Methods and systems for determining audio loudness levels in programming
A program asset is retrieved. The program asset has audio encoded at a first loudness setting and includes metadata specifying the first loudness setting. Dialog of the audio is identified. The loudness of the dialog is determined. The determined loudness is compared to the first loudness setting. The program asset is re-recorded at a second loudness setting corresponding to the determined loudness, if the first loudness setting and the determined loudness are different by more than a predetermined amount.
1. A method of correcting an audio level of a program asset, comprising:
retrieving the program asset, the program asset comprising audio and metadata specifying a first loudness setting;
identifying dialog of the audio;
determining a loudness of the dialog;
comparing the determined loudness to the first loudness setting; and
re-encoding the program asset at a second loudness setting corresponding to the determined loudness, when the first loudness setting and the determined loudness are different by more than a predetermined amount.
2. The method of claim 1 , wherein identifying the dialog comprises:
dividing the audio into time intervals;
determining a loudness of each time interval; and
identifying time intervals with intermediate loudnesses.
3. The method of claim 2 , wherein determining the loudness of each time interval is based at least in part on psycho-acoustic criteria.
4. The method of claim 2 , wherein determining the loudness of each time interval is based at least in part on Leq (A).
5. The method of claim 2 , wherein identifying the dialog further comprises determining a loudness of the time intervals with intermediate loudnesses.
6. The method of claim 5 , wherein determining the loudness of the time intervals with intermediate loudnesses comprises computing a function of the loudnesses of the time intervals with intermediate loudnesses.
7. The method of claim 6 , wherein the function is one of an average, a mean, and a median of the loudnesses of the time intervals with intermediate loudnesses.
8. The method of claim 5 , wherein determining the loudness of the time intervals with intermediate loudnesses comprises determining a DIALNORM of the time intervals with intermediate loudnesses.
9. The method of claim 1 , wherein identifying the dialog comprises filtering the audio.
10. The method of claim 9 , wherein filtering the audio comprises disregarding the audio outside of a range of from about 100 Hertz to about 1,000 Hertz.
11. The method of claim 1 , wherein the program asset comprises one of a program, a chapter of a program, and an advertisement.
12. The method of claim 1 , further comprising storing the program asset with the re-encoded loudness setting.
13. The method of claim 1 , further comprising normalizing the determined loudness of the dialog.
14. The method of claim 1 , wherein the metadata specifies the first loudness setting as a value.
15. The method of claim 14 , wherein the value corresponds to an intended gain for playback.
16. The method of claim 1 , wherein the program asset specifies the first loudness setting in a synchronization frame of the audio.
17. A system for correcting an audio level of a program asset, the system comprising:
a memory operative to store the program asset, the program asset comprising audio and metadata specifying a first loudness setting; and
a processor coupled to the memory, the processor programmed to:
retrieve the program asset;
identify dialog of the program asset;
determine a loudness of the dialog; and
re-encode the program asset at a second loudness setting corresponding to the determined loudness, when the first loudness setting and the determined loudness are different by more than a predetermined amount.
18. The system of claim 17 , wherein identifying the dialog comprises:
dividing the audio into time intervals;
determining a loudness of each time interval; and
identifying time intervals with intermediate loudnesses.
19. The system of claim 18 , wherein determining the loudness of each time interval is based at least in part on psycho-acoustic criteria.
20. The system of claim 18 , wherein determining the loudness of each time interval is based at least in part on Leq (A).
21. The system of claim 18 , wherein identifying the dialog further comprises determining a loudness of the time intervals with intermediate loudnesses.
22. The system of claim 21 , wherein determining the loudness of the time intervals with intermediate loudnesses comprises computing a function of the loudnesses of the time intervals with intermediate loudnesses.
23. The system of claim 21 , wherein determining the loudness of the time intervals with intermediate loudnesses comprises determining a DIALNORM of the time intervals with intermediate loudnesses.
24. The system of claim 23 , wherein identifying the dialog comprises filtering the audio.
25. The system of claim 17 , wherein the processor is further programmed to store the program asset with the re-encoded loudness setting.
26. The system of claim 17 , wherein the metadata specifies the first loudness setting as a value.
27. The system of claim 26 , wherein the value corresponds to an intended gain for playback.
28. The system of claim 17 , wherein the program asset specifies the first loudness setting in a synchronization frame of the audio.
29. The system of claim 17 , wherein the processor forms a portion of a head end of a broadband communications system.
30. The system of claim 17 , wherein the processor forms a portion of an acquisition and staging processor in a head end of a broadband communications system.
31. The system of claim 17 , wherein the processor forms a portion of a set-top terminal of a broadband communications system.
32. The system of claim 31 , wherein the program asset is stored locally to the set-top terminal.