Hi,
Resolution of the Publisher object completely depends on the client platform. What this means is that internally openvidu-browser entirely relies on standard WebAPI to set the desired resolution of the video stream: https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia#Syntax
This parameter is always used with “ideal” keyword (see the previous link) when setting the video capabilities. So, the client device will do its best effort to honor what you indicate in the resolution and framerate properties. But depending on the platform, the client device may behave one way or another. For example, Google Chrome will set the exact resolution and framerate you want, because it tweaks it with software (the process itself will resize the video stream to exactly match what you passed as resolution). But Firefox may require that the hardware natively supports the resolution or framerate in order to use it (so if the camera doesn’t natively support a ABCxDEF specific resolution, it won’t use it).
To sum up: openvidu-browser is using under-the-hood the standard web API. If you want complete control of the media stream, you can always pass as videoSource and audioSource the standard MediaStreamTrack object already initialized, with the properties you have defined using standard browser methods.