These ActiveX controls provide real-time compression and rendering of audio and video streams, supporting standard formats such as H.263, MPEG-4, G.723 and more. It appears that they are designed for IP Telephony, but they also advertise the ability to do straight-up compression to/from disk or memory. You can use a demo version for free, with limitations, but upgrading to the pro release is going to set you back a bit. Redistribution is included in the price, though.

Version 3.0 is shipping as of April, 2003.

http://www.banasoft.net/AVPhone.htm