Block incoming calls while video recording?

Is it possible to use the video recorder without being interrupted by a phone call? If not, will it ever be possible? If I am recording something, it's safe to guess that I would like to complete the recording. While it is great to have a video camera included with my phone, it is distruptive to have the use of it determined by phone traffic and, therefore, makes it unreliable for use in emergencies and any other situation where the moment is fleeting and cannot be recreated. I know it's a phone. I am looking for a technical response, not the philosophy of the intended use of a phone. Thank you.