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US 10,475,459 B2Granted
Audio upmixer operable in prediction or non-prediction mode
AssigneeDolby International AB
InventorsHeiko Purnhagen, Pontus Carlsson, Lars Villemoes
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Abstract
The invention provides methods and devices for outputting a stereo audio signal having a left channel and a right channel. The apparatus includes a demultiplexer, decoder, and upmixer. The upmixer is configured operate either in a prediction mode or a non-prediction mode based on a parameter encoded in the audio bitstream.
Claims16
An apparatus for outputting a stereo audio signal having a left channel and a right channel, the apparatus comprising:
- a demultiplexer configured to receive an audio bitstream and extract therefrom a prediction coefficient, wherein the audio bitstream is segmented into frames and a value of the prediction coefficient may change for each of the frames;
- a decoder configured to generate a downmix signal and a residual signal from the audio bitstream;
- and
- an upmixer configured to operate in either a prediction mode or a non-prediction mode based on a parameter encoded in the audio bitstream, and to output the left channel and the right channel as the stereo audio signal,
- wherein, when the upmixer operates in the prediction mode, the residual signal represents a difference between a side signal and a predicted version of the side signal, and the upmixer generates the left channel and the right channel from a combination of the downmix signal, the residual signal, and the prediction coefficient, and
- wherein, when the upmixer operates in the non-prediction mode, the residual signal represents the side signal, the upmixer generates the left channel based on a sum of the downmix signal and the residual signal, and the upmixer generates the right channel based on a difference of the downmix signal and the residual signal.
3 more elements
A method for outputting a stereo audio signal having a left channel and a right channel, the method comprising:
- receiving an audio bitstream and extract therefrom a prediction coefficient, wherein the audio bitstream is segmented into frames and a value of the prediction coefficient may change for each of the frames;
- generating in a decoder a downmix signal and a residual signal from the audio bitstream;
- upmixing in either a prediction mode or a non-prediction mode based on a parameter encoded in the audio bitstream;
- and
- outputting the left channel and the right channel as the stereo audio signal,
- wherein, when the upmixing operates in the prediction mode, the residual signal represents a difference between a side signal and a predicted version of the side signal, and the upmixing generates the left channel and the right channel from a combination of the downmix signal, the residual signal, and the prediction coefficient, and
- wherein, when the upmixing operates in the non-prediction mode, the residual signal represents the side signal, and the upmixing generates the left channel based on a sum of the downmix signal and the residual signal passed through from the decoder, and
- generates the right channel based on a difference of the downmix signal and the residual signal.
5 more elements
Dependencies are inferred from the claim text.