Sites like CloudConvert or FreeConvert provide easy web-based tools to fix these files without needing to learn video editing.
The specific filename doesn't point to a single viral meme or a specific "official" blog post. Instead, it looks like a technical byproduct of remuxing or converting a video file—likely a recording from OBS (Open Broadcaster Software) or a rip from a Blu-ray. 9700.mkv.mp4
If you are looking for a "good blog post" on this topic, it is usually found in discussions about to make high-quality video files compatible with social media or mobile devices. Why you see "mkv.mp4" 9700.mkv.mp4
FastPix has a detailed 2026 comparison on when to use each container for streaming versus storage. 9700.mkv.mp4