Prefer external video codecs over internal in SDP

webrtc/media/engine/webrtcvideoengine_unittest.cc

 /*
  *  Copyright (c) 2004 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 801 matching lines @@
 
 // Test that external codecs are added to the end of the supported codec list.
 TEST_F(WebRtcVideoEngineTest, ReportSupportedExternalCodecs) {
   cricket::FakeWebRtcVideoEncoderFactory encoder_factory;
   encoder_factory.AddSupportedVideoCodecType("FakeExternalCodec");
   engine_.SetExternalEncoderFactory(&encoder_factory);
   engine_.Init();
 
   std::vector<cricket::VideoCodec> codecs(engine_.codecs());
   ASSERT_GE(codecs.size(), 2u);
-  cricket::VideoCodec internal_codec = codecs.front();
-  cricket::VideoCodec external_codec = codecs.back();
+  cricket::VideoCodec external_codec = codecs[0];
+  cricket::VideoCodec internal_codec = codecs[1];
 
-  // The external codec will appear last in the vector.
+  // The external codec will appear first in the vector.
+  EXPECT_EQ("FakeExternalCodec", external_codec.name);
   EXPECT_EQ("VP8", internal_codec.name);
-  EXPECT_EQ("FakeExternalCodec", external_codec.name);
 }
 
 // Test that an external codec that was added after the engine was initialized
 // does show up in the codec list after it was added.
 TEST_F(WebRtcVideoEngineTest, ReportSupportedExternalCodecsWithAddedCodec) {
   // Set up external encoder factory with first codec, and initialize engine.
   cricket::FakeWebRtcVideoEncoderFactory encoder_factory;
   encoder_factory.AddSupportedVideoCodecType("FakeExternalCodec1");
   engine_.SetExternalEncoderFactory(&encoder_factory);
   engine_.Init();
 
-  // The first external codec will appear last in the vector.
+  // The first external codec will appear first in the vector.
   std::vector<cricket::VideoCodec> codecs_before(engine_.codecs());
-  EXPECT_EQ("FakeExternalCodec1", codecs_before.back().name);
+  EXPECT_EQ("FakeExternalCodec1", codecs_before.front().name);
 
   // Add second codec.
   encoder_factory.AddSupportedVideoCodecType("FakeExternalCodec2");
   std::vector<cricket::VideoCodec> codecs_after(engine_.codecs());
   EXPECT_EQ(codecs_before.size() + 1, codecs_after.size());
-  EXPECT_EQ("FakeExternalCodec2", codecs_after.back().name);
+  EXPECT_EQ("FakeExternalCodec2", codecs_after[1].name);
 }
 
 TEST_F(WebRtcVideoEngineTest, RegisterExternalDecodersIfSupported) {
   cricket::FakeWebRtcVideoDecoderFactory decoder_factory;
   decoder_factory.AddSupportedVideoCodecType(webrtc::kVideoCodecVP8);
   cricket::VideoRecvParameters parameters;
   parameters.codecs.push_back(GetEngineCodec("VP8"));
 
   std::unique_ptr<VideoMediaChannel> channel(
       SetUpForExternalDecoderFactory(&decoder_factory, parameters.codecs));
@@ skipping 201 matching lines @@
     engine_.Init();
     channel_.reset(engine_.CreateChannel(fake_call_.get(), GetMediaConfig(),
                                          VideoOptions()));
     channel_->OnReadyToSend(true);
     last_ssrc_ = 123;
     send_parameters_.codecs = engine_.codecs();
     recv_parameters_.codecs = engine_.codecs();
     ASSERT_TRUE(channel_->SetSendParameters(send_parameters_));
   }
 
+  void TearDown() override {
+    channel_ = nullptr;
+    fake_call_ = nullptr;
+  }
+
  protected:
   FakeVideoSendStream* AddSendStream() {
     return AddSendStream(StreamParams::CreateLegacy(++last_ssrc_));
   }
 
   FakeVideoSendStream* AddSendStream(const StreamParams& sp) {
     size_t num_streams = fake_call_->GetVideoSendStreams().size();
     EXPECT_TRUE(channel_->AddSendStream(sp));
     std::vector<FakeVideoSendStream*> streams =
         fake_call_->GetVideoSendStreams();
@@ skipping 889 matching lines @@
   void SetUp() override {
     engine_.SetExternalEncoderFactory(&encoder_factory_);
 
     WebRtcVideoChannelTest::SetUp();
   }
 
   void TearDown() override {
     // Remove references to encoder_factory_ since this will be destroyed
     // before channel_ and engine_.
     ASSERT_TRUE(channel_->SetSendParameters(send_parameters_));
+
+    WebRtcVideoChannelTest::TearDown();
   }
 
   cricket::FakeWebRtcVideoEncoderFactory encoder_factory_;
 };
 
 TEST_F(Vp9SettingsTest, VerifyVp9SpecificSettings) {
   cricket::VideoSendParameters parameters;
   parameters.codecs.push_back(GetEngineCodec("VP9"));
   ASSERT_TRUE(channel_->SetSendParameters(parameters));
 
@@ skipping 2693 matching lines @@
 
 TEST_F(WebRtcVideoChannelSimulcastTest,
        NoSimulcastScreenshareWithoutConference) {
   webrtc::test::ScopedFieldTrials override_field_trials_(
       "WebRTC-SimulcastScreenshare/Enabled/");
   VerifySimulcastSettings(cricket::VideoCodec("VP8"), 1280, 720, 3, 1, true,
                           false);
 }
 
 }  // namespace cricket