similar to: Paper on Speex and Vorbis

(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, Does anyone have an idea about the possibility to apply psychoacoustic models as the ones in mp3 or AAC to a CELP coder? Thanks! /Pontus <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the

Hello, I'd like to know there is any place (web, document...) where I can see which the vorbis' psychoacoustic model is, at least for the reference encoder (how it works, algorithms, filter banks, scalefactors, etc., or if it doesn't use any of this things at all...), or if the only way of looking at it is within the psy.c. I've been looking for it in the Vorbis' site and in

> Does anyone have an idea about the possibility to apply psychoacoustic > models as the ones in mp3 or AAC to a CELP coder? Thanks! > /Pontus This is (sort of) done in the decoder with the optional perceptual filtering. Speex tries to shape the noise so that it sounds more pleasant, I believe. To really use perceptual coding, one would require fine granular control over quantization

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

Hi, I chose speex initially because i had some work in VQ on speex i.e. modifying split VQ to GMM based parametric VQ and I thought If I train the GMM based VQ codebooks with audio signal and then do audio coding with speex, I probably get a better(smaller) residual signal even with speex. But I couldnt get that. I was trying to get a lossless bitstream by MUXing the speex-bitstream and the

I am studying the speex 1.0.5 C source code ,but i feel it is hard to understand the code ,especially the ltp.c and filters.c file. may you tell me the detail algorithm or the more detail notation of the source code of this two file.including below functions void open_loop_nbest_pitch(float *sw, int start, int end, int len, int *pitch, float *gain, int N, char *stack); float

We've implemented a vorbis decoder based on Tremor and as part of the documentation we're also writing about psycho acoustic models and encoding. We're quite up to date with the decoding process and psycho acoustics in general but unfortunately not on the psycho acoustic encoding used in Vorbis. We have a few questions that would we would be very thankful to have answer to: Which

Hi, I have looked through the documentation available from the downloads and the web and haven't yet come across a block diagram which shows exactly how the process of going from a .wav file to a .ogg file works. I suspect it is the same as the mp3 process (with a different psychoacoustic model). I found this document:

Hi, I have looked through the documentation available from the downloads and the web and haven't yet come across a block diagram which shows exactly how the process of going from a .wav file to a .ogg file works. I suspect it is the same as the mp3 process (with a different psychoacoustic model). I found this document:

After reading http://mp3.radified.com/mp3.htm I sent Rad an explanation of some things as I understand them. He liked it and posted it on his site (still unlinked, use the URL below). Can somebody with better understanding of psycho-acoustic terms and the vorbis model check it and comment on it? In particular I didn't know how vorbis handles quantization noise. If you reply with

Hello kind developers, I am planning on creating a steganographic extension for speex/CELP. Since speex/CELP is lossy, there should be quite many bits that one can use for hiding data. I'm familiar with the principles of CELP (two filter loops, one for pitch, the other for formants, let the raw speech frame run through those filter loops, take residue signal, map it on a codebook entry,

I wonder what psycho-acoustic model is used in ogg vorbis. Did they create their own model (this requires big listening tests) ? Or is it something that was already there, like gpsycho ? <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org'

Hi everyone, For those who like to play with experimental stuff, I've got something new to test. If you compile with --enable-vorbis-psy , Speex uses a variant of the Vorbis psycho-acoustic model to shape the coding noise. So far, I've obtained a slight increase in quality, but I'm interested in feedback from others. This still needs a lot of tuning and has received only a minimal

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hello everybody, first of all I want to excuse myself for crossposting. I can't estimate which mailinglist could be the right one for our concern. Struktur AG, member of the Linux Solutions Group e.V., wants to announce an Open Source tender for an implementation of an audio codec compatible with Nellymoser Asao Codec. Struktur wants to pay

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hello everybody, first of all I want to excuse myself for crossposting. I can't estimate which mailinglist could be the right one for our concern. Struktur AG, member of the Linux Solutions Group e.V., wants to announce an Open Source tender for an implementation of an audio codec compatible with Nellymoser Asao Codec. Struktur wants to pay

> Hi everyone, > > For those who like to play with experimental stuff, I've got something > new to test. If you compile with --enable-vorbis-psy , Speex uses a > variant of the Vorbis psycho-acoustic model to shape the coding noise. > So far, I've obtained a slight increase in quality, but I'm interested > in feedback from others. This still needs a lot of tuning

> I have one doubt again, that is Vorbis use DCT/MDCT based algorithm > and also use psychoacoustic model so this is lossy codec. Speex is also a lossy codec. > And I dont think it ca regenerate a better matching waveform than > speex. At bit-rates above 32 kbps, Vorbis tends to produce better results than Speex, even for speech. The only advantages of Speex over Vorbis at these

thanks for the support.i am a masters student who is doing thesis to work on the CELP algorithm specifically calculating the time,space complexities of the algorithm.so i jus need your help i.e if u can show me the site or forward the material where i can get the time the calculated time complexity of your Speex CELP algorithm and i can pick it from there.PLEASE Send instant messages to your

Hello Jean-Marc and all, I recently had a talk with somebody about CELP. He said, there is this federal standard 1016 (4.8kbps) with a reference implementation of the Department of Defense (only on Sun, unfortunately, if I got this right). This one is noticed in the manual already. He also said, since there is this implementation of the DoD, nobody would voluntarily re-implement CELP. If I read