FFTUnswizzle

Arranges Fast Fourier Transform function output by order of increasing frequency.

void FFTUnswizzle(XMVECTOR* pOutput, const XMVECTOR* pInput,
     const size_t uLog2Length);

Parameters

pOutput

[out] Caller-supplied output buffer. pOutput receives samples in order of increasing frequency. The buffer must have at least 1<<uLog2Length/4 elements.

pInput

[in] Input buffer containing samples in bit-reversed order as generated by FFT functions. The buffer must have at least 1<<uLog2Length/4 elements.

uLog2Length

[in] The log base 2 of the FFT length in samples. uLog2Length must be greater than or equal to 2.

Remarks

The FFT functions generate output in bit-reversed order (the FFT uses a split-radix FFT, radix 4 and 2, which impacts the bit-reversal pattern). Use FFTUnswizzle to rearrange FFT function output into order of increasing frequency.

All buffer parameters must be 16-byte aligned. Audio data must be 32-bit float mono.