Accessing the users camera or microfoon can open up a new universe of possibilities for your ads. But unfortunately, there are planety of restrictions and requirements which have made these features "unsafe" to use on ads. Not only is compatibility an obstacle, but also the secuirity aspect of it of course.
Luckily there are promissing developments on this matter that is making it more and more achievable on a cross-device and browser level. For example, the getUserMedia method.
We think it's still too early to ensure this will work everywhere, but we do recommended to read about the possibilities and their restrictions as we think that in the near future this will be supported virtually everywhere.
We recommend the following articles to dive into this subject:
Keep an eye on compatibility: