EFFICIENT RENDERING OF VIRTUAL SOUNDFIELDS
An audio system and method of spatially rendering audio signals that uses modified virtual speaker panning is disclosed. The audio system may include a fixed number F of virtual speakers, and the modified virtual speaker panning may dynamically select and use a subset P of the fixed virtual speakers. The subset P of virtual speakers may be selected using a low energy speaker detection and culling method, a source geometry-based culling method, or both. One or more processing blocks in the decoder/virtualizer may be bypassed based on the energy level of the associated audio signal or the location of the sound source relative to the user/listener, respectively. In some embodiments, a virtual speaker that is designated as an active virtual speaker at a first time, may also be designated as an active virtual speaker at a second time to ensure the processing completes.
1 . A method of spatially rendering an audio signal, the method comprising:
determining, via one or more sensors of a wearable head device, a spatial configuration of a virtual environment, wherein the spatial configuration comprises at least a user location, a sound source location, and a virtual speaker location;
determining whether a magnitude associated with one or more signals associated with the sound source location exceeds a predetermined threshold; and
in accordance with a determination that the magnitude associated with the one or more signals exceeds the predetermined threshold:
decoding the one or more signals, and
rendering the audio signal based on the decoded one or more signals.
2 . The method of claim 1 , further comprising:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, applying the one or more signals to a head-related transfer function (HRTF);
in accordance with a determination that the magnitude associated with the one or more signals does not exceed the predetermined threshold, forgoing applying the one or more signals to the HRTF.
3 . The method of claim 1 , wherein said decoding the one or more signals comprises applying a first set of processing blocks to the one or more signals, and wherein the method further comprises:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, bypassing a second set of processing blocks, the second set of processing blocks associated with one or more inactive virtual speakers.
4 . The method of claim 3 , wherein said bypassing the second set of processing blocks comprises forgoing transmitting the one or more signals to a decoder comprising the second set of processing blocks.
5 . The method of claim 3 , further comprising:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, transmitting the one or more signals to a decoder comprising the first set of processing blocks.
6 . The method of claim 5 , further comprising:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, applying an output of the decoder to a HRTF.
7 . The method of claim 1 , wherein said determining the spatial configuration of the virtual environment comprises:
receiving one or more input sound signals, the one or more input sound signals comprising a first input sound signal from a direct sound source and further comprising a second input sound signal from a reflection sound source;
modifying the one or more input sound signals to simulate a doppler effect;
applying a delay to the one or more input sound signals; and
panning the one or more input sound signals across a plurality of virtual speakers,
wherein said decoding the one or more signals comprises:
determining one or more virtualized sounds, wherein the one or more virtualized sounds are associated with a movement of one or more of the direct sound source, the reflection sound source, and a user.
8 . The method of claim 1 , wherein the magnitude associated with one or more signals comprises an energy level.
9 . The method of claim 8 , wherein the energy level is associated with a distance.
10 . The method of claim 1 , wherein the virtual environment comprises a plurality of sound source locations, and wherein the method further comprises:
determining whether a number of sound source locations in the virtual environment exceeds a predetermined sound source threshold; and
in accordance with a determination that the number of sound source locations does not exceed the predetermined sound source threshold, decoding the one or more signals.
11 . The method of claim 1 , wherein the one or more sensors comprises one or more of infrared sensor, accelerometer, GPS unit, inertial measurement unit, acoustic sensor, electromagnetic receiver, and camera.
12 . A system comprising:
a wearable head device comprising one or more sensors; and
one or more processors configured to perform a method comprising:
determining, via the one or more sensors, a spatial configuration of a virtual environment, wherein the spatial configuration comprises at least a user location, a sound source location, and a virtual speaker location;
determining whether a magnitude associated with one or more signals associated with the sound source location exceeds a predetermined threshold; and
in accordance with a determination that the magnitude associated with the one or more signals exceeds the predetermined threshold:
decoding the one or more signals, and
rendering the audio signal based on the decoded one or more signals.
13 . The system of claim 12 , wherein the method further comprises:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, applying the one or more signals to a head-related transfer function (HRTF);
in accordance with a determination that the magnitude associated with the one or more signals does not exceed the predetermined threshold, forgoing applying the one or more signals to the HRTF.
14 . The system of claim 12 , wherein said decoding the one or more signals comprises applying a first set of processing blocks to the one or more signals, and wherein the method further comprises:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, bypassing a second set of processing blocks, the second set of processing blocks associated with one or more inactive virtual speakers.
15 . The system of claim 12 , wherein said determining the spatial configuration of the virtual environment comprises:
receiving one or more input sound signals, the one or more input sound signals comprising a first input sound signal from a direct sound source and further comprising a second input sound signal from a reflection sound source;
modifying the one or more input sound signals to simulate a doppler effect;
applying a delay to the one or more input sound signals; and
panning the one or more input sound signals across a plurality of virtual speakers,
wherein said decoding the one or more signals comprises:
determining one or more virtualized sounds, wherein the one or more virtualized sounds are associated with a movement of one or more of the direct sound source, the reflection sound source, and a user.
16 . The system of claim 15 , wherein said bypassing the second set of processing blocks comprises forgoing transmitting the one or more signals to a decoder comprising the second set of processing blocks.
17 . The system of claim 15 , wherein the method further comprises:
further in accordance with the determination that the magnitude associated with the one or more signals exceeds the predetermined threshold, transmitting the one or more signals to a decoder comprising the first set of processing blocks.
18 . The system of claim 12 , wherein the magnitude associated with one or more signals comprises an energy level.
19 . The system of claim 18 , wherein the energy level is associated with a distance.
20 . The system of claim 12 , wherein the one or more sensors comprises one or more of infrared sensor, accelerometer, GPS unit, inertial measurement unit, acoustic sensor, electromagnetic receiver, and camera.