### Maximum Efficiency Configuration

Source: https://github.com/avaneev/r8brain-free-src/blob/master/README.md

Define R8B_IPP, R8B_FASTTIMING, and R8B_EXTFFT macros for maximum efficiency if initial processing delay and minor sample-timing errors are acceptable.

```c++
#define R8B_IPP 1
#define R8B_FASTTIMING 1
#define R8B_EXTFFT 1
```

--------------------------------

### Enable Intel IPP FFT Backend

Source: https://github.com/avaneev/r8brain-free-src/blob/master/README.md

Define the R8B_IPP macro to enable the Intel IPP backend for FFT functions, potentially speeding up sample rate conversion.

```c++
#define R8B_IPP 1
```

--------------------------------

### Enable PFFFT Double-Precision FFT

Source: https://github.com/avaneev/r8brain-free-src/blob/master/README.md

Define the R8B_PFFFT_DOUBLE macro to enable the PFFFT library for FFT calculations in double-precision, utilizing SSE2, AVX, and NEON intrinsics for precision equal to Intel IPP and Ooura FFT.

```c++
#define R8B_PFFFT_DOUBLE 1
```

--------------------------------

### Enable PFFFT Single-Precision FFT

Source: https://github.com/avaneev/r8brain-free-src/blob/master/README.md

Define the R8B_PFFFT macro to enable the PFFFT library for FFT calculations in single-precision. This limits resampler precision to 24-bit and is not recommended for mission-critical applications due to large peak error.

```c++
#define R8B_PFFFT 1
```

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