Update to current webrtc library

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

webrtc/audio/utility/audio_frame_operations.h

@@ -0,0 +1,105 @@
+/*
+ *  Copyright (c) 2012 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 AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_
+#define AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "api/audio/audio_frame.h"
+#include "rtc_base/deprecation.h"
+
+namespace webrtc {
+
+// TODO(andrew): consolidate this with utility.h and audio_frame_manipulator.h.
+// Change reference parameters to pointers. Consider using a namespace rather
+// than a class.
+class AudioFrameOperations {
+ public:
+  // Add samples in |frame_to_add| with samples in |result_frame|
+  // putting the results in |results_frame|.  The fields
+  // |vad_activity_| and |speech_type_| of the result frame are
+  // updated. If |result_frame| is empty (|samples_per_channel_|==0),
+  // the samples in |frame_to_add| are added to it.  The number of
+  // channels and number of samples per channel must match except when
+  // |result_frame| is empty.
+  static void Add(const AudioFrame& frame_to_add, AudioFrame* result_frame);
+
+  // |frame.num_channels_| will be updated. This version checks for sufficient
+  // buffer size and that |num_channels_| is mono. Use UpmixChannels
+  // instead. TODO(bugs.webrtc.org/8649): remove.
+  RTC_DEPRECATED static int MonoToStereo(AudioFrame* frame);
+
+  // |frame.num_channels_| will be updated. This version checks that
+  // |num_channels_| is stereo. Use DownmixChannels
+  // instead. TODO(bugs.webrtc.org/8649): remove.
+  RTC_DEPRECATED static int StereoToMono(AudioFrame* frame);
+
+  // Downmixes 4 channels |src_audio| to stereo |dst_audio|. This is an in-place
+  // operation, meaning |src_audio| and |dst_audio| may point to the same
+  // buffer.
+  static void QuadToStereo(const int16_t* src_audio,
+                           size_t samples_per_channel,
+                           int16_t* dst_audio);
+
+  // |frame.num_channels_| will be updated. This version checks that
+  // |num_channels_| is 4 channels.
+  static int QuadToStereo(AudioFrame* frame);
+
+  // Downmixes |src_channels| |src_audio| to |dst_channels| |dst_audio|.
+  // This is an in-place operation, meaning |src_audio| and |dst_audio|
+  // may point to the same buffer. Supported channel combinations are
+  // Stereo to Mono, Quad to Mono, and Quad to Stereo.
+  static void DownmixChannels(const int16_t* src_audio,
+                              size_t src_channels,
+                              size_t samples_per_channel,
+                              size_t dst_channels,
+                              int16_t* dst_audio);
+
+  // |frame.num_channels_| will be updated. This version checks that
+  // |num_channels_| and |dst_channels| are valid and performs relevant downmix.
+  // Supported channel combinations are N channels to Mono, and Quad to Stereo.
+  static void DownmixChannels(size_t dst_channels, AudioFrame* frame);
+
+  // |frame.num_channels_| will be updated. This version checks that
+  // |num_channels_| and |dst_channels| are valid and performs relevant
+  // downmix. Supported channel combinations are Mono to N
+  // channels. The single channel is replicated.
+  static void UpmixChannels(size_t target_number_of_channels,
+                            AudioFrame* frame);
+
+  // Swap the left and right channels of |frame|. Fails silently if |frame| is
+  // not stereo.
+  static void SwapStereoChannels(AudioFrame* frame);
+
+  // Conditionally zero out contents of |frame| for implementing audio mute:
+  //  |previous_frame_muted| &&  |current_frame_muted| - Zero out whole frame.
+  //  |previous_frame_muted| && !|current_frame_muted| - Fade-in at frame start.
+  // !|previous_frame_muted| &&  |current_frame_muted| - Fade-out at frame end.
+  // !|previous_frame_muted| && !|current_frame_muted| - Leave frame untouched.
+  static void Mute(AudioFrame* frame,
+                   bool previous_frame_muted,
+                   bool current_frame_muted);
+
+  // Zero out contents of frame.
+  static void Mute(AudioFrame* frame);
+
+  // Halve samples in |frame|.
+  static void ApplyHalfGain(AudioFrame* frame);
+
+  static int Scale(float left, float right, AudioFrame* frame);
+
+  static int ScaleWithSat(float scale, AudioFrame* frame);
+};
+
+}  // namespace webrtc
+
+#endif  // AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_