Checkpoint 4.5 : Start, stop, pause, and navigate multimedia
Allow the user to stop, pause, and resume rendered audio and animation content (including video and animated images) that last three or more seconds at their default playback rate.
Allow the user to navigate efficiently within rendered audio and animations (including video and animated images) that last three or more seconds at their default playback rate.
Sufficient techniques
The user agent may satisfy the navigation requirement of provision two of this checkpoint through forward and backward serial access techniques (e.g., advance five seconds), or direct access techniques (e.g., start playing at the 10-minute mark), or some combination.
Normative inclusions and exclusions
When using serial access techniques to satisfy provision two of this checkpoint, the user agent is not required to play back content during advance or rewind (though doing so may help orient the user).
When the user pauses a real-time audio or animation, the user agent may discard packets that continue to arrive during the pause.
This checkpoint applies to content that is either rendered automatically (e.g., on load) or on explicit request from the user.
The user agent is not required to satisfy this checkpoint for audio and animations whose recognized role is to create a purely stylistic effect; see checkpoint 4.4 for more information about what constitutes a stylistic effect.