Index: Mkv

Most casual users never think about the index—until something goes wrong. Consider these scenarios:

In short, the MKV index transforms a linear stream of data into a random-access multimedia archive.

Editors need sample-accurate seeking (each video frame). Use maximum cue density: mkv index

mkvmerge --cues every-frame -o edit_ready.mkv source.mkv

Warning: This increases file size slightly (cues are metadata) but dramatically improves scrub performance.

Some files have an index, but it’s "sparse" (e.g., only one cue point every 10 seconds). For video editing or precise seeking (like frame-by-frame analysis), this is insufficient. Most casual users never think about the index—until

If an MKV has no index or a corrupted index:

# Using MKVToolNix (preserves all tracks)
mkvmerge -o output.mkv --cues 0:all input.mkv
| Container | Index mechanism | Index location | Mandatory? |
|------------|----------------|----------------|-------------|
| MKV | Cues (separate element) | Within Segment, usually near end | No, but recommended |
| MP4/MOV | stco/co64 (chunk offset table) + stts (time-to-sample) | Within moov atom | Yes, for reliable seeking |
| AVI | idx1 chunk | At end of file (or rec list) | No (AVI v1.0), Yes (OpenDML) |
| WebM | Same as MKV Cues | Within Segment | Required for WebM compliance | In short, the MKV index transforms a linear
Not all MKV files are created equal. Many encoding tools optimize for speed over seekability. Here’s why you might have an index problem: