Fixing some issues with payload type mappings.

talk/session/media/mediasession_unittest.cc

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 1653 matching lines @@
   ASSERT_EQ("H264", updated_vcd->codecs()[0].name);
   ASSERT_EQ(std::string(cricket::kRtxCodecName), updated_vcd->codecs()[1].name);
   int new_h264_pl_type =  updated_vcd->codecs()[0].id;
   EXPECT_NE(used_pl_type, new_h264_pl_type);
   VideoCodec rtx = updated_vcd->codecs()[1];
   int pt_referenced_by_rtx = rtc::FromString<int>(
       rtx.params[cricket::kCodecParamAssociatedPayloadType]);
   EXPECT_EQ(new_h264_pl_type, pt_referenced_by_rtx);
 }
 
+// Create an updated offer with RTX after creating an answer to an offer
+// without RTX, and with different default payload types.
+// Verify that the added RTX codec references the correct payload type.
+TEST_F(MediaSessionDescriptionFactoryTest,
+       RespondentCreatesOfferWithRtxAfterCreatingAnswerWithoutRtx) {
+  MediaSessionOptions opts;
+  opts.recv_video = true;
+  opts.recv_audio = true;
+
+  std::vector<VideoCodec> f2_codecs = MAKE_VECTOR(kVideoCodecs2);
+  // This creates rtx for H264 with the payload type |f2_| uses.
+  AddRtxCodec(VideoCodec::CreateRtxCodec(125, kVideoCodecs2[0].id), &f2_codecs);
+  f2_.set_video_codecs(f2_codecs);
+
+  rtc::scoped_ptr<SessionDescription> offer(f1_.CreateOffer(opts, nullptr));
+  ASSERT_TRUE(offer.get() != nullptr);
+  rtc::scoped_ptr<SessionDescription> answer(
+      f2_.CreateAnswer(offer.get(), opts, nullptr));
+
+  const VideoContentDescription* vcd =
+      GetFirstVideoContentDescription(answer.get());
+
+  std::vector<VideoCodec> expected_codecs = MAKE_VECTOR(kVideoCodecsAnswer);
+  EXPECT_EQ(expected_codecs, vcd->codecs());
+
+  // Now, ensure that the RTX codec is created correctly when |f2_| creates an
+  // updated offer, even though the default payload types are different from
+  // those of |f1_|.
+  rtc::scoped_ptr<SessionDescription> updated_offer(
+      f2_.CreateOffer(opts, answer.get()));
+  ASSERT_TRUE(updated_offer);
+
+  const VideoContentDescription* updated_vcd =
+      GetFirstVideoContentDescription(updated_offer.get());
+
+  // New offer should attempt to add H263, and RTX for H264.
+  expected_codecs.push_back(kVideoCodecs2[1]);
+  AddRtxCodec(VideoCodec::CreateRtxCodec(125, kVideoCodecs1[1].id),
+              &expected_codecs);
+  EXPECT_EQ(expected_codecs, updated_vcd->codecs());
+}
+
 // Test that RTX is ignored when there is no associated payload type parameter.
 TEST_F(MediaSessionDescriptionFactoryTest, RtxWithoutApt) {
   MediaSessionOptions opts;
   opts.recv_video = true;
   opts.recv_audio = false;
   std::vector<VideoCodec> f1_codecs = MAKE_VECTOR(kVideoCodecs1);
   // This creates RTX without associated payload type parameter.
   AddRtxCodec(VideoCodec(126, cricket::kRtxCodecName, 0, 0, 0, 0), &f1_codecs);
   f1_.set_video_codecs(f1_codecs);
 
@@ skipping 88 matching lines @@
       f2_.CreateAnswer(offer.get(), opts, NULL));
   const VideoContentDescription* vcd =
       GetFirstVideoContentDescription(answer.get());
   std::vector<VideoCodec> expected_codecs = MAKE_VECTOR(kVideoCodecsAnswer);
   AddRtxCodec(VideoCodec::CreateRtxCodec(126, kVideoCodecs1[1].id),
               &expected_codecs);
 
   EXPECT_EQ(expected_codecs, vcd->codecs());
 }
 
+// Test that after one RTX codec has been negotiated, a new offer can attempt
+// to add another.
+TEST_F(MediaSessionDescriptionFactoryTest, AddSecondRtxInNewOffer) {
+  MediaSessionOptions opts;
+  opts.recv_video = true;
+  opts.recv_audio = false;
+  std::vector<VideoCodec> f1_codecs = MAKE_VECTOR(kVideoCodecs1);
+  // This creates RTX for H264 for the offerer.
+  AddRtxCodec(VideoCodec::CreateRtxCodec(126, kVideoCodecs1[1].id), &f1_codecs);
+  f1_.set_video_codecs(f1_codecs);
+
+  rtc::scoped_ptr<SessionDescription> offer(f1_.CreateOffer(opts, nullptr));
+  ASSERT_TRUE(offer);
+  const VideoContentDescription* vcd =
+      GetFirstVideoContentDescription(offer.get());
+
+  std::vector<VideoCodec> expected_codecs = MAKE_VECTOR(kVideoCodecs1);
+  AddRtxCodec(VideoCodec::CreateRtxCodec(126, kVideoCodecs1[1].id),
+              &expected_codecs);
+  EXPECT_EQ(expected_codecs, vcd->codecs());
+
+  // Now, attempt to add RTX for H264-SVC.
+  AddRtxCodec(VideoCodec::CreateRtxCodec(125, kVideoCodecs1[0].id), &f1_codecs);
+  f1_.set_video_codecs(f1_codecs);
+
+  rtc::scoped_ptr<SessionDescription> updated_offer(
+      f1_.CreateOffer(opts, offer.get()));
+  ASSERT_TRUE(updated_offer);
+  vcd = GetFirstVideoContentDescription(updated_offer.get());
+
+  AddRtxCodec(VideoCodec::CreateRtxCodec(125, kVideoCodecs1[0].id),
+              &expected_codecs);
+  EXPECT_EQ(expected_codecs, vcd->codecs());
+}
+
 // Test that when RTX is used in conjunction with simulcast, an RTX ssrc is
 // generated for each simulcast ssrc and correctly grouped.
 TEST_F(MediaSessionDescriptionFactoryTest, SimSsrcsGenerateMultipleRtxSsrcs) {
   MediaSessionOptions opts;
   opts.recv_video = true;
   opts.recv_audio = false;
 
   // Add simulcast streams.
   opts.AddSendVideoStream("stream1", "stream1label", 3);
 
@@ skipping 543 matching lines @@
   const ContentInfo* audio_content = GetFirstAudioContent(updated_offer.get());
   const ContentInfo* video_content = GetFirstVideoContent(updated_offer.get());
   const ContentInfo* data_content = GetFirstDataContent(updated_offer.get());
   ASSERT_TRUE(audio_content != nullptr);
   ASSERT_TRUE(video_content != nullptr);
   ASSERT_TRUE(data_content != nullptr);
   EXPECT_EQ("audio_modified", audio_content->name);
   EXPECT_EQ("video_modified", video_content->name);
   EXPECT_EQ("data_modified", data_content->name);
 }