v10/internal/design/spf/features/edit-list-compensation.md

status, date, definition

status	date	definition
draft	2026-05-20	coarse

Edit-list compensation

Interpret MP4 edit lists when container media time does not directly map to player presentation time.

Proposed direction

• Parse the relevant elst data from initialization segments.
• Convert it into the same explicit timeline mapping used by other timestamp offsets.
• Keep parsing independent from seek and append policy.
• Reject unsupported edit patterns with a clear diagnostic.

Before implementation

Choose the supported edit-list patterns and signed-time representation. Test empty edits, media-time offsets, audio/video alignment, seeks, and discontinuities.

Related

Non-zero PTS support and presentation modeling.