Audio level control for compressed audio
First Claim
Patent Images
1. A method of audio level control for compressed audio in a data stream, comprising:
- (a) extracting, in a processor, scale factors for the compressed audio from the data stream;
(b) performing, in the processor, a level detection for the compressed audio by;
(1) determining a square of a derived peak analog voltage value for each of the scale factors;
(2) performing a square root of a sum of the squares across a frame;
(3) normalizing the square root based on a number of channels present in the compressed audio; and
(4) comparing the normalized square root against a threshold to determine whether the compressed audio exceeds a specified level;
(c) altering, in the processor, only the extracted scale factors, based on the level detection, without decompressing the compressed audio or altering any other portion of the data stream; and
(d) updating, in the processor, the data stream with the altered scale factors, wherein the data stream otherwise remains unchanged.
6 Assignments
0 Petitions
Accused Products
Abstract
Audio level control is provided for compressed audio. Scale factors for the compressed audio are extracted from an MPEG audio data stream, the extracted scale factors are altered without decompressing the compressed audio, and the MPEG audio data stream is updated with the altered scale factors. All of the scale factors in the MPEG audio data stream are altered based on a parameter identifying how the gain levels in the MPEG data stream are to be altered.
67 Citations
33 Claims
-
1. A method of audio level control for compressed audio in a data stream, comprising:
-
(a) extracting, in a processor, scale factors for the compressed audio from the data stream; (b) performing, in the processor, a level detection for the compressed audio by;
(1) determining a square of a derived peak analog voltage value for each of the scale factors;
(2) performing a square root of a sum of the squares across a frame;
(3) normalizing the square root based on a number of channels present in the compressed audio; and
(4) comparing the normalized square root against a threshold to determine whether the compressed audio exceeds a specified level;(c) altering, in the processor, only the extracted scale factors, based on the level detection, without decompressing the compressed audio or altering any other portion of the data stream; and (d) updating, in the processor, the data stream with the altered scale factors, wherein the data stream otherwise remains unchanged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An apparatus for audio level control for compressed audio in a data stream, comprising:
-
(a) means, performed by a processor, for extracting scale factors for the compressed audio from the data stream; (b) means, performed by the processor, for performing a level detection for the compressed audio by;
(1) means for determining a square of a derived peak analog voltage value for each of the scale factors;
(2) means for performing a square root of a sum of the squares across a frame;
(3) means for normalizing the square root based on a number of channels present in the compressed audio; and
(4) means for comparing the normalized square root against a threshold to determine whether the compressed audio exceeds a specified level;(c) means, performed by the processor, for altering only the extracted scale factors, based on the level detection, without decompressing the compressed audio or altering any other portion of the data stream; and (d) means, performed by the processor, for updating the data stream with the altered scale factors, wherein the data stream otherwise remains unchanged. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. An article of manufacture comprising a storage device embodying instructions that, when read and executed by a processor, results in the processor performing a method of audio level control for compressed audio in a data stream, the method comprising:
-
(a) extracting, in a processor, scale factors for the compressed audio from the data stream; (b) performing, in the processor, a level detection for the compressed audio by;
(1) determining a square of a derived peak analog voltage value for each of the scale factors;
(2) performing a square root of a sum of the squares across a frame;
(3) normalizing the square root based on a number of channels present in the compressed audio; and
(4) comparing the normalized square root against a threshold to determine whether the compressed audio exceeds a specified level;(c) altering, in the processor, only the extracted scale factors, based on the level detection, without decompressing the compressed audio or altering any other portion of the data stream; and (d) updating, in the processor, the data stream with the altered scale factors, wherein the data stream otherwise remains unchanged. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
Specification