Dolby Laboratories Licensing Corporation

Dolby International Ab

Mark David De Burgh

Heiko Purnhagen

Dirk Jeroen Breebaart

Antonio Mateos Sole

David Matthew Cooper

Giulio Cengarle

Daniel Arteaga

Juan Felix Torres

Nicholas Luke Appleton

Michael William Mason

Mark William Gerrard

Adam J Mills

Ning Wang

Andrew Robert Owen

Tet Fei Yap

Antonio Mateos Solé

Chunghsin Yeh

Dirk Jeroen Breebart

Heiko Punrhagen

Methods for performing dynamic range compression (DRC) on audio in a manner intended to produce output audio for playback by systems or devices with limited power handling capabilities and preferably also to reduce or prevent undesirable artifacts (e.g., pumping and/or breathing) in the output audio. Some embodiments perform the DRC so as to maximize average loudness (while preventing loss of quieter elements) during playback, and also to reduce or prevent distortion. Other aspects are systems or devices configured to perform embodiments of the method. In some embodiments, reduced DRC is applied when average loudness of the input audio approaches (or matches or exceeds) a target (e.g., a knee point for DRC, or a signal level near to a maximum playback level of the intended playback system), since such input audio is assumed to have already been compressed, and otherwise applying full DRC to the input audio.

Dynamic range compression with reduced artifacts

The present document relates to methods and apparatus for rendering input audio for playback in a playback environment. The input audio includes at least one audio object and associated metadata, and the associated metadata indicates at least a location of the audio object. A method for rendering input audio including divergence metadata for playback in a playback environment comprises creating two additional audio objects associated with the audio object such that respective locations of the two additional audio objects are evenly spaced from the location of the audio object, on opposite sides of the location of the audio object when seen from an intended listener's position in the playback environment, determining respective weight factors for application to the audio object and the two additional audio objects, and rendering the audio object and the two additional audio objects to one or more speaker feeds in accordance with the determined weight factors. The present document further relates to methods and apparatus for rendering audio input including extent metadata and/or diffuseness metadata for playback in a playback environment.

Rendering of immersive audio content

A method of processing audio data for replay on a mobile device with a first speaker and a second speaker, wherein the audio data comprises a respective audio signal for each of the first and second speakers, includes: determining a device orientation of the mobile device; if the determined device orientation is vertical orientation, applying a first processing mode to the audio signals for the first and second speakers; and if the determined device orientation is horizontal orientation, applying a second processing mode to the audio signals for the first and second speakers. Applying the first processing mode involves: determining respective mono audio signals in at least two frequency bands based on the audio signals for the first and second speakers; in a first one of the at least two frequency bands, routing a larger portion of the respective mono audio signal to one of the first and second speakers; and in a second one of the at least two frequency bands, routing a larger portion of the respective mono audio signal to the other one of the first and second speakers. Applying the second processing mode involves applying cross-talk cancellation to the audio signals for the first and second speakers.

Methods, apparatus and systems for asymmetric speaker processing

A method in a computing device configured to perform volume-levelling processing on input audio data by at least applying one or more filters to the input audio data, the computing device being configured to obtain an estimated difference between a target output loudness level and a loudness level associated with the input audio data, and to adapt the filter coefficients of the one or more filters based on the estimated difference. The method involves starting, or stopping, the volume-levelling processing. The method comprises gradually increasing, or decreasing, a weighting applied to the estimated difference, in response to obtaining an indication to start, or stop, the volume-levelling processing.

Volume-levelling processing

Methods a provided for improving an audio scene for people suffering from hearing loss or for adverse hearing environments. Audio objects may be prioritized. In some implementations, audio objects that correspond to dialog may be assigned to a highest priority level. Other implementations may involve assigning the highest priority to other types of audio objects, such as audio objects that correspond to events. During a process of dynamic range compression, higher-priority objects may be boosted more, or cut less, than lower-priority objects. Some lower-priority audio objects may fall below the threshold of human hearing, in which case the audio objects may be dropped and not rendered.

Processing audio data to compensate for partial hearing loss or an adverse hearing environment

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Mount Colah, Australia

Mark David De Burgh