Include pt= in the answer if the simulcast recv offer has pt= in rid.
When the following offer is received,
a=rtpmap:96 VP8/90000
...
a=rtpmap:97 VP9/90000
...
a=rid:r0 recv pt=96
a=rid:r1 recv pt=97
generate the following answer:
a=rtpmap:96 VP8/90000
...
a=rtpmap:97 VP9/90000
...
a=rid:r0 send pt=96
a=rid:r1 send pt=97
Bug: webrtc:362277533
Change-Id: Ibd256d38acb0e2d95ce24e092d27499230d08b13
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/362880
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43141}
diff --git a/pc/sdp_offer_answer.cc b/pc/sdp_offer_answer.cc
index 5386faf..0542910 100644
--- a/pc/sdp_offer_answer.cc
+++ b/pc/sdp_offer_answer.cc
@@ -640,6 +640,22 @@
RtpEncodingParameters parameters;
parameters.rid = layer.rid;
parameters.active = !layer.is_paused;
+ // If a payload type has been specified for this rid, set the codec
+ // corresponding to that payload type.
+ auto rid_desc = std::find_if(
+ desc.receive_rids().begin(), desc.receive_rids().end(),
+ [&layer](const RidDescription& rid) { return rid.rid == layer.rid; });
+ if (rid_desc != desc.receive_rids().end() &&
+ !rid_desc->payload_types.empty()) {
+ int payload_type = rid_desc->payload_types[0];
+ auto codec = std::find_if(desc.codecs().begin(), desc.codecs().end(),
+ [payload_type](const cricket::Codec& codec) {
+ return codec.id == payload_type;
+ });
+ if (codec != desc.codecs().end()) {
+ parameters.codec = codec->ToCodecParameters();
+ }
+ }
result.push_back(parameters);
}
diff --git a/pc/sdp_offer_answer_unittest.cc b/pc/sdp_offer_answer_unittest.cc
index 3cbda98..029878f 100644
--- a/pc/sdp_offer_answer_unittest.cc
+++ b/pc/sdp_offer_answer_unittest.cc
@@ -673,6 +673,56 @@
EXPECT_EQ(send_rids2[1].payload_types[0], send_codecs2[1].id);
}
+TEST_F(SdpOfferAnswerTest, SimulcastAnswerWithPayloadType) {
+ test::ScopedKeyValueConfig field_trials(
+ field_trials_, "WebRTC-MixedCodecSimulcast/Enabled/");
+
+ auto pc = CreatePeerConnection();
+
+ // A SDP offer with recv simulcast with payload type
+ std::string sdp =
+ "v=0\r\n"
+ "o=- 4131505339648218884 3 IN IP4 127.0.0.1\r\n"
+ "s=-\r\n"
+ "t=0 0\r\n"
+ "a=ice-ufrag:zGWFZ+fVXDeN6UoI/136\r\n"
+ "a=ice-pwd:9AUNgUqRNI5LSIrC1qFD2iTR\r\n"
+ "a=fingerprint:sha-256 "
+ "AD:52:52:E0:B1:37:34:21:0E:15:8E:B7:56:56:7B:B4:39:0E:6D:1C:F5:84:A7:EE:"
+ "B5:27:3E:30:B1:7D:69:42\r\n"
+ "a=setup:passive\r\n"
+ "m=video 9 UDP/TLS/RTP/SAVPF 96 97\r\n"
+ "c=IN IP4 0.0.0.0\r\n"
+ "a=rtcp:9 IN IP4 0.0.0.0\r\n"
+ "a=mid:0\r\n"
+ "a=extmap:9 urn:ietf:params:rtp-hdrext:sdes:mid\r\n"
+ "a=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id\r\n"
+ "a=recvonly\r\n"
+ "a=rtcp-mux\r\n"
+ "a=rtcp-rsize\r\n"
+ "a=rtpmap:96 VP8/90000\r\n"
+ "a=rtpmap:97 VP9/90000\r\n"
+ "a=rid:1 recv pt=96\r\n"
+ "a=rid:2 recv pt=97\r\n"
+ "a=simulcast:recv 1;2\r\n";
+
+ auto offer = CreateSessionDescription(SdpType::kOffer, sdp);
+ EXPECT_TRUE(pc->SetRemoteDescription(std::move(offer)));
+
+ auto transceiver = pc->pc()->GetTransceivers()[0];
+ EXPECT_TRUE(
+ transceiver->SetDirectionWithError(RtpTransceiverDirection::kSendOnly)
+ .ok());
+
+ // Check the generated SDP.
+ auto answer = pc->CreateAnswer();
+ answer->ToString(&sdp);
+ EXPECT_THAT(sdp, testing::HasSubstr("a=rid:1 send pt=96\r\n"));
+ EXPECT_THAT(sdp, testing::HasSubstr("a=rid:2 send pt=97\r\n"));
+
+ EXPECT_TRUE(pc->SetLocalDescription(std::move(answer)));
+}
+
TEST_F(SdpOfferAnswerTest, ExpectAllSsrcsSpecifiedInSsrcGroupFid) {
auto pc = CreatePeerConnection();
std::string sdp =
