Processing Spatially Diffuse or Large Audio Objects

Patent metadata

Field	Value
Publication number	US-2016192105-A1
Application number	US-201414909058-A
Country	US
Kind code	A1
Filing date	Jul 24, 2014
Priority date	Jul 31, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

Diffuse or spatially large audio objects may be identified for special processing. A decorrelation process may be performed on audio signals corresponding to the large audio objects to produce decorrelated large audio object audio signals. These decorrelated large audio object audio signals may be associated with object locations, which may be stationary or time-varying locations. For example, the decorrelated large audio object audio signals may be rendered to virtual or actual speaker locations. The output of such a rendering process may be input to a scene simplification process. The decorrelation, associating and/or scene simplification processes may be performed prior to a process of encoding the audio data.

First claim

1 . A method, comprising:
receiving audio data comprising audio objects, the audio objects comprising audio object signals and associated metadata, the metadata including at least audio object size data; determining, based on the audio object size data, a large audio object having an audio object size that is greater than a threshold size; performing a decorrelation process on audio signals of the large audio object to produce decorrelated large audio object audio signals; and associating the decorrelated large audio object audio signals with object locations, the associating process being independent of an actual playback speaker configuration.

2 . The method of claim 1 , further comprising receiving decorrelation metadata for the large audio object, wherein the decorrelation process is performed, at least in part, according to the decorrelation metadata.

3 . The method of any previous claim, further comprising encoding audio data output from the associating process, wherein the encoding process does not involve encoding decorrelation metadata for the large audio object.

4 . The method of any previous claim, wherein at least some of the object locations are stationary.

5 . The method of any previous claim, wherein at least some of the object locations vary over time.

6 . The method of any previous claim, wherein the associating process involves rendering the decorrelated large audio object audio signals according to virtual speaker locations.

7 . The method of any previous claim, wherein the receiving process involves receiving one or more audio bed signals corresponding to speaker locations.

8 . The method of any previous claim, wherein the actual playback speaker configuration is used to render the decorrelated large audio object audio signals to speakers of a playback environment.

9 . The method of any previous claim, wherein the object locations comprise locations corresponding to at least some of the audio object position data of the received audio objects.

10 . The method of any previous claim, further comprising mixing the decorrelated large audio object audio signals with at least some of the received audio bed signals or the received audio object signals.

11 . The method of any previous claim, further comprising outputting the decorrelated large audio object audio signals as additional audio bed signals or audio object signals.

12 . The method of any previous claim, further comprising applying a level adjustment process to the decorrelated large audio object audio signals.

13 . The method of claim 12 , wherein the large audio object metadata includes audio object position metadata and wherein the level adjustment process depends, at least in part, on the audio object size metadata and the audio object position metadata of the large audio object.

14 . The method of any previous claim, further comprising attenuating or deleting the audio signals of the large audio object after the decorrelation process is performed.

15 . The method of any previous claim, further comprising retaining audio signals corresponding to a point source contribution of the large audio object after the decorrelation process is performed.

16 . The method of any previous claim, wherein the large audio object metadata includes audio object position metadata, further comprising:
computing contributions from virtual sources within an audio object area or volume defined by the large audio object position data and the large audio object size data; and determining a set of audio object gain values for each of a plurality of output channels based, at least in part, on the computed contributions.

17 . The method of any previous claim, further comprising performing an audio object clustering process after the decorrelation process.

18 . The method of claim 17 , wherein the audio object clustering process is performed after the associating process.

19 . The method of any previous claim, further comprising evaluating the audio data to determine content type, wherein the decorrelation process is selectively performed according to the content type.

20 . The method of claim 19 , wherein an amount of decorrelation to be performed depends on the content type.

21 . The method of any previous claim, wherein the decorrelation process involves one or more of delays, all-pass filters, pseudo-random filters or reverberation algorithms.

22 . The method of any previous claim, wherein the large audio object metadata includes audio object position metadata, further comprising mixing the decorrelated large audio object audio signals with audio signals for audio objects that are spatially separated by a threshold amount of distance from the large audio object.

23 . An apparatus, comprising:
an interface system; and a logic system capable of:
receiving, via the interface system, audio data comprising audio objects, the audio objects comprising audio object signals and associated metadata, the metadata including at least audio object size data;
determining, based on the audio object size data, a large audio object having an audio object size that is greater than a threshold size;
performing a decorrelation process on audio signals of the large audio object to produce decorrelated large audio object audio signals; and
associating the decorrelated large audio object audio signals with object locations, the associating process being independent of an actual playback speaker configuration.

24 . The apparatus of claim 23 , wherein the logic system includes at least one of a processor, such as a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or combinations thereof.

25 . The apparatus of any of claims 23 - 24 , wherein the interface system includes at least one of a user interface or a network interface.

26 . The apparatus of any of claims 23 - 25 , further comprising a memory system, wherein the interface system includes at least one interface between the logic system and the memory system.

27 . The apparatus of any of claims 23 - 26 , wherein the logic system is capable of receiving, via the interface system, decorrelation metadata for the large audio object, wherein the decorrelation process is performed, at least in part, according to the decorrelation metadata.

28 . The apparatus of any of claims 23 - 27 , wherein the logic system is capable of encoding audio data output from the associating process, wherein the encoding process does not involve encoding decorrelation metadata for the large audio object.

29 . The apparatus of any of claims 23 - 28 , wherein at least some of the object locations are stationary.

30 . The apparatus of any of claims 23 - 29 , wherein at least some of the object locations vary over time.

31 . The apparatus of any of claims 23 - 30 , wherein the associating process involves rendering the decorrelated large audio object audio signals according to virtual speaker locations.

32 . The apparatus of any of claims 23 - 31 , wherein the receiving process involves receiving one or more audio bed signals corresponding to speaker locations.

Assignees

• Dolby Lab Licensing Corp
• Dolby Int Ab

Inventors

• Breebaart Dirk Jeroen
• Lu Lie
• Tsingos Nicolas R
• Mateos Sole Antonio

Classifications

• H04S3/002

  Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S7/30) · CPC title

• H04S7/308 Primary

  Electronic adaptation dependent on speaker or headphone connection · 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

• H04S2400/15

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