Hierarchical decorrelation of multichannel audio
AssigneeGoogle Inc.
InventorsMinyue Li, Willem Bastiaan Kleijn, Jan Skoglund
Life of this patent
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Abstract
Provided are methods, systems, and apparatus for hierarchical decorrelation of multichannel audio. A hierarchical decorrelation algorithm is designed to adapt to possibly changing characteristics of an input signal, and also preserves the energy of the original signal. The algorithm is invertible in that the original signal can be retrieved if needed. Furthermore, the proposed algorithm decomposes the decorrelation process into multiple low-complexity steps. The contribution of these steps is generally in a decreasing order, and thus the complexity of the algorithm can be scaled.
Claims15
A method for separating sources of an audio signal comprised of a plurality of channels, the method comprising:
- segmenting the audio signal into frames;
- estimating, for each frame, a signal model;
- performing hierarchical decorrelation using the audio signal and the signal model for each of the frames to produce a plurality of decorrelated channels;
- reordering the plurality of decorrelated channels based on energy of each decorrelated channel;
- and
- combining the frames to obtain a source separated version of the audio signal,
- wherein performing the hierarchical decorrelation includes:
- selecting a set of channels, of the plurality of channels of the audio signal, based on minimizing remaining correlation across the plurality of channels, and
- performing a unitary transform on the selected set of channels, yielding a set of decorrelated channels.
An apparatus comprising:
- one or more processors operable to:
- segment an audio signal that includes a plurality of channels into frames;
- estimate, for each frame, a signal model;
- perform hierarchical decorrelation using the audio signal and the signal model for each of the frames to produce a plurality of decorrelated channels, wherein performing the hierarchical decorrelation includes:
- selecting a set of channels, of the plurality of channels of the audio signal, based on minimizing remaining correlation across the plurality of channels, and
- performing a unitary transform on the selected set of channels, yielding a set of decorrelated channels;
- reorder the plurality of decorrelated channels based on energy of each decorrelated channel;
- and
- combine the frames to obtain a source separated version of the audio signal.
A non-transitory computer-readable storage medium containing instructions that when executed cause a system to:
- segment an audio signal that includes a plurality of channels into frames;
- estimate, for each frame, a signal model;
- perform hierarchical decorrelation using the audio signal and the signal model for each of the frames to produce a plurality of decorrelated channels, wherein performing the hierarchical decorrelation includes:
- selecting a set of channels, of the plurality of channels of the audio signal, based on minimizing remaining correlation across the plurality of channels, and
- performing a unitary transform on the selected set of channels, yielding a set of decorrelated channels;
- reorder the plurality of decorrelated channels based on energy of each decorrelated channel;
- and
- combine the frames to obtain a source separated version of the audio signal.
Dependencies are inferred from the claim text.