MediaPeriod

Artifact: androidx.media3:media3-exoplayer

Kotlin |Java

@UnstableApi
interface MediaPeriod : SequenceableLoader

Known direct subclasses

ClippingMediaPeriod, FakeAdaptiveMediaPeriod, FakeMediaPeriod, MaskingMediaPeriod

`ClippingMediaPeriod`	Wraps a `MediaPeriod` and clips its `SampleStream`s to provide a subsequence of their samples.
`FakeAdaptiveMediaPeriod`	Fake `MediaPeriod` that provides tracks from the given `TrackGroupArray`.
`FakeMediaPeriod`	Fake `MediaPeriod` that provides tracks from the given `TrackGroupArray`.
`MaskingMediaPeriod`	Media period that defers calling `createPeriod` on a given source until `createPeriod` has been called.

Loads media corresponding to a Timeline.Period, and allows that media to be read. All methods are called on the player's internal playback thread, as described in the Javadoc.

A MediaPeriod may only able to provide one SampleStream corresponding to a group at any given time, however this SampleStream may adapt between multiple tracks within the group.

Summary

Nested types
`interface MediaPeriod.Callback : SequenceableLoader.Callback` A callback to be notified of `MediaPeriod` events.

Public functions
`Boolean`	`continueLoading(loadingInfo: LoadingInfo!)` Attempts to continue loading.
`Unit`	`discardBuffer(positionUs: Long, toKeyframe: Boolean)` Discards buffered media up to the specified position.
`Long`	`getAdjustedSeekPositionUs( positionUs: Long, seekParameters: SeekParameters! )` Returns the position to which a seek will be performed, given the specified seek position and `SeekParameters`.
`Long`	`getBufferedPositionUs()` Returns an estimate of the position up to which data is buffered for the enabled tracks.
`Long`	`getNextLoadPositionUs()` Returns the next load time, or `TIME_END_OF_SOURCE` if loading has finished.
`(Mutable)List<StreamKey!>!`	`getStreamKeys(trackSelections: (Mutable)List<ExoTrackSelection!>!)` Returns a list of `StreamKeys` which allow to filter the media in this period to load only the parts needed to play the provided `TrackSelections`.
`TrackGroupArray!`	`getTrackGroups()` Returns the `TrackGroup`s exposed by the period.
`Boolean`	`isLoading()` Returns whether the media period is currently loading.
`Unit`	`maybeThrowPrepareError()` Throws an error that's preventing the period from becoming prepared.
`Unit`	`prepare(callback: MediaPeriod.Callback!, positionUs: Long)` Prepares this media period asynchronously.
`Long`	`readDiscontinuity()` Attempts to read a discontinuity.
`Unit`	`reevaluateBuffer(positionUs: Long)` Re-evaluates the buffer given the playback position.
`Long`	`seekToUs(positionUs: Long)` Attempts to seek to the specified position in microseconds.
`Long`	`selectTracks( @NullableType selections: Array<@NullableType ExoTrackSelection!>!, mayRetainStreamFlags: BooleanArray!, @NullableType streams: Array<@NullableType SampleStream!>!, streamResetFlags: BooleanArray!, positionUs: Long )` Performs a track selection.

Public functions

continueLoading

fun continueLoading(loadingInfo: LoadingInfo!): Boolean

Attempts to continue loading.

This method may be called both during and after the period has been prepared.

A period may call onContinueLoadingRequested on the Callback passed to prepare to request that this method be called when the period is permitted to continue loading data. A period may do this both during and after preparation.

Parameters
`loadingInfo: LoadingInfo!`	The `LoadingInfo` when attempting to continue loading.

Returns
`Boolean`	True if progress was made, meaning that `getNextLoadPositionUs` will return a different value than prior to the call. False otherwise.

discardBuffer

fun discardBuffer(positionUs: Long, toKeyframe: Boolean): Unit

Discards buffered media up to the specified position.

This method is only called after the period has been prepared.

Parameters
`positionUs: Long`	The position in microseconds.
`toKeyframe: Boolean`	If true then for each track discards samples up to the keyframe before or at the specified position, rather than any sample before or at that position.

getAdjustedSeekPositionUs

fun getAdjustedSeekPositionUs(
    positionUs: Long,
    seekParameters: SeekParameters!
): Long

Returns the position to which a seek will be performed, given the specified seek position and SeekParameters.

This method is only called after the period has been prepared.

Parameters
`positionUs: Long`	The seek position in microseconds.
`seekParameters: SeekParameters!`	Parameters that control how the seek is performed. Implementations may apply seek parameters on a best effort basis.

Returns
`Long`	The actual position to which a seek will be performed, in microseconds.

getBufferedPositionUs

fun getBufferedPositionUs(): Long

Returns an estimate of the position up to which data is buffered for the enabled tracks.

This method is only called when at least one track is selected.

Returns
`Long`	An estimate of the absolute position in microseconds up to which data is buffered, or `TIME_END_OF_SOURCE` if the track is fully buffered.

getNextLoadPositionUs

fun getNextLoadPositionUs(): Long

Returns the next load time, or TIME_END_OF_SOURCE if loading has finished.

This method is only called after the period has been prepared. It may be called when no tracks are selected.

getStreamKeys

fun getStreamKeys(trackSelections: (Mutable)List<ExoTrackSelection!>!): (Mutable)List<StreamKey!>!

Returns a list of StreamKeys which allow to filter the media in this period to load only the parts needed to play the provided TrackSelections.

This method is only called after the period has been prepared.

Parameters
`trackSelections: (Mutable)List<ExoTrackSelection!>!`	The `TrackSelections` describing the tracks for which stream keys are requested.

Returns
`(Mutable)List<StreamKey!>!`	The corresponding `StreamKeys` for the selected tracks, or an empty list if filtering is not possible and the entire media needs to be loaded to play the selected tracks.

getTrackGroups

fun getTrackGroups(): TrackGroupArray!

Returns the TrackGroups exposed by the period.

This method is only called after the period has been prepared.

Returns
`TrackGroupArray!`	The `TrackGroup`s.

isLoading

fun isLoading(): Boolean

Returns whether the media period is currently loading.

maybeThrowPrepareError

fun maybeThrowPrepareError(): Unit

Throws an error that's preventing the period from becoming prepared. Does nothing if no such error exists.

This method is only called before the period has completed preparation.

Throws
`java.io.IOException`	The underlying error.

prepare

fun prepare(callback: MediaPeriod.Callback!, positionUs: Long): Unit

Prepares this media period asynchronously.

callback.onPrepared is called when preparation completes. If preparation fails, maybeThrowPrepareError will throw an IOException.

If preparation succeeds and results in a source timeline change (e.g. the period duration becoming known), onSourceInfoRefreshed will be called before callback.onPrepared.

Parameters
`callback: MediaPeriod.Callback!`	Callback to receive updates from this period, including being notified when preparation completes.
`positionUs: Long`	The expected starting position, in microseconds.

readDiscontinuity

fun readDiscontinuity(): Long

Attempts to read a discontinuity.

A discontinuity implies that the provided SampleStreams will start from a new playback position and any output pipelines need to be reset. This happens for example if the streams provide decode-only samples before the intended playback start position that need to be dropped.

After this method has returned a value other than TIME_UNSET, all SampleStreams provided by the period are guaranteed to start from a key frame.

This method is only called after the period has been prepared.

Returns
`Long`	The playback position after the discontinuity, in microseconds, or `TIME_UNSET` if there is no discontinuity.

reevaluateBuffer

fun reevaluateBuffer(positionUs: Long): Unit

Re-evaluates the buffer given the playback position.

This method is only called after the period has been prepared.

A period may choose to discard buffered media or cancel ongoing loads so that media can be re-buffered in a different quality.

Parameters
`positionUs: Long`	The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position in this period minus the duration of any media in previous periods still to be played.

seekToUs

fun seekToUs(positionUs: Long): Long

Attempts to seek to the specified position in microseconds.

After this method has been called, all SampleStreams provided by the period are guaranteed to start from a key frame.

This method is only called when at least one track is selected.

Parameters
`positionUs: Long`	The seek position in microseconds.

Returns
`Long`	The actual position to which the period was seeked, in microseconds.

selectTracks

fun selectTracks(
    @NullableType selections: Array<@NullableType ExoTrackSelection!>!,
    mayRetainStreamFlags: BooleanArray!,
    @NullableType streams: Array<@NullableType SampleStream!>!,
    streamResetFlags: BooleanArray!,
    positionUs: Long
): Long

Performs a track selection.

The call receives track selections for each renderer, mayRetainStreamFlags indicating whether the existing SampleStream can be retained for each selection, and the existing streams themselves. The call will update streams to reflect the provided selections, clearing, setting and replacing entries as required. If an existing sample stream is retained but with the requirement that the consuming renderer be reset, then the corresponding flag in streamResetFlags will be set to true. This flag will also be set if a new sample stream is created.

Note that previously passed TrackSelections are no longer valid, and any references to them must be updated to point to the new selections.

This method is only called after the period has been prepared.

Parameters
`@NullableType selections: Array<@NullableType ExoTrackSelection!>!`	The renderer track selections.
`mayRetainStreamFlags: BooleanArray!`	Flags indicating whether the existing sample stream can be retained for each track selection. A `true` value indicates that the selection is equivalent to the one that was previously passed, and that the caller does not require that the sample stream be recreated. If a retained sample stream holds any references to the track selection then they must be updated to point to the new selection.
`@NullableType streams: Array<@NullableType SampleStream!>!`	The existing sample streams, which will be updated to reflect the provided selections.
`streamResetFlags: BooleanArray!`	Will be updated to indicate new sample streams, and sample streams that have been retained but with the requirement that the consuming renderer be reset.
`positionUs: Long`	The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position.

Returns
`Long`	The actual position at which the tracks were enabled, in microseconds.

MediaPeriod

Summary

Nested types

Public functions

Public functions

continueLoading

discardBuffer

getAdjustedSeekPositionUs

getBufferedPositionUs

getNextLoadPositionUs

getStreamKeys

getTrackGroups

isLoading

maybeThrowPrepareError

prepare

readDiscontinuity

reevaluateBuffer

seekToUs

selectTracks