>On Fri, 2005-04-08 at 09:33 -0500, Brian West wrote: >> Speex is a CPU whore. Even more so than g729. > >How much of a whore are we talking about here? Clock cycles are cheap, >so if I can get 7 channels of speex with a dual 900Mhz PIII (my current >system) I'd say it's worth the savings in bandwidth. > >FWIW, I just spoke to VoicePulse and their engineering department said >they will support Speex with IAX termination within 1 to 2 days. > >-lee
It's about 3 times worse than G729 for encoding and just a tad bit faster on decoding. So, from a provider's standpoint, that means reduced capacity per machine, which in turn means higher overhead and less profit. Usually when you work out rates, you'll get your codecs worked out too. If your provider has to do expensive CPU work, expect to pay for it. Then again, if you're not running tons of traffic, it might just not make enough difference and they probably play the average (considering some use ULAW and some GSM, which could balance out your Speex usage). Just for comparison, here's a complete "show translation" table: Translation times between formats (in milliseconds) Source Format (Rows) Destination Format(Columns) g723 gsm ulaw alaw g726 adpcm slin lpc10 g729 speex ilbc g723 - 4 2 2 3 2 1 7 11 31 18 gsm 12 - 2 2 3 2 1 7 11 31 18 ulaw 12 4 - 1 3 2 1 7 11 31 18 alaw 12 4 1 - 3 2 1 7 11 31 18 g726 13 5 3 3 - 3 2 8 12 32 19 adpcm 12 4 2 2 3 - 1 7 11 31 18 slin 11 3 1 1 2 1 - 6 10 30 17 lpc10 13 5 3 3 4 3 2 - 12 32 19 g729 13 5 3 3 4 3 2 8 - 32 19 speex 12 4 2 2 3 2 1 7 11 - 18 ilbc 14 6 4 4 5 4 3 9 13 33 - Speex is definitely the worst performer here, as far as CPU time goes. (These numbers from a P4 2.4GHz, using Digium's G729 P4 codec, and Intel's G723, 5.3 rate, optimized for P4, and Speex 1.0.4-1, Asterisk CVS-HEAD-04/11/05-19:24:17). -Michael _______________________________________________ Asterisk-Biz mailing list Asterisk-Biz@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-biz