From a43953a5180828dda982663ff0d962edc0d4ee6f Mon Sep 17 00:00:00 2001
From: Hanna Silen <silen@webrtc.org>
Date: Wed, 2 Jun 2021 17:13:24 +0200
Subject: [PATCH] Add ClippingPredictor config in AudioProcessing config

Bug: webrtc:12774
Change-Id: Id8cdb6b5499a22cbca40d424cf936f81c1e7d8d7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/221104
Reviewed-by: Minyue Li <minyue@webrtc.org>
Commit-Queue: Hanna Silen <silen@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34204}
---
 .../include/audio_processing.cc               | 35 +++++++++++++++++--
 .../include/audio_processing.h                | 31 ++++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/modules/audio_processing/include/audio_processing.cc b/modules/audio_processing/include/audio_processing.cc
index 29dcd66040..44a90d6e76 100644
--- a/modules/audio_processing/include/audio_processing.cc
+++ b/modules/audio_processing/include/audio_processing.cc
@@ -81,7 +81,19 @@ bool Agc1Config::operator==(const Agc1Config& rhs) const {
          analog_lhs.clipped_level_step == analog_rhs.clipped_level_step &&
          analog_lhs.clipped_ratio_threshold ==
              analog_rhs.clipped_ratio_threshold &&
-         analog_lhs.clipped_wait_frames == analog_rhs.clipped_wait_frames;
+         analog_lhs.clipped_wait_frames == analog_rhs.clipped_wait_frames &&
+         analog_lhs.clipping_predictor.mode ==
+             analog_rhs.clipping_predictor.mode &&
+         analog_lhs.clipping_predictor.window_length ==
+             analog_rhs.clipping_predictor.window_length &&
+         analog_lhs.clipping_predictor.reference_window_length ==
+             analog_rhs.clipping_predictor.reference_window_length &&
+         analog_lhs.clipping_predictor.reference_window_delay ==
+             analog_rhs.clipping_predictor.reference_window_delay &&
+         analog_lhs.clipping_predictor.clipping_threshold ==
+             analog_rhs.clipping_predictor.clipping_threshold &&
+         analog_lhs.clipping_predictor.crest_factor_margin ==
+             analog_rhs.clipping_predictor.crest_factor_margin;
 }
 
 bool Agc2Config::AdaptiveDigital::operator==(
@@ -167,7 +179,26 @@ std::string AudioProcessing::Config::ToString() const {
       << gain_controller1.analog_gain_controller.clipped_ratio_threshold
       << ", clipped_wait_frames: "
       << gain_controller1.analog_gain_controller.clipped_wait_frames
-      << " }}, gain_controller2: { enabled: " << gain_controller2.enabled
+      << ", clipping_predictor:  { enabled: "
+      << gain_controller1.analog_gain_controller.clipping_predictor.enabled
+      << ", mode: "
+      << gain_controller1.analog_gain_controller.clipping_predictor.mode
+      << ", window_length: "
+      << gain_controller1.analog_gain_controller.clipping_predictor
+             .window_length
+      << ", reference_window_length: "
+      << gain_controller1.analog_gain_controller.clipping_predictor
+             .reference_window_length
+      << ", reference_window_delay: "
+      << gain_controller1.analog_gain_controller.clipping_predictor
+             .reference_window_delay
+      << ", clipping_threshold: "
+      << gain_controller1.analog_gain_controller.clipping_predictor
+             .clipping_threshold
+      << ", crest_factor_margin: "
+      << gain_controller1.analog_gain_controller.clipping_predictor
+             .crest_factor_margin
+      << " }}}, gain_controller2: { enabled: " << gain_controller2.enabled
       << ", fixed_digital: { gain_db: "
       << gain_controller2.fixed_digital.gain_db
       << " }, adaptive_digital: { enabled: "
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 66220979dd..1f3c19c464 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -343,6 +343,37 @@ class RTC_EXPORT AudioProcessing : public rtc::RefCountInterface {
         // Time in frames to wait after a clipping event before checking again.
         // Limited to values higher than 0.
         int clipped_wait_frames = 300;
+
+        // Enables clipping prediction functionality.
+        struct ClippingPredictor {
+          bool enabled = false;
+          enum Mode {
+            // Sets clipping prediction for clipping event prediction with fixed
+            // step estimation.
+            kClippingEventPrediction,
+            // Sets clipping prediction for clipped peak estimation with
+            // adaptive step estimation.
+            kAdaptiveStepClippingPeakPrediction,
+            // Sets clipping prediction for clipped peak estimation with fixed
+            // step estimation.
+            kFixedStepClippingPeakPrediction,
+          };
+          Mode mode = kClippingEventPrediction;
+          // Number of frames in the sliding analysis window. Limited to values
+          // higher than zero.
+          int window_length = 5;
+          // Number of frames in the sliding reference window. Limited to values
+          // higher than zero.
+          int reference_window_length = 5;
+          // Number of frames the reference window is delayed. Limited to values
+          // zero and higher. An additional requirement:
+          // |window_length < reference_window_length + reference_window_delay|.
+          int reference_window_delay = 5;
+          // Clipping predictor ste estimation threshold (dB).
+          float clipping_threshold = -1.0f;
+          // Crest factor drop threshold (dB).
+          float crest_factor_margin = 3.0f;
+        } clipping_predictor;
       } analog_gain_controller;
     } gain_controller1;