Data processing: speech signal processing – linguistics – language – Audio signal bandwidth compression or expansion
Reexamination Certificate
2005-11-08
2005-11-08
Ometz, David L. (Department: 2655)
Data processing: speech signal processing, linguistics, language
Audio signal bandwidth compression or expansion
C704S200100, C704S203000, C704S269000, C704S230000, C341S050000
Reexamination Certificate
active
06963842
ABSTRACT:
A memory-efficient system converting a signal from a first transform domain to a second transform domain. The system includes a first mechanism that obtains an input signal expressed via a first transform-domain signal representation. A second mechanism expresses the input signal via a second transform-domain signal representation without intermediate time-domain conversion. In the specific embodiment, the input signal is a Modified Discrete Cosine Transform (MDCT) signal. The second transform-domain signal representation is a Discrete Fourier Transform (DFT) signal. The second mechanism further includes a third mechanism that combines effects of an inverse MDCT, a synthesis window function, and an analysis window function, and provides a first signal in response thereto. A fourth mechanism converts the MDCT signal to the DFT signal based on the first signal. In a more specific embodiment, the synthesis window function is an MDCT synthesis window function, while the analysis window function is a DFT analysis window function. The fourth mechanism includes a mechanism for performing a fast transform on the MDCT signal and providing a first transformed signal in response thereto. The fourth mechanism further includes a mechanism for selectively delaying and updating the first transformed signal to yield second and third transformed signals, respectively, in response thereto. The fourth mechanism further includes a mechanism for operating on the first, second, and third transformed signals via third, second, and first combined window functions, respectively, and providing third, second, and first windowed signals, respectively, in response thereto. An adder adds the first, second, and third windowed functions to provide an added digital signal. An inverse DFT circuit performs an inverse DFT on the added digital signal to provide the DFT signal as output.
REFERENCES:
patent: 5651093 (1997-07-01), Nishiguchi
patent: 6356211 (2002-03-01), Shimoyoshi et al.
patent: 6415251 (2002-07-01), Oikawa et al.
patent: 6518891 (2003-02-01), Tsutsui et al.
Goodwin, Michael M., Transforming Between MDCT and DFT Representations for Audio Signal Modification, Draft paper, dated Aug. 4, 2000, 20 pages.
Creative Technology Ltd.
Jackson Jakieda
Ometz David L.
Schwegman Lundberg Woessner & Kluth P.A.
LandOfFree
Efficient system and method for converting between different... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient system and method for converting between different..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient system and method for converting between different... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3469799