Constructor
new Playhead(videonon-null, timelinenon-null, minBufferTime, config, startTimenullable, onSeek, onEvent)
Creates a Playhead, which manages the video's current time.
The Playhead provides mechanisms for setting the presentation's start time,
restricting seeking to valid time ranges, and stopping playback for startup
and re-buffering.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
video |
HTMLMediaElement | ||
timeline |
shaka.media.PresentationTimeline | ||
minBufferTime |
number | ||
config |
shaka.extern.StreamingConfiguration | ||
startTime |
number |
<nullable> |
The playhead's initial position in seconds. If null, defaults to the start of the presentation for VOD and the live-edge for live. |
onSeek |
function() | Called when the user agent seeks to a time within the presentation timeline. | |
onEvent |
function(!Event) | Called when an event is raised to be sent to the application. |
- Implements:
- Source:
Members
(private, static, constant) MIN_SEEK_RANGE_ :number
This is the minimum size (in seconds) that the seek range can be. If it is
smaller than this, change it to be this big so we don't repeatedly seek to
keep within a zero-width window.
This has been increased to 3s long, to account for the weaker hardware on
Chromecasts.
Type:
- number
- Source:
Methods
(private) clampSeekToDuration_(time) → {number}
Clamp seek times and playback start times so that we never seek to the
presentation duration. Seeking to or starting at duration does not work
consistently across browsers.
TODO: Clean up and simplify Playhead. There are too many layers of, methods
for, and conditions on timestamp adjustment.
Parameters:
| Name | Type | Description |
|---|---|---|
time |
number |
Returns:
The adjusted seek time.
- Type
- number
(private) clampTime_(time) → {number}
Clamps the given time to the seek range.
Parameters:
| Name | Type | Description |
|---|---|---|
time |
number | The time in seconds. |
- Source:
Returns:
The clamped time in seconds.
- Type
- number
getPlaybackRate() → {number}
Gets the current effective playback rate. This may be negative even if the
browser does not directly support rewinding.
- Source:
Returns:
- Type
- number
(private) getStartTime_(startTimenullable) → {number}
Gets the playhead's initial position in seconds.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
startTime |
number |
<nullable> |
- Source:
Returns:
- Type
- number
getTime() → {number}
Gets the playhead's current (logical) position.
- Source:
Returns:
- Type
- number
(private) onPollWindow_()
Called on a recurring timer to keep the playhead from falling outside the
availability window.
- Source:
(private) onSeeking_()
Handles when a seek happens on the video.
- Source:
onSegmentAppended()
Called when a segment is appended by StreamingEngine, but not when a clear is
pending. This means StreamingEngine will continue buffering forward from
what is buffered, so that we know about any gaps before the start.
- Source:
(export) release()
Request that this object release all internal references.
- Implements:
- Source:
(private) reposition_(currentTime) → {number}
Computes a new playhead position that's within the presentation timeline.
Parameters:
| Name | Type | Description |
|---|---|---|
currentTime |
number |
- Source:
Returns:
The time to reposition the playhead to.
- Type
- number
setBuffering(buffering)
Stops the playhead for buffering, or resumes the playhead after buffering.
Parameters:
| Name | Type | Description |
|---|---|---|
buffering |
boolean | True to stop the playhead; false to allow it to continue. |
- Source:
setPlaybackRate(rate)
Sets the playback rate.
Parameters:
| Name | Type | Description |
|---|---|---|
rate |
number |
- Source:
setStartTime(startTime)
Adjust the start time. Used by Player to implement the
streaming.startAtSegmentBoundary configuration.
Parameters:
| Name | Type | Description |
|---|---|---|
startTime |
number |
- Source: