Signalsmith Audio's DSP Library  1.6.0
Useful C++ classes/templates for audio effects
Here is a list of all modules:
[detail level 12]
 CommonDefinitions and helper classes used by the rest of the library
 CurvesUser-defined mapping functions
 Delay utilitiesStandalone templated classes for delays
 Envelopes and LFOsLFOs, envelopes and filters for manipulating them
 FFT (complex and real)Fourier transforms (complex and real)
 Basic filtersClasses for some common filter types
 Multichannel mixingUtilities for stereo/multichannel mixing operations
 Orthogonal matricesSome common matrices used for audio
 Performance helpersNothing serious, just some #defines and helpers
 Multi-rate processingClasses for oversampling/upsampling/downsampling etc
 Spectral ProcessingTools for frequency-domain manipulation of audio signals
 Window functionsWindows for spectral analysis