Patent ID: 8175729

Claim:
A method of transmitting a matrix-surround encoded audio stream, the method comprising: receiving a source audio stream comprising an amount of matrix surround encoded audio that varies within the stream; separating the source audio into a frequency spectrum having a plurality of discrete audio frequencies; identifying a cutoff threshold that varies within the stream in accordance with the varying amount of matrix surround encoded audio to distinguish which of the plurality of audio frequencies are to be encoded using a first matrix-surround preserving encoding method and which of the plurality of audio frequencies are to be encoded using a second non matrix-surround preserving encoding method; encoding a first set of the plurality of audio frequencies below the varying cutoff threshold using the first matrix-surround preserving audio encoding method; encoding a second set of the plurality of audio frequencies above the varying cutoff threshold using the second non matrix-surround preserving audio encoding method; and streaming the first and second sets of encoded audio to a decoder via one or more communications interfaces.