Adaptive Filter | ADPCM | ADSP | ADSP-2181 | Aliasing | AMR | Anti-Aliasing | ARMA | Autocorrelation | AutoCovariance | Beamforming | Bessel | Blackfin | Butterworth | C6713 | CCS | Chebyshev | CIC Filter | Circular Convolution | Code Composer Studio | Comb Filter | Compression | Convolution | Cross Correlation | DCT | Decimation | Deconvolution | Demodulation | DM642 | DSP Boards | DSP/BIOS | DTMF | Echo Cancellation | Equalization | Equalizer | ETSI | EZLITE (Ez-kit Lite) | FFT | FFTW | FIR Filter | Fixed Point | FSK | G.711 | G.723 | G.729 | Gaussian Noise | Goertzel | GPIO | Hilbert Transform | IFFT | IIR Filter | Interpolation | Invariance | JTAG | Kalman | Laplace Transform | Levinson | LPC | McBSP | MIPS | Modulation | MPEG | Multirate | Notch Filter | Nyquist | OFDM | Oversampling | Pink Noise | Pitch | PLL | Polyphase | QAM | QDMA | Quantization | Quantizer | Radar | Random Noise | Reed Solomon | Remez | Resampling | RTDX | Sampling | Sharc | TI C6711 | Undersampling | Viterbi | Wavelets | White Noise | Wiener Filter | Windowing | XDS510PP | Z Transform

Difference between LPC & LPC vocoder

I'm doing a speech recognition project. Can LPC vocoder be use for speech rocognition? Can anyone help me with the differences between LPC and LPC vocoder? I'm looking at the code which i found in the net and it seems that LPC method were used in LPC vocoder and it is dealing with pitch. I'm not...

LPC-10 vs. Texas Instruments LPC

Does anyone here possibly have detailed information on Texas Instruments implementation of the LPC algorithm for speech compression? I am in the process of writing an LPC-T1 and LPC-10 encoder/decoder library in C# and I have Andy Fingerhut's LPC-10 code (which is in C, converted from Fortran). ...

warped lpc cepstrum

Hi, I'm wondering if I can use standard LPC -> Cepstrum recursion proposed by Atal for warped LPC. What kind of error do I produce if it is wrong? Cheers, Kosta ...

lpc on seismic traces

Hi Need help to use matlab's lpc (linear prediction coefficients) on a set of seismic traces. If data is given in a matrix where each column represents a seismic trace (time is the vertical axis and space the horizontal) how do I use matlab's lpc ? I am in particular interested in cases wher...

Formant detection

Hi, I'm trying to implement an algorithm in Java for detecting the formants in a speech segment. I've found an information, that is a good way to detect it is from spectral envelope, which I can get as power spectrum from LPC. So what I need is to count the power spectrum for LPC, which I get af...

LPC and LSF

Dear Firndz I have one querry regarding the LPC and LSF parameters Why we compute the LSF paramenter when we already had computed the LPC coefficeint. As far as I know all the relevent info is embeded in the LPC coefficent then why we compute the LSF parameters ? Only on thing I ca...

LPC using cumulants

Hi All, I want to implement LPC using cumulants (instead of LPC using autocorrelation ) algorithms in C. Where can I find that algorithms. some formulas or c code. ...

lpc vocoder.clarification needed.pls

Hi i'm using lpc vocoder for my speech recognition. If i'm doing only alphabet A-Z, I only need the encoder part. Is that correct? As i know, lpc vocoder determine the lpc analysis and pitch detector. If i wan to get the coefficients only for my neural network recognition, I dun need the pi...

New to MFCC & LPC vocoder. Pls help

I'm new to speech recognition. I would like to ask after generating MFCC, we get the coefficients. What do these coefficients means? Do they represent the amplitude of the speech signal accordingly? Can LPC vocoder use for speech recognition? Is this method better than LPC and LPCC? or even MF...

Teaching Assistant seeking help.

Dear Sirs I am a teaching assistant at MSU, and have volunteered to create new labs for the ECE Senior Design class. I would like to make the intial project a real-time LPC encoder/decoder. I would have the students play with the pitch value, so they would learn about LPC and also get excited a...

Question about LPC analysis and noise suppression in speech

Hello, I conducted an experiment in MATLAB related to noise suppression. I have a noisy speech segment X=S+N where S is clean speech and N is noise. I did LPC analysis of a frame of X and obtained an estimate of a noisy excitation (residual) signal u_noisy. I also did LPC analysis of a...

Re: LPC Coefficients

Hi, I am using an autocorrelatoin method using the Levinson recursion. The algorithm I am using is adapted to java from some non-java code I found in a book. Do you know anywhere that I might find another basic LPC algorithm to test my own. Thanks, Tom wrote in message news:1107...

RLS and LPC comparison

Hi All, I have implemented a 10th order Recursive Least Squares filter on Matlab for speech and am comparing the weights thus obtained with the weights using the LPC function. Then I am comparing the speech quality using PESQ MOS values for various speech files. I run my RLS for lambda=...

Where to find the description for LPC -10 algorithm

Dear all, I have downloaded the source code for LPC-10 algorithm. But it maybe a little difficult for me to understand the source. So I want to find some materials about this algorithm. These two papers will be helpful, but I can't find them on Internet. 1) The U.S. DoD's Federal-Standard-1...

Regarding LPC to LSF conversion

Hi All, I into iLBC codec.I understood the basics that why the LPC coefs are transformed into LSF theortically, but I find it difficult to understand mathematically. Pls help me with the maths associated with it and links if any. Pradeep ...

speech to LPC coefficients

hello can anyone post me a C code for converting the original speech to its LPC coefficients and then to the LSP. Or just tell me the procedure to do it ..thanks This message was sent using the Comp.DSP web interface on www.DSPRelated.com ...

Re: using lpc to interpolate

Kamran wrote: > Rune Allnor wrote: > > > > Kamran wrote: > > > > > Hi > > > > > > > > > Could anyone help me on how to use lpc (linear prediction coeff) > > > for interpolation ? I have a vector where some elements(samples) are way > > > off what is reasonable and wonder...

LPC Question

In LPC we estimate a 10th order all pole model of quasi-stationary speech. The predicted speech is then y(k)=-a1y(k-1)-a2y(k-2)....-a10y(k-n) Is the 'gain' estimated at all ie the variance of the driving noise of the AR model? Also is this really a predictor? It is not a Wiener predictor ...

gaussian mixture model

i really need help. i'm doing a voice morphing project and is in need of help with the gaussian mixture model method. i know i will need to process an audio file into lpc datas and then using the lpc format to create a codebook. however, i do not know what comes after that. what am i to do so...

GMM morphed.

Hi all, can anyone help me with this? If i were to carry out a Gaussian Mixture Modelling on an LPC data, after that using the resultant i undergo some level of morphing. would i still need to do any reverse GMM on the morphed data in order to get back an LPC format? If yes, can someone roughl...

Speech identyfication...

Hi!!! I have problem with speech identyfication. I use LPC algorithm and extract reflection coeficient (rc). I have this 10 rc and try to identify the person using it. The problem is how I can do this with this rc??? I used Euklides distortion measures but I do not know what can I do next with ...

Re: Please Recommend Book on Audio/Speech

The modem speech coding is based on the LPC algorithm in the time domain , multiband algorthim in the frequency domain. LPC based speech codecs are EVRC, QCELP13, AMR series, and ITU-T G.723.1, G.729 series. multiband speech codec are IMBE, and AMBE. The audio coding is based on FFT, MDCT bas...

LPC cowfficient freeze

In recent past there was a suggestion thrown to me to freeze the LPC coefficient to save computation cycles and the "rational" is speech is stationary in nature! The application is a vocoder. I was shocked and still remain shocked but if you guys have an o...

Question: linear predictive coding, spectral estimation

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 ...

Re: too many combinations: Transition probability etc.

John wrote: > I am trying to do some statistics, but I don't know how to solve the problem > I am working on. > > I have N speech segments and I perform a 10th order LPC-analysis of each > segment and get a 10-dimensional LPC-vector A(j)=[a1(j),a2(j),....a10(j)] > for j=1 to N. > ...

Re: Speaker recognition software

hi guyz , im just a starter on speaker recognition using LPC , need some real tuts on it and any guidance regarding the programming in c - language. any advice would be helpful, thatd be helpful for the original author of the post 2. so if u have anythn to share plz do. email me on...

Voice conversion

Hi, I'm doing a project on Voice Morphing in JAVA. And I am new in DSP stuff. I am wondering if you could help me with the concepts behind this. Voice morphing converts the words of the source speaker to be spoken with the voice of the target speaker. e.g. input : Source speaker says "Hello" ...

Re: fastest way of calculating the roots of a polynomium??

John wrote: > > Why do you want them? If it is to check for stability, that is > > It is not to check for stability....It is because I am more interested in > finding the roots than the LPC-coefficients. If I have the roots I can > quickly calculate the LPC-coefficients if I want t...

Re: Block Processing Issue

> What type of signal are you filtering? A noise degraded speech signal x=s+n where s is clean speech and n is colored, gaussian noise. > How important is continuity? I don't know to be honest. Maybe you can tell me why you ask that particular question? > How/why are the coefficie...

Question regarding LPC Difference equation

Hi, I was going through the Source filter model of speech production given in "Digital Speech" by author Kondoz. The LPC sysnthesis filter looks like : H(z) = G / A(z) where, A(z) = 1 - SUM{a[j]*z^-j} ; j running from 1 to 10 for speech synthesis. If we transform the above ...

Re: Power Spectral density

Real_McCoy wrote: > "Stan Pawlukiewicz" wrote in message > news:dkiffa$ic7$1@newslocal.mitre.org... > > > Lars Hansen wrote: > > > > > > Fourier transform of a random process is another random process :) > > > > > > > > what you need to do is perform the above several dozen times (a...

Re: regarding white noise

> I want to know why white noise floor is added to the autocorrelation > function in the lpc analysis. I'm not an expert with LPC, but I know with adaptive dsp, you need to keep the inverse of the autocorrelation matrix stable. This is especially true with highly self-correlated signals. ...

Re: ask for help on Hi Fidelity Audio Compression with ADPCM

Jesse wrote: > Hi all, > > Currently, I am studying on how to get Hi Fidelity effects with > ADPCM related compression methods. But it seems that the traditional > IMA ADPCM and MS ADPCM will not get the satisfied results. ADPCM is just a simple form of (adaptive) LPC, with fix...

autocorrelation with 0 lag for LPC in speex library

Hi, I saw in the sources for the speex library (http://www.speex.org/) that they add some value to the first autocorrelation result. The results are used to produce a IIR with a levinson durbin recursion. float d; int i; while (lag--) { for (i = lag, d = 0; i < n...

Re: Understanding a simple Linear Predictive Coder

Ross Clement wrote: ... > What resources would people recommend that > I read to help me understand this material? J Makhoul: "Linear Prediction: A Tutorial Review", Proc. of the IEEE, Vol 63, No. 4, April 1975. It only mentions adaptive methods in passing (understanding this would requ...

Basic LPC Codec implemetation

Hi Friends, I have implemented a basic LPC coder in matlab using the following blocks. Kindly let me know your comments on some of my questions detailed down. I have taken sample .wav file with sampling frequency -8000 frame length =20 ms = 160 samples Overlap = 50% Block len...

MELPe MOS vs other vocoders

Hi everyone, I read that MELPe won the DoD & NATO competitions against many vocoders such as AMBE, EMBE, STC, FSHC, HSX, SB-LPC, CVSD, CELP and LPC-10e, so it has to be clearly better than all of them. See for example at: http://www.compandent.com/melpe_faq.htm#Q06 Although MOS is a very ...

LPC coding doubt

Hi I was reading about LPC coding, and I have a doubt. What i read is that the way we find the coeffecients of a filter is by using an energy eqn, minimize it wrt the coeff, and later find out (by backtracing) if the input function is closer to a white gaussian noise or a periodic impulse train...

Re: Whatand Why of "Power Spectrum Densities"

Richard Owlett wrote: > In another thread Rune recently said: > > Power Spectrum Densities (PSDs) don't contain phase information > > about the process, so there is little point in doing anything > > to PSDs where the phase needs to be known. > > That a PSD does NOT contain phase...

Re: How to divide signal into separate subbands?

jungledmnc wrote: > Hi, > I'm thinking (just teoretically) how to make e.g. an audio multiband > compressor - so divide signal into a few subbands (e.g. 0-200Hz, > 200Hz-1000Hz, 1kHz-..) If this is just the theory, then you can assume that the signal is perfectly divided into the ...