similar to: psycho-acoustic model in ogg vorbis

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

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

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

(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 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

> 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 think that it would be a good thing to know more about those 2 projects (and also the future patent free format). I think that many people as me know about Lame, but not about Vorbis, and vice-versa. It would be fine that someone (perhaps the maintainer) of every project would introduce to both group of people those projects. 2 things would be interesting (to my mind): - to know about the

We all know that currently Vorbis is the only codec out there that doesn't add any silence to the decoded file, so when you decode your .ogg file the resulting .wav will be exactly the same length as the original one. This is very useful when encoding gapless songs (like live concerts...). But since Vorbis is a lossy codec, even though there is no silence added, sometimes you can still hear a

>> When enabling and compiling this with mingw on Win32, my debugger >> complains about heap overruns when calling speex_encoder_destroy(). This >> could be a mingw issue though, as I also found a stackalignment bug which >> prevents me from _USING_SSE (apparantly -mpreferred-stack-size is just >> "prefered" and therefore ignored... *Sigh*). > > Just

Happy new year all! I have had a few issues with this sort of stuff- you could adjust NB_ENC_STACK or SB_ENC_STACK (which ever you may be fiddling with) and see if the problem goes away- could be the allocation for the vorbis psy tables takes up more space than the current stack size allows (not sure how allocated? Could be your settings for supporting alloca/etc. are set different than jm,

Hi Tom, None of the new code depends on the stack allocator, but I just fixed an off-by-one overflow on the heap. Maybe that was the error and your debugger is just reporting a wrong offset. Could you try what's in the current svn (you were using svn already, right)? Jean-Marc > I have had a few issues with this sort of stuff- you could adjust NB_ENC_STACK > or SB_ENC_STACK (which

> When enabling and compiling this with mingw on Win32, my debugger > complains about heap overruns when calling speex_encoder_destroy(). This > could be a mingw issue though, as I also found a stackalignment bug which > prevents me from _USING_SSE (apparantly -mpreferred-stack-size is just > "prefered" and therefore ignored... *Sigh*). Just so I understand, the

I first downloaded Vorbis about a month ago, around the time Rok Papez posted comparisons of Ogg and Lame [*]. Here's my much rougher test on a single file. CPU: AMD K6-233 MP3: LAME 3.70, mp3blaster 2.0b6 Ogg: Vorbize 0.6 (Xiphophorus libVorbis I 20000718), ogg123-0.1 Data set: Ministry, "The Fall" (51,955,724 byte WAV) * * * Ogg Vorbis command line: time vorbize -v -w

Hi All, In order to deal with acoustic echo cancellation problems of most PCs which sound cards have different capture and play frequencies. I made a trial. At first, a 1000Hz sine wave is played for a long time via a speaker and its acoustic echo is recoreded. Seconds, get the frequency of the echo by a FFT analyser. So the difference between capture and play frequencies is obtained. Thirdly,

Thank you, Andreas Engel. I downloaded the white paper of the Fraunhofer Acoustic Echo Control. http://www.iis.fraunhofer.de/bf/amm/download/whitepapers/Acoustic_Echo_Control-wp.pdf It said > "In the Fraunhofer Acoustic Echo Control, the frequency spectrum of the microphone signal is > modified so that the undesired echo components are removed from the signal transmitted to > the

Hi! Why is Ogg Vorbis better than mp3? Which basic technologies has Ogg Vorbis, that f.ex. lame doesn't have? Ogg Vorbis has a different psycho model than mp3, but what is the names of these models and what is the differences? Which advantages have Ogg Vorbis, that cant be implemented in mp3/lame due to compability reasons? <p>Thanks in advance! <p><p>--- >8 ---- List

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 all, We have discussed so many about sampling rate asynchronous (or offset) between rendering (D/A converter) and capturing (A/D converter) of most PC soundcards. It seems all acoustic echo cancellers, include AEC in speex, can not deal with this trouble, because it causes a drift of echo path and also buffer overflow and underflow which jumps the delay of echo path seriously. Unfortunately,

Hello everyone, I'm a student at the Universtiy of Delaware, and will be soon starting some research on the effects of lossy audio compression on speech sounds. I will be preforming test with both mp3 and vorbis. First of all, if I use the '--ogg' switch to lame, does lame use GPSYCHO to encode the wave, or some other psychoacoustic model (perhaps one designed for

Hello? My name is Hyeonwoo Oh. I?m developing video conference software using speex library. Can you give me some sample codes for acoustic echo canceller and noise reduction? I tried noise reduction API, but failed. Normal encode/decode API is working well. Thank you very much for your good job. I?m very pleased with speex. Best regards, Hyeonwoo Oh