chore: bring back DSP, remove stftFromWaveform

Author: chmjkb

packages/react-native-executorch/common/rnexecutorch/data_processing/dsp.cpp

@@ -1,6 +1,4 @@
-#include <algorithm>
 #include <cstddef>
-#include <limits>
 #include <math.h>
 #include <rnexecutorch/data_processing/FFT.h>
 #include <rnexecutorch/data_processing/dsp.h>
@@ -18,48 +16,4 @@ std::vector<float> hannWindow(size_t size) {
   return window;
 }
 
-std::vector<float> stftFromWaveform(std::span<const float> waveform,
-                                    size_t fftWindowSize, size_t hopSize) {
-  // Initialize FFT
-  FFT fft(fftWindowSize);
-
-  const auto numFrames = 1 + (waveform.size() - fftWindowSize) / hopSize;
-  const auto numBins = fftWindowSize / 2;
-  const auto hann = hannWindow(fftWindowSize);
-  auto inBuffer = std::vector<float>(fftWindowSize);
-  auto outBuffer = std::vector<std::complex<float>>(fftWindowSize);
-
-  // Output magnitudes in dB
-  std::vector<float> magnitudes;
-  magnitudes.reserve(numFrames * numBins);
-  const auto magnitudeScale = 1.0f / static_cast<float>(fftWindowSize);
-  constexpr auto epsilon = std::numeric_limits<float>::epsilon();
-  constexpr auto dbConversionFactor = 20.0f;
-
-  for (size_t t = 0; t < numFrames; ++t) {
-    const size_t offset = t * hopSize;
-    // Clear the input buffer first
-    std::ranges::fill(inBuffer, 0.0f);
-
-    // Fill frame with windowed signal
-    const size_t samplesToRead =
-        std::min(fftWindowSize, waveform.size() - offset);
-    for (size_t i = 0; i < samplesToRead; i++) {
-      inBuffer[i] = waveform[offset + i] * hann[i];
-    }
-
-    fft.doFFT(inBuffer.data(), outBuffer);
-
-    // Calculate magnitudes in dB (only positive frequencies)
-    for (size_t i = 0; i < numBins; i++) {
-      const auto magnitude = std::abs(outBuffer[i]) * magnitudeScale;
-      const auto magnitude_db =
-          dbConversionFactor * log10f(magnitude + epsilon);
-      magnitudes.push_back(magnitude_db);
-    }
-  }
-
-  return magnitudes;
-}
-
 } // namespace rnexecutorch::dsp

packages/react-native-executorch/common/rnexecutorch/models/voice_activity_detection/VoiceActivityDetection.cpp

@@ -6,7 +6,6 @@
 #include <array>
 #include <functional>
 #include <numeric>
-#include <ranges>
 #include <vector>
 
 namespace rnexecutorch::models::voice_activity_detection {
@@ -158,4 +157,4 @@ VoiceActivityDetection::postprocess(const std::vector<float> &scores,
   return speechSegments;
 }
 
-} // namespace rnexecutorch::models::voice_activity_detection
+} // namespace rnexecutorch::models::voice_activity_detection