlation with levinson durbin equation. I want to know is there any alternative method availble that still reduces the computational complexity to find the LPC coefficients.


LPC experiment

Started by Mauritz Jameson in comp.dsp7 years ago

I created a MATLAB script which runs through 10000 tests. In each test a random signal is created and IIR filtered. The IIR numerator is 1 and...

I created a MATLAB script which runs through 10000 tests. In each test a random signal is created and IIR filtered. The IIR numerator is 1 and the IIR denominator is: 1 -1.99240148160141 3.01948286335539 -2.81852242649452 2.03872063706253 -1.05454462109568 0.414446268750399 -0.115718625236828 ...


EVRC

Started by K. in comp.dsp13 years ago 1 reply
LPC

hi all, i would like to get a deeper undestanding of EVRC. could you direct me to some documents describing various parts of the standard,...

hi all, i would like to get a deeper undestanding of EVRC. could you direct me to some documents describing various parts of the standard, like bqiir filtering (how and why), LPC analysis, etc. i would like some educational stuff rather than just standard. also, any good educational links on speech coding are very welcome since i'm new to the area. thx


speech processing

Started by mari...@gmail.com in comp.dsp14 years ago 2 replies

I am a MSc. Student (beginner)and i am working in speech processing. I would like to know what is the input the I pass to the lpc.mat function...

I am a MSc. Student (beginner)and i am working in speech processing. I would like to know what is the input the I pass to the lpc.mat function to get the speech signal parameters(Note: I have sound files of English numbers and I want to get their parameters) Marian Mounir


Speech Recognition

Started by Sukrut in comp.dsp13 years ago 2 replies

Hi i am new to this group i am working on speech recognition for my last year project i have designed a gui in matlab for recognizing vowels...

Hi i am new to this group i am working on speech recognition for my last year project i have designed a gui in matlab for recognizing vowels and displaying them and used neural networks the problem is i have used filterbank coefficients(mel scale), lpc, and mfcc(probably as there are still some problems) to train the NN i dont know how to extract features from these co-eff i have decided ...


high quality results with LPC?

Started by igor b. in comp.dsp9 years ago 7 replies

Is it possible to get high quality results using linear prediction for voice modeling (singing voice, to be more specific) assuming we have...

Is it possible to get high quality results using linear prediction for voice modeling (singing voice, to be more specific) assuming we have enough processing power, bandwith and other stuff? All papers I've found focus on compression.


Speech Synthesis

Started by HardySpicer in comp.dsp10 years ago 14 replies
LPC

In the bad old days of LPC Speech synthesis, the best we could hope for was a robotic sounding voice. Now however it would often be hard to tell...

In the bad old days of LPC Speech synthesis, the best we could hope for was a robotic sounding voice. Now however it would often be hard to tell the difference between real speech and synthesised. I am guessing they use real speech samples - would this be right? The voices use huge amounts of disk space. H.


Levinson algo. wtih complex coef. required

Started by herbert arthur in comp.dsp15 years ago 7 replies

Hi, I am desperatly looking for a generalized Levinson algorithm that can cope with complex autocorrelation values and giving complex filter...

Hi, I am desperatly looking for a generalized Levinson algorithm that can cope with complex autocorrelation values and giving complex filter coefficients... I would like to implement it in C, and i have only found the classical LPC analysis but it can not deal with complex coefficients... Anyone can help ? Thanks in advance


levinson durbin algorithm

Started by John McDermick in comp.dsp8 years ago 3 replies

Why does the 10th order levinson durbin algorithm return these LP coefficients LPC 1 ...

Why does the 10th order levinson durbin algorithm return these LP coefficients LPC 1 -141.987085255646 379.380008989783 -652.562624856013 914.226857127382 -1069.00679555295 1068.49193530997 -912.915274765544 650.564278635448 -377.394102649473 140.21469138077 ...


LPC question

Started by Jack in comp.dsp13 years ago 5 replies

Hi, I have read some litterature about linear prediction. However, I haven't been able to find any litterature that explains in...

Hi, I have read some litterature about linear prediction. However, I haven't been able to find any litterature that explains in mathematical terms exactly why minimization of the variance of the residual leads to an estimate of the all-pole filter coefficients. The known output of a 10th order unknown all-pole filter is: x[k]=u[k]-sum(a[q]x[k-q],q=1,q=10) where the unknown u[k] i...