The audio/libsamplerate port
libsamplerate-0.1.9 – audio sample rate conversion library
Secret Rabbit Code (aka libsamplerate) is a Sample Rate Converter
for audio. One example of where such a thing would be useful is
converting audio from the CD sample rate of 44.1kHz to the 48kHz
sample rate used by DAT players.
SRC is capable of arbitrary and time varying conversions; from
downsampling by a factor of 256 to upsampling by the same factor.
Arbitrary in this case means that the ratio of input and output
sample rates can be an irrational number. The conversion ratio
can also vary with time for speeding up and slowing down effects.
SRC provides a small set of converters to allow quality to be
traded off against computation cost. The current best converter
provides a signal-to-noise ratio of 97dB with -3dB passband
extending from DC to 96% of the theoretical best bandwidth for
a given pair of input and output sample rates.