Method and apparatus for generating from a coefficient domain representation of HOA signals a mixed spatial/coefficient domain representation of said HOA signals

An apparatus for decoding an HOA representation, said decoding apparatus comprising:

• a processor for de-multiplexing multiplexed vector of PCM encoded spatial domain signals and vector of PCM encoded and normalized coefficient domain signals;
• wherein the processor is further configured to transform the vector of PCM encoded spatial domain signals to a corresponding vector of coefficient domain signals by multiplying the vector of PCM encoded spatial domain signals with a transform matrix;
• wherein the processor is further configured to de-normalize the vector of PCM encoded and normalized coefficient domain signals, including:
• wherein the processor is further configured to determine a transition vector based on a corresponding exponent of side information and a recursively computed gain value, wherein the corresponding exponent and the gain value are based on a running index of an input matrix of HOA signal vectors;
• wherein the processor is further configured to apply the corresponding inverse gain value to the vector of PCM encoded and normalized coefficient domain signals in order to determine a corresponding vector of PCM-coded and de-normalized signal;
• and
• wherein the processor is further configured to combine the vector of coefficient domain signals and the vector of de-normalized coefficient domain signals to determine a combined vector of HOA coefficient domain signals that can have a variable number of HOA coefficients.