Audio encoder and decoder with dynamic range compression metadata

A method performed by an audio processing unit, comprising:

• receiving an encoded audio bitstream comprising an audio program, the encoded audio bitstream including encoded audio data of a set of one or more audio channels and metadata associated with the set of audio channels, wherein the metadata includes dynamic range control (DRC) metadata, loudness metadata, and metadata indicating a number of channels in the set of audio channels, wherein the DRC metadata includes DRC values and DRC profile metadata indicative of a DRC profile used to generate the DRC values, and wherein the loudness metadata includes metadata indicative of a dialog loudness of the audio program;
• decoding the encoded audio data to obtain decoded audio data of the set of audio channels;
• obtaining the DRC values and the metadata indicative of the dialog loudness of the audio program from the metadata of the encoded audio bitstream;
• receiving pre-processing metadata;
• and
• modifying the decoded audio data of the set of audio channels in response to the DRC values, the pre-processing metadata, and the metadata indicative of the dialog loudness of the audio program, wherein modifying the decoded audio data comprises performing loudness control of the decoded audio data in response to the pre-processing metadata and the dialog loudness of the audio program.

A non-transitory, computer-readable storage medium having stored thereon instructions, which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving an encoded audio bitstream comprising an audio program, the encoded audio bitstream including encoded audio data of a set of one or more audio channels and metadata associated with the set of audio channels, wherein the metadata includes dynamic range control (DRC) metadata, loudness metadata, and metadata indicating a number of channels in the set of audio channels, wherein the DRC metadata includes DRC values and DRC profile metadata indicative of a DRC profile used to generate the DRC values, and wherein the loudness metadata includes metadata indicative of a dialog loudness of the audio program;
• decoding the encoded audio data to obtain decoded audio data of the set of audio channels;
• obtaining the DRC values and the metadata indicative of the dialog loudness of the audio program from the metadata of the encoded audio bitstream;
• receiving pre-processing metadata;
• and
• modifying the decoded audio data of the set of audio channels in response to the DRC values, the pre-processing metadata, and the metadata indicative of the dialog loudness of the audio program, wherein modifying the decoded audio data comprises performing loudness control of the decoded audio data in response to the pre-processing metadata and the dialog loudness of the audio program.