Capturing still image while video recording or playing back

[StevieRG]

In our embedded (Freescale i.MX) application we have a video camera which can also be used as a stills camera.

We have a requirement to record live video from the video camera, and also to allow the user to take a still image snapshot at any time during the recording.

We also have a requirement to play back the recorded video, and allow the user to take a still snapshot of what's being played back at any time then too.

We could allow a short pause in the recording or playback while the still is captured.

I'd appreciate some advice please on best ways to achieve this in either Qt or Mobility? Many thanks.