Integrated reconstruction and rendering of audio signals

A decoder system for rendering an audio output based on an audio data stream, comprising:

• a receiver for receiving a data stream including:
• M audio signals which are combinations of N audio objects, wherein N>1 and M≤N,
• side information including a series of reconstruction instances ci of a reconstruction matrix C and first timing data defining transitions between said instances, said side information allowing reconstruction of the N audio objects from the M audio signals, and
• time-variable object metadata including a series of metadata instances mi defining spatial relationships between the N audio objects and second timing data defining transitions between said metadata instances;
• a matrix generator for generating a synchronized rendering matrix Rsync based on the object metadata, the first timing data, and information relating to a current playback system configuration, said synchronized rendering matrix Rsync having a rendering instance ri corresponding in time with each reconstruction instance ci;
• and
• an integrated renderer including:
• a matrix combiner for multiplying each reconstruction instance ci with a corresponding rendering instance ri to form a corresponding instance of an integrated rendering matrix INT;
• and
• a matrix transform for applying the integrated rendering matrix INT to the M audio signals in order to render an audio output.