The suffix .mp4 and the numbering (2) are common for supplementary video materials in academic papers or conference proceedings (e.g., ACM Digital Library or IEEE Xplore). However, no current research papers under this name are widely indexed.
(e.g., is it a music video, an interview, a news report, or a tutorial?) Is it related to a specific event or date?
Providing any extra context about the or the source will allow me to track down the correct information for you.
