Add field trial to update quality scaler QP thresholds for Android HW encoder.

webrtc/modules/video_coding/utility/quality_scaler.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 94 matching lines @@
       observer_(observer),
       sampling_period_ms_(sampling_period),
       fast_rampup_(true),
       // Arbitrarily choose size based on 30 fps for 5 seconds.
       average_qp_(5 * 30),
       framedrop_percent_(5 * 30),
       thresholds_(thresholds) {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   RTC_DCHECK(observer_ != nullptr);
   check_qp_task_ = new CheckQPTask(this);
+  LOG(LS_INFO) << "QP thresholds: low: " << thresholds_.low
+               << ", high: " << thresholds_.high;
 }
 
 QualityScaler::~QualityScaler() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   check_qp_task_->Stop();
 }
 
 int64_t QualityScaler::GetSamplingPeriodMs() const {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   return fast_rampup_ ? sampling_period_ms_
                       : (sampling_period_ms_ * kSamplePeriodScaleFactor);
 }
 
 void QualityScaler::ReportDroppedFrame() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   framedrop_percent_.AddSample(100);
 }
 
 void QualityScaler::ReportQP(int qp) {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   framedrop_percent_.AddSample(0);
   average_qp_.AddSample(qp);
 }
 
 void QualityScaler::CheckQP() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   // Should be set through InitEncode -> Should be set by now.
   RTC_DCHECK_GE(thresholds_.low, 0);
-  LOG(LS_INFO) << "Checking if average QP exceeds threshold";
   // Check if we should scale down due to high frame drop.
   const rtc::Optional<int> drop_rate = framedrop_percent_.GetAverage();
   if (drop_rate && *drop_rate >= kFramedropPercentThreshold) {
     ReportQPHigh();
     return;
   }
 
   // Check if we should scale up or down based on QP.
   const rtc::Optional<int> avg_qp = average_qp_.GetAverage();
-  if (avg_qp && *avg_qp > thresholds_.high) {
-    ReportQPHigh();
-    return;
-  }
-  if (avg_qp && *avg_qp <= thresholds_.low) {
-    // QP has been low. We want to try a higher resolution.
-    ReportQPLow();
-    return;
+  if (avg_qp) {
+    LOG(LS_INFO) << "Checking average QP " << *avg_qp;
+    if (*avg_qp > thresholds_.high) {
+      ReportQPHigh();
+      return;
+    }
+    if (*avg_qp <= thresholds_.low) {
+      // QP has been low. We want to try a higher resolution.
+      ReportQPLow();
+      return;
+    }
   }
 }
 
 void QualityScaler::ReportQPLow() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
-  LOG(LS_INFO) << "QP has been low, asking for higher resolution.";
   ClearSamples();
   observer_->AdaptUp(AdaptationObserverInterface::AdaptReason::kQuality);
 }
 
 void QualityScaler::ReportQPHigh() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
-  LOG(LS_INFO) << "QP has been high , asking for lower resolution.";
   ClearSamples();
   observer_->AdaptDown(AdaptationObserverInterface::AdaptReason::kQuality);
   // If we've scaled down, wait longer before scaling up again.
   if (fast_rampup_) {
     fast_rampup_ = false;
   }
 }
 
 void QualityScaler::ClearSamples() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&task_checker_);
   framedrop_percent_.Reset();
   average_qp_.Reset();
 }
 }  // namespace webrtc