Using different rates of playback has an effect on what features
are enabled and what actions are allowed.
The following apply during trick-play mode (fast forward and fast
rewind):
- The master playlist must
contain I-frame-only segments.
- Only the key frames from the
I-frame track are displayed on the screen.
- Play and pause are enabled.
- Seek is disallowed. If you
need to seek, call
pause to get out of trick play mode and then call
seek.
- The adaptive bit rate (ABR)
logic is disabled. A single bit rate is chosen and used during the entire
trick-play session. The chosen bit rate is between the lowest provided one and
800 kbps.
- The audio track and closed
captions are disabled.
- When ads are incorporated
into the stream:
- Ad breaks are ignored
and no ad events are fired.
- The
MediaPlayerEvent.AD_BREAK_SKIPPED event is
raised right before an ad break is about to be skipped. The
reason property indicates that trick-play has
caused the skip operation (seek can also cause skips). Your player application
can use this event to implement custom logic related to the skipped ad breaks.
- When returning from
trick play, a seek operation is performed internally on the return position.
This means that the selected ad playback policy related to seek over ads
applies also when returning from trick play. The default behavior would be that
the last skipped ad break is played each time the player returns from
trick-play mode, forcing the playback to resume to the selected return position
only after the last skipped ad break plays. This behavior depends on your
application's selected ad policy and can change when the policy changes.
- The timeline exposed by
PSDK to your player app is not modified even if ad breaks are skipped. The PSDK
informs your application with the
AD_BREAK_SKIPPED event that an ad break is
about to be skipped, even it is present on the timeline.
- The
current time value jumps forward (on fast
forward) or backward (on fast rewind) with the duration of the skipped ad
break. This jump behavior for the current time allows the stream duration to
remain unmodified during trick play. Your player application can
get the local time value to track the time relative only
to the main content. No time jumps are performed on the values returned for the
local time when skipping an ad.
- Your player application
can transition to trick play only while playing the main content. An error is
dispatched if the application tries to switch to trick play while playing an ad
break.
- You cannot change the
rate to trick play mode when you are in the allowed playback rate range and
within an ad break.
- You can drop out of
trick play mode into play, pause, or slow motion (that is, the allowed playback
rates) and all the removed ads are restored.
- You can enter trick play
mode from any of the allowed playback rates, and only at that point ads are
removed from the timeline.
The following apply during slow-motion playback:
- All HLS streams support
slow-motion playback (the I-frame playlist is not used in this case).
- The audio track is disabled;
closed captions continue to render.
- ABR logic continues to work.
- Ad-related workflows are the
same as for normal playback.
- Play, pause, and seek
behavior is the same as for trick play.
- When ads are incorporated
into the stream:
- Ads are not removed from
the timeline and ad breaks are not skipped.