METAXPON ("Metachron" in Greek letters) is a small and fast audio DSP library for time-scale manipulation of 16-bit integer or 32-bit floating point stereo audio data streams. It employs a rigid phase-locked vocoder with dedicated transient detection and processing, and can work in real-time or non-real-time. Four editions are included - a portable edition and three x86 editions. The portable edition can be built with any ANSI C compiler and is OS- and architecture-independent. The three x86 editions are written in assembly using the FPU, 3DNow!, and SSE instruction sets, respectively, with automatic selection between them depending on the CPU capabilities. They can be compiled with MASM, JWASM, or NASM, producing libraries of object files in 8 formats.
PFFFT is a very small 1D Fast Fourier Transform library based on the venerable FFTPACK v4. It handles single precision real and complex transforms. Computations take advantage of SSE1 instructions on x86, Altivec on PowerPC, and NEON on ARM, allowing it to achieve a performance level that is not too far from the very best FFTs (FFTW, Intel MKL, Apple vDSP).
Orc is a library and set of tools for compiling and executing very simple programs that operate on arrays of data. The "language" is a generic assembly language that represents many of the features available in SIMD architectures, including saturated addition and subtraction, and many arithmetic operations.
SLEEF (SIMD Library for Evaluating Elementary Functions) is a library that facilitates programming with SIMD instructions. It implements the trigonometric functions, inverse trigonometric functions, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. This library also includes some functions for evaluation in single precision.