We are getting a blackmagic card for our mac and i want to broadcast live to the internet. right now we are using the composite-out and i'm just using a vcr to convert the composite signal to DV and using that as the input into Ustream via firewire. Do the blackmagic cards show your input as a camera in Ustream? If not, whats the best way to go about this? We are thinking about using SDI for input into the blackmagic card, but i can't find any readily available hardware that does sdi/dv transcoding.
If you have a Ustream Watershed account https://watershed.ustream.tv/
They can handle HD 16:9
The simplest way would be to set camera to SP (HDV) and use firewire out of the camera.
Then you don't have to worry about HD-SDI to HDV (or DV)
If it's a free Ustream account limited to SD 4:3 you might consider downconverting in camera out SDI.
You might want to consider looking at Wirecast forum on the COW and ask about Wirecast as a professional front end for Ustream or Ustream Watershed.
I haven't tested but Wirecast may handle the SDI input and do the encode. There's a free trial so you can certainly test it with the Blackmagic card.