Method And Apparatus For Encoding And Decoding Multi-Channel Audio Signal Using Virtual Source Location Information

An apparatus for decoding a multi-channel audio signal, the apparatus comprising:

• means for receiving the multi-channel audio signal;
• a signal distributor for separating the received multi-channel audio signal into an encoded downmixed audio signal and a quantized virtual source location vector signal;
• means for decoding the encoded downmixed audio signal;
• means for converting the decoded downmixed audio signal into a frequency axis signal;
• a VSLI extractor for extracting per-band VSLI from the quantized virtual source location vector signal;
• a channel gain calculator for calculating per-band channel gains using the extracted per-band VSLI;
• means for synthesizing a multi-channel audio signal spectrum using the converted frequency axis signal and the calculated per-band channel gains;
• and
• means for generating a multi-channel audio signal from the synthesized multi-channel spectrum.

A method of encoding a multi-channel audio signal, comprising the steps of:

• converting the multi-channel audio signal into a framed audio signal;
• downmixing the framed audio signal;
• encoding the downmixed audio signal;
• estimating source location information from the framed audio signal;
• quantizing the estimated source location information;
• and
• multiplexing the encoded downmixed audio signal and the quantized source location information, to generate an encoded multi-channel audio signal.

A method of decoding a multi-channel audio signal, comprising the steps of:

• receiving the multi-channel audio signal;
• separating the received multi-channel audio signal into an encoded downmixed audio signal and a quantized virtual source location vector signal;
• decoding the encoded downmixed audio signal;
• converting the decoded downmixed audio signal into a frequency axis signal;
• analyzing the quantized virtual source location vector signal and extracting per-band VSLI therefrom;
• calculating per-band channel gains from the extracted per-band VSLI;
• synthesizing a multi-channel audio signal spectrum using the converted frequency axis signal and the calculated per-band channel gains;
• and
• producing a multi-channel audio signal from the synthesized multi-channel spectrum.