Juan Reyes (juanig@ccrma.stanford.edu)
Fernando Lopez-Lezcano (nando@ccrma.stanford.edu
Center for Computer
Research in Music and Acoustics(CCRMA)
Department of Music, Stanford
University
Stanford, California 94305
Testing was performed with various commercial USB-MIDI and USB-AUDIO interfaces to the extend that we are able to consider USB as good as an alternative (or better in some cases) to serial and parallel interfaces and even to audio sound-cards. The ``usb-audio'' module of ALSA has been updated and improved to the extend that most hardware tested, behaved in a reliable fashion with standard Linux and PlanetCCRMA applications. In our tests hardware included not only interfaces but controllers such as keyboards and wheels.
MIDI is a very important part at CCRMA because of its close relationship with human computer interface (HCI). Our testing focused not only on ALSA sequencers but also with the PD Linux environment and more specialized software such as Max Matthews' Scanned synthesis program and Craig Sapp's Improv. In most cases USB-Audio performed accurately even with the combination of Scanned synthesis audio and Radio Baton MIDI input using M-Audio's Quattro interface. With the Quattro we were also able to listen to four discrete 44.1KHz audio channels and record audio at 96KHz sampling rate.
For more updated information on the ALSA ``usb-audio'' module and for
additional USB audio an related issues, poin to the USB audio web
pages on the Nano HOWTOs section at PlanetCCRMA:
http://www-ccrma.stanford.edu/planetccrma/software/
© Copyright 2003 CCRMA, Stanford University. All rights reserved.
Created and Mantained by Juan Reyes