Preprocessing of digital audio data for improving perceptual sound quality on a mobile phone
First Claim
1. A method for processing an audio signal, comprising the steps of:
- performing a pitch harmonic enhancement (“
PHE”
) preprocessing of the audio signal, wherein the PHE preprocessing enhances the pitch components of the audio signal;
determining an encoding rate from a plurality of encoding rates based on a characteristic of the PHE preprocessed audio signal; and
encoding the PHE preprocessed audio signal with the determined encoding rate at a codec having the plurality of encoding rates.
5 Assignments
0 Petitions
Accused Products
Abstract
Since music signals are encoded by a voice encoding method optimized to human voice signals such as EVRC (Enhanced Variable Rate Coding) in a cellular communication system, the music signals are often distorted by such encoding method, and listeners experience pauses in music caused by such voice-optimized encoding method. To improve the perceptual sound quality of music, a method for preprocessing digital audio data is provided in order to prevent the problem of pause in music signals in a cellular phone. In particular, AGC (Automatic Gain Control) preprocessing and PHE (Pitch Harmonics Enhancement) is performed to the digital audio data having low dynamic range. By this method, the number of pauses in music signal is reduced, and the perceptual sound quality of the music is improved.
-
Citations
23 Claims
-
1. A method for processing an audio signal, comprising the steps of:
-
performing a pitch harmonic enhancement (“
PHE”
) preprocessing of the audio signal, wherein the PHE preprocessing enhances the pitch components of the audio signal;determining an encoding rate from a plurality of encoding rates based on a characteristic of the PHE preprocessed audio signal; and encoding the PHE preprocessed audio signal with the determined encoding rate at a codec having the plurality of encoding rates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A system for processing an audio signal, comprising:
-
means for performing a pitch harmonic enhancement (“
PHE”
) preprocessing of the audio signal, wherein the PHE preprocessing enhances the pitch components of the audio signal;means for receiving and encoding the PHE preprocessed audio signal, wherein said means for performing PHE preprocessing comprises means for applying a smoothing filter in a frequency domain selectively depending on a characteristic of the audio signal; and means for performing residual peak enhancement, wherein said means for receiving and encoding the PHE preprocessed audio signal determines an encoding rate from a plurality of encoding rates based on a characteristic of the PHE preprocessed audio signal and encodes the PHE preprocessed audio signal with the determined encoding rate. - View Dependent Claims (19, 20, 21, 22, 23)
-
Specification