View source for Acoustic Echo Cancellation

=Description/Objective=
In this section, we will be discussing Acoustic Echo Cancellation, or "AEC". Its purpose is to remove audio feedback in a control room solution, with 2 mics and 2 speakers. 




=Physical Wiring/Line Diagram=

We will use the CRAS example configuration. The physical wiring is as follows: 

[[File:CRAS_Line_Diagram.png|link=https://ipivs.com/wiki/images/2/2e/CRAS_Line_Diagram.png|500px]]


=Tesira Software=

==Connections==

We will use the same software example config too, which looks like this: 

[[File:CRAS_Config_2.png]]




==AEC Block==

[[File:CRAS_with_Input_Blocks.png]]

#Phantom Power: We will need phantom power on for our mics, and proper levels on the preamps. 
#AEC: Enable the AEC feature with this button on the AEC Block. 


=How the AEC Block Works=

#* Let's say John is in the Control Room, using the push to talk mic. We are sending his audio 2 places: the camera and the OWISP. 
#* Steve is in the simulation room, responding in kind to John's instructions. Steve's audio is going 2 places also: the camera and the PSP speaker in the control room. 
#* John's OWISP audio will be captured by the room mic, and therefore sent back to the PSP speaker. 
#* Steve's PSP audio will be captured by the push to talk mic, and therefore sent back to the sim room over the OWISP. 
#* The Tesira AEC Block will remove the unwanted audio coming into the mic inputs, as long as we tell it what to cancel. 
#* We have to send the audio we need cancelled to the AEC Reference block. 


==How to use the Mixer==

There are 2 ways we can achieve our goal. They are functionally the same, but one may be conceptually easier to understand, and therefor configure correctly. We will look at them both here. 

===Method 1===




===Method 2===