kfr

KFR is an open-source C++ DSP framework offering high-performance building blocks for digital signal processing, audio, and scientific applications. It provides optimized implementations for FFT/DFT (including real, inverse, and multidimensional transforms), sample rate conversion, and a wide range of filters (IIR, FIR, Biquad, Elliptic, Butterworth, Chebyshev, Bessel). The library supports SIMD optimizations (SSE, AVX, AVX-512, ARM NEON, RISC-V RVV) for Intel, AMD, ARM, and RISC-V architectures. Additional features include audio file I/O (WAV, FLAC, MP3, AAC, etc.), tensor operations, statistical functions, and a C API for broader compatibility. KFR is cross-platform, supporting Linux, macOS, Windows, Android, iOS, and WebAssembly, with C++20 compatibility and no external C++ dependencies. It is dual-licensed under GPLv2+ and a commercial option.