ortc/ortcrtpreceiver_unittest.cc

/*
 *  Copyright 2017 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 <memory>

#include "api/audio_codecs/builtin_audio_decoder_factory.h"
#include "api/audio_codecs/builtin_audio_encoder_factory.h"
#include "media/base/fakemediaengine.h"
#include "ortc/ortcfactory.h"
#include "ortc/testrtpparameters.h"
#include "p2p/base/fakepackettransport.h"
#include "pc/test/fakevideotracksource.h"
#include "rtc_base/gunit.h"

namespace webrtc {

// This test uses an individual RtpReceiver using only the public interface,
// and verifies that it behaves as designed at an API level. Also tests that
// parameters are applied to the audio/video engines as expected. Network and
// media interfaces are faked to isolate what's being tested.
//
// This test shouldn't result any any actual media being sent. That sort of
// test should go in ortcfactory_integrationtest.cc.
class OrtcRtpReceiverTest : public testing::Test {
 public:
  OrtcRtpReceiverTest() : fake_packet_transport_("fake") {
    fake_media_engine_ = new cricket::FakeMediaEngine();
    // Note: This doesn't need to use fake network classes, since we already
    // use FakePacketTransport.
    auto ortc_factory_result = OrtcFactory::Create(
        nullptr, nullptr, nullptr, nullptr, nullptr,
        std::unique_ptr<cricket::MediaEngineInterface>(fake_media_engine_),
        CreateBuiltinAudioEncoderFactory(), CreateBuiltinAudioDecoderFactory());
    ortc_factory_ = ortc_factory_result.MoveValue();
    RtpTransportParameters parameters;
    parameters.rtcp.mux = true;
    auto rtp_transport_result = ortc_factory_->CreateRtpTransport(
        parameters, &fake_packet_transport_, nullptr, nullptr);
    rtp_transport_ = rtp_transport_result.MoveValue();
  }

 protected:
  // Owned by |ortc_factory_|.
  cricket::FakeMediaEngine* fake_media_engine_;
  rtc::FakePacketTransport fake_packet_transport_;
  std::unique_ptr<OrtcFactoryInterface> ortc_factory_;
  std::unique_ptr<RtpTransportInterface> rtp_transport_;
};

// See ortcrtpreceiverinterface.h for the current expectations of what GetTrack
// will return after calls to Receive.
// TODO(deadbeef): Replace this test when the non-standard behavior is fixed
// and GetTrack starts returning the same track for the lifetime of the
// receiver.
TEST_F(OrtcRtpReceiverTest, GetTrack) {
  auto receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  ASSERT_TRUE(receiver_result.ok());
  auto receiver = receiver_result.MoveValue();

  // Track initially expected to be null.
  EXPECT_EQ(nullptr, receiver_result.value().get());

  EXPECT_TRUE(receiver->Receive(MakeMinimalVp8ParametersWithNoSsrc()).ok());
  auto initial_track = receiver->GetTrack();
  EXPECT_NE(nullptr, initial_track);

  // Codec changing but SSRC (or lack thereof) isn't; shouldn't create new track
  EXPECT_TRUE(receiver->Receive(MakeMinimalVp9ParametersWithNoSsrc()).ok());
  EXPECT_EQ(initial_track, receiver->GetTrack());

  // Explicitly set SSRC and expect a different track.
  EXPECT_TRUE(
      receiver->Receive(MakeMinimalVp9ParametersWithSsrc(0xdeadbeef)).ok());
  auto next_track = receiver->GetTrack();
  EXPECT_NE(next_track, initial_track);

  // Deactivating the encoding shouldn't change the track.
  RtpParameters inactive_encoding =
      MakeMinimalVp9ParametersWithSsrc(0xdeadbeef);
  inactive_encoding.encodings[0].active = false;
  EXPECT_TRUE(receiver->Receive(inactive_encoding).ok());
  EXPECT_EQ(next_track, receiver->GetTrack());

  // Removing all encodings *is* expected to clear the track.
  RtpParameters no_encodings = MakeMinimalVp9ParametersWithSsrc(0xdeadbeef);
  no_encodings.encodings.clear();
  EXPECT_TRUE(receiver->Receive(no_encodings).ok());
  EXPECT_EQ(nullptr, receiver->GetTrack());
}

// Currently SetTransport isn't supported. When it is, replace this test with a
// test/tests for it.
TEST_F(OrtcRtpReceiverTest, SetTransportFails) {
  rtc::FakePacketTransport fake_packet_transport("another_transport");
  RtpTransportParameters parameters;
  parameters.rtcp.mux = true;
  auto rtp_transport_result = ortc_factory_->CreateRtpTransport(
      parameters, &fake_packet_transport, nullptr, nullptr);
  auto rtp_transport = rtp_transport_result.MoveValue();

  auto receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto receiver = receiver_result.MoveValue();
  EXPECT_EQ(RTCErrorType::UNSUPPORTED_OPERATION,
            receiver->SetTransport(rtp_transport.get()).type());
}

TEST_F(OrtcRtpReceiverTest, GetTransport) {
  auto result = ortc_factory_->CreateRtpReceiver(cricket::MEDIA_TYPE_AUDIO,
                                                 rtp_transport_.get());
  EXPECT_EQ(rtp_transport_.get(), result.value()->GetTransport());
}

// Test that "Receive" causes the expected parameters to be applied to the media
// engine level, for an audio receiver.
TEST_F(OrtcRtpReceiverTest, ReceiveAppliesAudioParametersToMediaEngine) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();

  // First, create parameters with all the bells and whistles.
  RtpParameters parameters;

  RtpCodecParameters opus_codec;
  opus_codec.name = "opus";
  opus_codec.kind = cricket::MEDIA_TYPE_AUDIO;
  opus_codec.payload_type = 120;
  opus_codec.clock_rate.emplace(48000);
  opus_codec.num_channels.emplace(2);
  opus_codec.parameters["minptime"] = "10";
  opus_codec.rtcp_feedback.emplace_back(RtcpFeedbackType::TRANSPORT_CC);
  parameters.codecs.push_back(std::move(opus_codec));

  // Add two codecs, expecting the first to be used.
  // TODO(deadbeef): Once "codec_payload_type" is supported, use it to select a
  // codec that's not at the top of the list.
  RtpCodecParameters isac_codec;
  isac_codec.name = "ISAC";
  isac_codec.kind = cricket::MEDIA_TYPE_AUDIO;
  isac_codec.payload_type = 110;
  isac_codec.clock_rate.emplace(16000);
  parameters.codecs.push_back(std::move(isac_codec));

  RtpEncodingParameters encoding;
  encoding.ssrc.emplace(0xdeadbeef);
  parameters.encodings.push_back(std::move(encoding));

  parameters.header_extensions.emplace_back(
      "urn:ietf:params:rtp-hdrext:ssrc-audio-level", 3);

  EXPECT_TRUE(audio_receiver->Receive(parameters).ok());

  // Now verify that the parameters were applied to the fake media engine layer
  // that exists below BaseChannel.
  cricket::FakeVoiceMediaChannel* fake_voice_channel =
      fake_media_engine_->GetVoiceChannel(0);
  ASSERT_NE(nullptr, fake_voice_channel);
  EXPECT_TRUE(fake_voice_channel->playout());

  // Verify codec parameters.
  ASSERT_GT(fake_voice_channel->recv_codecs().size(), 0u);
  const cricket::AudioCodec& top_codec = fake_voice_channel->recv_codecs()[0];
  EXPECT_EQ("opus", top_codec.name);
  EXPECT_EQ(120, top_codec.id);
  EXPECT_EQ(48000, top_codec.clockrate);
  EXPECT_EQ(2u, top_codec.channels);
  ASSERT_NE(top_codec.params.end(), top_codec.params.find("minptime"));
  EXPECT_EQ("10", top_codec.params.at("minptime"));

  // Verify encoding parameters.
  ASSERT_EQ(1u, fake_voice_channel->recv_streams().size());
  const cricket::StreamParams& recv_stream =
      fake_voice_channel->recv_streams()[0];
  EXPECT_EQ(1u, recv_stream.ssrcs.size());
  EXPECT_EQ(0xdeadbeef, recv_stream.first_ssrc());

  // Verify header extensions.
  ASSERT_EQ(1u, fake_voice_channel->recv_extensions().size());
  const RtpExtension& extension = fake_voice_channel->recv_extensions()[0];
  EXPECT_EQ("urn:ietf:params:rtp-hdrext:ssrc-audio-level", extension.uri);
  EXPECT_EQ(3, extension.id);
}

// Test that "Receive" causes the expected parameters to be applied to the media
// engine level, for a video receiver.
TEST_F(OrtcRtpReceiverTest, ReceiveAppliesVideoParametersToMediaEngine) {
  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_receiver = video_receiver_result.MoveValue();

  // First, create parameters with all the bells and whistles.
  RtpParameters parameters;

  RtpCodecParameters vp8_codec;
  vp8_codec.name = "VP8";
  vp8_codec.kind = cricket::MEDIA_TYPE_VIDEO;
  vp8_codec.payload_type = 99;
  // Try a couple types of feedback params. "Generic NACK" is a bit of a
  // special case, so test it here.
  vp8_codec.rtcp_feedback.emplace_back(RtcpFeedbackType::CCM,
                                       RtcpFeedbackMessageType::FIR);
  vp8_codec.rtcp_feedback.emplace_back(RtcpFeedbackType::NACK,
                                       RtcpFeedbackMessageType::GENERIC_NACK);
  parameters.codecs.push_back(std::move(vp8_codec));

  RtpCodecParameters vp8_rtx_codec;
  vp8_rtx_codec.name = "rtx";
  vp8_rtx_codec.kind = cricket::MEDIA_TYPE_VIDEO;
  vp8_rtx_codec.payload_type = 100;
  vp8_rtx_codec.parameters["apt"] = "99";
  parameters.codecs.push_back(std::move(vp8_rtx_codec));

  // Add two codecs, expecting the first to be used.
  // TODO(deadbeef): Once "codec_payload_type" is supported, use it to select a
  // codec that's not at the top of the list.
  RtpCodecParameters vp9_codec;
  vp9_codec.name = "VP9";
  vp9_codec.kind = cricket::MEDIA_TYPE_VIDEO;
  vp9_codec.payload_type = 102;
  parameters.codecs.push_back(std::move(vp9_codec));

  RtpCodecParameters vp9_rtx_codec;
  vp9_rtx_codec.name = "rtx";
  vp9_rtx_codec.kind = cricket::MEDIA_TYPE_VIDEO;
  vp9_rtx_codec.payload_type = 103;
  vp9_rtx_codec.parameters["apt"] = "102";
  parameters.codecs.push_back(std::move(vp9_rtx_codec));

  RtpEncodingParameters encoding;
  encoding.ssrc.emplace(0xdeadbeef);
  encoding.rtx.emplace(0xbaadfeed);
  parameters.encodings.push_back(std::move(encoding));

  parameters.header_extensions.emplace_back("urn:3gpp:video-orientation", 4);
  parameters.header_extensions.emplace_back(
      "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay", 6);

  EXPECT_TRUE(video_receiver->Receive(parameters).ok());

  // Now verify that the parameters were applied to the fake media engine layer
  // that exists below BaseChannel.
  cricket::FakeVideoMediaChannel* fake_video_channel =
      fake_media_engine_->GetVideoChannel(0);
  ASSERT_NE(nullptr, fake_video_channel);

  // Verify codec parameters.
  ASSERT_GE(fake_video_channel->recv_codecs().size(), 2u);
  const cricket::VideoCodec& top_codec = fake_video_channel->recv_codecs()[0];
  EXPECT_EQ("VP8", top_codec.name);
  EXPECT_EQ(99, top_codec.id);
  EXPECT_TRUE(top_codec.feedback_params.Has({"ccm", "fir"}));
  EXPECT_TRUE(top_codec.feedback_params.Has(cricket::FeedbackParam("nack")));

  const cricket::VideoCodec& rtx_codec = fake_video_channel->recv_codecs()[1];
  EXPECT_EQ("rtx", rtx_codec.name);
  EXPECT_EQ(100, rtx_codec.id);
  ASSERT_NE(rtx_codec.params.end(), rtx_codec.params.find("apt"));
  EXPECT_EQ("99", rtx_codec.params.at("apt"));

  // Verify encoding parameters.
  ASSERT_EQ(1u, fake_video_channel->recv_streams().size());
  const cricket::StreamParams& recv_stream =
      fake_video_channel->recv_streams()[0];
  EXPECT_EQ(2u, recv_stream.ssrcs.size());
  EXPECT_EQ(0xdeadbeef, recv_stream.first_ssrc());
  uint32_t rtx_ssrc = 0u;
  EXPECT_TRUE(recv_stream.GetFidSsrc(recv_stream.first_ssrc(), &rtx_ssrc));
  EXPECT_EQ(0xbaadfeed, rtx_ssrc);

  // Verify header extensions.
  ASSERT_EQ(2u, fake_video_channel->recv_extensions().size());
  const RtpExtension& extension1 = fake_video_channel->recv_extensions()[0];
  EXPECT_EQ("urn:3gpp:video-orientation", extension1.uri);
  EXPECT_EQ(4, extension1.id);
  const RtpExtension& extension2 = fake_video_channel->recv_extensions()[1];
  EXPECT_EQ("http://www.webrtc.org/experiments/rtp-hdrext/playout-delay",
            extension2.uri);
  EXPECT_EQ(6, extension2.id);
}

// Test changing both the receive codec and SSRC at the same time, and verify
// that the new parameters are applied to the media engine level.
TEST_F(OrtcRtpReceiverTest, CallingReceiveTwiceChangesParameters) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  RTCError error =
      audio_receiver->Receive(MakeMinimalOpusParametersWithSsrc(0x11111111));
  EXPECT_TRUE(error.ok());
  error =
      audio_receiver->Receive(MakeMinimalIsacParametersWithSsrc(0x22222222));
  EXPECT_TRUE(error.ok());

  cricket::FakeVoiceMediaChannel* fake_voice_channel =
      fake_media_engine_->GetVoiceChannel(0);
  ASSERT_NE(nullptr, fake_voice_channel);
  ASSERT_GT(fake_voice_channel->recv_codecs().size(), 0u);
  EXPECT_EQ("ISAC", fake_voice_channel->recv_codecs()[0].name);
  ASSERT_EQ(1u, fake_voice_channel->recv_streams().size());
  EXPECT_EQ(0x22222222u, fake_voice_channel->recv_streams()[0].first_ssrc());

  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_receiver = video_receiver_result.MoveValue();
  error = video_receiver->Receive(MakeMinimalVp8ParametersWithSsrc(0x33333333));
  EXPECT_TRUE(error.ok());
  error = video_receiver->Receive(MakeMinimalVp9ParametersWithSsrc(0x44444444));
  EXPECT_TRUE(error.ok());

  cricket::FakeVideoMediaChannel* fake_video_channel =
      fake_media_engine_->GetVideoChannel(0);
  ASSERT_NE(nullptr, fake_video_channel);
  ASSERT_GT(fake_video_channel->recv_codecs().size(), 0u);
  EXPECT_EQ("VP9", fake_video_channel->recv_codecs()[0].name);
  ASSERT_EQ(1u, fake_video_channel->recv_streams().size());
  EXPECT_EQ(0x44444444u, fake_video_channel->recv_streams()[0].first_ssrc());
}

// Ensure that if the |active| flag of RtpEncodingParameters is set to false,
// playout stops at the media engine level. Note that this is only applicable
// to audio (at least currently).
TEST_F(OrtcRtpReceiverTest, DeactivatingEncodingStopsPlayout) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  RtpParameters parameters = MakeMinimalOpusParameters();
  EXPECT_TRUE(audio_receiver->Receive(parameters).ok());

  // Expect "playout" flag to initially be true.
  cricket::FakeVoiceMediaChannel* fake_voice_channel =
      fake_media_engine_->GetVoiceChannel(0);
  ASSERT_NE(nullptr, fake_voice_channel);
  EXPECT_TRUE(fake_voice_channel->playout());

  // Deactivate encoding and expect it to change to false.
  parameters.encodings[0].active = false;
  EXPECT_TRUE(audio_receiver->Receive(parameters).ok());
  EXPECT_FALSE(fake_voice_channel->playout());
}

// Ensure that calling Receive with an empty list of encodings causes receive
// streams at the media engine level to be cleared.
TEST_F(OrtcRtpReceiverTest,
       CallingReceiveWithEmptyEncodingsClearsReceiveStreams) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  RtpParameters parameters = MakeMinimalOpusParameters();
  EXPECT_TRUE(audio_receiver->Receive(parameters).ok());
  parameters.encodings.clear();
  EXPECT_TRUE(audio_receiver->Receive(parameters).ok());

  cricket::FakeVoiceMediaChannel* fake_voice_channel =
      fake_media_engine_->GetVoiceChannel(0);
  ASSERT_NE(nullptr, fake_voice_channel);
  EXPECT_TRUE(fake_voice_channel->recv_streams().empty());

  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_receiver = video_receiver_result.MoveValue();
  parameters = MakeMinimalVp8Parameters();
  EXPECT_TRUE(video_receiver->Receive(parameters).ok());
  parameters.encodings.clear();
  EXPECT_TRUE(video_receiver->Receive(parameters).ok());

  cricket::FakeVideoMediaChannel* fake_video_channel =
      fake_media_engine_->GetVideoChannel(0);
  ASSERT_NE(nullptr, fake_video_channel);
  EXPECT_TRUE(fake_video_channel->recv_streams().empty());
}

// These errors should be covered by rtpparametersconversion_unittest.cc, but
// we should at least test that those errors are propogated from calls to
// Receive, with a few examples.
TEST_F(OrtcRtpReceiverTest, ReceiveReturnsErrorOnInvalidParameters) {
  auto result = ortc_factory_->CreateRtpReceiver(cricket::MEDIA_TYPE_AUDIO,
                                                 rtp_transport_.get());
  auto receiver = result.MoveValue();
  // CCM feedback missing message type.
  RtpParameters invalid_feedback = MakeMinimalOpusParameters();
  invalid_feedback.codecs[0].rtcp_feedback.emplace_back(RtcpFeedbackType::CCM);
  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER,
            receiver->Receive(invalid_feedback).type());
  // Payload type greater than 127.
  RtpParameters invalid_pt = MakeMinimalOpusParameters();
  invalid_pt.codecs[0].payload_type = 128;
  EXPECT_EQ(RTCErrorType::INVALID_RANGE, receiver->Receive(invalid_pt).type());
  // Duplicate header extension IDs.
  RtpParameters duplicate_ids = MakeMinimalOpusParameters();
  duplicate_ids.header_extensions.emplace_back("foo", 5);
  duplicate_ids.header_extensions.emplace_back("bar", 5);
  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER,
            receiver->Receive(duplicate_ids).type());
}

// Two receivers using the same transport shouldn't be able to use the same
// payload type to refer to different codecs, same header extension IDs to
// refer to different extensions, or same SSRC.
TEST_F(OrtcRtpReceiverTest, ReceiveReturnsErrorOnIdConflicts) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  auto video_receiver = video_receiver_result.MoveValue();

  // First test payload type conflict.
  RtpParameters audio_parameters = MakeMinimalOpusParameters();
  RtpParameters video_parameters = MakeMinimalVp8Parameters();
  audio_parameters.codecs[0].payload_type = 100;
  video_parameters.codecs[0].payload_type = 100;
  EXPECT_TRUE(audio_receiver->Receive(audio_parameters).ok());
  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER,
            video_receiver->Receive(video_parameters).type());

  // Test header extension ID conflict.
  video_parameters.codecs[0].payload_type = 110;
  audio_parameters.header_extensions.emplace_back("foo", 4);
  video_parameters.header_extensions.emplace_back("bar", 4);
  EXPECT_TRUE(audio_receiver->Receive(audio_parameters).ok());
  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER,
            video_receiver->Receive(video_parameters).type());

  // Test SSRC conflict. Have an RTX SSRC that conflicts with a primary SSRC
  // for extra challenge.
  video_parameters.header_extensions[0].uri = "foo";
  audio_parameters.encodings[0].ssrc.emplace(0xabbaabba);
  audio_parameters.encodings[0].rtx.emplace(0xdeadbeef);
  video_parameters.encodings[0].ssrc.emplace(0xdeadbeef);
  EXPECT_TRUE(audio_receiver->Receive(audio_parameters).ok());
  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER,
            video_receiver->Receive(video_parameters).type());

  // Sanity check that parameters can be set if the conflicts are all resolved.
  video_parameters.encodings[0].ssrc.emplace(0xbaadf00d);
  EXPECT_TRUE(video_receiver->Receive(video_parameters).ok());
}

// Ensure that deleting a receiver causes receive streams at the media engine
// level to be cleared.
TEST_F(OrtcRtpReceiverTest, DeletingReceiverClearsReceiveStreams) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  EXPECT_TRUE(audio_receiver->Receive(MakeMinimalOpusParameters()).ok());

  // Also create an audio sender, to prevent the voice channel from being
  // completely deleted.
  auto audio_sender_result = ortc_factory_->CreateRtpSender(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_sender = audio_sender_result.MoveValue();
  EXPECT_TRUE(audio_sender->Send(MakeMinimalOpusParameters()).ok());

  audio_receiver.reset(nullptr);
  cricket::FakeVoiceMediaChannel* fake_voice_channel =
      fake_media_engine_->GetVoiceChannel(0);
  ASSERT_NE(nullptr, fake_voice_channel);
  EXPECT_TRUE(fake_voice_channel->recv_streams().empty());

  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_receiver = video_receiver_result.MoveValue();
  EXPECT_TRUE(video_receiver->Receive(MakeMinimalVp8Parameters()).ok());

  // Also create an video sender, to prevent the video channel from being
  // completely deleted.
  auto video_sender_result = ortc_factory_->CreateRtpSender(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_sender = video_sender_result.MoveValue();
  EXPECT_TRUE(video_sender->Send(MakeMinimalVp8Parameters()).ok());

  video_receiver.reset(nullptr);
  cricket::FakeVideoMediaChannel* fake_video_channel =
      fake_media_engine_->GetVideoChannel(0);
  ASSERT_NE(nullptr, fake_video_channel);
  EXPECT_TRUE(fake_video_channel->recv_streams().empty());
}

// If Receive hasn't been called, GetParameters should return empty parameters.
TEST_F(OrtcRtpReceiverTest, GetDefaultParameters) {
  auto result = ortc_factory_->CreateRtpReceiver(cricket::MEDIA_TYPE_AUDIO,
                                                 rtp_transport_.get());
  EXPECT_EQ(RtpParameters(), result.value()->GetParameters());
  result = ortc_factory_->CreateRtpReceiver(cricket::MEDIA_TYPE_VIDEO,
                                            rtp_transport_.get());
  EXPECT_EQ(RtpParameters(), result.value()->GetParameters());
}

// Test that GetParameters returns the last parameters passed into Receive,
// along with the implementation-default values filled in where they were left
// unset.
TEST_F(OrtcRtpReceiverTest,
       GetParametersReturnsLastSetParametersWithDefaultsFilled) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();

  RtpParameters opus_parameters = MakeMinimalOpusParameters();
  EXPECT_TRUE(audio_receiver->Receive(opus_parameters).ok());
  EXPECT_EQ(opus_parameters, audio_receiver->GetParameters());

  RtpParameters isac_parameters = MakeMinimalIsacParameters();
  // Sanity check that num_channels actually is left unset.
  ASSERT_FALSE(isac_parameters.codecs[0].num_channels);
  EXPECT_TRUE(audio_receiver->Receive(isac_parameters).ok());
  // Should be filled with a default "num channels" of 1.
  // TODO(deadbeef): This should actually default to 2 for some codecs. Update
  // this test once that's implemented.
  isac_parameters.codecs[0].num_channels.emplace(1);
  EXPECT_EQ(isac_parameters, audio_receiver->GetParameters());

  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto video_receiver = video_receiver_result.MoveValue();

  RtpParameters vp8_parameters = MakeMinimalVp8Parameters();
  // Sanity check that clock_rate actually is left unset.
  EXPECT_TRUE(video_receiver->Receive(vp8_parameters).ok());
  // Should be filled with a default clock rate of 90000.
  vp8_parameters.codecs[0].clock_rate.emplace(90000);
  EXPECT_EQ(vp8_parameters, video_receiver->GetParameters());

  RtpParameters vp9_parameters = MakeMinimalVp9Parameters();
  // Sanity check that clock_rate actually is left unset.
  EXPECT_TRUE(video_receiver->Receive(vp9_parameters).ok());
  // Should be filled with a default clock rate of 90000.
  vp9_parameters.codecs[0].clock_rate.emplace(90000);
  EXPECT_EQ(vp9_parameters, video_receiver->GetParameters());
}

TEST_F(OrtcRtpReceiverTest, GetKind) {
  auto audio_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_AUDIO, rtp_transport_.get());
  auto video_receiver_result = ortc_factory_->CreateRtpReceiver(
      cricket::MEDIA_TYPE_VIDEO, rtp_transport_.get());
  auto audio_receiver = audio_receiver_result.MoveValue();
  auto video_receiver = video_receiver_result.MoveValue();
  EXPECT_EQ(cricket::MEDIA_TYPE_AUDIO, audio_receiver->GetKind());
  EXPECT_EQ(cricket::MEDIA_TYPE_VIDEO, video_receiver->GetKind());
}

}  // namespace webrtc