@m3iaz Hi,
the Reolink cams provide a fluent and a high quality stream.
You can select three different stream types in the Surveillance Station. The MJPEG stream is generated of the one for reduced speed which in my setup is the fluent stream of the Reolink cam.
I can select a 640x stream in my Reolink but it may depend of the camera.
I do not have much time to program at the moment but you may checkout my EmbedURL module. It is able to embed images and a refresh rate can be configured. Some people use it to embed JPEG of public webcams already.