Preserving matrix surround information in encoded audio/video system and method
View Patent ↗A method and apparatus for preserving matrix-surround information in encoded audio/video includes a receiver operative to receive matrix-surround encoded audio signals via a modem, separate the audio signals into a frequency spectrum having discrete audio frequencies, and determine a cutoff threshold used to encode the matrix-surround encoded audio signals. The method and apparatus further includes a decoder operative to decode a first set of the audio frequencies below the determined cutoff threshold using a first matrix-surround preserving audio encoding method and to decode a second set of audio frequencies above the cutoff threshold using a second non matrix-surround preserving audio encoding method.
1. A method of encoding matrix-surround-encoded audio for transmission over a low bitrate connection that is less than about 96 kbps, comprising:
identifying a source audio content comprising matrix-surround-encoded audio;
separating said source audio content into a frequency spectrum having a plurality of discrete audio frequencies;
determining a frequency cutoff threshold;
encoding a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio encoding method including dual-mono or mid/side coding; and
encoding a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio encoding method including joint-stereo coding.
2. The method of claim 1 , wherein said frequency cutoff threshold is determined based at least in part on descriptive information associated with said source audio content.
3. The method of claim 1 , wherein said frequency cutoff threshold is determined based at least in part on the content of said source audio content.
4. An apparatus comprising a processor to execute instructions; a communication interface; and a memory device communicatively coupled to the processor and communication interface and having stored thereon a plurality of instructions, which when executed by said processor, operate to:
identify a source audio content comprising matrix-surround-encoded audio;
separate said source audio content into a frequency spectrum having a plurality of discrete audio frequencies;
determine a frequency cutoff threshold;
encode a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio encoding method including dual-mono or mid/side coding; and
encode a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio encoding method including joint-stereo coding.
5. A non-transitory computer-readable medium including a plurality of instructions stored thereon, which when executed by a processor, cause a computing device to:
identify a source audio content comprising matrix-surround-encoded audio;
separate said source audio content into a frequency spectrum having a plurality of discrete audio frequencies;
determine a frequency cutoff threshold;
encode a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio encoding method including dual-mono or mid/side coding; and
encode a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio encoding method including joint-stereo coding.
6. A method of decoding matrix-surround-encoded audio, comprising:
identifying a bit stream comprising matrix-surround-encoded audio;
decoding said bit stream into a frequency spectrum having a plurality of discrete audio frequencies;
determining a frequency cutoff threshold;
decoding a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio decoding method including dual-mono or mid/side coding; and
decoding a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio decoding method including joint-stereo coding.
7. An apparatus comprising a processor to execute instructions; a communication interface; and a memory device communicatively coupled to the processor and communication interface and having stored thereon a plurality of instructions, which when executed by said processor, operate to:
identify a bit stream comprising matrix-surround-encoded audio;
decode said bit stream into a frequency spectrum having a plurality of discrete audio frequencies;
determine a frequency cutoff threshold;
decode a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio decoding method including dual-mono or mid/side coding; and
decode a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio decoding method including joint-stereo coding.
8. A non-transitory computer-readable medium including a plurality of instructions stored thereon, which when executed by a processor, cause a computing device to:
identify a bit stream comprising matrix-surround-encoded audio;
decode said bit stream into a frequency spectrum having a plurality of discrete audio frequencies;
determine a frequency cutoff threshold;
decode a first set of the plurality of audio frequencies below said frequency cutoff threshold using a matrix-surround-preserving audio decoding method including dual-mono or mid/side coding; and
decode a second set of the plurality of audio frequencies above said frequency cutoff threshold using a non-matrix-surround-preserving audio decoding method including joint-stereo coding.