No, you can't change video resolution and frame rate in real-time.
You can just setup maximum values, for example: 640x480, 30 fps, 500000 bps.
WebRTC may automatically adjust these values targeting low-latency.
For example, it can reduce to: 320x240, 20 fps, 300000 bps dynamically.
See chrome://webrtc-internals charts for more information.
When i try to change the "video.frameRate" to something different from 30
I get error: STREAM_STATUS.FAILED, and i could not connect and create new Stream.
I get success connection only on video.frameRate = 30
Any idea way?
Unlike Chrome, which adjusts the frame rate if it is not supported by the selected camera, Firefox checks which of the available devices meet the constraint, and if there are no such devices MediaDevices.getUserMedia() results in OverconstrainedError. So, publishing fails even without device access request if the specified constraints are not met.