topic Re: Echo and echo level in Intel® Integrated Performance Primitives

Echo and echo level

harald85 — Tue, 05 May 2009 11:19:56 GMT

Hi

I want to use the EC in the kernel mode but the echo has an higher level then the normal signal so I have to decrease the level of the echo. Is there any possibility to do that with the IPP oder did somebody know how i can change the level of an Signal (16 Bit 8KHz)?

Harald

Re: Echo and echo level

Vyacheslav_Baranniko — Thu, 07 May 2009 14:27:33 GMT

Quoting - harald85

Hi

Prior to playing a far end signaloutyou maynormalize it by usingIPP ALC (audio level control) functions:

ippsALCGetStateSize_G169_16s - reports the size of the state memory required for AC algorithm,
ippsALCInit_G169_16s - initializes the state memory of required size allocated by user

ippsALCSetLevel_G169_16s - setstarget (desired)and clipping level in dBm0(with sign dropped).
ippsALCSetGain_G169_16s - sets gain whichcontrols output signal level change rate vsinput. 0 - mingain.

ippsALC_G169_16s - performs ALC.

Vyacheslav, IPP, Speech coding

Re: Echo and echo level

harald85 — Mon, 18 May 2009 13:54:17 GMT

Hi
The function works very well. I use it with the parameters:

ippsALCSetLevel_G169_16s(6.f, 6.f, pALCState);
ippsALCSetGain_G169_16s(0.f ,pALCState);

But know the level is too low. In which function and with which parameter can i choose the level of the file?

Harald

Quoting - vbaranni

Re: Echo and echo level

harald85 — Tue, 19 May 2009 07:52:47 GMT

Hi

I changed the parameters for gain and level but the result is always the same. With level 6.f and gain 0.f is the result to low and the Nr clears the signal. So which parameter must I change to increase the level of the result?

THANKS

Harald

Quoting - harald85

Re: Echo and echo level

Ivan_Ryzhachkin__Int — Wed, 20 May 2009 07:08:09 GMT

Quoting - harald85

Hi,
you may try the lower levels. For exampe:

ippsALCSetGain_G169_16s(0.f ,pALCState); //ippsALCSetGain_G169_16s - sets gain which controlsoutput signal level change rate vs input. 0 - min gain.
ippsALCSetLevel_G169_16s(2.f, 2.f, pALCState);//ippsALCSetLevel_G169_16s - sets target (desired) and clipping level in dBm0 (with sign dropped).
Ivan R