Audio signal processing method

An audio signal processing method, comprising:

• receiving a bit-stream including both a normal channel signal and an exceptional channel signal;
• decoding the exceptional channel signal and the normal channel signal from the received bit-stream;
• generating correlation information using the decoded exceptional channel signal and the decoded normal channel signal;
• generating a gain value through at least one of a first downmix method, which applies a uniform downmix gain value using the correlation information, and a second downmix method, which applies a variable gain value according to time;
• and
• outputting the exceptional channel signal as multiple channel signals using the gain value.

An audio signal processing method, comprising:

• receiving a bit-stream including an object signal and object position information;
• decoding the object signal and the object position information from the received bit-stream;
• receiving past object position information from a storage medium;
• generating an object moving path using the decoded object position information and the received past object position information;
• selecting either a first downmix method, which applies a uniform gain value using the object moving path, or a second downmix method, which applies a variable gain value according to time;
• generating a gain value using the selected downmix method;
• and
• generating a channel signal from the decoded object signal using the generated gain value.