Allow default video receive channel to receive on any unsignalled SSRC,

webrtc/media/engine/webrtcvideoengine2_unittest.cc

Index: webrtc/media/engine/webrtcvideoengine2_unittest.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2_unittest.cc b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
index f60af340aaf4e2313bd84ff905587c4f789a12c3..1039f5f115f28f1efc6f7874cb7735b20e752868 100644
--- a/webrtc/media/engine/webrtcvideoengine2_unittest.cc
+++ b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
@@ -20,6 +20,7 @@
 #include "webrtc/common_video/h264/profile_level_id.h"
 #include "webrtc/logging/rtc_event_log/rtc_event_log.h"
 #include "webrtc/media/base/mediaconstants.h"
+#include "webrtc/media/base/rtputils.h"
 #include "webrtc/media/base/testutils.h"
 #include "webrtc/media/base/videoengine_unittest.h"
 #include "webrtc/media/engine/constants.h"
@@ -3754,6 +3755,66 @@ TEST_F(WebRtcVideoChannel2Test, RedRtxPacketDoesntCreateUnsignalledStream) {
                                   false /* expect_created_receive_stream */);
 }
 
+// Test that receiving any unsignalled SSRC works even if it changes.
+// The first unsignalled SSRC received will create a default receive stream.
+// Any different unsignalled SSRC received will replace the default.
+TEST_F(WebRtcVideoChannel2Test, RecvDiffUnsignalledSsrc) {

[Taylor Brandstetter, 2017/02/16 00:36:34]

nit: "ReceiveDifferentUnsignaledSsrcs"

[mo.zanaty, 2017/02/17 00:43:04]

Done.

+
+  // Allow receiving VP8, VP9, H264 (if enabled)

[Taylor Brandstetter, 2017/02/16 00:36:34]

nit: Our style is to have periods even after one-line comments.

[mo.zanaty, 2017/02/17 00:43:03]

Done.

+  cricket::VideoRecvParameters parameters;
+  parameters.codecs.push_back(GetEngineCodec("VP8"));
+  parameters.codecs.push_back(GetEngineCodec("VP9"));
+
+#if defined(WEBRTC_USE_H264)
+  cricket::VideoCodec H264codec(126, "H264");
+  parameters.codecs.push_back(H264codec);
+#endif
+
+  EXPECT_TRUE(channel_->SetRecvParameters(parameters));
+  // No receive streams yet
+  ASSERT_EQ(0u, fake_call_->GetVideoReceiveStreams().size());

[Taylor Brandstetter, 2017/02/16 00:36:34]

To make this test more robust, it would also be good to test that the recreated
receive streams hook up to a video renderer (which equates to a MediaStreamTrack
at the API level).

To do this, you can do:

cricket::FakeVideoRenderer renderer;
EXPECT_TRUE(channel_->SetSink(kDefaultRecvSsrc, &renderer));

(defining kDefaultRecvSsrc to 0 at the top of the file)

[mo.zanaty, 2017/02/17 00:43:03]

Done.

+
+  // Receive VP8 packet on first SSRC
+  uint8_t data[kMinRtpPacketLen];
+  cricket::RtpHeader rtpHeader;
+  rtpHeader.payload_type = GetEngineCodec("VP8").id;
+  rtpHeader.seq_num = rtpHeader.timestamp = 0;
+  rtpHeader.ssrc = kIncomingUnsignalledSsrc+1;
+  cricket::SetRtpHeader(data, sizeof(data), rtpHeader);
+  rtc::CopyOnWriteBuffer packet(data, sizeof(data));
+  rtc::PacketTime packet_time;
+  channel_->OnPacketReceived(&packet, packet_time);
+  // VP8 packet should create default receive stream
+  ASSERT_EQ(1u, fake_call_->GetVideoReceiveStreams().size());
+  FakeVideoReceiveStream* recv_stream =
+    fake_call_->GetVideoReceiveStreams()[0];
+  EXPECT_EQ(rtpHeader.ssrc, recv_stream->GetConfig().rtp.remote_ssrc);

[Taylor Brandstetter, 2017/02/16 00:36:34]

Then here, you can do:

recv_stream->InjectFrame(frame);
EXPECT_EQ(1, renderer.num_rendered_frames());

And same below. You can look elsewhere in this file for examples of constructing
black video frames for testing.

[mo.zanaty, 2017/02/17 00:43:03]

Done.

+
+  // Receive VP9 packet on second SSRC
+  rtpHeader.payload_type = GetEngineCodec("VP9").id;
+  rtpHeader.ssrc = kIncomingUnsignalledSsrc+2;
+  cricket::SetRtpHeader(data, sizeof(data), rtpHeader);
+  rtc::CopyOnWriteBuffer packet2(data, sizeof(data));
+  channel_->OnPacketReceived(&packet2, packet_time);
+  // VP9 packet should replace the default receive SSRC
+  ASSERT_EQ(1u, fake_call_->GetVideoReceiveStreams().size());
+  recv_stream = fake_call_->GetVideoReceiveStreams()[0];
+  EXPECT_EQ(rtpHeader.ssrc, recv_stream->GetConfig().rtp.remote_ssrc);
+
+#if defined(WEBRTC_USE_H264)
+  // Receive H264 packet on third SSRC
+  rtpHeader.payload_type = 126;
+  rtpHeader.ssrc = kIncomingUnsignalledSsrc+3;
+  cricket::SetRtpHeader(data, sizeof(data), rtpHeader);
+  rtc::CopyOnWriteBuffer packet3(data, sizeof(data));
+  channel_->OnPacketReceived(&packet3, packet_time);
+  // H264 packet should replace the default receive SSRC
+  ASSERT_EQ(1u, fake_call_->GetVideoReceiveStreams().size());
+  recv_stream = fake_call_->GetVideoReceiveStreams()[0];
+  EXPECT_EQ(rtpHeader.ssrc, recv_stream->GetConfig().rtp.remote_ssrc);
+#endif
+}
+
 TEST_F(WebRtcVideoChannel2Test, CanSentMaxBitrateForExistingStream) {
   AddSendStream();