com.google.android.exoplayer

Interface SampleSource.SampleSourceReader

All Known Implementing Classes:

ChunkSampleSource, ExtractorSampleSource, FrameworkSampleSource, HlsSampleSource, SingleSampleSource

Enclosing interface:

SampleSource

public static interface SampleSource.SampleSourceReader

An interface providing read access to a SampleSource.

Method Summary

Modifier and Type	Method and Description
boolean	continueBuffering(int track, long positionUs) Indicates to the source that it should still be buffering data for the specified track.
void	disable(int track) Disable the specified track.
void	enable(int track, long positionUs) Enable the specified track.
long	getBufferedPositionUs() Returns an estimate of the position up to which data is buffered.
MediaFormat	getFormat(int track) Returns the format of the specified track.
int	getTrackCount() Returns the number of tracks exposed by the source.
void	maybeThrowError() If the source is currently having difficulty preparing or loading samples, then this method throws the underlying error.
boolean	prepare(long positionUs) Prepares the source.
int	readData(int track, long positionUs, MediaFormatHolder formatHolder, SampleHolder sampleHolder) Attempts to read a sample or a new format from the source.
long	readDiscontinuity(int track) Attempts to read a pending discontinuity from the source.
void	release() Releases the SampleSource.SampleSourceReader.
void	seekToUs(long positionUs) Seeks to the specified time in microseconds.

Method Detail

maybeThrowError

void maybeThrowError()
              throws IOException

If the source is currently having difficulty preparing or loading samples, then this method throws the underlying error. Otherwise does nothing.

Throws:

IOException - The underlying error.

prepare

boolean prepare(long positionUs)

Prepares the source.

Preparation may require reading from the data source (e.g. to determine the available tracks and formats). If insufficient data is available then the call will return false rather than block. The method can be called repeatedly until the return value indicates success.

Parameters:

positionUs - The player's current playback position.

Returns:

True if the source was prepared, false otherwise.

getTrackCount

int getTrackCount()

Returns the number of tracks exposed by the source.

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

Returns:

The number of tracks.

getFormat

MediaFormat getFormat(int track)

Returns the format of the specified track.

Note that whilst the format of a track will remain constant, the format of the actual media stream may change dynamically. An example of this is where the track is adaptive (i.e. @link MediaFormat.adaptive is true). Hence the track formats returned through this method should not be used to configure decoders. Decoder configuration should be performed using the formats obtained when reading the media stream through calls to readData(int, long, MediaFormatHolder, SampleHolder).

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

Parameters:

track - The track index.

Returns:

The format of the specified track.

enable

void enable(int track,
            long positionUs)

Enable the specified track. This allows the track's format and samples to be read from readData(int, long, MediaFormatHolder, SampleHolder).

This method should only be called after the source has been prepared, and when the specified track is disabled.

Parameters:

track - The track to enable.

positionUs - The player's current playback position.

continueBuffering

boolean continueBuffering(int track,
                          long positionUs)

Indicates to the source that it should still be buffering data for the specified track.

This method should only be called when the specified track is enabled.

Parameters:

track - The track to continue buffering.

positionUs - The current playback position.

Returns:

True if the track has available samples, or if the end of the stream has been reached. False if more data needs to be buffered for samples to become available.

readDiscontinuity

long readDiscontinuity(int track)

Attempts to read a pending discontinuity from the source.

This method should only be called when the specified track is enabled.

Parameters:

track - The track from which to read.

Returns:

If a discontinuity was read then the playback position after the discontinuity. Else SampleSource.NO_DISCONTINUITY.

readData

int readData(int track,
             long positionUs,
             MediaFormatHolder formatHolder,
             SampleHolder sampleHolder)

Attempts to read a sample or a new format from the source.

This method should only be called when the specified track is enabled.

Note that where multiple tracks are enabled, SampleSource.NOTHING_READ may be returned if the next piece of data to be read from the SampleSource corresponds to a different track than the one for which data was requested.

This method will always return SampleSource.NOTHING_READ in the case that there's a pending discontinuity to be read from readDiscontinuity(int) for the specified track.

Parameters:

track - The track from which to read.

positionUs - The current playback position.

formatHolder - A MediaFormatHolder object to populate in the case of a new format.

sampleHolder - A SampleHolder object to populate in the case of a new sample. If the caller requires the sample data then it must ensure that SampleHolder.data references a valid output buffer.

Returns:

The result, which can be SampleSource.SAMPLE_READ, SampleSource.FORMAT_READ, SampleSource.NOTHING_READ or SampleSource.END_OF_STREAM.

seekToUs

void seekToUs(long positionUs)

Seeks to the specified time in microseconds.

This method should only be called when at least one track is enabled.

Parameters:

positionUs - The seek position in microseconds.

getBufferedPositionUs

long getBufferedPositionUs()

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

This method should only be called when at least one track is enabled.

Returns:

An estimate of the absolute position in microseconds up to which data is buffered, or TrackRenderer.END_OF_TRACK_US if data is buffered to the end of the stream, or TrackRenderer.UNKNOWN_TIME_US if no estimate is available.

disable

void disable(int track)

Disable the specified track.

This method should only be called when the specified track is enabled.

Parameters:

track - The track to disable.

release

void release()

Releases the SampleSource.SampleSourceReader.

This method should be called when access to the SampleSource is no longer required.