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I have a question to everybody. After log10 transfprmation, I have done ordinary kriging in gstat in R? I need to back trnasform the prediction values to orgiginal scale. How do I do this in gstat in R? Thanks Zia -- Zia Uddin Ahmed 915 Brad Field Hall Department of Crop and Soil Cornell University Ithaca NY 14850 USA

Hello Vorbis folks, I'm one of the FFTW authors (www.fftw.org), and a few days ago I was playing with our codelet generator for fun and modified it to spit out hard-coded MDCTs of small sizes. The code (at jdj.mit.edu/~stevenj/mdct_128nr.c) for 256 samples (128 outputs) seems to be almost twice as fast as the Vorbis MDCT code for that size on my 2.2GHz P-IV (gcc 3.2.2 and flags "-O1

After a few experiments, I found that both alternatives are very similar, and 2~5% slower compared to the following: diff --git a/celt/mdct.c b/celt/mdct.c index 1634e8e..e490c3b 100644 --- a/celt/mdct.c +++ b/celt/mdct.c @@ -277,7 +277,7 @@ void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scala it in-place. */ { kiss_fft_scalar * OPUS_RESTRICT yp0 =

I tracked down the bug to an incorrect use of restrict. I would not consider this a compiler bug: we are lying to the optimizer by telling it that a pointer is restrict when in fact it isn't. This can be fixed like so: diff --git a/celt/mdct.c b/celt/mdct.c index 1634e8e..fa5098c 100644 --- a/celt/mdct.c +++ b/celt/mdct.c @@ -276,8 +276,8 @@ void clt_mdct_backward(const mdct_lookup *l,

I am attempting to port CELT to the TI C5515 DSP. I am compiling/assembling/linking with Code Composer Studio 4. I have enabled the TI_55 specific optimizations in my config.h file per this <http://lists.xiph.org/pipermail/celt-dev/2008-December/000033.html> post. However, I am getting several "undefined symbol" linking errors that do not make sense to me. According to the error

My ogg library is located in /home/warren/local. So when I configure and compile the vorbis module on my linux box using configure --with-ogg-prefix=/home/warren/local make I get the following error during the make: gcc -DPACKAGE=\"libvorbis\" -DVERSION=\"1.0.0\" -DHAVE_ALLOCA_H=1 -DHAVE_ALLOCA=1 -I. -I. -I../include -O20 -ffast-math -mno-ieee-fp -D_REENTRANT

Dear Sebastian and all, This is a Japanese to live in Japan. I have a question. Ogg's window functon is f(x)=sin(1/2*pi*sin^2((x+0.5)/n*pi)) for 0 <= x < n But I cannot understand why this window function satisfys the equation f^2(x)+f^2(x+n/2)=2 which is for MDCT's perfect signal reconstruction. reference: Analysis/Synthesis Filter Bank Design Based on Time Domain Aliasing

Hi all, The decoder is down 30% execution time, identical bit output. Didn't get the mdct yet; 1024 point mdct is a bit much to brute-force, and I'm not going to hand-unroll the whole thing either (the machine- unrolled version produced a 1.5M executable; understandably, it wasn't very fast. Still waiting for processors with 1.5M L1 code caches ;-) Slowest parts now are: -- mdct --

Thread-split from the vorbis-mailing list ("Vorbis determined to be as good as MPC at 128 kbps!") <p>On Sun, 30 May 2004, Segher Boessenkool wrote: [Steven So] SS>> If iTunes AAC can encode castanets with much less pre-echo at SS>> ABR 128 kbps, then hopefully there will be an imaginative SS>> (and non-patented) way of doing this in Vorbis without the SS>>

Dear all I'm working on the implementation of the MDCT for the processor ARM-Cortex-M4 I'm trying to replicate the behavior of the MDCT for several overlapped values however I realized that current implementation of the MDCT is very close to the theory only in case in which we have and overlap exactly equal to N/2 where N is the size of the input vector as is shown in the examples for

I've made a block diagram of the encoder because I tried to find out, how it works http://stoffke.freeshell.65535.net/ogg/block.html Although there are specifiation docs, that give very detailed information about single aspects of the encoding (or decoding) , I'm missing documenations that give a more general overview, about how the encoder works. (Vorbis Illuminated seems a bit

Hi Any help is appreciate! These days I studied ogg vorbis encoder with sample rate 44.1kbsp,and I thought the whole chart was as follows: 1. read the PCM data and store them in a buffer 2. do MDCT on those PCM data 3. do FFT on those PCM data 4. use both the FFT and MDCT coefficient to the psychoacustic modle and derive an maximum allowable noise curve, and during this curse ,do the

Hi vorbis-dev! I'm working with Pattara in the oggonachip project, and wondering about the implementation of mdct.c as hardware. According your recomendations about using the floating point version, I would say, we have to implement the integerized version of mdct as a core, and use the fpu only to round the input values. By doing that, you think the result would be still acceptable? How

Dear Experts, Can anybody please direct me to proper MDCT theory reference which will help me understand the code better? I'm trying to optimize MDCT for a embedded platform. So need good understanding about theory behind & implementation. Thanks in advance for your time. Warm Regards, Mahantesh -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hello, I have used "MDCT_INTEGERIZED" version of mdct and the resulting bitstream is absolutely silent. Do I have to make some other changes to the source code to get it working? I mean some int->float or float->int conversion before/after call a mdct function. Thanks Rado --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage:

Hi, Can someone tell me which MDCT and invMDCT equation uses? I implemented the invMDCT one given in eusipco.corrected.ps file (handed out by Monty way back) and it produces different time domain samples. I tried both the FFT method and the slow way directly from the equation and couldn't reproduce the results from the original code. This leads me to believe that the forward MDCT used in

After playing with the vorbis code for a while and doing tons of hacks and analysis on it, I've found it to perform very poorly with impulse signals. The MDCT seems to cause lots of spreading, and it seems to result in much worse impulse performance then mp3. What is the current plan on handling this? Will a smart quantizer be able to avoid it? I've been looking at various ways of

VorbisHi Any help is appreciate. I have two questions. First, I looked into the vorbis-?-specific and was confused by the floor1 algorithm. I think at last the aim is to derive the piecewise curve with the list X and Y,then when encodering ,why not use the selected point orderly to get the curve ? In other words, the specific use the list of [0,128,64,32,96,16,48,80] , why can not use

I found this sentence in the Ogg format specs: http://www.xiph.org/ogg/vorbis/doc/vorbis-spec-res.html "A residue vector may represent spectral lines, spectral magnitude, spectral phase or hybrids as mixed by channel coupling." But where does the spectral phase information come from ? AFAIK MDCT doesn't provide any phase information. And in OGG-encoding, MDCT is taking place a few

Okay, my responsibilities at school have recently eased up a bit, and I might have some actual free time over the coming months. So I'd like to volunteer my services to write some needed documentation, tutorials, FAQs, etc. I am "fluent" in C and C++ and am not bad at Perl. I have been told I'm good at explaining things. I am anal-retentive about grammar, syntax, and