An audio encoder capable of implementing a plurality of encoding functions, wherein an adaptation controller adjusts the implementation of the encoding functions in response to feedback received by the adaptation controller during use. The adjustment may involve adapting encoding algorithms or selecting alternative encoding algorithms. The encoder may also include an operations scheduler to adjust the order in which the encoding functions are applied. The feedback may be received from internally of the encoder, for example from the currently implemented encoding functions, or from externally of the encoder. A corresponding decoder is also provided.