Fix for video protection_bitrate in BWE with overhead.

webrtc/video/video_send_stream_tests.cc

 /*
  *  Copyright (c) 2013 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 <algorithm>  // max
@@ skipping 3154 matching lines @@
 TEST_F(VideoSendStreamTest,
        RequestSourceRotateIfVideoOrientationExtensionNotSupported) {
   TestRequestSourceRotateVideo(false);
 }
 
 TEST_F(VideoSendStreamTest,
        DoNotRequestsRotationIfVideoOrientationExtensionSupported) {
   TestRequestSourceRotateVideo(true);
 }
 
-// Flaky on Win32 Release: http://crbug.com/webrtc/6886
-#if defined(WEBRTC_WIN)
-#define MAYBE_RemoveOverheadFromBandwidth DISABLED_RemoveOverheadFromBandwidth
-#else
-#define MAYBE_RemoveOverheadFromBandwidth RemoveOverheadFromBandwidth
-#endif
 // This test verifies that overhead is removed from the bandwidth estimate by
 // testing that the maximum possible target payload rate is smaller than the
 // maximum bandwidth estimate by the overhead rate.
-TEST_F(VideoSendStreamTest, MAYBE_RemoveOverheadFromBandwidth) {
+TEST_F(VideoSendStreamTest, RemoveOverheadFromBandwidth) {
   test::ScopedFieldTrials override_field_trials(
       "WebRTC-SendSideBwe-WithOverhead/Enabled/");
   class RemoveOverheadFromBandwidthTest : public test::EndToEndTest,
                                           public test::FakeEncoder {
    public:
     RemoveOverheadFromBandwidthTest()
         : EndToEndTest(test::CallTest::kDefaultTimeoutMs),
           FakeEncoder(Clock::GetRealTimeClock()),
           call_(nullptr),
-          max_bitrate_kbps_(0) {}
+          max_bitrate_bps_(0),
+          first_packet_send_(false),
+          bitrate_changed_event_(false, false) {}
 
     int32_t SetRateAllocation(const BitrateAllocation& bitrate,
                               uint32_t frameRate) override {
       rtc::CritScope lock(&crit_);
-      if (max_bitrate_kbps_ < bitrate.get_sum_kbps())
-        max_bitrate_kbps_ = bitrate.get_sum_kbps();
+      if (first_packet_send_) {
+        max_bitrate_bps_ = bitrate.get_sum_bps();
+        bitrate_changed_event_.Set();
+      }
       return FakeEncoder::SetRateAllocation(bitrate, frameRate);
     }
 
     void OnCallsCreated(Call* sender_call, Call* receiver_call) override {
       call_ = sender_call;
     }
 
     void ModifyVideoConfigs(
         VideoSendStream::Config* send_config,
         std::vector<VideoReceiveStream::Config>* receive_configs,
         VideoEncoderConfig* encoder_config) override {
       send_config->rtp.max_packet_size = 1200;
       send_config->encoder_settings.encoder = this;
       EXPECT_FALSE(send_config->rtp.extensions.empty());
     }
 
+    Action OnSendRtp(const uint8_t* packet, size_t length) override {
+      rtc::CritScope lock(&crit_);
+      // Wait for the first sent packet so that videosendstream know's

[minyue-webrtc, 2017/01/26 09:28:50]

knows

And does this comment belong to line 3196

[michaelt, 2017/01/26 12:12:54]

Yeap, it would fit better to 3196. 
Moved it an fixed "knows".

+      // rtp_overhead.
+      first_packet_send_ = true;
+      return SEND_PACKET;
+    }
+
     void PerformTest() override {
       call_->OnTransportOverheadChanged(webrtc::MediaType::VIDEO, 20);
       Call::Config::BitrateConfig bitrate_config;
-      constexpr int kStartBitrateBps = 50000;
+      constexpr int kStartBitrateBps = 60000;
       constexpr int kMaxBitrateBps = 60000;
+      constexpr int kMinBitrateBps = 10000;
       bitrate_config.start_bitrate_bps = kStartBitrateBps;
       bitrate_config.max_bitrate_bps = kMaxBitrateBps;
+      bitrate_config.min_bitrate_bps = kMinBitrateBps;

[minyue-webrtc, 2017/01/26 09:28:50]

how did it work when no min was used.

[michaelt, 2017/01/26 12:12:54]

When i see this right, then default min was used in the case it not defined. But
I think this way its cleaner.  

       call_->SetBitrateConfig(bitrate_config);
 
       // At a bitrate of 60kbps with a packet size of 1200B video and an
-      // overhead of 40B per packet video produces 2kbps overhead.
-      // So with a BWE should reach 58kbps but not 60kbps.
-      Wait();
+      // overhead of 40B per packet video produces 2240bps overhead.
+      // So the encoder BW should be set to 57760bps.
+      bitrate_changed_event_.Wait(VideoSendStreamTest::kDefaultTimeoutMs);
       {
         rtc::CritScope lock(&crit_);
-        EXPECT_EQ(58u, max_bitrate_kbps_);
+        EXPECT_EQ(57760u, max_bitrate_bps_);
       }
     }
 
    private:
     Call* call_;
     rtc::CriticalSection crit_;
-    uint32_t max_bitrate_kbps_ GUARDED_BY(&crit_);
+    uint32_t max_bitrate_bps_ GUARDED_BY(&crit_);
+    bool first_packet_send_ GUARDED_BY(&crit_);

[minyue-webrtc, 2017/01/26 09:28:50]

send -> sent

[michaelt, 2017/01/26 12:12:54]

Done.

+    rtc::Event bitrate_changed_event_;
   } test;
 
   RunBaseTest(&test);
 }
 
 }  // namespace webrtc