If you're looking for technical information about the MP4 format itself:
: An article in the Journal of the American Chemical Society regarding Asymmetric CO Oxidation includes supplemental "PLIF ignition movies" with ratios like 1:5 saved as MP4 files. 1_5.mp4
In academic research, "1_5.mp4" often refers to supplemental video files attached to research articles: If you're looking for technical information about the