similar to: integerization

Hey. The problems with Levinson -type algorithms and integrization are well known. Older codecs have usually solved the problem by using Schur decomposition for inversion of the autocorrelation matrix instead of Levinson. Another solution sometimes used is to use double precision - in this case you probably could code some pseudo-64bit implementation (using only 32bit commands), but that

Le ven 27/06/2003 à 05:10, Christian Buchner a écrit : > Hi there. > > Just a little status update how that integerization is coming along. > I am trying to limit myself to 32 bit arithmetics. That means > not using any __int64 or long long datatypes at any point. If possible, it would be nice to restrict ourselves to 32x32->64 multiplies, so the code could run on almost any

hi, am trying to understand speex's algo. have a few questions. 1) autocorrelation: in the function, _spx_autocorr (for floating point version), there is a line ac[0] += 10; correct me if i am wrong, i suppose the addition of 10 is used to condition the autocorrelation matrix. wonder how the value of 10 is arrived at? 2) levinson durbin (LD) algo in the function _spx_lpc, i referred

(This is almost out of topic but anyway...) It is surprising how little research effort have been put into psy-acou models for CELP. The basic problem lies in that it is not easy to alter the LP model without distroying the minimum-phase property (ie. the stability of the predictor). That leaves us with psy-acou modelling of the noise-part only. However, my own research is in constrained

Hi, I wanted to understand exactly how acf and pacf works, so I tried to calculate ac and pac manually. For ac, I used the standard acf formula: acf(k) = sum(X(t)-Xbar)(X(t-k)-Xbar))/sum(X(t)-Xbar)^2. But for pac, I could not figure out how to calculate it by hand. I understand that in both R and EVIEWS, it is done using the Durbin-Levinson algorithm by the computer. However, I don't

I generated a new rails app then installed rspec and rspec_on_rails from trunk. I then created a sample story: require File.dirname(__FILE__) + "/helper" Story "View Home Page", %{ As a user I want to view my home page So that I can get a birds eye view of the system }, :type => RailsStory do Scenario "Publisher with no videos" do When

There is an option "--reverse" to run examples in the reverse order which is good for detecting inter-dependencies between examples. Is it feasible for rspec to automatically switch between "forward" and "reverse" order each time a spec is run? My goal is to detect inter-dependencies sooner than later... Thanks Alvin.

Since two people have asked me to open the source code on my work-in-progress Integer Speex project, I have put it up onto my site www.openacm.org as a download in the project tree. the suggested directory structure is as follows, i.e. the speex source folder should be on the same directory level as the sphinx filder. peex-1.0.1 (ideally the folder from within the SpeexACM source archive)

> 3) a more general question: > i have not been able to find any reason why > 10 lpcs are used. i suppose 10 lpcs are > enough for prediction and using more coeffs > would not have made too much difference. > and 10 is even, good for lpc->lsf. had read > somewhere "historically", during the analog > era, this number is used. or maybe 10 is analagous > to

I'm copying the flac-dev list to see if anyone has any feedback also... --- Juhana Sadeharju <kouhia@nic.funet.fi> wrote: > Hello again. I had time to check the paper out. I have filled the > steps given in the paper with formulae, and then written a piece of > C code. It is not complete code, but could be a reasonable start. > Maybe there is one typo in the paper -- I have

(Disclaimer: this is not an LPC vs. LSP question) After looking at the Vorbis code I was wondering why you were using LSP to quantize the spectral envelope instead of simply quantizing the cepstrum (DCT(log(envelope))) or modified cepstrum (DCT(envelope.^alpha)). To me it seems like when the information is already in the frequency domain, there's no need to go back to LPC. Also, I think a DCT

After trying RailsStory for a few days, I have learned: 1. Rails testing support does not serve up static pages 2. RailsStory masks errors generated by the app under test 3. The masked errors are available in log/test 4. I should read log/test more often See http://pastie.caboo.se/107876 for an example for points 2 and 3 The welcome controller fails when the HTTP_USER_AGENT is missing.

Hi, I am currently encoding 32 Khz/Qual-10/UWB encode mode, with MANUAL_ALLOC enabled ( similar to the c5x/c6x configuration). In file sb_celp.c, I noticed the scratch memory grow during recursive (UWB -> WB) calls to 'sb_encode'. 1. 'stack' was not tracked (with 'tmp_stack' as done at other palaces) after/before - auto-correlation/Levinson-Durbin scope (~line

Hi Jean-Marc I'm looking at the 1.0.5 source, and I'm not seeing an _spx_lpc(). There's an _spx_autocorr(), which is in lpc.c and is called near the start of the encoder function in nb_celp.c. The encoder seems to call the autocorr() function, then calls wld() to do something called Levinson-Durbin. Am I right in thinking that after the call to wld(), the st->lpc[] array

O.k., some more info: I just tested bandwidth widening to fix this. But I need to go to gamma values below 0.9 to become stable -- clearly too much widening, I think. I looked inside the Levinson-Durbin algorithm next. The lines #ifdef FIXED_POINT r = DIV32_16(rr+PSHR32(error,1),ADD16(error,8)); #else r = rr/(error+.003*ac[0]); #endif look interesting. While for floating point,

> check the resulting file for subset blocksizes, sample rates, bits per sample, LPC filter order and rice partition order. That's all parameters that I need to check? FLAC tools have a lots of warnings about non-subset files during encoding, but unfortunately don't have easy way to check/test existing FLAC stream for subset compliance. "flac -a" generates the big text file

Hi, I'm looking for more documentation on the Vorbis bitstream format. The goal for me is to write an optimized decoder using only integer or fixed point math for use on the Phatnoise Car Audio System (see http://www.phatnoise.com). I've already found the info on the Ogg framing system and I've already written my own thing for parsing through Ogg frames (easy). Also, is RTP

In a newly downloaded version (today) of R-2-4-0alpha, with all packages from CRAN also installed today, I get: > library(Matrix) Erro en loadNamespace(package, c(which.lib.loc, lib.loc), keep.source = keep.source) : in 'Matrix' methods specified for export, but none defined: BIC, anova, coef, confint, deviance, fitted, fixef, formula, head, lmer, logLik, mcmcsamp, plot,

With rspec 1.0.8 I have a spec in the directory: spec/units/controllers/application_controller_spec.rb require File.dirname(__FILE__) + ''/../../spec_helper'' class DummyController < ApplicationController def index raise "Prevent index from rendering" end end describe ApplicationController, "Handling errors in production", :behaviour_type =>

I thought that the function eigen(A) will return a matrix with eigenvectors that are independent of each other (thus forming a base and the matrix being invertible). This seems not to be the case in the following example A=matrix(c(1,2,0,1),nrow=2,byrow=T) eigen(A) ->ev solve(ev$vectors) note that I try to get the upper triangular form with eigenvalues on the diagonal and (possibly) 1 just