Reflected and direct rendering of upmixed content to individually addressable drivers

Patent metadata

Field	Value
Publication number	US-9532158-B2
Application number	US-201314417680-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Aug 31, 2012
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

Embodiments are described for a system of rendering spatial audio content in a listening environment. The system includes a rendering component configured to generate a plurality of audio channels including information specifying a playback location in a listening area, an upmixer component receiving the plurality of audio channels and generating, for each audio channel, at least one reflected sub-channel configured to cause a majority of driver energy to reflect off of one or more surfaces of the listening area, and at least one direct sub-channel configured to cause a majority of driver energy to propagate directly to the playback location.

First claim

What is claimed is:

1. A system for processing audio signals, comprising:
a rendering component configured to generate a plurality of audio channels including information specifying a playback location in a listening area of a respective audio channel; wherein the plurality of audio channels comprises object-based audio, and wherein the information specifying the playback location is encoded in one or more metadata sets associated with each of the audio channels; and
an upmixer component receiving the plurality of audio channels and generating, for each audio channel, at least one reflected sub-channel for a reflected driver of an array of individually addressable drivers, configured to cause a majority of driver energy of the reflected driver to reflect off of one or more surfaces of the listening area in order to simulate the presence of a playback location at the one or more surfaces of the listening area, and at least one direct sub-channel for a direct driver of the array of individually addressable drivers, configured to cause a majority of driver energy of the direct driver to propagate directly to the playback location within the listening area; wherein the at least one reflected sub-channel is generated based on spatial reproduction information of the object-based audio; wherein the upmixer component is configured to compute, for each audio channel, an inter-channel correlation value between the two spatially adjacent audio channels to determine a quantity of common signal between a pair of sub-channels; wherein the inter-channel correlation value is used to alter the mix of the audio channel by increasing that portion which is routed to the direct sub-channel while decreasing that portion which is routed to the reflected sub-channel such that the portion which is routed to the direct sub-channel increases linearly with decreasing inter-channel correlation value, with the constraint that a sum of energy between the pair of sub-channels is conserved.

2. The system of claim 1 further comprising the array of individually addressable drivers coupled to the upmixer component and comprising at least one reflected driver for propagation of sound waves off of the one or more surfaces, and at least one direct driver for propagation of sound waves directly to the playback location, using the at least one reflected sub-channel and the at least one direct sub-channel, respectively.

3. The system of claim 2 wherein the plurality of input audio channels also comprise channel-based audio; and further 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.

4. The system of claim 3 wherein the speaker in the speaker array are distributed around the listening area in accordance with a defined audio surround sound configuration, and wherein the listening area comprises one of: a home, a cinema, a theater, a professional studio, and an audio listening console; and further wherein the plurality of audio channels comprises audio content selected from the group consisting of: cinema content, cinema content transformed for playback in a home environment, television content, user generated content, computer game content, and digital streaming audio content.

5. The system of claim 4 wherein the playback location of a sub-channel comprises a location perceptively above a person's head in the listening area, and wherein the at least one reflected driver comprises an upward-firing driver configured to project sound waves toward a ceiling of the listening area for reflection down to the location.

6. The system of claim 5 wherein a metadata set associated with the sub-channel transmitted to the upward-firing driver defines one or more characteristics pertaining to the reflection.

7. The system of claim 4 wherein the playback location of an audio channel comprises a location perceptively surrounding a person in the listening area, and wherein the at least one reflected driver comprises a side-firing driver configured to project sound waves toward a wall of the listening area for reflection to the location.

8. The system of claim 7 wherein a metadata set associated with a sub-channel transmitted to the side-firing driver defines one or more characteristics pertaining to the reflection.

9. A method comprising:
receiving a plurality of input audio channels from an audio renderer; wherein the plurality of input audio channels comprises object-based audio; wherein the plurality of input audio channels include information specifying a playback location in a listening area of a respective audio channel;
dividing each input audio channel into at least one reflected sub-channel and at least one direct sub-channel in a first decomposition process; wherein the at least one reflected sub-channel is generated based on spatial reproduction information of the object-based audio; wherein the at least one reflected sub-channel is for a reflected driver of an array of individually addressable drivers; wherein the at least one reflected sub-channel is configured to cause a majority of driver energy of the reflected driver to reflect off of one or more surfaces of the listening area in order to simulate the presence of a playback location at the one or more surfaces of the listening area; wherein the at least one direct sub-channel is for a direct driver of the array of individually addressable drivers; and wherein the at least one direct sub-channel is configured to cause a majority of driver energy of the direct driver to propagate directly to the playback location within the listening area;
verifying that an amount of energy expended in propagation of sound waves generated by the reflected sub-channel and direct sub-channel is conserved during the first decomposition process;
computing, for each input audio channel, an inter-channel correlation value between two spatially adjacent input audio channels to determine a quantity of common signal between a pair of sub-channels;
using the inter-channel correlation value to alter the mix of the input audio channel by increasing that portion which is routed to the direct sub-channel while decreasing that portion which is routed to the reflected sub-channel such that the portion which is routed to the direct sub-channel increases linearly with decreasing inter-channel correlation value, with the constraint that a sum of energy between the pair of sub-channels is conserved.

10. The method of claim 9 further comprising transmitting audio signals corresponding to each sub-channel of the respective sub-channels to the array of individually addressable drivers, the array comprising at least one reflected driver for propagation of sound waves off of one or more surfaces, and at least one direct driver for propagation of sound waves directly to the location.

11. The method of claim 9 wherein the amount of energy expended in propagation of sound waves generated by the reflected sub-channel and direct sub-channel is determined using a frequency domain transform process.

12. The method of claim 9 further comprising:
computing, for each input audio channel, one or more transient scaling terms, wherein a scaling term represents a value proportional to an energy in a transient for each input audio channel;
using the transient scaling term to alter the mix of the input audio channel by increasing that portion which is routed to the direct sub-channel while decreasing that portion which is routed to the reflected sub-channel, with the constraint that a sum of energy between the pair of sub-channels is conserved; and
performing eq

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Lando Joshua Brandon
• Fellers Matthew

Classifications

• H04S2420/07

  Synergistic effects of band splitting and sub-band processing · CPC title

• H04S7/301

  Automatic calibration of stereophonic sound system, e.g. with test microphone · CPC title

• H04S7/30

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

• H04S5/005 Primary

  of the pseudo five- or more-channel type, e.g. virtual surround · CPC title

• H04S2420/01

  Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD] · CPC title