Methods for parametric multi-channel encoding

An apparatus comprising:

• one or more processors;
• memory storing instructions, which, when executed by the one or more processors, causes the one or more processors to perform operations comprising:
• receiving a multi-channel input audio signal and downmix instructions comprising a set of frequency-invariant gain values;
• determining a first set of dynamic range control (DRC) values configured for controlling a dynamic range of an output audio signal;
• determining a second set of DRC values configured for preventing the multi-channel input audio signal from clipping during downmixing by the apparatus;
• applying the second set of DRC values to the multi-channel input audio signal to obtain an attenuated multi-channel input audio signal;
• downmixing the attenuated multi-channel input audio signal, in response to the downmix instructions, to obtain a downmix signal;
• and
• generating the output audio signal from the first set of DRC values and the downmix audio signal.

A non-transitory computer readable storage medium comprising a sequence of instructions which, when performed by an audio signal processing device cause the audio signal processing device to perform a method comprising:

• receiving, by an audio processor, a multi-channel input audio signal and downmix instructions comprising a set of frequency-invariant gain values;
• determining a first set of dynamic range control (DRC) values configured for controlling a dynamic range of an output audio signal;
• determining a second set of DRC values configured for preventing the multi-channel input audio signal from clipping during downmixing by the audio processor;
• applying the second set of DRC values to the multi-channel input audio signal to obtain an attenuated multi-channel input audio signal;
• downmixing the attenuated multi-channel input audio signal, in response to the downmix instructions, to obtain a downmix signal;
• and
• generating the output audio signal from the first set of DRC values and the downmix audio signal.