Make the BWE threshold adaptive.

This improves self-fairness and competing for resources with TCP flows.

BUG=4711

Review URL: https://codereview.webrtc.org/1151603008

Cr-Commit-Position: refs/heads/master@{#9545}

webrtc/modules/remote_bitrate_estimator/test/bwe.h

@@ -80,7 +80,7 @@ class LinkedSet {
   std::list<PacketIdentifierNode*> list_;
 };
 
-const int kMinBitrateKbps = 150;
+const int kMinBitrateKbps = 20;
 const int kMaxBitrateKbps = 3000;
 
 class BweSender : public Module {

webrtc/modules/remote_bitrate_estimator/test/bwe_test.cc

@@ -254,7 +254,7 @@ void BweTest::RunFairnessTest(BandwidthEstimatorType bwe_type,
   std::vector<VideoSource*> sources;
   std::vector<PacketSender*> senders;
 
-  size_t i = 0;
+  size_t i = 1;
   for (int media_flow : media_flow_ids) {
     // Streams started 20 seconds apart to give them different advantage when
     // competing for the bandwidth.

webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc

@@ -94,33 +94,6 @@ class RateCounter {
   std::list<TimeSizePair> window_;
 };
 
-Random::Random(uint32_t seed)
-    : a_(0x531FDB97 ^ seed),
-      b_(0x6420ECA8 + seed) {
-}
-
-float Random::Rand() {
-  const float kScale = 1.0f / 0xffffffff;
-  float result = kScale * b_;
-  a_ ^= b_;
-  b_ += a_;
-  return result;
-}
-
-int Random::Gaussian(int mean, int standard_deviation) {
-  // Creating a Normal distribution variable from two independent uniform
-  // variables based on the Box-Muller transform, which is defined on the
-  // interval (0, 1], hence the mask+add below.
-  const double kPi = 3.14159265358979323846;
-  const double kScale = 1.0 / 0x80000000ul;
-  double u1 = kScale * ((a_ & 0x7ffffffful) + 1);
-  double u2 = kScale * ((b_ & 0x7ffffffful) + 1);
-  a_ ^= b_;
-  b_ += a_;
-  return static_cast<int>(mean + standard_deviation *
-      sqrt(-2 * log(u1)) * cos(2 * kPi * u2));
-}
-
 Packet::Packet()
     : flow_id_(0), creation_time_us_(-1), send_time_us_(-1), payload_size_(0) {
 }

webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.h

@@ -28,6 +28,7 @@
 #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/bwe_test_logging.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/packet.h"
+#include "webrtc/modules/remote_bitrate_estimator/test/random.h"
 #include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp_defines.h"
 #include "webrtc/system_wrappers/interface/clock.h"
 
@@ -142,26 +143,6 @@ template<typename T> class Stats {
   T max_;
 };
 
-class Random {
- public:
-  explicit Random(uint32_t seed);
-
-  // Return pseudo random number in the interval [0.0, 1.0].
-  float Rand();
-
-  // Normal Distribution.
-  int Gaussian(int mean, int standard_deviation);
-
-  // TODO(solenberg): Random from histogram.
-  // template<typename T> int Distribution(const std::vector<T> histogram) {
-
- private:
-  uint32_t a_;
-  uint32_t b_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(Random);
-};
-
 bool IsTimeSorted(const Packets& packets);
 
 class PacketProcessor;

webrtc/modules/remote_bitrate_estimator/test/random.cc

@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2015 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.
+ */
+
+#include "webrtc/modules/remote_bitrate_estimator/test/random.h"
+
+#include <math.h>
+
+namespace webrtc {
+
+Random::Random(uint32_t seed) : a_(0x531FDB97 ^ seed), b_(0x6420ECA8 + seed) {
+}
+
+float Random::Rand() {
+  const float kScale = 1.0f / 0xffffffff;
+  float result = kScale * b_;
+  a_ ^= b_;
+  b_ += a_;
+  return result;
+}
+
+int Random::Gaussian(int mean, int standard_deviation) {
+  // Creating a Normal distribution variable from two independent uniform
+  // variables based on the Box-Muller transform, which is defined on the
+  // interval (0, 1], hence the mask+add below.
+  const double kPi = 3.14159265358979323846;
+  const double kScale = 1.0 / 0x80000000ul;
+  double u1 = kScale * ((a_ & 0x7ffffffful) + 1);
+  double u2 = kScale * ((b_ & 0x7ffffffful) + 1);
+  a_ ^= b_;
+  b_ += a_;
+  return static_cast<int>(
+      mean + standard_deviation * sqrt(-2 * log(u1)) * cos(2 * kPi * u2));
+}
+}  // namespace webrtc

webrtc/modules/remote_bitrate_estimator/test/random.h

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2015 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 WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_TEST_RANDOM_H_
+#define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_TEST_RANDOM_H_
+
+#include "webrtc/typedefs.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace webrtc {
+
+class Random {
+ public:
+  explicit Random(uint32_t seed);
+
+  // Return pseudo-random number in the interval [0.0, 1.0].
+  float Rand();
+
+  // Normal Distribution.
+  int Gaussian(int mean, int standard_deviation);
+
+  // TODO(solenberg): Random from histogram.
+  // template<typename T> int Distribution(const std::vector<T> histogram) {
+
+ private:
+  uint32_t a_;
+  uint32_t b_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Random);
+};
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_TEST_RANDOM_H_