similar to: Modified discrete cosine transform

The Vorbis audio format, uses something called the Modified Discrete Cosine Transform (MDCT). I was interested in how this worked, but did not know where to start. Is this the name of a particular algorithm, or does it just mean something like a cosine transform, but not quite right? So I asked the Vorbis mailing list. Nobody answered. It was not a high priority, so I did other things for

I've been trying to tackle the vorbis source. I ran across what I think is a missing dependency in the vorbis-tools directory. Since ogg123 and vorbize are staticly linked to libvorbis and vorbisfile, when those file change, the executables should be rebuilt. Below I've attached a patch. (I hope it works. I am sort of new to patch and diff.) BTW, I've been trying to find a good

...as promised. This describes the mdct used in my d.m.l patch. I think it is the same as the Lee fast-dct. I typed it in a kind of pseudo-TeX, 'cause the ascii art would kill me. Hope you can read TeX source; if not, ask someone who can to make a .ps/.gif/.whatever of the TeX output, and put it on a webpage or something. I'm to lazy to do it (and besides, I don't have access to TeX,

Hello, I am thinking about plugging in Discrete Wavelet Transform as described in Vorbis I spec: 1.1.2. Classification Vorbis I is a forward-adaptive monolithic transform CODEC based on the Modified Discrete Cosine Transform. The codec is structured to allow addition of a hybrid wavelet filterbank in Vorbis II to offer better transient response and reproduction using a transform better suited to

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

I'm in teaching mode, kernel densities. {History: density() was newly introduced in version 0.15, 19 Dec 1996; most probably by Ross or Robert } When I was telling the students about different kernels (and why their choice is not so important, and "equivalent bandwidths" etc,etc) I wondered about the "Cosine" in my teaching notes which is defined there as k(x)

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

I did composition of butterfly8 and butterfly16 and I found, that these functions are well decomposed - decomposition doesn't lower computional speed. On the other hand the same can be done with butterfly8 - decomposition to butterfly4 (further decomposition is not possible) but there's no reason to do this. I think little improvement can be done by inlining them. Compiler and processor

Dear all. According with my question. CELT CFFT size configuration I'm not completely sure about how the kiss_fft works for sizes which are not power of two, as occur in the case of celt which calculate the mdct using a fft sizes of 480, 240, 120, and 60, I guess that internally the input data is padded with zeros in order to compute efficiently the mdct using the Cooley and Tukey

Dear all, below you find enclosed my message from January 9th and my program (attention: beginner). Thanks for both answers! a. However, as far as I know the cosine is not the same as the Pearson correlation (only in special cases). b. Reid Huntsinger's hint was very useful, however I had to transpose the matrix first, for I want to calculate the distance of the _rows_. Regards, Petra

Dear all, Sorry for this simple and maybe stupid question, I'm working in the implementation of opus for ARMv7e microcontroller using a library CMSIS/DSP used to calculate the CFFT and MDCT based on the DCT-IV. my question is: In the implementation of Celt you have used a fixed length CFFT equal to 1920, I want to know if there is some issues which can appear if a change that configuration

Hello, a. is there a possibility to obtain a distance matrix with the cosine between vectors?? hclust, hierclust, dist will not work and seem to be hard to extend. b. if there is not: Is the cosine between vectors implemented somewhere? Thanks for all hints and advice! Petra Steiner -------------- next part -------------- An HTML attachment was scrubbed... URL:

does anybody have a suggestion as to how to use R to fit some date to a cosine function and then have some output statistics that will evaluate the fit? -- View this message in context: http://r.789695.n4.nabble.com/cosine-curve-fit-tp4650866.html Sent from the R help mailing list archive at Nabble.com.

I have been thinking about what is needed to make language teaching/learning tools. (Like talking flash cards.) The main thing needed is a low bit-rate encoding of human voice. At first I thought I could take one of the gevernment standard vocoders and embed it as an Ogg stream. But: (1) there is not a standard vocoder, there is are half a dozen, at least. (2) they are fixed bit rate, we

OK, into the nitty-gritty, albeit a high-level version. If it sounds like I'm glossing important details, you're right. This discusses only the basic DSP; precise coding, framing, sync, etc, will be in another mail. Vorbis is a hybrid transform domain general purpose audio encoder, like MPEG in some respects (it is rooted in much of the same basic theory). For the most part, the

Hi everybody! I have intended to use library(lsa) on R 64-bits for Windows but it was not possible. Every time I try to launch library(lsa) function R give me back next message: Loading required package: SnowballError : .onLoad failed in loadNamespace() for 'Snowball', details: call: NULL error: .onLoad failed in loadNamespace() for 'rJava', details: call: stop("No

Hi: I am trying to implement interval arithmetic through llvm. I have a problem with the rounding mode with llvm.experimental.constrained.cos I have two pieces of codes: ; Function Attrs: norecurse nounwind readnone ssp uwtable define double @cosine_down(double returned) local_unnamed_addr #0 {   ; call the llvm intrinsic to perform downward cosine

Hi lily, You can get fairly good starting values just by eyeballing the curves: plot(y) lines(supsmu(1:20,y)) lines(0.6*cos((1:20)/3+0.6*pi)+17.2) Jim On Wed, Jun 21, 2017 at 9:17 AM, lily li <chocold12 at gmail.com> wrote: > Hi R users, > > I have a question about fitting a cosine curve. I don't know how to set the > approximate starting values. Besides, does the method

Hello, I am not expert in wavelet. i am working with a discrete dataset in 3D. I applied the D4 wavelet transform to each dimension sequentially. I made some analysis in the transformed space and i detected some interesting vowel. My question is. How is it possible to map a 3d coordinate in the transformed space to the related coordinate in the 3d original dataset? (i think that probably one

Hi, I have one doubt again, that is Vorbis use DCT/MDCT based algorithm and also use psychoacoustic model so this is lossy codec. And I dont think it ca regenerate a better matching waveform than speex. Then there comes FLAC which is the perfect answer to my question, I suppose. But my concern is this that FLAC use simple prediction algorithm and doesnt use any CELP based algo which could have