Adding "adapter" ORTC objects on top of ChannelManager/BaseChannel/etc.

webrtc/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 "webrtc/base/gunit.h"
+#include "webrtc/media/base/fakemediaengine.h"
+#include "webrtc/p2p/base/fakepackettransport.h"
+#include "webrtc/ortc/ortcfactory.h"
+#include "webrtc/ortc/testrtpparameters.h"
+#include "webrtc/pc/test/fakevideotracksource.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_));
+    ortc_factory_ = ortc_factory_result.MoveValue();
+    RtcpParameters rtcp_parameters;
+    rtcp_parameters.mux = true;
+    auto rtp_transport_result = ortc_factory_->CreateRtpTransport(
+        rtcp_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");
+  RtcpParameters rtcp_parameters;
+  rtcp_parameters.mux = true;
+  auto rtp_transport_result = ortc_factory_->CreateRtpTransport(
+      rtcp_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