Applies to: mpv 0.42.0 stable manual; command-line options; no playback test
The useful distinctions
- ab-loop-a and ab-loop-b define loop points.
- Both points are needed to enable the loop.
- Seeking beyond the end point intentionally does not trigger that loop.
Write the review interval
A reproducible loop begins with an editorial question. For example, a demonstration reviewer may need to watch the handoff between two tools several times. Choose enough lead-in and follow-through to understand that transition, then write both boundaries in the review note. This is more useful than asking someone else to watch an entire recording and guess which moment caused concern.
Keep the command with the note
The example records a short fictional interval directly in the launch. Anyone reviewing their own equivalent source can see which passage was intended without relying on a remembered interactive click sequence. Verify the boundaries after launch because the right timestamps for one edit may be wrong for another cut of the same demonstration. A clear filename and interval together provide a useful reference for that distinction.
Distinguish navigation from extraction
The loop changes the review session’s navigation; it does not produce another file or establish an exact edit decision for every encoding workflow. If you move outside the chosen interval, record that action before diagnosing the loop as broken. Finish by launching without the temporary options when normal playback is desired. If the behavior remains unexpected on the documented version, provide the smallest command and describe how the playhead crossed the boundary.
A focused way to proceed
- Choose an earlier start and later end within the file.
- Launch with both A-B timestamp options.
- Inspect the passage boundaries and remove the options for ordinary playback.
Worked example · synthetic
mpv --ab-loop-a=18 --ab-loop-b=34 workshop-demo.mkvRead the comparison
A player loop supplies repeated viewing; it does not create a shareable excerpt.
When to stop or ask for help
Report exact option values and the playhead action that produced a surprising result.