Audio encoder and decoder with dynamic range compression metadata

1. An audio processing unit, comprising:

a buffer memory which is a non-transitory medium, configured to store at least one frame of an encoded audio bitstream, wherein the encoded audio bitstream includes audio data and a metadata container, wherein the metadata container includes a header and one or more metadata payloads after the header, the one or more metadata payloads include dynamic range compression (DRC) metadata, and the DRC metadata is or includes profile metadata indicative of whether the DRC metadata includes dynamic range compression (DRC) control values for use in performing dynamic range compression in accordance with at least one compression profile on audio content indicated by at least one block of the audio data;

a subsystem configured to:

determine that the profile metadata indicates that DRC metadata includes DRC control values for use in performing dynamic range compression in accordance with one said compression profile;

parse the encoded audio bitstream to extract the DRC control values; and

perform dynamic range compression, on at least some of the audio data or on decoded audio data generated by decoding the at least some of the audio data using at least some of the extracted DRC control values on at least some of the audio data or decoded audio data.

2. The audio processing unit of claim 1 , wherein one said compression profile is a profile for dynamic range compression of audio data indicative of speech.

3. The audio processing unit of claim 1 , wherein one said compression profile is a film standard compression profile, a film light compression profile, a music standard compression profile, or a music light compression profile.

4. The audio processing unit of claim 1 , also including:

an audio decoder coupled to the buffer memory and configured to decode the audio data thereby generating decoded audio data.

5. The audio processing unit of claim 4 , wherein the subsystem coupled to the parser is also coupled to the audio decoder, and is configured to perform dynamic range compression on at least some of the decoded audio data using at least some of the DRC metadata.

6. An audio decoding method, comprising steps of:

receiving an encoded audio bitstream, wherein the encoded audio bitstream is segmented into one or more frames;

extracting audio data and a container of metadata from the encoded audio bitstream, wherein the container of metadata includes a header, and one or more metadata payloads after the header, and

wherein the one or more metadata payloads include dynamic range compression (DRC) metadata, and the DRC metadata is or includes profile metadata indicative of whether the DRC metadata includes dynamic range compression (DRC) control values for use in performing dynamic range compression in accordance with at least one compression profile on audio content indicated by at least one block of the audio data, and wherein

determining that the profile metadata indicates that DRC metadata includes DRC control values for use in performing dynamic range compression in accordance with one said compression profile;

parsing the encoded audio bitstream to extract the DRC control values; and

performing dynamic range compression, on at least some of the audio data or on decoded audio data generated by decoding said at least some of the audio data, and using at least some of the extracted DRC control values on at least some of the audio data or decoded audio data.

7. The method of claim 6 , wherein one said compression profile is a profile for dynamic range compression of audio data indicative of speech.

8. The method of claim 6 , wherein one said compression profile is a film standard compression profile, a film light compression profile, a music standard compression profile, or a music light compression profile.

9. The method of claim 6 , wherein the audio data are encoded audio data, and also comprising a step of:

decoding the encoded audio data to generate decoded audio data.

10. The method of claim 9 , also comprising:

performing dynamic range compression on at least some of the decoded audio data using at least some of the DRC metadata.

11. A non-transitory, computer-readable storage medium having instructions stored thereon that when executed by one or more audio processing units, cause the one or more audio processing units to perform operations comprising:

receiving an encoded audio bitstream, wherein the encoded audio bitstream is segmented into one or more frames;

extracting audio data and a container of metadata from the encoded audio bitstream, wherein the container of metadata includes a header, and one or more metadata payloads after the header, and

wherein the one or more metadata payloads include dynamic range compression (DRC) metadata, and the DRC metadata is or includes profile metadata indicative of whether the DRC metadata includes dynamic range compression (DRC) control values for use in performing dynamic range compression in accordance with at least one compression profile on audio content indicated by at least one block of the audio data, and wherein

if the profile metadata indicates that DRC metadata includes DRC control values for use in performing dynamic range compression in accordance with one said compression profile, the DRC metadata also includes a set of DRC control values generated in accordance with the compression profile;

parsing the encoded audio bitstream to extract the DRC control values; and

performing dynamic range compression, on at least some of the audio data or on decoded audio data generated by decoding said at least some of the audio data, and using at least some of the extracted DRC control values on at least some of the audio data or decoded audio data.

12. The storage medium of claim 11 , wherein one said compression profile is a profile for dynamic range compression of audio data indicative of speech.

13. The storage medium of claim 11 , wherein one said compression profile is a film standard compression profile, a film light compression profile, a music standard compression profile, or a music light compression profile.