Rendering of audio objects with apparent size to arbitrary loudspeaker layouts

Patent metadata

Field	Value
Publication number	US-2016007133-A1
Application number	US-201414770709-A
Country	US
Kind code	A1
Filing date	Mar 10, 2014
Priority date	Mar 28, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

Multiple virtual source locations may be defined for a volume within which audio objects can move. A set-up process for rendering audio data may involve receiving reproduction speaker location data and pre-computing gain values for each of the virtual sources according to the reproduction speaker location data and each virtual source location. The gain values may be stored and used during “run time,” during which audio reproduction data are rendered for the speakers of the reproduction environment. During run time, for each audio object, contributions from virtual source locations within an area or volume defined by the audio object position data and the audio object size data may be computed. A set of gain values for each output channel of the reproduction environment may be computed based, at least in part, on the computed contributions. Each output channel may correspond to at least one reproduction speaker of the reproduction environment.

First claim

1 - 46 . (canceled)

47 . A method, comprising:
receiving audio reproduction data comprising one or more audio objects, the audio objects comprising audio signals and associated metadata, the metadata including at least audio object position data and audio object size data; computing, for an audio object from the one or more audio objects, virtual source gain values from virtual sources at respective virtual source locations within an audio object area or volume defined by the audio object position data and the audio object size data; and computing a set of audio object gain values for each of a plurality of output channels based, at least in part, on the computed virtual source gain values, wherein each output channel corresponds to at least one reproduction speaker of a reproduction environment and each of said virtual source locations corresponds to a respective static location within the reproduction environment.

48 . The method of claim 47 , wherein the process of computing the set of audio object gain values involves computing a weighted average of virtual source gain values from the virtual sources within the audio object area or volume.

49 . The method of claim 48 , wherein weights for the weighted average depend on the audio object's position, the audio object's size and each virtual source location within the audio object area or volume.

50 . The method of claim 47 , further comprising:
receiving reproduction environment data including reproduction speaker location data.

51 . The method of claim 50 , further comprising:
defining a plurality of virtual source locations according to the reproduction environment data; and computing, for each of the virtual source locations, a virtual source gain value for each of the plurality of output channels.

52 . The method of claim 51 , wherein at least some of the virtual source locations correspond to locations outside of the reproduction environment.

53 . The method of claim 51 , wherein the virtual source locations are spaced uniformly along x, y and z axes.

54 . The method of claim 51 , wherein the virtual source locations have a first uniform spacing along x and y axes and a second uniform spacing along a z axis.

55 . The method of claim 53 , wherein the process of computing the set of audio object gain values for each of the plurality of output channels involves independent computations of virtual source gain values from virtual sources along the x, y and z axes.

56 . The method of claim 51 , wherein the virtual source locations are spaced non-uniformly.

57 . The method of claim 50 , further comprising storing computed virtual source gain values in a memory system.

58 . The method of claim 57 , wherein the process of computing the set of audio object gain values involves:
retrieving, from the memory system, computed virtual source gain values corresponding to an audio object position and size; and interpolating between the computed virtual source gain values.

59 . The method of claim 58 , wherein the process of interpolating between the computed virtual source gain values involves:
determining a plurality of neighboring virtual source locations near the audio object position; determining computed virtual source gain values for each of the neighboring virtual source locations; determining a plurality of distances between the audio object position and each of the neighboring virtual source locations; and interpolating between the computed virtual source gain values according to the plurality of distances.

60 . The method of claim 47 , wherein the audio object area or volume is at least one of a rectangle, a rectangular prism, a circle, a sphere, an ellipse or an ellipsoid.

61 . The method of claim 47 , wherein the reproduction environment comprises a cinema sound system environment.

62 . The method of claim 47 , further comprising decorrelating at least some of the audio reproduction data.

63 . The method of claim 47 , further comprising decorrelating audio reproduction data for audio objects having an audio object size that exceeds a threshold value.

64 . The method of claim 47 , wherein the reproduction environment data includes reproduction environment boundary data, further comprising:
determining that the audio object area or volume includes an outside area or volume outside of a reproduction environment boundary; and applying a fade-out factor based, at least in part, on the outside area or volume.

65 . The method of claim 64 , further comprising:
determining that an audio object is within a threshold distance from a reproduction environment boundary; and providing no speaker feed signals to reproduction speakers on an opposing boundary of the reproduction environment.

66 . The method of claim 47 , further comprising:
receiving reproduction environment data including reproduction speaker location data and reproduction environment boundary data; determining that the audio object area or volume includes an outside area or volume outside of a reproduction environment boundary; and determining a fade-out factor based, at least in part, on the outside area or volume, wherein computing the set of gain values for each of the plurality of output channels is also based on the associated metadata and the fade-out factor.

67 . The method of claim 66 , wherein the fade-out factor is proportional to the outside area.

68 . The method of claim 66 , further comprising:
determining that an audio object is within a threshold distance from a reproduction environment boundary; and providing no speaker feed signals to reproduction speakers on an opposing boundary of the reproduction environment.

69 . The method of claim 66 , further comprising:
defining a plurality of virtual source locations according to the reproduction environment data; and computing, for each of the virtual source locations, a virtual source gain for each of a plurality of output channels.

70 . The method of claim 69 , wherein the virtual source locations are spaced uniformly.

71 . A non-transitory medium having software stored thereon, the software including instructions for controlling at least one apparatus to perform the following operations:
receiving audio reproduction data comprising one or more audio objects, the audio objects comprising audio signals and associated metadata, the metadata including at least audio object position data and audio object size data; computing, for an audio object from the one or more audio objects, virtual source gain values from virtual sources at respective virtual source locations within an audio object area or volume defined by the audio object position data and the audio object size data; and computing a set of audio object gain values for each of a plurality of output channels based, at least in part, on the computed virtual source gain values, wherein each output channel corresponds to at least one reproduction speaker of a reproduction environment and each of said virtual source locations corresponds to a respective static location within the reproduction environment.

72 . An apparatus, comprising:
an interface system; and a logic system adapted for: receiving, from the interface system, audio reproduction data comprising one or more audio objects, the audio objects comprising audio signals and associated metadata, the metadata including at least

Assignees

• Dolby Lab Licensing Corp
• Dolby Int Ab

Inventors

• Mateos Sole Antonio
• Tsingos Nicolas R

Classifications

• H04S2400/15

  Aspects of sound capture and related signal processing for recording or reproduction · CPC title

• H04S7/30 Primary

  Control circuits for electronic adaptation of the sound field · CPC title

• H04S2400/13

  Aspects of volume control, not necessarily automatic, in stereophonic sound systems · CPC title

• H04S2400/11

  Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence) · CPC title

• H04S2400/01

  Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved · CPC title