Major AEC3 render pipeline changes

webrtc/modules/audio_processing/aec3/render_buffer.cc

Index: webrtc/modules/audio_processing/aec3/render_buffer.cc
diff --git a/webrtc/modules/audio_processing/aec3/fft_buffer.cc b/webrtc/modules/audio_processing/aec3/render_buffer.cc
similarity index 58%
rename from webrtc/modules/audio_processing/aec3/fft_buffer.cc
rename to webrtc/modules/audio_processing/aec3/render_buffer.cc
index 6542d108ef99d9c363ef715af2ace132c03b656b..65dbc8fc2b4610c261e2b35e0246c07ea4e43fb0 100644
--- a/webrtc/modules/audio_processing/aec3/fft_buffer.cc
+++ b/webrtc/modules/audio_processing/aec3/render_buffer.cc
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "webrtc/modules/audio_processing/aec3/fft_buffer.h"
+#include "webrtc/modules/audio_processing/aec3/render_buffer.h"
 
 #include <algorithm>
 
@@ -17,19 +17,28 @@
 
 namespace webrtc {
 
-FftBuffer::FftBuffer(Aec3Optimization optimization,
-                     size_t num_partitions,
-                     const std::vector<size_t> num_ffts_for_spectral_sums)
+RenderBuffer::RenderBuffer(Aec3Optimization optimization,
+                           size_t num_bands,
+                           size_t num_partitions,
+                           const std::vector<size_t> num_ffts_for_spectral_sums)
     : optimization_(optimization),
       fft_buffer_(num_partitions),
       spectrum_buffer_(num_partitions, std::array<float, kFftLengthBy2Plus1>()),
       spectral_sums_(num_ffts_for_spectral_sums.size(),
-                     std::array<float, kFftLengthBy2Plus1>()) {
+                     std::array<float, kFftLengthBy2Plus1>()),
+      last_block_(num_bands, std::vector<float>(kBlockSize, 0.f)) {
   // Current implementation only allows a maximum of one spectral sum lengths.
   RTC_DCHECK_EQ(1, num_ffts_for_spectral_sums.size());
   spectral_sums_length_ = num_ffts_for_spectral_sums[0];
   RTC_DCHECK_GE(fft_buffer_.size(), spectral_sums_length_);
 
+  Clear();
+}
+
+RenderBuffer::~RenderBuffer() = default;
+
+void RenderBuffer::Clear() {
+  position_ = 0;
   for (auto& sum : spectral_sums_) {
     sum.fill(0.f);
   }
@@ -41,19 +50,32 @@ FftBuffer::FftBuffer(Aec3Optimization optimization,
   for (auto& fft : fft_buffer_) {
     fft.Clear();
   }
+
+  for (auto& b : last_block_) {
+    std::fill(b.begin(), b.end(), 0.f);
+  }
 }
 
-FftBuffer::~FftBuffer() = default;
+void RenderBuffer::Insert(const std::vector<std::vector<float>>& block) {
+  // Compute the FFT of the data in the lowest band.
+  FftData X;
+  fft_.PaddedFft(block[0], last_block_[0], &X);
+
+  // Copy the last render frame.
+  RTC_DCHECK_EQ(last_block_.size(), block.size());
+  for (size_t k = 0; k < block.size(); ++k) {
+    RTC_DCHECK_EQ(last_block_[k].size(), block[k].size());
+    std::copy(block[k].begin(), block[k].end(), last_block_[k].begin());
+  }
 
-void FftBuffer::Insert(const FftData& fft) {
-  // Insert the fft into the buffer.
-  position_ = (position_ - 1 + fft_buffer_.size()) % fft_buffer_.size();
-  fft_buffer_[position_].Assign(fft);
+  // Insert X into the buffer.
+  position_ = position_ > 0 ? position_ - 1 : fft_buffer_.size() - 1;
+  fft_buffer_[position_].Assign(X);
 
   // Compute and insert the spectrum for the FFT into the spectrum buffer.
-  fft.Spectrum(optimization_, &spectrum_buffer_[position_]);
+  X.Spectrum(optimization_, &spectrum_buffer_[position_]);
 
-  // Pre-compute and cachec the spectral sums.
+  // Pre-compute and cache the spectral sums.
   std::copy(spectrum_buffer_[position_].begin(),
             spectrum_buffer_[position_].end(), spectral_sums_[0].begin());
   size_t position = (position_ + 1) % fft_buffer_.size();