Transformer.Listener

Artifact: androidx.media3:media3-transformer

Kotlin |Java

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

Public methods

onCompleted

default void onCompleted(Composition composition, ExportResult exportResult)

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

default void onError(
    Composition composition,
    ExportResult exportResult,
    ExportException exportException
)

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

default void onFallbackApplied(
    Composition composition,
    TransformationRequest originalTransformationRequest,
    TransformationRequest fallbackTransformationRequest
)

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.
`TransformationRequest originalTransformationRequest`	The unsupported `TransformationRequest` used when building `Transformer`.
`TransformationRequest fallbackTransformationRequest`	The alternative `TransformationRequest`, with supported `audioMimeType`, `videoMimeType`, `outputHeight`, and `hdrMode` values set.