I'm trying to set up a system where a presenter gives short presentations (typically 60 seconds) in front of a backdrop on a daily basis, with the files being ultimately destined for the web.

The limiting factor here though is that ideally the system should be operable by the presenter only - no technical or production staff will necessarily be available to help. So what I'd like is a way for the capture to be triggered remotely by the presenter standing in front of the camera (by a foot switch most likely, but I'm open to other options), and the take will then be recorded to file on the associated capture PC, and will stop after a pre-defined time (60 seconds, 90 seconds, etc). If it's not possible to set a timer, we do have the ability to use a hardware timer device which will send a serial signal.

The studio is all set up and ready, the only missing link is the actual capture solution. We were looking initially at the Aja Ki Pro Rack, but it doesn't make it particularly easy to get at the files - the device has to be put into a different mode, and the files have to be downloaded either through a web interface, or by removing the hard drives and copying the files to the PC.

Then we were looking at various BlackMagic devices, such as the H264 Pro Recorder, but I couldn't see how I could remotely trigger the capture using the bundled MediaExpress software.

I'm open to using alternate software such as Final Cut or Premiere. Does anyone know of a solution that will let me trigger a remote capture with no human operator sitting at the PC, ideally with the ability to set a timer to stop the record as well?

  • This is interesting, but out of my depth. Just curious, why do you prefer the timer instead of a stop command? Apr 23, 2014 at 17:00
  • Because the videos in question will (almost) always be destined for an automated system, which is designed to have specific-length videos. As stated, ideally the recording/producing system will be operated by only one person - the presenter in front of the camera. So automating as many things as possible - including stopping the record after the predefined time period - is required.
    – chuz
    Apr 25, 2014 at 10:39

1 Answer 1


I have no practical experience, but you might take a look at using a (linux) computer with blackmagic decklink or intensity pro card.

There are command line tools like bmdtools which (should) allow you to interface the capture card. https://github.com/lu-zero/bmdtools

You could then pipe the video input to ffmpeg to record. I don't know of a setting to provide to ffmpeg to limit the capture-duration, but you could maybe create a script starting and stopping both commands at the right time. This might be helpful: http://forum.blackmagicdesign.com/viewtopic.php?f=12&t=5109

If you are using such a setup with a computer, the next stages of your workflow could be scripted as well.

edit: I can't really find any information about this, but if you can read/record the H264 stream which the BMD H264 recorder outputs in ffmpeg or vlc, It will be a lot less demanding for your system. The other two options mentioned above will have to do the encoding in software.

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