avaneev / r8brain-free-src

High-quality pro audio resampler / sample rate conversion header-only C++ library. Very fast, for both audio resampling and time-series interpolation.

digistoremaster / sample-rate-converter-432hz-batch

Fast, lossless audio frequency converter tool to batch convert 440Hz to 432Hz / 528Hz tuning. Preserves audio tempo, ID3 tags, and Hi-Fi quality across FLAC, MP3, WAV, and M4A.