Video can be embedded in H5P course presentation and the the dimension set there relative to the size of the total course presentation. This however may make it appear to small on some devices.
If you are embedding content with the H5P filter you can embed the link with a HTML container and set the max-width on the container on better use bootstrap col classes to choose with based on available screen resolution. For activities this coudl be done by overriding a template in the theme.
If you are embedding content with the H5P filter you can embed the link with a HTML container and set the max-width on the container on better use bootstrap col classes to choose with based on available screen resolution. For activities this coudl be done by overriding a template in the theme.
Generally though I think the idea of responsive design is for users to control the sizing by changing their window size.