[theora] Theora encode/decode performance is poor with resolution 640X480

[jpeng at viacube.com]

Hi,
  We build a Voip client with Iaxclient(Jiaxclient+Iaxclient2.1beta1+Theora1.0+libvidcap0.21),when we established video call with resolution 640X480 in both sides,the CPU is consumed about 100%,the workload of Asterisk server is good at that moment.This issue does not exist with the resolution 320X240,  the environment is as following,
    - CPU Interl  Celeron 2.66GHz,RAM1GB,
    - Windows XP SP2
  According to profile about Iaxclient and our analysis it is found what consumed most of the CPU resources are Theora encode/decode functions,we recompiled Theora lib with the argument "USE_ASM" and make it MMX instruction set,but the effect is not obvious.
  Is there anyone else met this issue too? Is there any suggestion or solution about the issue?