com.google.android.exoplayer2

Class Timeline

java.lang.Object

com.google.android.exoplayer2.Timeline

Direct Known Subclasses:

SinglePeriodTimeline

public abstract class Timeline
extends java.lang.Object

A representation of media currently available for playback.

Timeline instances are immutable. For cases where the available media is changing dynamically (e.g. live streams) a timeline provides a snapshot of the media currently available.

A timeline consists of related Timeline.Periods and Timeline.Windows. A period defines a single logical piece of media, for example a media file. A window spans one or more periods, defining the region within those periods that's currently available for playback along with additional information such as whether seeking is supported within the window. Each window defines a default position, which is the position from which playback will start when the player starts playing the window. The following examples illustrate timelines for various use cases.

Single media file or on-demand stream

A timeline for a single media file or on-demand stream consists of a single period and window. The window spans the whole period, indicating that all parts of the media are available for playback. The window's default position is typically at the start of the period (indicated by the black dot in the figure above).

Playlist of media files or on-demand streams

A timeline for a playlist of media files or on-demand streams consists of multiple periods, each with its own window. Each window spans the whole of the corresponding period, and typically has a default position at the start of the period. The properties of the periods and windows (e.g. their durations and whether the window is seekable) will often only become known when the player starts buffering the corresponding file or stream.

Live stream with limited availability

A timeline for a live stream consists of a period whose duration is unknown, since it's continually extending as more content is broadcast. If content only remains available for a limited period of time then the window may start at a non-zero position, defining the region of content that can still be played. The window will have Timeline.Window.isDynamic set to true if the stream is still live. Its default position is typically near to the live edge (indicated by the black dot in the figure above).

Live stream with indefinite availability

A timeline for a live stream with indefinite availability is similar to the Live stream with limited availability case, except that the window starts at the beginning of the period to indicate that all of the previously broadcast content can still be played.

Live stream with multiple periods

This case arises when a live stream is explicitly divided into separate periods, for example at content and advert boundaries. This case is similar to the Live stream with limited availability case, except that the window may span more than one period. Multiple periods are also possible in the indefinite availability case.

On-demand pre-roll followed by live stream

This case is the concatenation of the Single media file or on-demand stream and Live stream with multiple periods cases. When playback of the pre-roll ends, playback of the live stream will start from its default position near the live edge.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Timeline.Period Holds information about a period in a Timeline.
static class	Timeline.Window Holds information about a window in a Timeline.

Field Summary

Fields

Modifier and Type	Field and Description
static Timeline	EMPTY An empty timeline.

Constructor Summary

Constructors

Constructor and Description
Timeline()

Method Summary

Modifier and Type	Method and Description
abstract int	getIndexOfPeriod(java.lang.Object uid) Returns the index of the period identified by its unique id, or C.INDEX_UNSET if the period is not in the timeline.
Timeline.Period	getPeriod(int periodIndex, Timeline.Period period) Populates a Timeline.Period with data for the period at the specified index.
abstract Timeline.Period	getPeriod(int periodIndex, Timeline.Period period, boolean setIds) Populates a Timeline.Period with data for the period at the specified index.
abstract int	getPeriodCount() Returns the number of periods in the timeline.
Timeline.Window	getWindow(int windowIndex, Timeline.Window window) Populates a Timeline.Window with data for the window at the specified index.
Timeline.Window	getWindow(int windowIndex, Timeline.Window window, boolean setIds) Populates a Timeline.Window with data for the window at the specified index.
abstract Timeline.Window	getWindow(int windowIndex, Timeline.Window window, boolean setIds, long defaultPositionProjectionUs) Populates a Timeline.Window with data for the window at the specified index.
abstract int	getWindowCount() Returns the number of windows in the timeline.
boolean	isEmpty() Returns whether the timeline is empty.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY

public static final Timeline EMPTY

An empty timeline.

Constructor Detail

Timeline

public Timeline()

Method Detail

isEmpty

public final boolean isEmpty()

Returns whether the timeline is empty.

getWindowCount

public abstract int getWindowCount()

Returns the number of windows in the timeline.

getWindow

public final Timeline.Window getWindow(int windowIndex,
                                       Timeline.Window window)

Populates a Timeline.Window with data for the window at the specified index. Does not populate Timeline.Window.id.

Parameters:

windowIndex - The index of the window.

window - The Timeline.Window to populate. Must not be null.

Returns:

The populated Timeline.Window, for convenience.

getWindow

public Timeline.Window getWindow(int windowIndex,
                                 Timeline.Window window,
                                 boolean setIds)

Populates a Timeline.Window with data for the window at the specified index.

Parameters:

windowIndex - The index of the window.

window - The Timeline.Window to populate. Must not be null.

setIds - Whether Timeline.Window.id should be populated. If false, the field will be set to null. The caller should pass false for efficiency reasons unless the field is required.

Returns:

The populated Timeline.Window, for convenience.

getWindow

public abstract Timeline.Window getWindow(int windowIndex,
                                          Timeline.Window window,
                                          boolean setIds,
                                          long defaultPositionProjectionUs)

Populates a Timeline.Window with data for the window at the specified index.

Parameters:

windowIndex - The index of the window.

window - The Timeline.Window to populate. Must not be null.

setIds - Whether Timeline.Window.id should be populated. If false, the field will be set to null. The caller should pass false for efficiency reasons unless the field is required.

defaultPositionProjectionUs - A duration into the future that the populated window's default start position should be projected.

Returns:

The populated Timeline.Window, for convenience.

getPeriodCount

public abstract int getPeriodCount()

Returns the number of periods in the timeline.

getPeriod

public final Timeline.Period getPeriod(int periodIndex,
                                       Timeline.Period period)

Populates a Timeline.Period with data for the period at the specified index. Does not populate Timeline.Period.id and Timeline.Period.uid.

Parameters:

periodIndex - The index of the period.

period - The Timeline.Period to populate. Must not be null.

Returns:

The populated Timeline.Period, for convenience.

getPeriod

public abstract Timeline.Period getPeriod(int periodIndex,
                                          Timeline.Period period,
                                          boolean setIds)

Populates a Timeline.Period with data for the period at the specified index.

Parameters:

periodIndex - The index of the period.

period - The Timeline.Period to populate. Must not be null.

setIds - Whether Timeline.Period.id and Timeline.Period.uid should be populated. If false, the fields will be set to null. The caller should pass false for efficiency reasons unless the fields are required.

Returns:

The populated Timeline.Period, for convenience.

getIndexOfPeriod

public abstract int getIndexOfPeriod(java.lang.Object uid)

Returns the index of the period identified by its unique id, or C.INDEX_UNSET if the period is not in the timeline.

Parameters:

uid - A unique identifier for a period.

Returns:

The index of the period, or C.INDEX_UNSET if the period was not found.