Here are some notes about a working analogue playout setup, using Ubuntu 12.04 LTS (Precise Pangolin) and Shotcut (v13.10.07) for video signal chain signal tests (DVA-Fidelity)
1) Blackmagic output settings:
Multimedia > Blackmagic Control Panel
This outputs any video sent to the Decklink card over its analogue outputs, without the playback application being required to know anything about that.
2) Shotcut settings:
We've tested Shotcut as playout system over SDI-out on a Decklink SDI on Linux.
DVA-Fidelity tests have shown that if the whole signal chain is connected to a Genlock reference, the field-timing is flawless over the whole 4 hour test length. Therefore, we can assume that it can be used as a reliable output source for further signal chain tests over analogue outputs.
Additional notes:
Properly loaded Blackmagic Decklink driver kernel modules look like this:
lsmod | grep blackmagic
blackmagic_io 410757 2
blackmagic 575757 0