For DNxHD you can use Resolve for free.
There are not many apps which can do it- you either have to know how to use things like ffmepg or pay for "real" capture tool and those are not cheap.
On PC cheapest would be probably:
http://www.drastic.tv/sales/medianxsMake sure you try it first with trial version.
It also important if you want Rs-422 control or not.
Other apps which support BM cards (some do DNxHD some may not):
Tools On Air Just: Play & Live & In, Softron MovieRecorder & MReplay, CyberLink PowerDirector, CasparCG Server, Magicsoft CG, Xsplit Broadcaster,
Metus Ingest, Boinx Software MimoLive,
Cinegy Capture Pro, Open Broadcaster Software Studio.
bold are reliable ones but expensive as well.