SubtitleExtractor

Artifact: androidx.media3:media3-extractor

Kotlin |Java

@UnstableApi
class SubtitleExtractor : Extractor

Generic extractor for extracting subtitles from various subtitle formats.

Summary

Constants
`const Int`	`TRACK_ID = 0` The ID of the single track emitted by this extractor.

Public constructors
`SubtitleExtractor(subtitleParser: SubtitleParser!, format: Format?)` Creates an instance.

Public functions
`Unit`	`init(output: ExtractorOutput!)` Initializes the extractor with an `ExtractorOutput`.
`Int`	`read(input: ExtractorInput!, seekPosition: PositionHolder!)` Extracts data read from a provided `ExtractorInput`.
`Unit`	`release()` Releases the extractor's resources, including resetting the `SubtitleParser`.
`Unit`	`seek(position: Long, timeUs: Long)` Notifies the extractor that a seek has occurred.
`Boolean`	`sniff(input: ExtractorInput!)` Returns whether this extractor can extract samples from the `ExtractorInput`, which must provide data from the start of the stream.

Inherited Constants

From androidx.media3.extractor.Extractor

`const Int`	`RESULT_CONTINUE = 0` Returned by `read` if the `ExtractorInput` passed to the next `read` is required to provide data continuing from the position in the stream reached by the returning call.
`const Int`	`RESULT_END_OF_INPUT = -1` Returned by `read` if the end of the was reached.
`const Int`	`RESULT_SEEK = 1` Returned by `read` if the `ExtractorInput` passed to the next `read` is required to provide data starting from a specified position in the stream.

Inherited functions

From androidx.media3.extractor.Extractor

`(Mutable)List<SniffFailure!>!`	`getSniffFailureDetails()` Returns additional details about the last call to `sniff`.
`Extractor!`	`@SideEffectFree getUnderlyingImplementation()` Returns the 'real' `Extractor` implementation if this is a delegating instance, or `this` if this instance does the extraction directly without delegating (the default behaviour).

Constants

TRACK_ID

const val TRACK_ID = 0: Int

The ID of the single track emitted by this extractor.

Public constructors

SubtitleExtractor

SubtitleExtractor(subtitleParser: SubtitleParser!, format: Format?)

Creates an instance.

Parameters
`subtitleParser: SubtitleParser!`	The parser used for parsing the subtitle data. The extractor will reset the parser in `release`.
`format: Format?`	`Format` that describes subtitle data. Can be null if `format`, `seekMap` and `endTracks` will be called outside this extractor.

Public functions

init

fun init(output: ExtractorOutput!): Unit

Initializes the extractor with an ExtractorOutput. Called at most once.

Parameters
`output: ExtractorOutput!`	An `ExtractorOutput` to receive extracted data.

read

fun read(input: ExtractorInput!, seekPosition: PositionHolder!): Int

Extracts data read from a provided ExtractorInput. Must not be called before init.

A single call to this method will block until some progress has been made, but will not block for longer than this. Hence each call will consume only a small amount of input data.

In the common case, RESULT_CONTINUE is returned to indicate that the passed to the next read is required to provide data continuing from the position in the stream reached by the returning call. If the extractor requires data to be provided from a different position, then that position is set in seekPosition and RESULT_SEEK is returned. If the extractor reached the end of the data provided by the ExtractorInput, then RESULT_END_OF_INPUT is returned.

When this method throws an IOException, extraction may continue by providing an ExtractorInput with an unchanged read position to a subsequent call to this method.

Parameters
`input: ExtractorInput!`	The `ExtractorInput` from which data should be read.
`seekPosition: PositionHolder!`	If `RESULT_SEEK` is returned, this holder is updated to hold the position of the required data.

Returns
`Int`	One of the `RESULT_` values defined in this interface.

Throws
`java.io.IOException`	If an error occurred reading from or parsing the input.

release

fun release(): Unit

Releases the extractor's resources, including resetting the SubtitleParser.

seek

fun seek(position: Long, timeUs: Long): Unit

Notifies the extractor that a seek has occurred.

Following a call to this method, the ExtractorInput passed to the next invocation of read is required to provide data starting from position in the stream. Valid random access positions are the start of the stream and positions that can be obtained from any SeekMap passed to the ExtractorOutput.

Parameters
`position: Long`	The byte offset in the stream from which data will be provided.
`timeUs: Long`	The seek time in microseconds.

sniff

fun sniff(input: ExtractorInput!): Boolean

Returns whether this extractor can extract samples from the ExtractorInput, which must provide data from the start of the stream.

If true is returned, the input's reading position may have been modified. Otherwise, only its peek position may have been modified.

Parameters
`input: ExtractorInput!`	The `ExtractorInput` from which data should be peeked/read.

Returns
`Boolean`	Whether this extractor can read the provided input.

Throws
`java.io.IOException`	If an error occurred reading from the input.