I think you area saying that you want to host your own videos rather than hosting them on a service like YouTube.
Video streaming is quite a specialised domain and if you want to get good quality and allow for different devices and network conditions then it is often easiest to use a speciality video streaming server to host the video.
Examples of solutions include:
These are all commercial solutions but they usually have free trails.
All support HLS and DASH, which are the most common ABR protocols to stream videos - these support multiple bit rates with the video broken into chunks allow the client choose the best bit rate for the device and network conditions (https://stackoverflow.com/a/42365034/334402).
There are also some open source media frameworks which you could explore streaming examples or tutorial for - a good place to start would be:
Video streaming is complex and if you want to support at scale you need to consider the ongoing support effort also. If it meets your needs it may be worth looking at some of the commercial video hosting services also, like Vimeo etc, which can take care of that complexity for you and provide you a simple interface, typically some code to embed on your website.
If you simply want to host the mp4 files on your site yourself, then a key thing to note is to move the 'Mood" atom to the start of the video as noted in the comments above.