To control Transformer's behavior, you can configure options in the API surface or replace pieces of functionality completely by writing custom implementations of interfaces and passing those in. This page describes some examples.
Control codec configuration
By default, Transformer will fall back to a supported resolution if the device's hardware encoder doesn't accept the requested output resolution. For example, Transformer can align the output width and height to be a multiple of 2 or 16 as is often required by hardware encoders. You can turn off this behavior so that Transformer instead throws an error if it can't produce the required output resolution:
Kotlin
transformerBuilder .setEncoderFactory( DefaultEncoderFactory.Builder(context) .setEnableFallback(false) .build())
Java
transformerBuilder .setEncoderFactory( new DefaultEncoderFactory.Builder(context) .setEnableFallback(false) .build());
Similarly, the DefaultEncoderFactory
also supports using custom encoding
settings with the setRequestedVideoEncoderSettings
option.
You can also completely replace the factories for encoders and decoders to get full control over how the codecs are set up.
Custom muxers
You can set a custom muxer for writing media containers by calling
Transformer.setMuxerFactory
. For example, if you implement your own muxer at
the application level, you can write a wrapper that implements the Muxer
interface and then use setMuxerFactory
to inject it into Transformer.