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

[Jason Bell]

Henry

 

If I could provide a brief comment...  I have found many video
conferencing software, including skype, do struggle with poor audio and
echo cancelling issues...  That being said, some do work a lot better
than others.

 

But it should be noted that I am a big fan on using superior hardware to
provide superior quality.  

 

Have you considered using any of the USB echo cancelling
speaker/microphone devices?  See
http://www.accessgrid.org/test/taxonomy/term/23 for some examples.  I
personally use the Chat150 and Chat50 devices and I think they are
great.  They tend to work like a plug-a-play device, no tweaking
required.

 

The great thing about these devices is that not only can they be used
within the AG (Across the different platforms [Windows, Linux and Mac]),
but can be used on a variety of other conferencing software, such as
Skype, EVO, etc.

 

Now these devices are not as good as a proper fully blown AV system, but
in my opinion they work well and I have seen them deployed all over the
place.

 

Anyway, hope you don't mind me adding in my 2 cents worth.

 

Thanks,

Jason.

 

 

From: Henry Hernando Caballero Corzo
[mailto:hh.caballero921 at uniandes.edu.co] 
Sent: Tuesday, 22 September 2009 02:38 PM
To: ag-tech at lists.mcs.anl.gov
Subject: [AG-TECH] RAT audio quality - Alternative codecs?

 

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 <https://developer.skype.com/silk> 

[3] http://www.nchc.org.tw/en/core_content/download.php?FILE_ID=152

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/ag-tech/attachments/20090924/f3ad078c/attachment.htm>