[AG-TECH] RAT audio quality - Alternative codecs?

[Henry Hernando Caballero Corzo]

Hi everyone,

Hope you can advise me in the following issue.

Scenario:
Say we're holding a videoconference which joins people from two different types of nodes:
-A conference room with an adequate AG node setup (audio equipment for echo cancelling (ClearOne RAV 600), ambient microphone, high-end speakers, etc.)
-A "casual participant" (an academic who joins the conference from his workplace and uses his personal AG-equipped laptop sporting integrated microphone and speakers)

Then a lot of -predictible- problems related to audio arise. Audio quality can degrade so badly (enormous echo and noise) that ends up ruining the meeting. We certainly know we're dealing with a "non-recommendable" scenario, but the fact is, we need it to work.

First question:

1. How do you guys deal with this kind of setups? (if there's some way)

Going deeper in this issue, I -almost inevitably- turned my eyes on RAT. Even though RAT works well under controlled setups, We certainly expect it to perform much better when used in uncontrolled environments like the described above. So, there're some more questions to ask:

3. Is RAT lacking important features like: ultra-wideband sampling, echo cancelling, noise suppression, active voice detection, discontinuous transmission (among others) ?

4. Or it's all about tweaking with RAT options? (some of the above features seem to be included, not sure if they work well though)

5. What about Speex[1] and/or SILK[2] codecs? Would it be feasible to integrate these codecs to the Access Grid?
* I'm aware of this development[3], which is part of a contribution from NCHC. It involves the integration of Speex into RAT, but I'm really not sure if these features are included in the current version of RAT that ships with the latest AG release
* SILK claims excellent voicecall quality and the truth is, Skype can in fact deal with our "problematic setup" with absolutely no problem

Thanks in advance!

Henry Caballero
----------------
AG node administrator - Universidad de los Andes (http://ag-mox.uniandes.edu.co)

[1] http://speex.org/
[2] https://developer.skype.com/silk
[3] http://www.nchc.org.tw/en/core_content/download.php?FILE_ID=152
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