Reland "Refactoring of the noise suppressor and adding true multichannel support"
This is a reland of 87a7b82520b83a6cf42da27cdc46142c2eb6248c
Original change's description:
> Refactoring of the noise suppressor and adding true multichannel support
>
> This CL adds proper multichannel support to the noise suppressor.
> To accomplish that in a safe way, a full refactoring of the noise
> suppressor code has been done.
>
> Due to floating point precision, the changes made are not entirely
> bitexact. They are, however, very close to being bitexact.
>
> As a safety measure, the former noise suppressor code is preserved
> and a kill-switch is added to allow revering to the legacy noise
> suppressor in case issues arise.
>
> Bug: webrtc:10895, b/143344262
> Change-Id: I0b071011b23265ac12e6d4b3956499d122286657
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158407
> Commit-Queue: Per Åhgren <peah@webrtc.org>
> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#29646}
Bug: webrtc:10895, b/143344262
Change-Id: I236f1e67bb0baa4e30908a4cf7a8a7bb55fbced3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158747
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29663}
diff --git a/modules/audio_processing/ns/ns_fft.h b/modules/audio_processing/ns/ns_fft.h
new file mode 100644
index 0000000..539251e
--- /dev/null
+++ b/modules/audio_processing/ns/ns_fft.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2019 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
+#define MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_
+
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/ns/ns_common.h"
+
+namespace webrtc {
+
+// Wrapper class providing 256 point FFT functionality.
+class NrFft {
+ public:
+ NrFft();
+ NrFft(const NrFft&) = delete;
+ NrFft& operator=(const NrFft&) = delete;
+
+ // Transforms the signal from time to frequency domain.
+ void Fft(rtc::ArrayView<float, kFftSize> time_data,
+ rtc::ArrayView<float, kFftSize> real,
+ rtc::ArrayView<float, kFftSize> imag);
+
+ // Transforms the signal from frequency to time domain.
+ void Ifft(rtc::ArrayView<const float> real,
+ rtc::ArrayView<const float> imag,
+ rtc::ArrayView<float> time_data);
+
+ private:
+ std::vector<size_t> bit_reversal_state_;
+ std::vector<float> tables_;
+};
+
+} // namespace webrtc
+
+#endif // MODULES_AUDIO_PROCESSING_NS_NS_FFT_H_