These are the key factors that should be considered with regards to video regardless of BW.
You should post 3 formats when possible, to serve the proper device used.
This not only saves you bandwidth but also the users who do not need large video files for clarity.
Next you should encode the video file into a h264 format wrapped in a mp4 container.
Also use variable bitrates. This drops the mbps when there are dark scenes or low action.
The same applies for the audio, when the music is not as active.
Lastly use a fast start streaming which is also known as web streaming depending what OS and APP you use.
And a good program to go with would be FFMPEG/X or Handbrake