Provide two versions of your video data: the original recordings and a compressed version in mp4 as a working copy.
First, do your original video recordings with the best quality and highest resolution your camera can produce. Archive these recordings as material that researchers later on can work with if they want to build on your data.
Second, compress your original recordings into smaller mp4 files that you can work with in ELAN and that you can stream over the internet. Compress the original file to mp4 and use the setting H264. For compression, keep the remaining settings as close to the original settings as possible, only change the frame size to half the original size (e.g. if your original file is 1920 x 1080, resize to 960 x 540).
Teaching materials for video conversion that explain which tools you can use with which settings and all the steps you have to take, together with a set of example files to practice video conversion, can be downloaded from the links below: