com.google.android.exoplayer2.source.chunk

Interface ChunkSource

public interface ChunkSource

A provider of Chunks for a ChunkSampleStream to load.

Method Summary

Modifier and Type	Method and Description
long	getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) Adjusts a seek position given the specified SeekParameters.
void	getNextChunk(MediaChunk previous, long playbackPositionUs, long loadPositionUs, ChunkHolder out) Returns the next chunk to load.
int	getPreferredQueueSize(long playbackPositionUs, java.util.List<? extends MediaChunk> queue) Evaluates whether MediaChunks should be removed from the back of the queue.
void	maybeThrowError() If the source is currently having difficulty providing chunks, then this method throws the underlying error.
void	onChunkLoadCompleted(Chunk chunk) Called when the ChunkSampleStream has finished loading a chunk obtained from this source.
boolean	onChunkLoadError(Chunk chunk, boolean cancelable, java.lang.Exception e) Called when the ChunkSampleStream encounters an error loading a chunk obtained from this source.

Method Detail

getAdjustedSeekPositionUs

long getAdjustedSeekPositionUs(long positionUs,
                               SeekParameters seekParameters)

Adjusts a seek position given the specified SeekParameters. Chunk boundaries are used as sync points.

Parameters:

positionUs - The seek position in microseconds.

seekParameters - Parameters that control how the seek is performed.

Returns:

The adjusted seek position, in microseconds.

maybeThrowError

void maybeThrowError()
              throws java.io.IOException

If the source is currently having difficulty providing chunks, then this method throws the underlying error. Otherwise does nothing.

This method should only be called after the source has been prepared.

Throws:

java.io.IOException - The underlying error.

getPreferredQueueSize

int getPreferredQueueSize(long playbackPositionUs,
                          java.util.List<? extends MediaChunk> queue)

Evaluates whether MediaChunks should be removed from the back of the queue.

Removing MediaChunks from the back of the queue can be useful if they could be replaced with chunks of a significantly higher quality (e.g. because the available bandwidth has substantially increased).

Parameters:

playbackPositionUs - The current playback position.

queue - The queue of buffered MediaChunks.

Returns:

The preferred queue size.

getNextChunk

void getNextChunk(MediaChunk previous,
                  long playbackPositionUs,
                  long loadPositionUs,
                  ChunkHolder out)

Returns the next chunk to load.

If a chunk is available then ChunkHolder.chunk is set. If the end of the stream has been reached then ChunkHolder.endOfStream is set. If a chunk is not available but the end of the stream has not been reached, the ChunkHolder is not modified.

Parameters:

previous - The most recently loaded media chunk.

playbackPositionUs - The current playback position in microseconds. If playback of the period to which this chunk source belongs has not yet started, the value will be the starting position in the period minus the duration of any media in previous periods still to be played.

loadPositionUs - The current load position in microseconds. If previous is null, this is the starting position from which chunks should be provided. Else it's equal to previous.endTimeUs.

out - A holder to populate.

onChunkLoadCompleted

void onChunkLoadCompleted(Chunk chunk)

Called when the ChunkSampleStream has finished loading a chunk obtained from this source.

This method should only be called when the source is enabled.

Parameters:

chunk - The chunk whose load has been completed.

onChunkLoadError

boolean onChunkLoadError(Chunk chunk,
                         boolean cancelable,
                         java.lang.Exception e)

Called when the ChunkSampleStream encounters an error loading a chunk obtained from this source.

This method should only be called when the source is enabled.

Parameters:

chunk - The chunk whose load encountered the error.

cancelable - Whether the load can be canceled.

e - The error.

Returns:

Whether the load should be canceled. Should always be false if cancelable is false.