Changes

ConTeXt LMTX supports renditions only, since from PDF–2.0 getting any specification relateds to the format is complicated and not free at all.<ref>Just an example, _ ''ECMAScript for PDF_ PDF'' (short title for ''Document management — ECMAScript for PDF — Part 1: Use of ISO 32000-2 (PDF 2.0)'') only means CHF 208 in payment (https://www.iso.org/standard/71559.html). According to https://www.pdfa.org/wp-content/uploads/2022/08/1615-Zellmann.pdf#page=16, just joining working groups—such as the one that deals with rich media—requires membership (which may be achieved a liaison, through a non–profit organization).</ref>

The resulting PDF document requires a A <code>video.mp4</code> file is required to be on the same directory as your ConTeXt source file, so the resulting PDF file can have it embedded. If the file isn’t embedded, it needs to be on the same directory as the PDF document (so it can be invoked as external file).