## Forums Search for: LPC

## Gain Quantization ??

hi, can anyone help me how to quantize gain in LPC 10 coding scheme? thanks Eris

hi, can anyone help me how to quantize gain in LPC 10 coding scheme? thanks Eris

## Please make comment

Thanks for the info about LPC 10 Coding Scheme .. i have surfed all the address you gave, i found many new reference. In this...

Thanks for the info about LPC 10 Coding Scheme .. i have surfed all the address you gave, i found many new reference. In this email, i attached a sample of my decoder output, would you please to hear it and see if you can understand the word in it . Maybe like MOS or something like t

## Estimate LPC's

inHello, I am trying to compute a solution using the least- square- error principle to an overdetermined system of equations. ...

Hello, I am trying to compute a solution using the least- square- error principle to an overdetermined system of equations. The equation is as below: Error = summation (y[n] ? summation (ai x[n-i] ) ).... in 'ai' term `i' is subscript where `n'

## Info regarding AMBE codec

Hi all, I am having a study of the multi band excitation speech model. This is having a quite different approach from the LPC...

Hi all, I am having a study of the multi band excitation speech model. This is having a quite different approach from the LPC model. I could not find much details of algorithm and all from net. Kindly give me some pointers to sites where i can have further more information. Ex

## Regarding LPC parameters in G.729

Hi All, I am a beginner in speech processing area, In G.729 fixed point algorithm implementation, in the function...

Hi All, I am a beginner in speech processing area, In G.729 fixed point algorithm implementation, in the function Get_lsp_pol(),line 88,i.e after 2 for loop, why has he left shifting by 9 when in the standard he has shifted by one(i.e multiplied by 2). Can anyone help me?

## LPC to LSF Source Code

inHello; I was wondering if anyone would be willing to share or direct me towards some Java or C code on how to convert from Linear Prediction...

Hello; I was wondering if anyone would be willing to share or direct me towards some Java or C code on how to convert from Linear Prediction Coefficients to Line Spectral Frequencies and vice versa. I am able to generate the LP coefficients using the Levinson algorithm, but am looking for some help to get to LS frequencies. Thanks. Regards, Ray

## SCALING OF LPC COEFFICIENTS

inI have written a LPC10 encoder which produces the reflection cofficients,gain, pitch parameters etc using a 6711. These values are ...

I have written a LPC10 encoder which produces the reflection cofficients,gain, pitch parameters etc using a 6711. These values are in floating point notation. What I want to know is how are these values are converted to a integer representation, for transmission, considering that for

## Estimating coefficients of digital filter

inHello all! I'm using the Autocorrelation method as the PDA in an assignment entitled: Synthesis By Analysis using LPC. I've read so many...

Hello all! I'm using the Autocorrelation method as the PDA in an assignment entitled: Synthesis By Analysis using LPC. I've read so many literature implying forming a matrix equation with p unknowns: How does one estimate the coefficients of the digital filter or model from a segment of speech. Thanks

## Problem about LPC-10 and LPC10e

Dear all, I'm involved in a project of speech coding of LPC10. And I downloaded the source of LPC10e, and found it's complex....

Dear all, I'm involved in a project of speech coding of LPC10. And I downloaded the source of LPC10e, and found it's complex. Especially the pitch tracking, voicing detection part. Is there any materials about the details of LPC10e? And another question:

## LSF quantizer

inHi all! Does anyone know what=C2=92s the latest & greatest LSF quantizer available = for wideband speech coding? :-) For example, what=C2=92s...

Hi all! Does anyone know what=C2=92s the latest & greatest LSF quantizer available = for wideband speech coding? :-) For example, what=C2=92s the minimum number bits/frame required for quantiz= ing a 16-th order LPC operating at 16-kHz sampling?=20 If anyone is aware of any nice references please let me know. Best Regards, Arijit =20

## Pre-emphasize and First Formant

inHi there, can anyone explain to me about the use of pre-emphasize in LPC coding ? If we see in the DOD Standard, they use...

Hi there, can anyone explain to me about the use of pre-emphasize in LPC coding ? If we see in the DOD Standard, they use pre-emphasize before the speech is analyzed with 1 - 0.9375z**1. I checked using MATLAB that the frequency response of this filter is high pas

## What's the meaning of the binomial coefficients in G.723.1 LPC analysis?

inHi all, Now I am reading the standard documents and reference source code of G.723.1. There is an extra windowing multiplication...

Hi all, Now I am reading the standard documents and reference source code of G.723.1. There is an extra windowing multiplication in between the Levinson-Durbin recursion and autocorrelation coefficient calculation. But I do not know why this extra step is necessary. Could anybo

## problems in G 723.1

Hi all, I am facing few problems while debugging the Standard C code of G 723.1 for TI processors. Problems: 1) Even...

Hi all, I am facing few problems while debugging the Standard C code of G 723.1 for TI processors. Problems: 1) Even after disabling the High pass filter why the Rem_DC function downscales the samples???? 2) Why the LPC filter we use is of 10th order

## Method of Finding LPC Coefficients for Digital Filter

Hi, I'm doing some speech processing using Linear Predictive Coding, and I'm trying to use MATLAB to find the feedback coefficients, ai, for a...

Hi, I'm doing some speech processing using Linear Predictive Coding, and I'm trying to use MATLAB to find the feedback coefficients, ai, for a digital filter of the form y[n] = x[n] + Ʃ(ai * y[n-i]) (sum goes from i = 1 to i = N where N is the order of the filter) where n is the index of the sample point, y[n] is the output, x[n] is a pulse input with period equal to the pitch per

## AMR-NB

inHi friends, I have implemented complete AMR-NB Enc-Dec on proprietary DSP chip. As we know AMR-NB works on 8 rates from...

Hi friends, I have implemented complete AMR-NB Enc-Dec on proprietary DSP chip. As we know AMR-NB works on 8 rates from 12.2kb/s to 4.75kb/s. One thing I'll still not clear is - Why in 12.2kb/s rate LPC analysis is done twice as compared to other rates whe

## Help regarding Cepstral Coeffs (LPCC)

inHi , I need some help regarding getting Cepstral coeffs from LPC coeffs. I have found 2 variation for the algo to do this. 1)...

Hi , I need some help regarding getting Cepstral coeffs from LPC coeffs. I have found 2 variation for the algo to do this. 1) One algo (given in fundamentals of Speech recogntion by Rabiner/Juang) says that the initial cepstral coeff is the residual gain term as calculated in the

## Bandwidth expansion in G.723 and G.729

inHello, I am new to Speech Coding. I was reading through the ITU-T specs for G.723 and G.729. Can anyone enlighten me on the...

Hello, I am new to Speech Coding. I was reading through the ITU-T specs for G.723 and G.729. Can anyone enlighten me on the following aspects: The importance of bandwidth expansion after LPC estimation? Why this expansion is different for G.723(7.5 Hz) and

## 50th order LPC

inHi Hari, What ever you have said may be applicable for processing music signals(may be MP3).But G.728 is a speech codec whose...

Hi Hari, What ever you have said may be applicable for processing music signals(may be MP3).But G.728 is a speech codec whose inputs are sampled at 8khz .As a matter of fact,all the basic speech codecs expect input signals which are sampled at 8KHz. So your answer will not be

## line spectral frequencies

dear all i have some difficulties with some algorithms. could anyone explain to me about the LPC and LSF (line spectral ...

dear all i have some difficulties with some algorithms. could anyone explain to me about the LPC and LSF (line spectral frequencies) algorithms that are being used in AMR system? coz i've found out in the ETSI doc or 3GPP doc. not clear enough for me to understand it.

## MELP: peakiness thresholds

Ladies & Gentlemen The additional criterion for voicing measure in MELP is peakiness. For r=1.4 the voicing in the first band is set 1...

Ladies & Gentlemen The additional criterion for voicing measure in MELP is peakiness. For r=1.4 the voicing in the first band is set 1 (strong voicing), for r=1.6 the voicing at second and third bands also set to 1. According to the classical paper "Selective Modeling of the LPC residual during unvoiced frames: White noise or pulse e