Method and an apparatus for processing an audio signal

An apparatus for processing an audio signal, comprising:

• a receiving unit configured to receive a downmix signal including at least one normal object signal, and a bitstream including object information determined when the downmix signal is generated;
• an extension type identifier extracting part configured to extract, from an extension part of the bitstream, an extension type identifier indicating whether the downmix signal further includes a multi-channel object signal;
• a spatial information extracting part configured to generate spatial information using the object information and mix information when mode information indicates that the multi-channel object signal is to be suppressed and the extension type identifier indicates that the downmix signal further includes the multi-channel object signal;
• and
• a multi-channel object transcoder configured to transmit the spatial information,
• wherein the mix information is to control an object position or an object level of the at least one normal object signal.

A non-transitory computer-readable medium having instructions stored thereon, which, when executed by a processor, causes the processor to perform operations, comprising:

• receiving a downmix signal including at least one normal object signal, and a bitstream including object information determined when the downmix signal is generated;
• extracting, from an extension part of the bitstream, an extension type identifier indicating whether the downmix signal further includes a multi-channel object signal;
• generating spatial information using the object information and mix information when mode information indicates that the multi-channel object signal is to be suppressed and the extension type identifier indicates that the downmix signal further includes the multi-channel object signal;
• and
• transmitting the spatial information,
• wherein the mix information is to control an object position or an object level of the at least one normal object signal.