Documentation
- Introduction
- SDIF sound modeling
- Getting a good analysis
- Using Loris within Csound
- Credits and Thanks
SDIF, Csound and Loris
The SDIF sound analysis file format was created at IRCAM in 1983 and is currently maintained by the University of California, Berkley. An SDIF analysis contains time-varying data which usually describes the frequency, amplitude and phase of sinusoids whos sum approximates an analyzed soundfile. SDIF was created to be flexible and allows for user-specified data structures. While most sound applications that support SDIF use the standard 1RTC frame (Audioscuplt, SPEAR), the Loris sound-modeling application stores partials in SDIF RBEP frames. Each RBEP frame contains one RBEP matrix, and each row in a RBEP matrix describes one breakpoint in a Loris partial. A RBEL frame containing one RBEL matrix describing the labeling of the partials may precede the first RBEP frame in the SDIF file. The RBEP and RBEL frame and matrix definitions are included in the SDIF file's header. In addition to RBEP frames, Loris can also read and write SDIF 1TRC frames. Since 1TRC frames do not represent bandwidth-enhancement or the exact timing of Loris breakpoints, their use is not recommended. 1TRC capabilities are provided to allow interchange with programs that are unable to handle RBEP frames.
the Loris opcodes (both the standard and extended versions) will synthesize both 1RTC and RBEP frame types.
opcodes work with data stored in memory, not files
While SDIF has many potential uses, the interest of the author is artifact-free, faithful modeling of acoustic sound.
Getting a Good Analysis
Using Loris within Csound
Credits
The Loris unit generators were written by Kelly Fitz (loris@cerlsoundgroup.org). It is patterned after a prototype implementation of the lorisplay unit generator written by Corbin Champion, and based on the method of Bandwidth-Enhanced Additive Synthesis and on the sound morphing algorithms implemented in the Loris library for sound modeling and manipulation. The opcodes were further adapted as a plugin for Csound 5 by Michael Gogins. Ben Hackbarth (hackbarth@ucsd.edu) wrote the Extended Loris Opcodes.