From 56b3a00d52c7adaa7ff987bdb07709e35357d2aa Mon Sep 17 00:00:00 2001
From: Hanna Silen <silen@webrtc.org>
Date: Fri, 30 Sep 2022 19:06:04 +0200
Subject: [PATCH] MonoAgc: Move error computation outside UpdateGain

Bug: webrtc:7494
Change-Id: If95f44bf404316b8fadf28e3fd01a25f87c96a5b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/277625
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Commit-Queue: Hanna Silen <silen@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38282}
---
 .../agc/agc_manager_direct.cc                 | 23 ++++++++++---------
 .../audio_processing/agc/agc_manager_direct.h |  2 +-
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/modules/audio_processing/agc/agc_manager_direct.cc b/modules/audio_processing/agc/agc_manager_direct.cc
index 6633dccde6..8203bc6646 100644
--- a/modules/audio_processing/agc/agc_manager_direct.cc
+++ b/modules/audio_processing/agc/agc_manager_direct.cc
@@ -215,7 +215,12 @@ void MonoAgc::Process(rtc::ArrayView<const int16_t> audio) {
 
   agc_->Process(audio);
 
-  UpdateGain();
+  // Update gain if `agc_` has an RMS error estimate ready.
+  int rms_error = 0;
+  if (agc_->GetRmsErrorDb(&rms_error)) {
+    UpdateGain(rms_error);
+  }
+
   if (!disable_digital_adaptive_) {
     UpdateCompressor();
   }
@@ -342,19 +347,15 @@ int MonoAgc::CheckVolumeAndReset() {
   return 0;
 }
 
-// Requests the RMS error from AGC and distributes the required gain change
-// between the digital compression stage and volume slider. We use the
-// compressor first, providing a slack region around the current slider
-// position to reduce movement.
+// Distributes the required gain change between the digital compression stage
+// and volume slider. We use the compressor first, providing a slack region
+// around the current slider position to reduce movement.
 //
 // If the slider needs to be moved, we check first if the user has adjusted
 // it, in which case we take no action and cache the updated level.
-void MonoAgc::UpdateGain() {
-  int rms_error = 0;
-  if (!agc_->GetRmsErrorDb(&rms_error)) {
-    // No error update ready.
-    return;
-  }
+void MonoAgc::UpdateGain(int rms_error_db) {
+  int rms_error = rms_error_db;
+
   // The compressor will always add at least kMinCompressionGain. In effect,
   // this adjusts our target gain upward by the same amount and rms_error
   // needs to reflect that.
diff --git a/modules/audio_processing/agc/agc_manager_direct.h b/modules/audio_processing/agc/agc_manager_direct.h
index 498e486bf1..5c29ddf204 100644
--- a/modules/audio_processing/agc/agc_manager_direct.h
+++ b/modules/audio_processing/agc/agc_manager_direct.h
@@ -228,7 +228,7 @@ class MonoAgc {
   void SetMaxLevel(int level);
 
   int CheckVolumeAndReset();
-  void UpdateGain();
+  void UpdateGain(int rms_error_db);
   void UpdateCompressor();
 
   const int min_mic_level_;