CLEP voice codec questions

[hartford]

This is a request that I'm not even certain of what
I'm asking

There is a voice compression codec called CLEP. I
gather that it is an AAC MPEG4 derivative.

Is it something that is available as a "standalone?"

Or is it incorporated in some way in some AAC codec
that can be downloaded?

What I'm trying to do is to make available a better
voice codec than the current one that is used in the
online game "Day of Defeat:Source."

I have no idea at present how to do any of this.

I'm attempting to improve the default voice communications
of this game on my server.

I gather that Microsoft uses this codec in NetMeeting and
perhaps other programs.

TIA.

[foxyshadis]

Not an mpeg-4 derivative or related to aac; it predates mpeg completely, though modern variants do include AMR (3gpp/mpeg4 standard) and Speex. Windows comes with an older CLEP, Lernout & Hauspie, as an ACM by default ever since Win95, which is the one used in Netmeeting. Speex can nearly match its quality at half the bitrate (2.8 kbps vs 4.5) on the lowest setting, or exceed it at higher settings, and is also available as an ACM codec. If DoD uses ACM, it might be possible to switch it to one or the other.

Since almost all the ACM versions of speex are years old, and even the standalone encoders are pretty dated, I always have to build my own, so I attached one from current SVN (built with SSE2 I think). (Source)