search for: suppressor

...hines I have tested. I am trying to put together a "backup" strategy to cover the cases where it does not work. I might eventually settle for detecting non-convergence and enforcing half-duplex in that case, but I'd like to better than that if I can. I initially assumed that the echo suppressor is similar to other echo suppressors (also called "nonlinear processors" or "loss controls"). Those suppressors use cruder algorithms that exhibit artifacts but that may not depend on the fine time structure of the audio signals. Is this not true of the preprocessor echo suppres...

...ression Selon "Coffey, Michael" <mcoffey@avistar.com>: > Believe me; I've "played with" priorities and buffering. Then either you haven't played well enough or you're using a braindead OS. > Did you just say you have no idea how the Speex residual echo suppressor > works? If that is the case, can you tell me where I could get some > information about it? What I'm saying is that I've no idea how the residual echo suppressor reacts when it's used in a way it wasn't designed for (i.e. working around broken audio capture/playback). Je...

Believe me; I've "played with" priorities and buffering. Did you just say you have no idea how the Speex residual echo suppressor works? If that is the case, can you tell me where I could get some information about it? -----Original Message----- From: Jean-Marc Valin [mailto:jean-marc.valin@usherbrooke.ca] Sent: Friday, June 29, 2007 7:38 PM To: Coffey, Michael Cc: speex-dev@xiph.org Subject: Re: [Speex-dev] Backup Echo Sup...

What is the current status of the residual echo suppressor in the preprocessor? I ask this because I have occasional problems with the AEC, in which it fails to cancel echo. I think the problems have to do with samples being dropped by the audio IO system, which is effectively impossible to detect and counteract reliably. A colleague recommended using an...

Hello, I resolved my echo issue using grandstream/estara etc etc sip phones and wcfxo interfaces from digium. I swapped out my via kt400 based msi kt4vl motherboard for an asus p4pe? i845? based motherboard and the echo has completly gone away along with aggressive suppressor option in the makefile. I hope this helps others. Brian J. Schrock Anistone Technologies, LLC 6926 Avery Rd. Dublin, OH 43017 Phone: 614-798-9106

...ey, Michael" <mcoffey@avistar.com>: > > Believe me; I've "played with" priorities and buffering. > > Then either you haven't played well enough or you're using a braindead OS. > > > Did you just say you have no idea how the Speex residual echo suppressor > > works? If that is the case, can you tell me where I could get some > > information about it? > > What I'm saying is that I've no idea how the residual echo suppressor reacts > when it's used in a way it wasn't designed for (i.e. working around broken > a...

Selon "Coffey, Michael" <mcoffey@avistar.com>: > Believe me; I've "played with" priorities and buffering. Then either you haven't played well enough or you're using a braindead OS. > Did you just say you have no idea how the Speex residual echo suppressor > works? If that is the case, can you tell me where I could get some > information about it? What I'm saying is that I've no idea how the residual echo suppressor reacts when it's used in a way it wasn't designed for (i.e. working around broken audio capture/playback). Je...

...he amount of buffering you do. Also, there are sometimes ways to make sure that the drops don't change rec/play synchronisation (the key is the sync, not the lost samples). As for how the residual echo suppression works, I've no idea, you need to try. > I initially assumed that the echo suppressor is similar to other echo > suppressors (also called "nonlinear processors" or "loss controls"). > Those suppressors use cruder algorithms that exhibit artifacts but that > may not depend on the fine time structure of the audio signals. Is this > not true of the prepr...

...o suppression is supposed to be working decently well now. However, it's not designed to counter the effects of samples being dropped off the soundcard. You'll just need to fix that problem for real. Jean-Marc Coffey, Michael a ?crit : > What is the current status of the residual echo suppressor in the > preprocessor? > > I ask this because I have occasional problems with the AEC, in which it > fails to cancel echo. I think the problems have to do with samples being > dropped by the audio IO system, which is effectively impossible to > detect and counteract reliably. &gt...

I've got echo problems. *** I'm looking for paid support. *** I'll accept free support, but don't mind paying if someone really knows what they are doing. I've read the wiki, etc. Played with the settings in zapata.conf Using V400P PSTN->_T1->_ASTERISK->_BROADVOICE->_PSTN ECHO ON CALLED PHONE PSTN->_T1->_ASTERISK->_T1->_PSTN NO ECHO

...e seeing, though, is that the canceller seems to take some time (a few seconds) to "learn", so initially the echo is clearly audible and it slowly fades out. This sometimes occurs in the middle of a call as well (the echo becomes loud again and fades away in a few seconds). With the echo suppressor enabled, the learning time seems to drop, but the final echo remains higher than without suppression, and is still sufficiently audible to be annoying. Is this known behaviour? Any clues w.r.t. what might be going wrong? Cheers, Arun

Hi, We are looking at consolidating our lines with PRI. This will allow the elimination of many fax lines. Some of them will be replaced with this type of config ... PRI * IAX * Channel-Bank FAX We will have daggressor suppressor enabled. Is anyone doing this and should I expect smooth operation? John This e-mail was scanned and found clean by Monroe-Woodbury CSD Antivirus.

I'm having trouble with the preprocessor's noise reduction feature. The basic issue is that it simply doesn't work very well. With my laptop (whose microphone is otherwise quite capable) I routinely hear transient background noise, typing, and other "quiet" sounds leaking through to the speex stream. Even worse, the AGC feature is blowing these things up into just awful

...nely hear transient background noise, typing, and other "quiet" > sounds leaking through to the speex stream. Even worse, the AGC > feature is blowing these things up into just awful explosions and > whines. It may sound odd to you, but there's actually no way for the noise suppressor to know whether you want to keep these sounds or not. The noise suppressor will only attempt to remove stationary noise, such as thermal noise, fans, ... The AGC can indeed do strange things in these cases, but it's been improved in svn (compared to 1.2beta1). > Honestly, it works so badly...

...sion in speex works, but I have some > knowledge in the area of noise suppression. > > In general, if you have information about the nature of the noise you > are trying to suppress, you can do much better than just assuming white > noise. Nobody assumes white noise. The Speex noise suppressor applies an MCRA-like algorithm to estimate the noise and then it has a spectral amplitude estimator (similar to Wiener, but with a better criterion than MSE). Jean-Marc

Like most others on this list I also have some really annoying echo whenever a call goes out to the PSTN from a SIP phone... SNOM/Budgettone -> Asterisk -> X100P -> PSTN I have tried every echo canceler in the makefile and turned on and off aggressive suppressor etc. etc. etc. tried 32,16,128, and 256 bridgetaps and I can get it reduced to only a few seconds on the intro of the call and after silence, as well as a really annoying beep every so often, and some audio artifacts. I am using KT400 VIA based motheroards MSI KT4VL and x100P and the new tdm400p....

...s a good thing to do, but you need to be really careful when doing that because: 1) Any change in the analogue gain automatically de-adapts the echo canceller so you only want to do that when really necessary (e.g. clipping screws up the EC anyway) 2) The processing chain goes "AEC -> noise suppressor -> AGC", but for the analog gain, you really want to measure the signal that goes into the echo cancellation, not at the AGC. Otherwise, you risk increasing the analog gain to a level that creates clipping before the AEC (even if the signal at the AGC is lower. Hmm, or does that mean the a...

...e using grandstream/estara > etc etc Brian> sip phones and wcfxo interfaces from digium. I > swapped out my Brian> via kt400 based msi kt4vl motherboard for an > asus p4pe? i845? Brian> based motherboard and the echo has > completly gone away along Brian> with aggressive suppressor option > in the makefile. I hope this Brian> helps others. I'm curious if you tried experimenting with any settings in the via kt4vl bios? Or did you just swap motherboards first? For bios settings, I mean things like timing settings or other PCI bus attributes, even memory speeds....

...What did you do to the phone...it sounds terrible!") Any ideas or suggestions? Will the path affect the rxgain setting? Will that need to be re-adjusted? What would cause echo to show up on the TDM400P FXS phones? Is the success people are seeing with the echo patch using the AGRESSIVE suppressor? Thanks in advance, Ed Rubright

...e been pretty happy with the flexibility and ease of *. My major problem is one that has been discussed on this list many times before. The echo from the X100P cards is completely irritating to my users. I have tweaked the system as much as I can, IE: switching tip and ring, using aggressive suppressor, tweaking the TX/RX settings. There is still echo in the first 0-8 seconds of the call while the echo cancellation is catching up. I understand the problem is that you do not hear this echo in analog systems even though it is present and it is only heard in the digital system because it is no...