Merge "Add some missing math in DCTIV computation" (e40d6044) · Commits · e / os / android_packages_modules_Bluetooth

system/embdrv/lc3/Common/DctIV.cpp

+35 −4

Original line number	Diff line number	Diff line
		@@ -116,6 +116,8 @@ class KissfftConfig {
		};

		#elif defined USE_OWN_FFT
		#include <complex>

		#include "fft.h"
		#endif

		@@ -136,7 +138,17 @@ DctIVDbl::DctIVDbl(uint16_t NF_)
		dctIVconfig = new KissfftConfig(NF / 2);

		#elif defined USE_OWN_FFT
		// setup is not needed

		int N = NF / 2;
		std::complex<double>* twiddle = new std::complex<double>[N];
		dctIVconfig = twiddle;
		const double pi = std::acos(-1);
		for (uint16_t n = 0; n < N; n++) {
		twiddle[n] =
		std::complex<double>(std::cos(-pi * (8 * n + 1) / (8.0 * N * 2)),
		std::sin(-pi * (8 * n + 1) / (8.0 * N * 2)));
		}

		#endif

		for (uint16_t n = 0; n < NF; n++) {
		@@ -159,7 +171,9 @@ DctIVDbl::~DctIVDbl() {
		}

		#elif defined USE_OWN_FFT
		// cleanup is not needed
		std::complex<double>* twiddle = (std::complex<double>*)dctIVconfig;
		delete[] twiddle;

		#endif
		if (nullptr != in) {
		delete[] in;
		@@ -250,6 +264,14 @@ void DctIVDbl::run() {
		in[NF - n] = buffer;
		}

		std::complex<double>* twiddle = (std::complex<double>*)dctIVconfig;
		for (uint16_t n = 0; n < NF / 2; n++) {
		double real = in[2 * n + 0];
		double imag = in[2 * n + 1];
		in[2 * n + 0] = real * twiddle[n].real() - imag * twiddle[n].imag();
		in[2 * n + 1] = real * twiddle[n].imag() + imag * twiddle[n].real();
		}

		for (uint16_t n = 0; n < NF / 2; n++) {
		inbuf[n].re = in[2 * n];
		inbuf[n].im = in[2 * n + 1];
		@@ -258,8 +280,17 @@ void DctIVDbl::run() {
		fft_complex* actal_output = fft(false, inbuf, NF / 2, inbuf, outbuf);

		for (uint16_t n = 0; n < NF / 2; n++) {
		out[2 * n] = actal_output[n].re;
		out[NF - 2 * n - 1] = actal_output[n].im;
		double real = actal_output[n].re;
		double imag = actal_output[n].im;
		out[2 * n + 0] = 2 * (real * twiddle[n].real() - imag * twiddle[n].imag());
		out[2 * n + 1] = 2 * (real * twiddle[n].imag() + imag * twiddle[n].real());
		}

		for (uint16_t n = 1; n < NF / 2; n += 2) {
		double buffer;
		buffer = out[n];
		out[n] = -out[NF - n];
		out[NF - n] = -buffer;
		}

		#else