Bit rate reduction in audio encoders by exploiting...

Details Bit rate reduction in audio encoders by exploiting... Bit rate reduction in audio encoders by exploiting...

2008-07-08

2008-07-08

Chin, Vivian (Department: 2615)

Data processing: speech signal processing, linguistics, language

Speech signal processing

For storage or transmission

C704S200100

Reexamination Certificate

active

10647320

ABSTRACT:
The present invention relates to a method for encoding an audio signal. In a first embodiment a model relating to temporal masking of sound provided to a human ear is provided. A temporal masking index is determined in dependence upon a received audio signal and the model using a forward and a backward masking function. Using a psychoacoustic model a masking threshold is determined in dependence upon the temporal masking index. Finally, the audio signal is encoded in dependence upon the masking threshold. The method has been implemented using the MPEG-1 psychoacoustic model 2. Semiformal listening test showed that using the method for encoding an audio signal according to the present invention the subjective high quality of the decoded compressed sounds has been maintained while the bit rate was reduced by approximately 10%. In a second embodiment, the inharmonic structure of audio signals is modeled and incorporated into the MPEG-1 psychoacoustic model 2. In the model, the relationship between the spectral components of the input audio signal is considered and an inharmonicity index is defined and incorporated into the MPEG-1 psychoacoustic model 2. Informal listening tests have shown that the bit rate required for transparent coding of inharmonic (multi-tonal) audio material can be reduced by 10% if the modified psychoacoustic model 2 is used in the MPEG 1 Layer II encoder.

REFERENCES:
patent: 5706392 (1998-01-01), Goldberg et al.
patent: 5790759 (1998-08-01), Chen
patent: 6064954 (2000-05-01), Cohen et al.
patent: 6477489 (2002-11-01), Lockwood et al.
patent: 2004/0122662 (2004-06-01), Crockett
Huang et al., “A New Forward Masking Model and its Application to Perceptual Audio Coding”, 1999 IEEE Int'l Conference on Acoustics, Speech, and Signal Processing, vol. 2, pp. 905-908, Pheonix, AZ, Mar. 15-19, 1999.
Usagawa et al., “Speech Parameter Extraction in Noisy Environment Using a Masking Model”, Acoustics, Speech, and Signal Processing, 1994. ICASSP-94, 1999 IEEE Int'l Conference on Adelaide, SA, Australia, Apr. 19-22, 1994.

Affiliated with

Also associated with

Rating

Bit rate reduction in audio encoders by exploiting... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Bit rate reduction in audio encoders by exploiting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bit rate reduction in audio encoders by exploiting... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3918480