System and method for adaptive audio signal generation, coding and rendering

Patent metadata

Field	Value
Publication number	US-9942688-B2
Application number	US-201715672656-A
Country	US
Kind code	B2
Filing date	Aug 9, 2017
Priority date	Jul 1, 2011
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Embodiments are described for an adaptive audio system that processes audio data comprising a number of independent monophonic audio streams. One or more of the streams has associated with it metadata that specifies whether the stream is a channel-based or object-based stream. Channel-based streams have rendering information encoded by means of channel name; and the object-based streams have location information encoded through location expressions encoded in the associated metadata. A codec packages the independent audio streams into a single serial bitstream that contains all of the audio data. This configuration allows for the sound to be rendered according to an allocentric frame of reference, in which the rendering location of a sound is based on the characteristics of the playback environment (e.g., room size, shape, etc.) to correspond to the mixer's intent. The object position metadata contains the appropriate allocentric frame of reference information required to play the sound correctly using the available speaker positions in a room that is set up to play the adaptive audio content.

First claim

What is claimed is:

1. A system for processing audio signals, comprising an authoring component configured to:
receive a plurality of audio signals;
generate an adaptive audio mix comprising a plurality of monophonic audio streams and metadata associated with each of the audio streams and indicating a playback location of a respective monophonic audio stream, wherein at least some of the plurality of monophonic audio streams are identified as channel-based audio and the others of the plurality of monophonic audio streams are identified as object-based audio, and wherein the playback location of a channel-based monophonic audio stream comprises a designation of a speaker in a speaker array, and the playback location of an object-based monophonic audio stream comprises a location in three-dimensional space, and wherein each object-based monophonic audio stream is rendered in at least one specific speaker of the speaker array; and
encapsulate the plurality of monophonic audio streams and the metadata in a bitstream for transmission to a rendering system configured to render the plurality of monophonic audio streams to a plurality of speaker feeds corresponding to speakers in a playback environment, wherein the speakers of the speaker array are placed at specific positions within the playback environment, and wherein metadata elements associated with each respective object-based monophonic audio stream indicate independent amounts of spreading to apply to the object-based monophonic audio stream in each of two or more dimensions, such that the object-based monophonic audio stream is rendered into the plurality of speaker feeds with spatial extents in each of the two or more dimensions corresponding to the independent amounts of spreading indicated by the metadata.

2. The system of claim 1 , wherein the two or more dimensions include one or more of length, width, height, x, y, or z.

3. A system for processing audio signals, comprising a rendering system configured to:
receive a bitstream encapsulating an adaptive audio mix comprising a plurality of monophonic audio streams and metadata associated with each of the audio streams and indicating a playback location of a respective monophonic audio stream, wherein at least some of the plurality of monophonic audio streams are identified as channel-based audio and the others of the plurality of monophonic audio streams are identified as object-based audio, and wherein the playback location of a channel-based monophonic audio stream comprises a designation of a speaker in a speaker array, and the playback location of an object-based monophonic audio stream comprises a location in three-dimensional space, and wherein each object-based monophonic audio stream is rendered in at least one specific speaker of the speaker array; and
render the plurality of monophonic audio streams to a plurality of speaker feeds corresponding to speakers in a playback environment, wherein the speakers of the speaker array are placed at specific positions within the playback environment, and wherein metadata elements associated with each respective object-based monophonic audio stream indicate independent amounts of spreading to apply to the object based monophonic audio stream in each of two or more dimensions, such that the object-based monophonic audio stream is rendered into the plurality of speaker feeds with spatial extents in each of the two or more dimensions corresponding to the independent amounts of spreading indicated by the metadata.

4. The system of claim 3 , wherein the two or more dimensions are include one or more of length, width, height, x, y, or z.

5. The system of claim 3 , wherein the metadata elements associated with each object-based monophonic audio stream further indicate spatial parameters controlling the playback of a corresponding sound component comprising one or more of: sound position, sound width, and sound velocity.

6. The system of claim 3 , wherein the playback location for each of the plurality of object-based monophonic audio streams is independently specified with respect to either an egocentric frame of reference or an allocentric frame of reference, wherein the egocentric frame of reference is taken in relation to a listener in the playback environment, and wherein the allocentric frame of reference is taken with respect to a characteristic of the playback environment.

7. A method for authoring audio content for rendering, comprising:
receiving a plurality of audio signals;
generating an adaptive audio mix comprising a plurality of monophonic audio streams and metadata associated with each of the audio streams and indicating a playback location of a respective monophonic audio stream, wherein at least some of the plurality of monophonic audio streams are identified as channel-based audio and the others of the plurality of monophonic audio streams are identified as object-based audio, and wherein the playback location of the channel-based audio comprises speaker designations of speakers in a speaker array, and the playback location of the object-based audio comprises a location in three-dimensional space, and wherein each object-based monophonic audio stream is rendered in at least one specific speaker of the speaker array; and
encapsulating the plurality of monophonic audio streams and the metadata in a bitstream for transmission to a rendering system configured to render the plurality of monophonic audio streams to a plurality of speaker feeds corresponding to speakers in a playback environment, wherein the speakers of the speaker array are placed at specific positions within the playback environment, and wherein metadata elements associated with each respective object-based monophonic audio stream indicate independent amounts of spreading to apply to the object-based monophonic audio stream in each of two or more dimensions, such that the object-based monophonic audio stream is rendered into the plurality of speaker feeds with spatial extents in each of the two or more dimensions corresponding to the independent amounts of spreading indicated by the metadata.

8. The method of claim 7 , wherein the two or more dimensions include one or more of length, width, height, x, y, or z.

9. A method for rendering audio signals, comprising:
receiving a bitstream encapsulating an adaptive audio mix comprising a plurality of monophonic audio streams and metadata associated with each of the audio streams and indicating a playback location of a respective monophonic audio stream, wherein at least some of the plurality of monophonic audio streams are identified as channel-based audio and the others of the plurality of monophonic audio streams are identified as object-based audio, and wherein the playback location of a channel-based monophonic audio stream comprises a designation of a speaker in a speaker array, and the playback location of an object-based monophonic audio stream comprises a location in three-dimensional space, and wherein each object-based monophonic audio stream is rendered in at least one specific speaker of the speaker array; and
rendering the plurality of monophonic audio streams to a plurality of speaker feeds corresponding to speakers in a playback environment, wherein the speakers of the speaker array are placed at specific positions within the playback environment, and wherein metadata elements associated with each respective object-based monophonic audio stream indicate independent amounts of spreading to apply to the object-based monophonic audio stream in each of two or more dimensions, such that the object-based monophonic audio stream is rendered into the plurality of speaker feeds with spatial extents in each of the two or more dimensions corresponding to the independent amounts o

Assignees

• Dolby Laboratories Licensing Corp
• Dolby Laboraties Licensing Corp

Inventors

• Robinson Charles Q
• Tsingos Nicolas R
• Chabanne Christophe

Classifications

• H04S2420/13

  Application of wave-field synthesis in stereophonic audio systems · CPC title

• H04S2420/03

  Application of parametric coding in stereophonic audio systems · CPC title

• H04S2400/11

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

• H04S2400/03

  Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 (H04S2400/01 takes precedence) · CPC title

• H04R27/00 Primary

  Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; {monitoring or testing arrangements for public address systems H04R29/007}; amplifiers H03F) · CPC title