Generation and playback of near-field audio content
Audio signals are received. The audio signals include left and right surround channels. The audio signals are played back using far-field loudspeakers distributed around a space having a plurality of listener positions. The left and right surround channels are played back by a pair of far-field loudspeakers arranged at opposite sides of the space having the plurality of listener positions. An audio component coinciding with or approximating audio content common to the left and right surround channels is obtained. The audio component is played back using at least a pair of near-field transducers arranged at one of the listener positions. Associated systems, methods and computer program products are provided. Systems, methods and computer program products providing a bitstream comprising the audio signals and the audio component are also provided, as well as a computer-readable medium with data representing such audio content.
1. An audio processing method comprising:
receiving a plurality of audio signals including a left surround channel and a right surround channel;
extracting an audio component coinciding with or approximating audio content common to the left and right surround channels;
providing a bitstream, the bitstream comprising the plurality of audio signals and at least one additional audio channel comprising the extracted audio component for playback through one or more near-field transducers placed proximate the user; and
applying a gain to the extracted audio component to control its relative contribution to the playback through the near-field transducers and to obtain a weighted extracted audio component.
2. The method of claim 1 wherein the extracting is performed through a center channel extraction process determining that if the audio component was extracted from the left and right surround channels, resulting channels would be orthogonal or uncorrelated to each other.
3. The method of claim 1 , further comprising:
obtaining dialogue audio content by applying a dialogue extraction algorithm to one or more of the received audio signals; and
including at least one dialogue channel in the bitstream in addition to the plurality of audio signals, wherein the at least one dialogue channel comprises the dialogue audio content.
4. The method of claim 1 wherein the near-field transducers comprise one of: conventional headphones, bone-conduction headphones, and speakers placed in a seat occupied by the user, and wherein the near-field transducers supplement playback of a plurality of audio signals using far-field loudspeakers to help distinguish the dialogue audio content from other audio content.
5. The method of claim 1 , further comprising:
receiving an object-based audio signal;
rendering at least the object-based audio signal as two audio channels for playback at two transducers; and
including the object-based audio signal and the two rendered audio channels in the bitstream.
6. The method of claim 5 further comprising a near-field rendering scheme in which the object-based audio is rendered with respect to a predefined virtual configuration of two or more speaker positions.
7. The method of claim 5 further comprising a near-field rendering scheme in which the object-based audio is rendered using an amplitude panning scheme based on X, Y, Z coordinates of the object-based audio, weights for the near-field channels, and a distance between two of the near-field transducers.
8. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:
receiving a plurality of audio signals including a left surround channel and a right surround channel;
extracting an audio component coinciding with or approximating audio content common to the left and right surround channels;
providing a bitstream, the bitstream comprising the plurality of audio signals and at least one additional audio channel comprising the extracted audio component for playback through one or more near-field transducers placed proximate the user; and
applying a gain to the extracted audio component to control its relative contribution to the playback through the near-field transducers and to obtain a weighted extracted audio component.
9. The non-transitory computer-readable medium of claim 8 , the operations further comprising:
obtaining dialogue audio content by applying a dialogue extraction algorithm to one or more of the received audio signals; and
including at least one dialogue channel in the bitstream in addition to the plurality of audio signals, wherein the at least one dialogue channel comprises the dialogue audio content, wherein the near-field transducers comprise one of: conventional headphones, bone-conduction headphones, and speakers placed in a seat occupied by the user, and wherein the near-field transducers supplement playback of a plurality of audio signals using far-field loudspeakers to help distinguish the dialogue audio content from other audio content.
10. The non-transitory computer-readable medium of claim 9 , the operations further comprising:
receiving an object-based audio signal;
rendering at least the object-based audio signal as two audio channels for playback at two transducers; and
including the object-based audio signal and the two rendered audio channels in the bitstream.
11. The non-transitory computer-readable medium of claim 10 , the operations further comprising a near-field rendering scheme in which the object-based audio is rendered with respect to a predefined virtual configuration of two or more speaker positions.
12. The non-transitory computer-readable medium of claim 10 , the operations further comprising a near-field rendering scheme in which the object-based audio is rendered using an amplitude panning scheme based on X, Y, Z coordinates of the object-based audio, weights for the near-field channels, and a distance between two of the near-field transducers.
13. An audio processing system comprising:
one or more processors; and
a non-transitory computer-readable medium storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising:
receiving a plurality of audio signals including a left surround channel and a right surround channel;
extracting an audio component coinciding with or approximating audio content common to the left and right surround channels;
providing a bitstream, the bitstream comprising the plurality of audio signals and at least one additional audio channel comprising the extracted audio component for playback through one or more near-field transducers placed proximate the user; and
applying a gain to the extracted audio component to control its relative contribution to the playback through the near-field transducers and to obtain a weighted extracted audio component.
14. The audio processing system of claim 13 , the operations further comprising:
obtaining dialogue audio content by applying a dialogue extraction algorithm to one or more of the received audio signals; and
including at least one dialogue channel in the bitstream in addition to the plurality of audio signals, wherein the at least one dialogue channel comprises the dialogue audio content, wherein the near-field transducers comprise one of: conventional headphones, bone-conduction headphones, and speakers placed in a seat occupied by the user, and wherein the near-field transducers supplement playback of a plurality of audio signals using far-field loudspeakers to help distinguish the dialogue audio content from other audio content.
15. The audio processing system of claim 14 , the operations further comprising:
receiving an object-based audio signal;
rendering at least the object-based audio signal as two audio channels for playback at two transducers; and
including the object-based audio signal and the two rendered audio channels in the bitstream.
16. The audio processing system of claim 15 , the operations further comprising one of: a near-field rendering scheme in which the object-based audio is rendered with respect to a predefined virtual configuration of two or more speaker positions, or a near-field rendering scheme in which the object-based audio is rendered using an amplitude panning scheme based on X, Y, Z coordinates of the object-based audio, weights for the near-field channels, and a distance between two of the near-field transducers.