Cea608Decoder

Artifact: androidx.media3:media3-extractor

Kotlin |Java

@UnstableApi
class Cea608Decoder : SubtitleDecoder

A SubtitleDecoder for CEA-608 (also known as "line 21 captions" and "EIA-608").

Summary

Constants
`const Long`	`MIN_DATA_CHANNEL_TIMEOUT_MS = 16000` The minimum value for the `validDataChannelTimeoutMs` constructor parameter permitted by ANSI/CTA-608-E R-2014 Annex C.9.

Public constructors
`Cea608Decoder( mimeType: String!, accessibilityChannel: Int, validDataChannelTimeoutMs: Long )` Constructs an instance.

Public functions
`SubtitleInputBuffer?`	`dequeueInputBuffer()` Dequeues the next input buffer to be filled and queued to the decoder.
`SubtitleOutputBuffer?`	`dequeueOutputBuffer()` Dequeues the next output buffer from the decoder.
`Unit`	`flush()` Flushes the decoder.
`String!`	`getName()` Returns the name of the decoder.
`Unit`	`queueInputBuffer(inputBuffer: SubtitleInputBuffer!)` Queues an input buffer to the decoder.
`Unit`	`release()` Releases the decoder.
`Unit`	`setOutputStartTimeUs(outputStartTimeUs: Long)` Sets the timestamp from which output buffers should be produced, in microseconds.
`Unit`	`setPositionUs(positionUs: Long)` Informs the decoder of the current playback position.

Protected functions
`Subtitle!`	`createSubtitle()` Creates a `Subtitle` from the available data.
`Unit`	`decode(inputBuffer: SubtitleInputBuffer!)` Filters and processes the raw data, providing `Subtitle`s via `createSubtitle` when sufficient data has been processed.
`SubtitleOutputBuffer?`	`getAvailableOutputBuffer()`
`Long`	`getPositionUs()`
`Boolean`	`isNewSubtitleDataAvailable()` Returns whether there is data available to create a new `Subtitle`.
`Unit`	`releaseOutputBuffer(outputBuffer: SubtitleOutputBuffer!)`

Inherited functions

From androidx.media3.decoder.Decoder

`abstract I?`	`dequeueInputBuffer()` Dequeues the next input buffer to be filled and queued to the decoder.
`abstract O?`	`dequeueOutputBuffer()` Dequeues the next output buffer from the decoder.
`abstract Unit`	`queueInputBuffer(inputBuffer: I!)` Queues an input buffer to the decoder.

Constants

MIN_DATA_CHANNEL_TIMEOUT_MS

const val MIN_DATA_CHANNEL_TIMEOUT_MS = 16000: Long

The minimum value for the validDataChannelTimeoutMs constructor parameter permitted by ANSI/CTA-608-E R-2014 Annex C.9.

Public constructors

Cea608Decoder

Cea608Decoder(
    mimeType: String!,
    accessibilityChannel: Int,
    validDataChannelTimeoutMs: Long
)

Constructs an instance.

Parameters
`mimeType: String!`	The MIME type of the CEA-608 data.
`accessibilityChannel: Int`	The Accessibility channel, or `NO_VALUE` if unknown.
`validDataChannelTimeoutMs: Long`	The timeout (in milliseconds) permitted by ANSI/CTA-608-E R-2014 Annex C.9 to clear "stuck" captions where no removal control code is received. The timeout should be at least `MIN_DATA_CHANNEL_TIMEOUT_MS` or `TIME_UNSET` for no timeout.

Public functions

dequeueInputBuffer

fun dequeueInputBuffer(): SubtitleInputBuffer?

Dequeues the next input buffer to be filled and queued to the decoder.

Returns
`SubtitleInputBuffer?`	The input buffer, which will have been cleared, or null if a buffer isn't available.

Throws
`E`	If a decoder error has occurred.
`androidx.media3.extractor.text.SubtitleDecoderException`

dequeueOutputBuffer

fun dequeueOutputBuffer(): SubtitleOutputBuffer?

Dequeues the next output buffer from the decoder.

Returns
`SubtitleOutputBuffer?`	The output buffer, or null if an output buffer isn't available.

Throws
`E`	If a decoder error has occurred.
`androidx.media3.extractor.text.SubtitleDecoderException`

flush

fun flush(): Unit

Flushes the decoder. Ownership of dequeued input buffers is returned to the decoder. The caller is still responsible for releasing any dequeued output buffers.

getName

fun getName(): String!

Returns the name of the decoder.

Returns
`String!`	The name of the decoder.

queueInputBuffer

fun queueInputBuffer(inputBuffer: SubtitleInputBuffer!): Unit

Queues an input buffer to the decoder.

Parameters
`inputBuffer: SubtitleInputBuffer!`	The input buffer.

Throws
`E`	If a decoder error has occurred.
`androidx.media3.extractor.text.SubtitleDecoderException`

release

fun release(): Unit

Releases the decoder. Must be called when the decoder is no longer needed.

setOutputStartTimeUs

fun setOutputStartTimeUs(outputStartTimeUs: Long): Unit

Sets the timestamp from which output buffers should be produced, in microseconds.

Any decoded buffer with a timestamp less than outputStartTimeUs should be skipped by the implementation and not made available via dequeueOutputBuffer.

This method must only be called before queuing the first input buffer initially or after flush.

Parameters
`outputStartTimeUs: Long`	The time from which output buffer should be produced, in microseconds.

setPositionUs

fun setPositionUs(positionUs: Long): Unit

Informs the decoder of the current playback position.

Must be called prior to each attempt to dequeue output buffers from the decoder.

Parameters
`positionUs: Long`	The current playback position in microseconds.

Protected functions

createSubtitle

protected fun createSubtitle(): Subtitle!

Creates a Subtitle from the available data.

decode

protected fun decode(inputBuffer: SubtitleInputBuffer!): Unit

Filters and processes the raw data, providing Subtitles via createSubtitle when sufficient data has been processed.

getAvailableOutputBuffer

protected fun getAvailableOutputBuffer(): SubtitleOutputBuffer?

getPositionUs

protected fun getPositionUs(): Long

isNewSubtitleDataAvailable

protected fun isNewSubtitleDataAvailable(): Boolean

Returns whether there is data available to create a new Subtitle.

releaseOutputBuffer

protected fun releaseOutputBuffer(outputBuffer: SubtitleOutputBuffer!): Unit