ref: b2df9275bddc1c491bd493127ef7be787307b277
dir: /COPYING/
SoX source code is distributed under two main licenses. The two types of licenses are described in detail in the files LICENSE.GPL and LICENSE.LGPL. sox.c, and thus SoX-the user application, is distributed under the GPL. The remaining files that make up libst are licensed under the less restrictive license LGPL. There is currently only one exception to this. The files FFT.c and FFT.h are original from the Audacity program and fall under its license of GPL. The noise profiling and noise reduction effects both make use of this FFT code and would need to be removed from any program that requires LGPL only software.