national open studio for

Development & Research in Electro-Acoustic
Media

#### Sliding Discrete Fourier Transform

The page is under continuing develoment to present sound files and code for the
Sliding Discrete Fourier Transform as additional information to the
paper in ICMC2005, and for the Sliding Phase Vocoder described at ICMC2007.

#### Sliding Phase Vocoder

The paper given at ICMC2007 is here.
The overhead projected slides for the presentation at ICMC2007 are
available here.

In the following, all examples begin with source sound.
Example 1,2: source from Csound book ("late_show.aif") and examples 3
through 5 are from the EBU SQAM set (converted to mono) :
http://sound.media.mit.edu/mpeg4/audio/sqam/

- Musical example 1: A "standard"
multiplicative pitch shift using SPV (N=1024, 2048).
- Musical example 2: A pure
additive shift (500Hz) with SPV (compressed frequency ratios, tight
drums).
- Musical example 3: Trumpet sound
with Frequency Modulation using SPV.
- Musical example 4: A
glockenspiel followed by two different downward harmonic shifts using SPV, and finally
all three played together.
- Musical example 5: A horn with
two time-varying TFM (Transformational FM) transformations.

#### Constant Q Sliding

The Constant-Q variant of the Sliding Dicrete Fourier Transform is descibed in the DAFx 2008 paper, available here.

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jpff@cs.bath.ac.uk
Last modified: Thu Sep 6 12:44:58 BST 2007