Echo cancellation

This manual consist info about Acoustic Echo Cancellation feature.

What is the Acoustic Echo?

Acoustic Echo is just like Usual echo, but there is one deffrerence

• Usual echo is your own voice, reflected from the walls.
  (Arise in the echoing rooms, caves and mountains)
• Acoustic echo is your own voice, came from the speakers of your collocutor.
  (Arises when your friend use open dynamics)

Acoustic Echo appears every time when you use open dynamics.
In some cases, the echo suppressed by desktop phone applications like Skype, Bria and other.

But there is problem with browser Flash applications.
Untill now, Flash does not support real echo cancellation.
And if you wanted to make a web phone - you had to implement echo cancellation on the server side.
It was very difficult to do technically, and it use a lot of server resources during the further work.

But now problem is solved!
Finally Adobe implement AEC (Acoustic Echo Cancellation) in the Flash Player 10.3 and now this problem solved!
(Check related issue in the Adobe bug tracking system).
Acoustic Echo Cancellation included in Flash Player 10.3 (beta) and higher.
More info here.

How to use Flash AEC with Flashphoner?

Use

<use_enhanced_mic>true</use_enhanced_mic>

in flashphoner.xml client-side config

See also configuring section

Bug with non-english names of playback and recording devices

There is a major bug in flash player 10.3 release(all versions). See http://bugs.adobe.com/jira/browse/FP-6888
This bug is reproduced on Win7 and WinXP systems, where sound devices has non-english names.

Examples:

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How to fix it:

1. If your customers has Windows7 or WindowsXP english localization, you do not need any fixes. It works for you.
   If your users has custom locales, see recommendations described below:
2. Do not use

   Microphone.getEnhancedMicrophone()

   in ActionScript code.
   If you have

   Microphone.getEnhancedMicrophone()

   in your code, you should change it to

   Microphone.getMicrophone()

   and recompile an application.

   Using not enhanced microphone turns off echo cancellation feature. But it is better than no sound at all.

3. Wait for Flash Player 11 release. This bug should be fixed there.
4. Recommend your users change playback and recording device names to english.
   Examples:
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