Update to current webrtc library

This is from the upstream library commit id
3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium
88.0.4290.1.

webrtc/modules/audio_processing/transient/transient_suppressor_impl.h

@@ -0,0 +1,123 @@
+/*
+ *  Copyright (c) 2013 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_TRANSIENT_TRANSIENT_SUPPRESSOR_IMPL_H_
+#define MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_IMPL_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+
+#include "modules/audio_processing/transient/transient_suppressor.h"
+#include "rtc_base/gtest_prod_util.h"
+
+namespace webrtc {
+
+class TransientDetector;
+
+// Detects transients in an audio stream and suppress them using a simple
+// restoration algorithm that attenuates unexpected spikes in the spectrum.
+class TransientSuppressorImpl : public TransientSuppressor {
+ public:
+  TransientSuppressorImpl();
+  ~TransientSuppressorImpl() override;
+
+  int Initialize(int sample_rate_hz,
+                 int detector_rate_hz,
+                 int num_channels) override;
+
+  // Processes a |data| chunk, and returns it with keystrokes suppressed from
+  // it. The float format is assumed to be int16 ranged. If there are more than
+  // one channel, the chunks are concatenated one after the other in |data|.
+  // |data_length| must be equal to |data_length_|.
+  // |num_channels| must be equal to |num_channels_|.
+  // A sub-band, ideally the higher, can be used as |detection_data|. If it is
+  // NULL, |data| is used for the detection too. The |detection_data| is always
+  // assumed mono.
+  // If a reference signal (e.g. keyboard microphone) is available, it can be
+  // passed in as |reference_data|. It is assumed mono and must have the same
+  // length as |data|. NULL is accepted if unavailable.
+  // This suppressor performs better if voice information is available.
+  // |voice_probability| is the probability of voice being present in this chunk
+  // of audio. If voice information is not available, |voice_probability| must
+  // always be set to 1.
+  // |key_pressed| determines if a key was pressed on this audio chunk.
+  // Returns 0 on success and -1 otherwise.
+  int Suppress(float* data,
+               size_t data_length,
+               int num_channels,
+               const float* detection_data,
+               size_t detection_length,
+               const float* reference_data,
+               size_t reference_length,
+               float voice_probability,
+               bool key_pressed) override;
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(TransientSuppressorImplTest,
+                           TypingDetectionLogicWorksAsExpectedForMono);
+  void Suppress(float* in_ptr, float* spectral_mean, float* out_ptr);
+
+  void UpdateKeypress(bool key_pressed);
+  void UpdateRestoration(float voice_probability);
+
+  void UpdateBuffers(float* data);
+
+  void HardRestoration(float* spectral_mean);
+  void SoftRestoration(float* spectral_mean);
+
+  std::unique_ptr<TransientDetector> detector_;
+
+  size_t data_length_;
+  size_t detection_length_;
+  size_t analysis_length_;
+  size_t buffer_delay_;
+  size_t complex_analysis_length_;
+  int num_channels_;
+  // Input buffer where the original samples are stored.
+  std::unique_ptr<float[]> in_buffer_;
+  std::unique_ptr<float[]> detection_buffer_;
+  // Output buffer where the restored samples are stored.
+  std::unique_ptr<float[]> out_buffer_;
+
+  // Arrays for fft.
+  std::unique_ptr<size_t[]> ip_;
+  std::unique_ptr<float[]> wfft_;
+
+  std::unique_ptr<float[]> spectral_mean_;
+
+  // Stores the data for the fft.
+  std::unique_ptr<float[]> fft_buffer_;
+
+  std::unique_ptr<float[]> magnitudes_;
+
+  const float* window_;
+
+  std::unique_ptr<float[]> mean_factor_;
+
+  float detector_smoothed_;
+
+  int keypress_counter_;
+  int chunks_since_keypress_;
+  bool detection_enabled_;
+  bool suppression_enabled_;
+
+  bool use_hard_restoration_;
+  int chunks_since_voice_change_;
+
+  uint32_t seed_;
+
+  bool using_reference_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_IMPL_H_