Index: webrtc/common_audio/lapped_transform.cc |
diff --git a/webrtc/common_audio/lapped_transform.cc b/webrtc/common_audio/lapped_transform.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..0edf586d78357b4ade2c94aaf48b96207f4c6825 |
--- /dev/null |
+++ b/webrtc/common_audio/lapped_transform.cc |
@@ -0,0 +1,102 @@ |
+/* |
+ * Copyright (c) 2014 The WebRTC project authors. All Rights Reserved. |
+ * |
+ * Use of this source code is governed by a BSD-style license |
+ * that can be found in the LICENSE file in the root of the source |
+ * tree. An additional intellectual property rights grant can be found |
+ * in the file PATENTS. All contributing project authors may |
+ * be found in the AUTHORS file in the root of the source tree. |
+ */ |
+ |
+#include "webrtc/common_audio/lapped_transform.h" |
+ |
+#include <algorithm> |
+#include <cstdlib> |
+#include <cstring> |
+ |
+#include "webrtc/base/checks.h" |
+#include "webrtc/common_audio/real_fourier.h" |
+ |
+namespace webrtc { |
+ |
+void LappedTransform::BlockThunk::ProcessBlock(const float* const* input, |
+ size_t num_frames, |
+ size_t num_input_channels, |
+ size_t num_output_channels, |
+ float* const* output) { |
+ RTC_CHECK_EQ(num_input_channels, parent_->num_in_channels_); |
+ RTC_CHECK_EQ(num_output_channels, parent_->num_out_channels_); |
+ RTC_CHECK_EQ(parent_->block_length_, num_frames); |
+ |
+ for (size_t i = 0; i < num_input_channels; ++i) { |
+ memcpy(parent_->real_buf_.Row(i), input[i], |
+ num_frames * sizeof(*input[0])); |
+ parent_->fft_->Forward(parent_->real_buf_.Row(i), |
+ parent_->cplx_pre_.Row(i)); |
+ } |
+ |
+ size_t block_length = RealFourier::ComplexLength( |
+ RealFourier::FftOrder(num_frames)); |
+ RTC_CHECK_EQ(parent_->cplx_length_, block_length); |
+ parent_->block_processor_->ProcessAudioBlock(parent_->cplx_pre_.Array(), |
+ num_input_channels, |
+ parent_->cplx_length_, |
+ num_output_channels, |
+ parent_->cplx_post_.Array()); |
+ |
+ for (size_t i = 0; i < num_output_channels; ++i) { |
+ parent_->fft_->Inverse(parent_->cplx_post_.Row(i), |
+ parent_->real_buf_.Row(i)); |
+ memcpy(output[i], parent_->real_buf_.Row(i), |
+ num_frames * sizeof(*input[0])); |
+ } |
+} |
+ |
+LappedTransform::LappedTransform(size_t num_in_channels, |
+ size_t num_out_channels, |
+ size_t chunk_length, |
+ const float* window, |
+ size_t block_length, |
+ size_t shift_amount, |
+ Callback* callback) |
+ : blocker_callback_(this), |
+ num_in_channels_(num_in_channels), |
+ num_out_channels_(num_out_channels), |
+ block_length_(block_length), |
+ chunk_length_(chunk_length), |
+ block_processor_(callback), |
+ blocker_(chunk_length_, |
+ block_length_, |
+ num_in_channels_, |
+ num_out_channels_, |
+ window, |
+ shift_amount, |
+ &blocker_callback_), |
+ fft_(rtc::ScopedToUnique( |
+ RealFourier::Create(RealFourier::FftOrder(block_length_)))), |
+ cplx_length_(RealFourier::ComplexLength(fft_->order())), |
+ real_buf_(num_in_channels, |
+ block_length_, |
+ RealFourier::kFftBufferAlignment), |
+ cplx_pre_(num_in_channels, |
+ cplx_length_, |
+ RealFourier::kFftBufferAlignment), |
+ cplx_post_(num_out_channels, |
+ cplx_length_, |
+ RealFourier::kFftBufferAlignment) { |
+ RTC_CHECK(num_in_channels_ > 0 && num_out_channels_ > 0); |
+ RTC_CHECK_GT(block_length_, 0u); |
+ RTC_CHECK_GT(chunk_length_, 0u); |
+ RTC_CHECK(block_processor_); |
+ |
+ // block_length_ power of 2? |
+ RTC_CHECK_EQ(0u, block_length_ & (block_length_ - 1)); |
+} |
+ |
+void LappedTransform::ProcessChunk(const float* const* in_chunk, |
+ float* const* out_chunk) { |
+ blocker_.ProcessChunk(in_chunk, chunk_length_, num_in_channels_, |
+ num_out_channels_, out_chunk); |
+} |
+ |
+} // namespace webrtc |