Multichannel signal processing method, and multichannel signal processing apparatus for performing the method

A multichannel signal processing method comprising:

• decoding an N/2-channel downmix signal encoded based on a first coding scheme;
• and
• generating an N-channel output signal from the N/2-channel downmix signal based on a second coding scheme,
• when the number of channels of the output signal exceeds predetermined number of channels, decorrelators are reused,
• wherein N denoting the number of channels of the output signal is an even number more than 1.

A multichannel signal processing apparatus comprising a processor to implement a multichannel signal processing method, wherein the processor is configured to

• identify an N/2-channel downmix signal derived from an N-channel input signal, and
• generate an N-channel output signal from the identified N/2-channel downmix signal using a plurality of one-to-two (OTT) boxes, and
• wherein, if a low frequency effect (LFE) channel is absent in the output signal, a maximum number of N/2 decorrelators are used,
• wherein N denoting the number of channels of the output signal is an even number more than 1.