Need Help: Unable to upload MP4 videos on web or app, got error message: “Your video file is not compatible. Please see tips for uploading videos.” - Media APIs - Twitter Developers
MP4, MKV, AVI: Video file formats explained - Dignited
Sample WebM, Ogg, and MP4 Video Files for HTML5 | TechSlides
Video For Everybody” Test Page
MP4 video file – Nuanced guide to the file type | Canto
Sample MP4 video files
You can now test MP3 and MP4 files with Design surveys - UsabilityHub updates
Audio/video files not being reproduced (mp3/mp4) - Fault reporting - The meet.coop Forum
Guide to Video File Formats, Codecs and Containers | The TechSmith Blog
sample-mp4-file - SchoolTube - Safe video sharing and management for K12