Adaptive stereo parameter synthesis

A decoder adapted to perform operations comprising:

• receiving encoded stereo signals and at least one encoded stereo parameter, wherein the encoded stereo signals includes a first type of stereo signals encoded in a first encoding mode and a second type of stereo signals encoded in a second encoding mode;
• processing the encoded stereo signals on a frame-by-frame basis;
• decoding the encoded stereo signals encoded in the first encoding mode to produce a first set of decoded stereo signals;
• synthesizing stereo signals based on the first set of decoded stereo signals;
• decoding the encoded stereo signals encoded in the second encoding mode and the at least one encoded stereo parameter;
• determining at least one designated stereo parameter based on the at least one decoded stereo parameter and an indicator indicating whether or not foreground signals and background signals are efficiently separated in the first encoding mode;
• and
• synthesizing stereo signals encoded in the second encoding mode based on the at least one designated stereo parameter.

A decoder comprising:

• processing circuitry;
• and
• memory coupled with the processing circuitry, wherein the memory includes instructions that when executed by the processing circuitry causes the decoder to perform operations comprising:
• receiving encoded stereo signals and at least one encoded stereo parameter, wherein the encoded stereo signals includes a first type of stereo signals encoded in a first encoding mode and a second type of stereo signals encoded in a second encoding mode;
• processing the encoded stereo signals on a frame-by-frame basis;
• decoding the encoded stereo signals encoded in the first encoding mode to produce a first set of decoded stereo signals;
• synthesizing stereo signals based on the first set of decoded stereo signals;
• decoding the encoded stereo signals encoded in the second encoding mode and the at least one encoded stereo parameter;
• determining at least one designated stereo parameter based on the at least one decoded stereo parameter and an indicator indicating whether or not foreground signals and background signals are efficiently separated in the first encoding mode;
• and
• synthesizing stereo signals encoded in the second encoding mode based on the at least one designated stereo parameter.

A computer program product comprising a non-transitory computer readable storage medium having program code, to be executed by processing circuitry of a decoder, whereby execution of the program code causes the decoder to perform operations comprising:

• receiving encoded stereo signals and at least one encoded stereo parameter, wherein the encoded stereo signals includes a first type of stereo signals encoded in a first encoding mode and a second type of stereo signals encoded in a second encoding mode;
• processing the encoded stereo signals on a frame-by-frame basis;
• decoding the encoded stereo signals encoded in the first encoding mode to produce a first set of decoded stereo signals;
• synthesizing stereo signals based on the first set of decoded stereo signals;
• decoding the encoded stereo signals encoded in the second encoding mode and the at least one encoded stereo parameter;
• determining at least one designated stereo parameter based on the at least one decoded stereo parameter and an indicator indicating whether or not foreground signals and background signals are efficiently separated in the first encoding mode;
• and
• synthesizing stereo signals encoded in the second encoding mode based on the at least one designated stereo parameter.