search for: agc

HI Philippos, Try this: dat1<- read.csv("Validation_data_set3.csv",sep=",",stringsAsFactors=FALSE) #converted to csv str(dat1) #'data.frame':??? 12573 obs. of? 17 variables: # $ Removed.AGC????????????????????????????? : num? 65.67 46.17 41.26 14.09 5.38 ... # $ Removed.SST????????????????????????????? : chr? "" "46.1658" "41.2566" "14.0931" ... # $ Removed.Kurtosis???????????????????????? : num? NA NA NA NA 5.38 ... # $ Removed.Skewness????????...

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)...

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 a...

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 >...

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 party is recorded in a different channel? Thank you, Yanick Bourbeau

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

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 havin...

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 inte...

...me length is 2880 samples and the sampling rate is 48000. The source of the data is a microphone using ALSA. That platform is Ubuntu. The version of speex is 1.2rc1. When I run with the default settings, the audio seems OK. It's not clear if preprocess is actually doing anything. If I turn AGC on, the sound level becomes almost inaudible. When I print the control parameters (the defaults), I get: DENOISE = 1 AGC = 0 AGC_LEVEL = 1174011904 AGC_INCREMENT = 12 AGC_DECREMENT = -40 AGC_MAX_GAIN = 30 VAD = 0 DEREVERB = 0 NOISE_SUPPRESS = -15 QUESTION number 1: Is there a guide to "tunin...

Steve, You're right. The AGC gain does not max out when using VAD (via the preprocessor). So instead of not transmitting when the AGC max gain is reached, I now do this instead: Start the call with VAD enabled and AGC disabled. When speech is detected, disable VAD (if 100% continuous transmission is desired for the call) an...

Hello All, I'm using speex codec in ARM based embedded project and really satisfied by its performances and quality (thanks a lot for speex development team for great work!). I'd like to add AGC functionality and as I actually understood it is not supported in FPU-less platforms. Is it correct? If it is, do you have any updates of preprocessor or an experience to run AGC in FIXED POINT mode? Thanks a lot in advance, Michael. -------------- next part -------------- An HTML a...

Hi, The leakage problem you describe is very, very common and you will need to do something to address it. I modified the version of Speex I use to implement an adjustable max gain. If you look at speex_compute_agc in preprocess.c, you will see: if (agc_gain>200) agc_gain = 200; This max of 200 is usually more than enough to amplify leakage which occurs either in the sound hardware or in a headset to the point where it is as loud as normal speech. You can replace this max of 200 with a confi...

>> 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 to increase a...

> As you can tell, the AAGC integration with speex was really a classic > hack. Instead of re-creating the hack, what's probably best here is to > integrate AAGC back into speex, and have a proper API. Agreed here. If you can come up with a clean patch to add that feature, it's something I'd like to see in...

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, > > > > > > > > I'm using speex codec in ARM based embedded project and really satisfied > > by its performan...

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 adaptatio...

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...

...me length is 2880 samples and the sampling rate is 48000. The source of the data is a microphone using ALSA. That platform is Ubuntu. The version of speex is 1.2rc1. When I run with the default settings, the audio seems OK. It's not clear if preprocess is actually doing anything. If I turn AGC on, the sound level becomes almost inaudible. When I print the control parameters (the defaults), I get: DENOISE = 1 AGC = 0 AGC_LEVEL = 1174011904 AGC_INCREMENT = 12 AGC_DECREMENT = -40 AGC_MAX_GAIN = 30 VAD = 0 DEREVERB = 0 NOISE_SUPPRESS = -15 QUESTION number 1: Is there a guide to "tunin...

Hi Thank you for your work. We are trying to use the speex SW with a C6000 TI DSP. I am working with an HW codec that does AGC by HW inside. Will doing the AGC before the preprocessor make a problem? Does VAD work well in a noisy eviroment? In SW there are some remarks on things to be fixed, can I count on SW as working or are some part still to be improved. I also tried to understand SW but I guess I was unable to. Where...

Jean-Marc Valin wrote: >> As you can tell, the AAGC integration with speex was really a classic >> hack. Instead of re-creating the hack, what's probably best here is to >> integrate AAGC back into speex, and have a proper API. >> > > Agreed here. If you can come up with a clean patch to add that feature, > it...