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Please use this identifier to cite or link to this item:
http://hdl.handle.net/10066/1488
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| Title: | The Fast Fourier Transform in the MPEG Encoding Algorithm |
| Author(s): | Breimyer, Paul |
| Department: | Haverford College. Dept. of Computer Science |
| Abstract: | This paper presents some of the encoding methods necessary to transform a PCM wave audio file into a recognizable MPEG Layer III (MP3) file, as defined by the International Standards Organization (ISO). It focuses on the psychoacoustic model and the FFT (Fast Fourier Transform) algorithms used in the MPEG algorithm. These two algorithms are the principal factors in the nearly 10:1 file size reduction accomplished by the MP3 format. The psychoacoustic model exploits a central philosophy behind the compression algorithm: the PCM format, while syntactically highly logical, is highly inefficient in that it contains a wealth of information that is imperceptible to the human ear. The psychoacoustic model removes this superfluous data and thus creates a much more
efficient storage format. This reduction is achieved in great part by the FFT algorithm
that takes the time-domain input signals and transforms them to the frequency-domain.
By comparing these frequencies to those audible by the human ear, many can be removed, thereby greatly reducing the size of the file.
Chapter 1 deals with the MPEG fundamentals; Chapter 2 with the Psychoacoustic Model within the MPEG encoding algorithm; Chapter 3 with Fourier analysis and the mathematical principles behind the Fast Fourier Transform; and Chapter 4 briefly
presents a concrete MP3 example. |
| URI: | http://hdl.handle.net/10066/1488 |
| Appears in Collections: | Computer Science
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Files in This Item:
| File |
Description |
Size | Format |
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| 2001BreimyerP.pdf | Thesis | 10251Kb | Adobe PDF | View/Open |
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