Compression of Wav files?

[admin_2]

What issues could arise if a site used compresson on the wav files on the Unity Server? <br><br>(My gut feeling is that this isn't a good idea - will it mess with voice quality?)<br><br>

[dgrant]

Have they considered using g729a instead?

-Dustin

[#3]

What version of Codec is Unity using in build 2.4.6.135 and lower? Isn't the point: the more compression allowed, the worse voice quality?

[#4]

In general that's a true statement but a lot of sites use G729a and are OK with it. The human voice has farily limited range a highly compressed codec can take advantage of that assumption... music, for instance, sounds like garbage compressed into G729a but a voice message sounds OK.

You can use the SetRecordFormat.EXE tool (found in the commServer\Utilities direcory) to switch between the various ADPCM, MuLaw and G729a (if installed) formats etc... and try it out. You'll need to restart before the new codec takes effect.

here's a post that runs down the storage space requirements for the various codecs:

http://avforums.isomedia.com/cgi-bin/showthreaded.pl?Cat=&Board=unityent&Number=869&Search=true&Forum=unityent&Words=ADPCM&Match=Entire Phrase&Searchpage=0&Limit=25&Old=allposts&Main=866

Jeff Lindborg
Unity Product Architect/Answer Monkey
Cisco Systems
lindborg@cisco.com
http://www.AnswerMonkey.net (new page for Unity support tools and scripts)

[#5]

In builds 2.4.5.73 and higher, is G729a included with the Unity software or purchased separately? Is it on the instalation CD's?

[dgrant]

You should find it in the Utilities folder on Disk1. sl_g729a_setup.exe is the program you are looking for.

-Dustin

[#7]

Here's the procedure I'm understanding for enabling G729a Codec, please correct as needed:
1. Run sl_g729a_setup.exe from the first CD
2. Run SetRecordFormat.exe from Commserver\Utilities and restart for change to take effect.
3. Check HKLM|Software\Active Voice\MIU\1.0\Initialization and check that under "Default Wav Format" the setting is for G729a (5).

If I'm missing or adding steps not needed, please let me know. I plan to do this for a site this week. (Note: the site is also running D42NE2's.)