We are attempting to setup a live streaming site, which will take about 30 incoming RTSP/RTP streams (at about 1mbit/sec each), and transcode them down to something no more than about 250 kbits/sec (360x240 or 280/160). So about 15 mbits/sec outbound.
We want to service about 20,000 users, but we'll be doing all this over HLS so we should be able to scale up that bit at the HTTP proxy. What I'm more interested in is how to size the server for the transcoding: rough rules-of-thumb in terms of number of CPU cores, and how is that affected if we get a CUDA compliant graphics card?
It'll be a Win 2008 R2 x64 OS.
We'll load test, but I need to get an approximate baseline to start from.