Non-Integer Sample Rate Conversion

This repository contains a comparison of sample-rate conversion (SRC) algorithms, with an emphasis on performance for non-integer SRC factors. Currently two oversampling algorithms are implemented:

• libsamplerate (Sinc interpolation, using SRC_SINC_FASTEST mode)
• Holters-Parker Resampler (using 4th-order Butterworth filters)
• Lanczos Resampler (borrowed from the Surge Synthesizer project)

Results:

On my Linux machine, the HP resampler is faster than libsamplerate by the following amounts:

Building

$ cmake -Bbuild
$ cmake --build build --config Release

Then to run the testing tool, run ./build/src_test.

Credits

• libsamplerate
• The Holters-Parker Resampler is based on the filters derived in their 2018 DAFx paper
• matplotlibcpp
• The HP-Resampler, and Lanczos Resampler use a ton of code borrowed from the Surge Synthesizer project (in particular, the SSEComplex and LanczosResampler classes written by Paul Walker)

License

The code in this repository is licensed under the GPLv3. Enjoy!