CDP Documentation Home Page
~ Welcome to CDP Sound Transformations
Release 8 ~
CDP (Composers' Desktop Project) is a suite of around 500 processes, designed for the in-depth exploration of sound transformation. CDP is not a real-time system, but mostly transforms soundfiles ('samples') or spectral (frequency-analysis) files, and writes other sound or spectral files as output. Most CDP processes run very quickly on modern computers (normally much faster than real-time).
CDP processes cover almost every aspect of sound manipulation. There is also a small group of functions for sound synthesis, and several sound-processing functions can be adapted for synthesis. The emphasis is on sound design in the tradition of musique concrète, either for fully electro-acoustic music compositions or as sound clips or tracks in songs or other media. Many people use CDP alongside other software in a hybrid studio environment.
Running CDP programs
Natively, CDP programs are written for a Command-Line Interpreter Terminal on the Mac or Linux, or the Windows Command Processor on the PC. CDP commands typically consist of a program name (and possibly a program mode), followed by the input and outout filenames; then the various parameter values (settings) for the program, plus some optional flags. (See Usage below.)
Alternatively, CDP has two main graphical interface programs (see USER INTERFACES below) Sound Loom (Mac/PC) and Soundshaper (PC). Both of these assemble the command-lines for you behind the scenes: you simply choose input files, processes and settings (parameter values) for the processes, as you would in most music software (such as plugins).
Automation (time-varying values) is achieved in CDP using textfiles, mostly of the 'breakpoint' type a list of time and value pairs. (The GUIs have facillities to help contruct these.) Other more specialist textfiles are also used, which are catalogued on the FILE FORMATS page.
A powerful command-line option is to construct batch files (PC) or shell scripts (Mac/Linux). Sharing a very similar syntax, these text scripts consist of one or more CDP (and other) command-lines. You can run a chain of processes as a single procedure, using different input and output files each time.
CDP RELEASE 8
CDP's eighth software release (2023) introduces over 70 new processes. These cover a wide variety of spectral, multi-channel, segmentation, waveset and synth functions, among others. Some are updates or alternatives to previous processes, while some are at the more 'experimental' end of sound processing. A few are yet to be fully documented and will be added in due course. SPECFNU, in particular, is worth a special mention as a whole new process group of 23 functions, transforming sounds spectrally while aiming to retain the original formants.
All of the new (documented) processes have been assigned to the various Function Groups within this documentation, with links where appropriate.
You can also view them separately, in two html files and a pdf list (by Function Group)
Most users will probably run CDP software via a graphical user interface (GUI).
The two main GUIs for the whole CDP system are:
Sound Loom (PC and MAC)
Both of these have:
- access to a comprehensive set of CDP processes
- a built-in soundfile editor
- built-in knowledge of CDP parameters and their ranges
- presets for storing parameter settings (called 'Patches' in SoundLoom)
- facilities to store and run multi-process patches (called 'Instruments' in SoundLoom)
- a graphical breakpoint editor
- a Table Editor (Sound Loom) / Data Editor (Soundshaper) for massaging numerical data
- a means of keeping text records of each working session
SoundLoom has developed a Test Bed for new processes. Soundshaper has concentrated on ease of use, with support for stereo and multi-channel files throughout and automatic conversion of CDP file types.
Two further CDP GUIs have been developed as extensions to the REAPER and RENOISE DAWs, each supporting only part of the CDP suite.
See the GRAPHIC page for a full list of graphic programs for CDP, with links to further information and reference manuals.
THE REFERENCE DOCUMENTATION
The CDP processes are grouped into FUNCTION GROUPS, most of which are the names of programs, each containing a number of processes. Newer single-process programs have also been allocated to a group, for reference purposes. The Reference Documentation has an HTML page for each Function Group with a separate reference section for each process, documenting and describing command-line usage.
The Function Groups have two main divisions: TIME-DOMAIN and SPECTRAL (or FREQUENCY DOMAIN).
The processes in each group are listed in the MAIN INDEX. This list and the individual Function-Group pages are also available as printable PDF files (see Downloads page).
USAGE AND PARAMETERS
The reference section for each function or process comprises a command-line Usage statement
and a list of Modes (where applicable) and Parameters, followed by a description of the process and (usually) suggestions for Musical Applications.
Usage describes what you would type on the command-line if using the Command Line or what is assembled by one of the User Interfaces (GUIs - see above).
Modes represent different aspects of the process. Not all functions have them, and sometimes they are radically different from each other; some are more like separate functions.
Parameters are the controls you have over the process and are the key to understanding what the function does. They typically have a single numerical value or the name of a breakpoint text file containing time-varying values. Some require a specialist text data file or text code: see the FILE FORMATS page for an explanation of these.
For further details, see the Technical Glossary article on the Command Line.
- MAIN INDEX this links to the reference documentation for all Function Groups and lists all the processes in each group.
- TIME DOMAIN INDEX this links to the reference documentation for the Time-Domain (soundfile) Function Groups (known as 'Groucho'), and has an alphabetical index, by process-name.
- SPECTRAL INDEX this links to the reference documentation for the Spectral (Frequency-Domain) Function Groups, and has an alphabetical index, by process-name.
- A-Z INDEX an overall alphabetical index of all CDP processes, each linked to its Reference Documentation.
- TABLE INDEX this has Table 'button' Indexes of CDP Time-Domain and Spectral functions, plus a further table (up to Release 7) in which the Function Groups (and their processes) are grouped into higher-level Component Packages.
- OPERATIONS INDEX this lists processes (up to Release 7) alphabetically by the operation each one does: accelerate, accumulate, envelope, filter, etc. (Sometimes referred to as the Alphabetical Index.)
- DESK REFERENCE CHART (pdf) Printable list of all CDP functions (up to Release 7) classified into function groups and CDP packages. (See also Charts Page)
Various Starter Documents are available in PDF format the top level of the documentation folder:
A classified guide (Oct. 2021) to CDP processes and functions in five categories:
- Soundfile Processes: Envelope, Filter, Pitch, Reverb/Delay, Segmentation, Granular, Pitch-Sync. Grains, Texture, Retime, Wavesets
- Spectral Processes: Reshape, Filter, Pitch & Frequency, Morph, Formants, Combine, Time, Spec Utils
- Pitch Data: Conversions, Pitch Processes, Support functions
- Editing and Mixing soundfiles: Cut, Paste, Splice, Sequence, Level, Channels, Spatial, Mix and Mixfiles, Soundfile Utils
- Other functions: Synthesis, Information, Data generation and manipulation, System Utils
The guide groups related functions together in familiar categories to help you find your way around CDP. (See the Downloads page
to download a copy.)
The Tutorials page links to a number of Tutorials, Workshops and Guides for the CDP system. Archer Endrich has written several tutorials introducing key CDP processes; his CDP-Lite collection highlights many of these. There are many worked examples to be found in the 12-step tutorial, the Demo Examples and the Tutorial Workshops. His latest addition is A Learning Manual for CDP, which covers most of the CDP sound transformation processes from the point of view of composition objectives and can be downloaded from the
The Texture Workshop presents a carefully prepared set of introductory examples for the TEXTURE functions.
CHARTS and GUIDES
The CHARTS page links to several charts and glossaries that give further background and reference material. PDF versions of these are also available.
On the Downloads Page you can download a zip file of the CDP documentation as HTML. The page also lists changes to the documentation, by HTML page and date. This will help you keep your HTML documents up-to-date.
The core reference docs and charts are also available in printable PDF format. You can download PDFs individually or as a single zip file on the Downloads Page.
The CDP documentation is also available online here: CDP DOCS Home Page. The online docs are always the latest available; PDFs and other updates may be delayed.