# 1.1.0 playback position and indexed chapters

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> Version: 1.1.0. Release requirements. [Verification status](/Riff/1-1-0/status).

This owner replaces only unknown-duration position presentation and singleton chapter retention. The
remaining [transport](/Riff/LATEST/player-transport) and
[chapter navigation](/Riff/LATEST/player-chapters) rules remain in force. Observation cadence and
history are owned by [playback events](/Riff/1-1-0/events).

## Unknown duration

Until Media3 reports a usable positive duration for the current occurrence, display the saved or
observed elapsed time and keep the position slider at its neutral position with seeking disabled. Do
not infer a duration from a fixed constant, a previous occurrence or the current library mode. When
the current occurrence's duration becomes available, derive the slider fraction and seek position
from that duration. A new occurrence invalidates the previous duration immediately.

## Indexed chapters

Navigation and the chapter line use the indexed TOC of the actual selected playback binding. They
require more than one distinct valid chronological start within the playable duration, when known.
Fallback to another binding also changes the TOC source. Fragment-relative playback uses relative
chapter positions within its bounds. Player does not parse media metadata, invent chapter zero or
repair malformed chapter sequences.

A single Nero chapter does not need to be retained or exported. It does not create an Album/Title,
enable chapter navigation or add a chapter line. This replaces the baseline requirement to retain a
valid Nero singleton; ordinary multi-chapter admission remains unchanged.