com.google.android.exoplayer2

Class DefaultLoadControl

java.lang.Object

com.google.android.exoplayer2.DefaultLoadControl

All Implemented Interfaces:

LoadControl

public class DefaultLoadControl
extends java.lang.Object
implements LoadControl

The default LoadControl implementation.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS The default duration of media that must be buffered for playback to resume after a rebuffer, in milliseconds.
static int	DEFAULT_BUFFER_FOR_PLAYBACK_MS The default duration of media that must be buffered for playback to start or resume following a user action such as a seek, in milliseconds.
static int	DEFAULT_MAX_BUFFER_MS The default maximum duration of media that the player will attempt to buffer, in milliseconds.
static int	DEFAULT_MIN_BUFFER_MS The default minimum duration of media that the player will attempt to ensure is buffered at all times, in milliseconds.
static boolean	DEFAULT_PRIORITIZE_TIME_OVER_SIZE_THRESHOLDS The default prioritization of buffer time constraints over size constraints.
static int	DEFAULT_TARGET_BUFFER_BYTES The default target buffer size in bytes.

Constructor Summary

Constructors

Constructor and Description
DefaultLoadControl() Constructs a new instance, using the DEFAULT_* constants defined in this class.
DefaultLoadControl(DefaultAllocator allocator) Constructs a new instance, using the DEFAULT_* constants defined in this class.
DefaultLoadControl(DefaultAllocator allocator, int minBufferMs, int maxBufferMs, int bufferForPlaybackMs, int bufferForPlaybackAfterRebufferMs, int targetBufferBytes, boolean prioritizeTimeOverSizeThresholds) Constructs a new instance.
DefaultLoadControl(DefaultAllocator allocator, int minBufferMs, int maxBufferMs, int bufferForPlaybackMs, int bufferForPlaybackAfterRebufferMs, int targetBufferBytes, boolean prioritizeTimeOverSizeThresholds, PriorityTaskManager priorityTaskManager) Constructs a new instance.

Method Summary

Modifier and Type	Method and Description
protected int	calculateTargetBufferSize(Renderer[] renderers, TrackSelectionArray trackSelectionArray) Calculate target buffer size in bytes based on the selected tracks.
Allocator	getAllocator() Returns the Allocator that should be used to obtain media buffer allocations.
long	getBackBufferDurationUs() Returns the duration of media to retain in the buffer prior to the current playback position, for fast backward seeking.
void	onPrepared() Called by the player when prepared with a new source.
void	onReleased() Called by the player when released.
void	onStopped() Called by the player when stopped.
void	onTracksSelected(Renderer[] renderers, TrackGroupArray trackGroups, TrackSelectionArray trackSelections) Called by the player when a track selection occurs.
boolean	retainBackBufferFromKeyframe() Returns whether media should be retained from the keyframe before the current playback position minus LoadControl.getBackBufferDurationUs(), rather than any sample before or at that position.
boolean	shouldContinueLoading(long bufferedDurationUs, float playbackSpeed) Called by the player to determine whether it should continue to load the source.
boolean	shouldStartPlayback(long bufferedDurationUs, float playbackSpeed, boolean rebuffering) Called repeatedly by the player when it's loading the source, has yet to start playback, and has the minimum amount of data necessary for playback to be started.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MIN_BUFFER_MS

public static final int DEFAULT_MIN_BUFFER_MS

The default minimum duration of media that the player will attempt to ensure is buffered at all times, in milliseconds.

See Also:

Constant Field Values

DEFAULT_MAX_BUFFER_MS

public static final int DEFAULT_MAX_BUFFER_MS

The default maximum duration of media that the player will attempt to buffer, in milliseconds.

See Also:

Constant Field Values

DEFAULT_BUFFER_FOR_PLAYBACK_MS

public static final int DEFAULT_BUFFER_FOR_PLAYBACK_MS

The default duration of media that must be buffered for playback to start or resume following a user action such as a seek, in milliseconds.

See Also:

Constant Field Values

DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS

public static final int DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS

The default duration of media that must be buffered for playback to resume after a rebuffer, in milliseconds. A rebuffer is defined to be caused by buffer depletion rather than a user action.

See Also:

Constant Field Values

DEFAULT_TARGET_BUFFER_BYTES

public static final int DEFAULT_TARGET_BUFFER_BYTES

The default target buffer size in bytes. When set to C.LENGTH_UNSET, the load control automatically determines its target buffer size.

See Also:

Constant Field Values

DEFAULT_PRIORITIZE_TIME_OVER_SIZE_THRESHOLDS

public static final boolean DEFAULT_PRIORITIZE_TIME_OVER_SIZE_THRESHOLDS

The default prioritization of buffer time constraints over size constraints.

See Also:

Constant Field Values

Constructor Detail

DefaultLoadControl

public DefaultLoadControl()

Constructs a new instance, using the DEFAULT_* constants defined in this class.

DefaultLoadControl

public DefaultLoadControl(DefaultAllocator allocator)

Constructs a new instance, using the DEFAULT_* constants defined in this class.

Parameters:

allocator - The DefaultAllocator used by the loader.

DefaultLoadControl

public DefaultLoadControl(DefaultAllocator allocator,
                          int minBufferMs,
                          int maxBufferMs,
                          int bufferForPlaybackMs,
                          int bufferForPlaybackAfterRebufferMs,
                          int targetBufferBytes,
                          boolean prioritizeTimeOverSizeThresholds)

Constructs a new instance.

Parameters:

allocator - The DefaultAllocator used by the loader.

minBufferMs - The minimum duration of media that the player will attempt to ensure is buffered at all times, in milliseconds.

maxBufferMs - The maximum duration of media that the player will attempt buffer, in milliseconds.

bufferForPlaybackMs - The duration of media that must be buffered for playback to start or resume following a user action such as a seek, in milliseconds.

bufferForPlaybackAfterRebufferMs - The default duration of media that must be buffered for playback to resume after a rebuffer, in milliseconds. A rebuffer is defined to be caused by buffer depletion rather than a user action.

targetBufferBytes - The target buffer size in bytes. If set to C.LENGTH_UNSET, the target buffer size will be calculated using calculateTargetBufferSize(Renderer[], TrackSelectionArray).

prioritizeTimeOverSizeThresholds - Whether the load control prioritizes buffer time

DefaultLoadControl

public DefaultLoadControl(DefaultAllocator allocator,
                          int minBufferMs,
                          int maxBufferMs,
                          int bufferForPlaybackMs,
                          int bufferForPlaybackAfterRebufferMs,
                          int targetBufferBytes,
                          boolean prioritizeTimeOverSizeThresholds,
                          PriorityTaskManager priorityTaskManager)

Constructs a new instance.

Parameters:

allocator - The DefaultAllocator used by the loader.

minBufferMs - The minimum duration of media that the player will attempt to ensure is buffered at all times, in milliseconds.

maxBufferMs - The maximum duration of media that the player will attempt buffer, in milliseconds.

bufferForPlaybackMs - The duration of media that must be buffered for playback to start or resume following a user action such as a seek, in milliseconds.

bufferForPlaybackAfterRebufferMs - The default duration of media that must be buffered for playback to resume after a rebuffer, in milliseconds. A rebuffer is defined to be caused by buffer depletion rather than a user action.

targetBufferBytes - The target buffer size in bytes. If set to C.LENGTH_UNSET, the target buffer size will be calculated using calculateTargetBufferSize(Renderer[], TrackSelectionArray).

prioritizeTimeOverSizeThresholds - Whether the load control prioritizes buffer time constraints over buffer size constraints.

priorityTaskManager - If not null, registers itself as a task with priority C.PRIORITY_PLAYBACK during loading periods, and unregisters itself during draining

Method Detail

onPrepared

public void onPrepared()

Description copied from interface: LoadControl

Called by the player when prepared with a new source.

Specified by:

onPrepared in interface LoadControl

onTracksSelected

public void onTracksSelected(Renderer[] renderers,
                             TrackGroupArray trackGroups,
                             TrackSelectionArray trackSelections)

Description copied from interface: LoadControl

Called by the player when a track selection occurs.

Specified by:

onTracksSelected in interface LoadControl

Parameters:

renderers - The renderers.

trackGroups - The TrackGroups from which the selection was made.

trackSelections - The track selections that were made.

onStopped

public void onStopped()

Description copied from interface: LoadControl

Called by the player when stopped.

Specified by:

onStopped in interface LoadControl

onReleased

public void onReleased()

Description copied from interface: LoadControl

Called by the player when released.

Specified by:

onReleased in interface LoadControl

getAllocator

public Allocator getAllocator()

Description copied from interface: LoadControl

Returns the Allocator that should be used to obtain media buffer allocations.

Specified by:

getAllocator in interface LoadControl

getBackBufferDurationUs

public long getBackBufferDurationUs()

Description copied from interface: LoadControl

Returns the duration of media to retain in the buffer prior to the current playback position, for fast backward seeking.

Note: If LoadControl.retainBackBufferFromKeyframe() is false then seeking in the back-buffer will only be fast if the back-buffer contains a keyframe prior to the seek position.

Note: Implementations should return a single value. Dynamic changes to the back-buffer are not currently supported.

Specified by:

getBackBufferDurationUs in interface LoadControl

Returns:

The duration of media to retain in the buffer prior to the current playback position, in microseconds.

retainBackBufferFromKeyframe

public boolean retainBackBufferFromKeyframe()

Description copied from interface: LoadControl

Returns whether media should be retained from the keyframe before the current playback position minus LoadControl.getBackBufferDurationUs(), rather than any sample before or at that position.

Warning: Returning true will cause the back-buffer size to depend on the spacing of keyframes in the media being played. Returning true is not recommended unless you control the media and are comfortable with the back-buffer size exceeding LoadControl.getBackBufferDurationUs() by as much as the maximum duration between adjacent keyframes in the media.

Note: Implementations should return a single value. Dynamic changes to the back-buffer are not currently supported.

Specified by:

retainBackBufferFromKeyframe in interface LoadControl

Returns:

Whether media should be retained from the keyframe before the current playback position minus LoadControl.getBackBufferDurationUs(), rather than any sample before or at that position.

shouldContinueLoading

public boolean shouldContinueLoading(long bufferedDurationUs,
                                     float playbackSpeed)

Description copied from interface: LoadControl

Called by the player to determine whether it should continue to load the source.

Specified by:

shouldContinueLoading in interface LoadControl

Parameters:

bufferedDurationUs - The duration of media that's currently buffered.

playbackSpeed - The current playback speed.

Returns:

Whether the loading should continue.

shouldStartPlayback

public boolean shouldStartPlayback(long bufferedDurationUs,
                                   float playbackSpeed,
                                   boolean rebuffering)

Description copied from interface: LoadControl

Called repeatedly by the player when it's loading the source, has yet to start playback, and has the minimum amount of data necessary for playback to be started. The value returned determines whether playback is actually started. The load control may opt to return false until some condition has been met (e.g. a certain amount of media is buffered).

Specified by:

shouldStartPlayback in interface LoadControl

Parameters:

bufferedDurationUs - The duration of media that's currently buffered.

playbackSpeed - The current playback speed.

rebuffering - Whether the player is rebuffering. A rebuffer is defined to be caused by buffer depletion rather than a user action. Hence this parameter is false during initial buffering and when buffering as a result of a seek operation.

Returns:

Whether playback should be allowed to start or resume.

calculateTargetBufferSize

protected int calculateTargetBufferSize(Renderer[] renderers,
                                        TrackSelectionArray trackSelectionArray)

Calculate target buffer size in bytes based on the selected tracks. The player will try not to exceed this target buffer. Only used when targetBufferBytes is C.LENGTH_UNSET.

Parameters:

renderers - The renderers for which the track were selected.

trackSelectionArray - The selected tracks.

Returns:

The target buffer size in bytes.