search for: agc_gain

...e 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(): if (!st->agc_frozen) { agc_gain = st->agc_level/st->loudness2; /*fprintf (stderr, "%f %f %f %f\n", active_bands, st->loudness, st->loudness2, agc_gain);*/ if (agc_gain>st->agc_max_gain) /* was 200 */ agc_gain = st->agc_max_gain; /* was 200*/ } else agc_gain = st->agc_gain;...

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...

...g as it listens for something useful. For example, as I tested this today, the faint sound of birds chirping outside was enough to prevent the AGC from spazzing out! Anyway, what I propose are the following commands to let an application interface a little more with the AGC: SPEEX_PREPROCESS_GET_AGC_GAIN SPEEX_PREPROCESS_GET_AGC_MAX_GAIN SPEEX_PREPROCESS_SET_AGC_MAX_GAIN I've implemented these and use them for the following: 1) I display the current AGC gain to the user. 2) If the AGC gain has reached its maximum, I don't transmit any audio. This condition indicates to me that the AGC ha...

...ou speak, does the level of the > noise start going up again? > Ah, apologies, I should have mentioned that. This is against current SVN (rev 12997), built on Win32 with mingw gcc 3.4.5 using SSE. 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 little bit. If I understood...

...easons, so I tried just making SpeexPreprocessState visible again, but it turns out neither of these members are present in the new SpeexPreprocessState_ structure anyway. I was able to re-create the speech_prob member by setting it from Pframe before speex_preprocess_run returns, and I've used agc_gain as the basis for adjusting the mixer (i.e. if agc_gain is high, the input is low, so turn the mixer up and v.v.). This appears to be effective. So is there a way to make these items available to speex clients? The speex_preprocess_ctl interface could be extended, but it's not really what it...

> 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 little > bit....

>> 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 littl...

...========================================================== --- libspeex/preprocess.c (revision 14530) +++ libspeex/preprocess.c (working copy) @@ -236,7 +236,6 @@ float *loudness_weight; /**< Perceptual loudness curve */ float loudness; /**< Loudness estimate */ float agc_gain; /**< Current AGC gain */ - int nb_loudness_adapt; /**< Number of frames used for loudness adaptation so far */ float max_gain; /**< Maximum gain allowed */ float max_increase_step; /**< Maximum increase in gain from one frame to another */ float ma...

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 -------------- --- speex/libspeex/preprocess.c 2...

...ust making > SpeexPreprocessState visible again, but it turns out neither of these > members are present in the new SpeexPreprocessState_ structure anyway. > I was able to re-create the speech_prob member by setting it from Pframe > before speex_preprocess_run returns, and I've used agc_gain as the basis > for adjusting the mixer (i.e. if agc_gain is high, the input is low, so > turn the mixer up and v.v.). This appears to be effective. > > So is there a way to make these items available to speex clients? The > speex_preprocess_ctl interface could be extended, but it...

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 configurable max gain, which is what I've done....

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

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.

Hi, Here are the next two patches for the data export. speex_get_psd should be applied after speex_get_agc_gain (sent in previous mail). It allows applications to get the power spectrum for the signal and the noise estimate. speex_get_prob should be applied last. It allows fetching the speech probability of the current frame (the value that the _PROB_START and _PROB_CONTINUE parameters are compared to i...

...===== --- include/speex/speex_preprocess.h (revision 14443) +++ include/speex/speex_preprocess.h (working copy) @@ -182,6 +182,26 @@ /** Get loudness */ #define SPEEX_PREPROCESS_GET_AGC_LOUDNESS 33 +/* Can't get gain */ +/** Get current gain (int32 percent) */ +#define SPEEX_PREPROCESS_GET_AGC_GAIN 35 + +/* Can't set spectrum size */ +/** Get spectrum size for power and noise spectrum (int32) */ +#define SPEEX_PREPROCESS_GET_SPECTRUM_SIZE 37 + +/* Can't set power spectrum */ +/** Get power spectrum (int32[] of squared values) */ +#define SPEEX_PREPROCESS_GET_POWER_SPECTRUM 39 + +/*...