MLECO-1252 ASR sample application using the public ArmNN C++ API.
Change-Id: I98cd505b8772a8c8fa88308121bc94135bb45068
Signed-off-by: Éanna Ó Catháin <eanna.ocathain@arm.com>
diff --git a/samples/SpeechRecognition/src/MathUtils.cpp b/samples/SpeechRecognition/src/MathUtils.cpp
new file mode 100644
index 0000000..bf99083
--- /dev/null
+++ b/samples/SpeechRecognition/src/MathUtils.cpp
@@ -0,0 +1,112 @@
+//
+// Copyright © 2020 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "MathUtils.hpp"
+#include <vector>
+#include <cmath>
+#include <cstdio>
+
+void MathUtils::FftF32(std::vector<float>& input,
+ std::vector<float>& fftOutput)
+{
+ const int inputLength = input.size();
+
+ for (int k = 0; k <= inputLength / 2; k++)
+ {
+ float sumReal = 0, sumImag = 0;
+
+ for (int t = 0; t < inputLength; t++)
+ {
+ float angle = 2 * M_PI * t * k / inputLength;
+ sumReal += input[t] * cosf(angle);
+ sumImag += -input[t] * sinf(angle);
+ }
+
+ /* Arrange output to [real0, realN/2, real1, im1, real2, im2, ...] */
+ if (k == 0)
+ {
+ fftOutput[0] = sumReal;
+ }
+ else if (k == inputLength / 2)
+ {
+ fftOutput[1] = sumReal;
+ }
+ else
+ {
+ fftOutput[k*2] = sumReal;
+ fftOutput[k*2 + 1] = sumImag;
+ };
+ }
+}
+
+float MathUtils::DotProductF32(float* srcPtrA, float* srcPtrB,
+ const int srcLen)
+{
+ float output = 0.f;
+
+ for (int i = 0; i < srcLen; ++i)
+ {
+ output += *srcPtrA++ * *srcPtrB++;
+ }
+ return output;
+}
+
+bool MathUtils::ComplexMagnitudeSquaredF32(float* ptrSrc,
+ const int srcLen,
+ float* ptrDst,
+ const int dstLen)
+{
+ if (dstLen < srcLen/2)
+ {
+ printf("dstLen must be greater than srcLen/2");
+ return false;
+ }
+
+ for (int j = 0; j < srcLen; ++j)
+ {
+ const float real = *ptrSrc++;
+ const float im = *ptrSrc++;
+ *ptrDst++ = real*real + im*im;
+ }
+ return true;
+}
+
+void MathUtils::VecLogarithmF32(std::vector <float>& input,
+ std::vector <float>& output)
+{
+ for (auto in = input.begin(), out = output.begin();
+ in != input.end(); ++in, ++out)
+ {
+ *out = logf(*in);
+ }
+}
+
+float MathUtils::MeanF32(float* ptrSrc, const uint32_t srcLen)
+{
+ if (!srcLen)
+ {
+ return 0.f;
+ }
+
+ float acc = std::accumulate(ptrSrc, ptrSrc + srcLen, 0.0);
+ return acc/srcLen;
+}
+
+float MathUtils::StdDevF32(float* ptrSrc, const uint32_t srcLen,
+ const float mean)
+{
+ if (!srcLen)
+ {
+ return 0.f;
+ }
+ auto VarianceFunction = [=](float acc, const float value) {
+ return acc + (((value - mean) * (value - mean))/ srcLen);
+ };
+
+ float acc = std::accumulate(ptrSrc, ptrSrc + srcLen, 0.0,
+ VarianceFunction);
+ return sqrtf(acc);
+}
+