similar to: A question about AGC usage

Displaying 20 results from an estimated 2000 matches similar to: "A question about AGC usage"

2008 Sep 16
1
A question about AGC usage
Hi, where I can found that patch? Thanks Seif 2008/7/16 Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> > Hi Michael, > > Thorval Natvig posted an experimental patch to get the AGC working in > fixed-point. Can you try that and see if it works well? > > Jean-Marc > > Michael Evseev a ?crit : > > Hello All, > > > > > > > >
2005 Jun 22
1
Speech detection in preprocessor with echo
agc_gain seemed to fit with the idea of what I wanted to do, it was easy to understand its units and behavior, and freezing it produced the desired results. Also I wanted to cap it, so that's done at the same place, and that definitely works. All I want to do is be able to freeze AGC adaptation and put an upper bound on the AGC (for example, 2x amplification). Both of these things seem
2005 Jun 20
1
Speech detection in preprocessor with echo
I think you'll have to modify Speex to get the functionality you're looking for. I've made a few simple modifications to the AGC to prevent it from 1) exceeding a specified level of amplification and 2) enable and disable adaptation, so I can freeze it at a certain level while speech is not detected. It's mostly just a matter of doing this at the end of speex_compute_agc():
2009 May 28
1
DC component coming back after AGC
I'm getting confused, what's the problem exactly? The AGC doesn't remove the DC or it adds one? Jean-Marc Aymeric Moizard a ?crit : > Hi Jean-Marc & all, > > I'm currently working on a wav file with very low volume. > This wav also contains a DC component. > > Using testdenoise with modification (AGC turned on with > 20000.0 value) I'm able to
2004 Aug 06
1
Proposed AGC additions
I've been using Speex's AGC in my VoIP program with mixed results. One of the problems I had was: At the beginning of the call, if the user hadn't spoken yet and there weren't any background sounds for the AGC to lock on to, most of the time the AGC would almost immediately jump way up to 200x gain (the default max). This is undesirable and usually results in nasty feedback. If
2007 May 29
2
Noise suppression less than AGC gain
Hi, I've had a small case with noise suppression and AGC. I have a fairly noisy environment here, and with the default parameters, noise suppression works fairly well while I talk. However, when I shut up, AGC starts slowly increasing the gain until it has amplified whatever noise is left to levels about equal to having no filtering at all. As soon as I talk, AGC backs down fairly quick
2007 Feb 06
2
svn AGC
Hi Jean Marc, I found that the AGC API and algorithm has changed in svn head trunk. Is it safe to use it? Or is it for testing purpose only? You also said that VAD in svn is broken in a previous post, is it related to the AGC change? or can we mix the old VAD algorithm with the new AGC safely? kind regards, fredo
2011 Aug 19
2
AGC on a phone conversation
I have a recorded conversation from an analog trunk. As usual one side is stronger that the other one. In my case, the gap between signal levels are even bigger. How does speex AGC preprocessor will perform on this type of audio recording? Maybe I am wrong and AGC is not really what I need to equalize the two persons in my phone conversation? As I Understand, AGC will perform better if each
2014 Jan 08
1
Some Speex AGC Questions
I'm attempting to use speex preprocess for automatic gain control in an application I'm working on and could use some help. I'm using Opus as my codec. In order to keep the number of packets down, I'm using 60msec frames. I'm sampling at 48KHz as is recommended for Opus. So, the frame length is 2880 samples and the sampling rate is 48000. The source of the data is a
2013 May 18
1
Asterisk 1.8-cert and AGC
Hi, I'm trying to use AGC in combination with Asterisk 1.8 and an odd telephone which is very loud when used with a headset and more quiet when used "normal". Regarding to the documentation, AGC should be available since * 1.6 - but every time I want to set it, the CLI tells me: -- Executing [0160xxxxxxx at intern:2] Set("SIP/intern-xxx-000000d2",
2007 May 29
2
Noise suppression less than AGC gain
Jean-Marc Valin wrote: >> I've had a small case with noise suppression and AGC. I have a fairly >> noisy environment here, and with the default parameters, noise >> suppression works fairly well while I talk. However, when I shut up, AGC >> starts slowly increasing the gain until it has amplified whatever noise >> is left to levels about equal to having no
2008 Mar 18
1
Patch to make SPEEX_PREPROCESS_GET_AGC_GAIN use dB, and _SET_AGC_LEVEL use a int32
Hi, The attached patch fixes an incistency in my earlier patch. Whereas the rest of the AGC ctls are in dB, GET_AGC_GAIN was linear. This patch fixes that. It also changes the API for _GET and _SET_AGC_LEVEL to use a int32 instead of a float, meaning we don't need to do a API change when we get a fixed point AGC. Best regards, Thorvald -------------- next part -------------- ---
2005 Jun 20
1
Speech detection in preprocessor with echo
Echo cancellation works like a charm, but it seems to confuse the preprocessor a bit. If listening to background music (properly fed through the echo cancellator), the music is removed but the result is still detected as speech even if almost silence remains in the signal. Also, the AGC keeps adjusting to the minute remains in the signal, meaning that sooner or later it will amplify the
2007 May 29
2
Noise suppression less than AGC gain
>> Yes, after I stop speaking, the noise slowly starts climbing again, and >> if I peek at st->agc_gain, that's slowly climbing too. I think part of >> the trouble is that the noise in here isn't uniform white noise; there's >> traffic outside the window and people walking in the hallway outside my >> door. Each little event is enough to cause the AGC
2005 Aug 11
1
Help needed regarding AGC
Hello All, I use AGC as one of speex preprocess options in VOIP application. In most cases it works very fine. However, at the very beginning of a call when no one has started talking [ and some times in the middle of calls], AGC makes large noise and it gradually increases. Interestingly, when someone starts talking, from that point it works very well. Is it the normal behaviour? Since
2006 Oct 04
2
Crash in cb_search.c, line 414
Jean-Marc Valin wrote: >> gcc version 3.4.5 (mingw special) > > Can you try 4.0 or 4.1 just to be sure? mingw (native gcc for win32) doesn't officially support using gcc 4.0 and 4.1 yet (apparantly there have been some issues), so there are no binary packages. But if you think it helps, I can compile gcc 4.1 and give it a shot. >> Compile flags: >> DEFINES +=
2005 Nov 04
3
Compile failure current SVN
Current SVN compilation fails on Win32 (Intel C++ compiler 9.0): ..\..\libspeex\mdf.c(317): error: declaration may not appear after executable statement in block float adapt_rate; Just moved it up to the variable declaration block to solve it locally, but as it's not valid C, I thought I'd mention it ;) PS: With the same compiler, AGC fails horribly (Zlast goes to several
2008 May 25
3
FFTW3 for libspeexdsp
Hi, Attached is a patch which enables FFTW3 to be used by libspeexdsp. Using SSE, the FFT code is more than twice as fast, and it's 50% faster even without SSE. To enable the library, you'll need to call configure with '--with-gpl-fftw3'. Based on the benchmarking we did, this also changes the default FFT to smallft for floating point implementations when not using FFTW3.
2006 Jan 23
1
AGC control and how to echo cancellation?
Hi, all. When AGC enabled, I can hear echo and electronic noise. (in newest svn version) In my thought the computed gain value is too big. Which value exactly can affect to max boost level? And I want to implement the echo cancellation. Is there any example? Forgive my poor question. Thanks. -------------- next part -------------- An HTML attachment was scrubbed... URL:
2007 Jun 01
1
Noise suppression less than AGC gain
Jean-Marc Valin escreveu: > > Well, I can change the defaults and then people with different setups > (e.g. no noise and low input volume) will ask me to change it the other > way... In the end, the only fix is to improve the AGC adaptation > decision, including (but not only) the VAD. Could that be a run time variable? So it could be adjusted somehow by a user interface, for