spandsp - A DSP library for telephony ----------------------------------------------- SpanDSP is a library of DSP functions for telephony, in the 8000 sample per second world of E1s, T1s, and higher order PCM channels. It contains low level functions, such as basic filters. It also contains higher level functions, such as cadenced supervisory tone detection, and a complete software FAX machine. The software has been designed to avoid intellectual property issues, using mature techniques where all relevant patents have expired. See the file DueDiligence for important information about these intellectual property issues. The library is licenced under the LGPL 2.1 licence. The test suite, and some support programs are licenced under the GPL 2 licence. The full text of these licences can be found in the file COPYING.