What is RTcmix?

RTcmix is a real-time software "language" for doing digital sound synthesis and signal-processing. It is written in C/C++, and is distributed open-source, free of charge. In certain respects, it is similar in function to other extant unit-generator-based software languages such as CSOUND, SuperCollider and (to a lesser extent) JSyn and Max/MSP -- they do share a common heritage, after all. There are some differences, however, between all these languages... and variety is of course the spice of life!

So if you've been searching the web high and low for just the right library of DSP functions to include in your latest&greatest "killer" (or maybe "peacefully coexisting"?) app, then RTcmix may just be the Right Package for You.

RTcmix currently includes the following components:

RTcmix compiles and runs on most Unix-like systems, including various flavors of Linux, Mac OSX, IRIX, FreeBSD. A windows port is available making use of the max/msp rtcmix~ object.

The Ancient History of RTcmix

Luke Dubois wrote a brief history of RTcmix back in the mid-1990's, quoting from an earlier brief history of CMIX written by Brad Garton (me!). The histories are in fact still historical, but a few recent (c. 2000-2003) RTcmix events worth noting -- if you are the kind that likes noting these things.

With the demise of SGI machines as a semi-platform-of-choice for the computer music community, RTcmix went into a period of 'underground' usage. As noted in Luke's document, it was ported to Linux and was further developed by a core group of RTcmix users who also adopted Linux for musical work. Dave Topper and John Gibson at the University of Virginia (John is presently at Indiana University) and Doug Scott (formerly of SGI, now with Beatnik) in particular added extensive new features to the language and greatly expanded RTcmix capabilities -- perl/python interface, instrument interconnecting ability, much larger instrument base, etc.

But by and large, not too many new users began working with RTcmix, primarily because we never took the time to create a coherent body of documentation. Luke, followed with additional work by Dave and John, added to the tiny existing RTcmix documentation (and much of their work has been incorporated into these web pages), but to use RTcmix you sort-of had to know how to use it already.

I was still using RTcmix a fair amount in my own musical work, but I also began to look at other languages (like JSyn, Max/MSP and SuperCollider). One of the things I didn't like about these languages was the difficulty in incorporating them into C/C++ applications with a high degree of data-sharing. I also rediscovered how much I enjoy the straightforward algorthmic processing capabilities of RTcmix. So, with help from Doug/Dave/John, I wrote an 'imbedded' RTcmix object to facilitate the C/C++ connection, and decided to get our documentation house in order so that others who might want a language like RTcmix could gain entry.

I had noticed that many of our students at Columbia were adopting Max/MSP as a base for their computer music operations. The Max/MSP rtcmix~ object was created to bring the Joy of RTcmix to this environment. The recent Windows XP port of this object allowed us to build an executable RTcmix for Windows without too much additional pain.

That's the story so far. With a solid Linux version and an equally solid port to Mac OSX (and the hybrid RTcmix-Max/MSP Windows version), we believe that RTcmix should be attractive for other programmers-musicians-audio people. Please browse through the documentation here (especially the tutorials), download and try a few instruments, join the RTcmix mailing list, etc.

We hope you find the language useful!

Brad Garton
March, 2005

NOTE: click here for the older, version 3.6 documentation