Granted Patent B1

US 12,279,104 · App. 18/984,971 · Granted Apr 15, 2025

Inventors: Michael C. Ward (Orinda, CA); Jeffrey Riedmiller (Novato, CA); Scott Gregory Norcross (San Rafael, CA); Alexander Stahlmann (Bubenreuth, DE)

Assignees: Dolby Laboratories Licensing Corporation; DOLBY INTERNATIONAL AB

H04S7/30G10L19/008G10L21/0324H04S1/002H04S1/007H04S2400/03H04S2400/13

Abstract

Claims (23)

1. A method for loudness adjustment of at least an audio signal, the method comprising:

receiving, by an audio decoder, the audio signal comprising audio sample data for a reference channel configuration and encoder-generated loudness metadata corresponding to a plurality of specific channel configurations, wherein the audio decoder is configured to operate in at least one of the plurality of specific channel configurations;

selecting a specific playback environment corresponding to one of the plurality of specific channel configurations;

selecting specific loudness metadata based on the encoder-generated loudness metadata and the specific playback environment;

determining loudness information based on the specific loudness metadata;

determining at least a gain as a part of overall gains to applied to the audio sample data based on the loudness information; and

applying the gain to the audio sample data to generate output audio.

2. The method of claim 1 , further comprising applying a gain limiter for the specific playback environment.

3. The method of claim 1 , further comprising clipping the gain.

4. The method of claim 3 , wherein the clipping ensures loudness levels to be no more than a clipping level for the specific playback environment.

5. The method of claim 1 , further comprising determining a downmixing and further determining the loudness information based on the downmixing.

6. A non-transitory computer readable storage medium, storing software instructions, which when executed by one or more processors cause performing the method of claim 1 .

7. An audio signal processing device for gain adjusting audio signals based on encoder-generated loudness metadata, wherein the audio signal processing device:

receives, by an audio decoder, the audio signal comprising audio sample data for a reference channel configuration and encoder-generated loudness metadata corresponding to a plurality of specific channel configurations, wherein the audio decoder is configured to operate in at least one of the plurality of specific channel configurations;

selects a specific playback environment corresponding to one of the plurality of specific channel configurations;

selects specific loudness metadata based on the encoder-generated loudness metadata and the specific playback environment;

determines loudness information based on the specific loudness metadata;

determines at least a gain as a part of overall gains to applied to the audio sample data based on the loudness information; and

applies the gain to the audio sample data to generate output audio.

8. The apparatus of claim 7 , wherein the audio signal processing device further applies a gain limiter for the specific playback environment.

9. The apparatus of claim 7 , wherein the audio signal processing device further clips the gain.

10. The apparatus of claim 9 , wherein the clipping ensures loudness levels to be no more than a clipping level for the specific playback environment.

11. The apparatus of claim 7 , wherein the audio signal processing device further determines a downmixing and further determining the loudness information based on the downmixing.

Assignments (1)

Continuity (12)

References Cited (191)