Transformer.Listener

Artifact: androidx.media3:media3-transformer

Kotlin |Java

interface Transformer.Listener

A listener for the export events.

If the export is not cancelled, either onError or onCompleted will be called once for each export.

Summary

Public functions
`Unit`	`onCompleted(composition: Composition!, exportResult: ExportResult!)` Called when the export is completed successfully.
`Unit`	`onError( composition: Composition!, exportResult: ExportResult!, exportException: ExportException! )` Called if an exception occurs during the export.
`Unit`	`onFallbackApplied( composition: Composition!, originalTransformationRequest: TransformationRequest!, fallbackTransformationRequest: TransformationRequest! )` Called when falling back to an alternative `TransformationRequest` or changing the video frames' resolution is necessary to comply with muxer or device constraints.

Public functions

onCompleted

fun onCompleted(composition: Composition!, exportResult: ExportResult!): Unit

Called when the export is completed successfully.

Parameters
`composition: Composition!`	The `Composition` for which the export is completed.
`exportResult: ExportResult!`	The `ExportResult` of the export.

onError

fun onError(
    composition: Composition!,
    exportResult: ExportResult!,
    exportException: ExportException!
): Unit

Called if an exception occurs during the export.

The export output file (if any) is not deleted in this case.

Parameters
`composition: Composition!`	The `Composition` for which the exception occurs.
`exportResult: ExportResult!`	The `ExportResult` of the export.
`exportException: ExportException!`	The `ExportException` describing the exception. This is the same instance as the `exception` in `result`.

onFallbackApplied

fun onFallbackApplied(
    composition: Composition!,
    originalTransformationRequest: TransformationRequest!,
    fallbackTransformationRequest: TransformationRequest!
): Unit

Called when falling back to an alternative TransformationRequest or changing the video frames' resolution is necessary to comply with muxer or device constraints.

Parameters
`composition: Composition!`	The `Composition` for which the export is requested.
`originalTransformationRequest: TransformationRequest!`	The unsupported `TransformationRequest` used when building `Transformer`.
`fallbackTransformationRequest: TransformationRequest!`	The alternative `TransformationRequest`, with supported `audioMimeType`, `videoMimeType`, `outputHeight`, and `hdrMode` values set.