Dts, Inc.

David Corsello

Edward Stein

Guangji Shi

Martin Walsh

Robert Demaa

A graphical user interface (GUI) can specify a three-dimensional position. The GUI can include a puck that is user-positionable in two dimensions. A distance between the puck and a reference point on the graphical user interface can determine a radius of the three-dimensional position. An azimuthal orientation of the puck with respect to the reference point can determine an azimuthal angle of the three-dimensional position. The GUI can include an elevation controller, separate from the puck, to specify an elevation of the three-dimensional position. The elevation controller can specify an elevation angle, which can determine a position along the surface of a virtual sphere as a function of elevation angle. In addition, or alternatively, the elevation controller can specify an elevation height, which can determine a position along a line, such as directly upward or downward, as a function of elevation height.

Graphical user interface for specifying 3D position

The method and apparatus described herein make use of multiple sets of head related transfer functions (HRTFs) that have been synthesized or measured at various distances from a reference head, spanning from the near-field to the boundary of the far-field. Additional synthetic or measured transfer functions maybe used to extend to the interior of the head, i.e., for distances closer than near-field. In addition, the relative distance-related gains of each set of HRTFs are normalized to the far-field HRTF gains.

Near-field binaural rendering

The methods and apparatus described herein optimally represent full 3D audio mixes (e.g., azimuth, elevation, and depth) as 'sound scenes' in which the decoding process facilitates head tracking. Sound scene rendering can be modified for the listener's orientation (e.g., yaw, pitch, roll) and 3D position (e.g., x, y, z). This provides the ability to treat sound scene source positions as 3D positions instead of being restricted to positions relative to the listener. Sound scene rendering can be augmented by encoding depth to a source directly. This provides the ability to modify the transmission format and panning equations to support adding depth indicators during content production. Unlike typical methods that apply depth cues such as loudness and reverberation changes in the mix, this method would enable recovering the distance of a source in the mix so that it can be rendered for the final playback capabilities rather than those on the production side.

Ambisonic audio rendering with depth decoding

A GPEQ filter and tuning methods for asymmetric transaural audio reproduction on mobile consumer devices. The GPEQ filter includes an asymmetric FIR filter bank configured to normalize the magnitude responses of at least two audio speakers to a target response above a low frequency cross-over of the audio speakers as reproduced at the listener position and a symmetric IIR filter bank component configured to high pass filter above the low frequency cross-over and equalize the magnitude responses of the at least two audio speakers. In some embodiments the FIR filter bank is configured to normalize the group delay of the audio channels and in some embodiments the IIR filter bank includes an asymmetric IIR filter bank component configured to correct any residual asymmetry in the magnitude responses of the at least two audio speakers. Phase preservation may be accomplished using phase-balanced or phase-compensated IIR filter sections.

Gain phase equalization (GPEQ) filter and tuning methods for asymmetric transaural audio reproduction

The methods and apparatus described herein optimally represent full 3D audio mixes (e.g., azimuth, elevation, and depth) as 'sound scenes' in which the decoding process facilitates head tracking. Sound scene rendering can be performed for the listener's orientation (e.g., yaw, pitch, roll) and 3D position (e.g., x, y, z), and can be modified for a change in the listener's orientation or 3D position. As described below, the ability to render an audio object in both the near-field and far-field enables the ability to fully render depth of not just objects, but any spatial audio mix decoded with active steering/panning, such as Ambisonics, matrix encoding, etc., thereby enabling full translational head tracking (e.g., user movement) beyond simple rotation in the horizontal plane, or 6-degrees-of-freedom (6-DOF) tracking and rendering.

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Redwood City, CA, United States of America

David Corsello