mkvinfo your_video.mkv Look for a section labeled Cues . If it’s missing or very small relative to file size, your index is likely incomplete.
The culprit? What is an MKV Index? The Matroska Multimedia Container ( .mkv ) is like a shipping crate. It holds video streams, audio tracks, subtitles, and chapters all in one file. But without a map, your video player would have to scan the entire crate to find anything. mkv index
That map is the , officially called the Cues element (or Cueing Data ) in the MKV structure. mkvinfo your_video