remove mslabel and mslabel ssrc-specific attributes

Removes support for parsing and serializing
  a=ssrc:1 mslabel:stream
  a=ssrc:1 label:track
which have been superceeded by
  a=ssrc:1 msid:stream track
a long time ago.

Bug: webrtc:7110
Change-Id: I3aca47728098b6e7e049b82ed34c59426d411c41
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168244
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30801}

4 files changed, 38 insertions, 119 deletions

diff --git a/pc/data_channel_controller.cc b/pc/data_channel_controller.cc
index 2800992ab6..865620491d 100644
--- a/pc/data_channel_controller.cc
+++ b/pc/data_channel_controller.cc
@@ -429,8 +429,8 @@ void DataChannelController::UpdateRemoteRtpDataChannels(
   RTC_DCHECK_RUN_ON(signaling_thread());
   // Find new and active data channels.
   for (const cricket::StreamParams& params : streams) {
-    // The data channel label is either the mslabel or the SSRC if the mslabel
-    // does not exist. Ex a=ssrc:444330170 mslabel:test1.
+    // The data channel label is either the msid stream id or the SSRC if
+    // the msid does not exist. Ex a=ssrc:444330170 msid:test1 test1.
     std::string label = params.first_stream_id().empty()
                             ? rtc::ToString(params.first_ssrc())
                             : params.first_stream_id();
diff --git a/pc/peer_connection_interface_unittest.cc b/pc/peer_connection_interface_unittest.cc
index 2a36970597..b6a8dd43ef 100644
--- a/pc/peer_connection_interface_unittest.cc
+++ b/pc/peer_connection_interface_unittest.cc
@@ -135,8 +135,7 @@ static const char kSdpStringWithStream1PlanB[] =
     "a=rtcp-mux\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
     "a=ssrc:1 cname:stream1\r\n"
-    "a=ssrc:1 mslabel:stream1\r\n"
-    "a=ssrc:1 label:audiotrack0\r\n"
+    "a=ssrc:1 msid:stream1 audiotrack0\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
@@ -147,11 +146,10 @@ static const char kSdpStringWithStream1PlanB[] =
     "a=rtcp-mux\r\n"
     "a=rtpmap:120 VP8/90000\r\n"
     "a=ssrc:2 cname:stream1\r\n"
-    "a=ssrc:2 mslabel:stream1\r\n"
-    "a=ssrc:2 label:videotrack0\r\n";
-// Same string as above but with the MID changed to the Unified Plan default.
-// This is needed so that this SDP can be used as an answer for a Unified Plan
-// offer.
+    "a=ssrc:2 msid:stream1 videotrack0\r\n";
+// Same string as above but with the MID changed to the Unified Plan default and
+// a=msid added. This is needed so that this SDP can be used as an answer for a
+// Unified Plan offer.
 static const char kSdpStringWithStream1UnifiedPlan[] =
     "v=0\r\n"
     "o=- 0 0 IN IP4 127.0.0.1\r\n"
@@ -166,9 +164,8 @@ static const char kSdpStringWithStream1UnifiedPlan[] =
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
+    "a=msid:stream1 audiotrack0\r\n"
     "a=ssrc:1 cname:stream1\r\n"
-    "a=ssrc:1 mslabel:stream1\r\n"
-    "a=ssrc:1 label:audiotrack0\r\n"
     "m=video 1 RTP/AVPF 120\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
@@ -178,9 +175,8 @@ static const char kSdpStringWithStream1UnifiedPlan[] =
     "a=sendrecv\r\n"
     "a=rtcp-mux\r\n"
     "a=rtpmap:120 VP8/90000\r\n"
-    "a=ssrc:2 cname:stream1\r\n"
-    "a=ssrc:2 mslabel:stream1\r\n"
-    "a=ssrc:2 label:videotrack0\r\n";
+    "a=msid:stream1 videotrack0\r\n"
+    "a=ssrc:2 cname:stream1\r\n";
 
 // Reference SDP with a MediaStream with label "stream1" and audio track with
 // id "audio_1";
@@ -198,8 +194,7 @@ static const char kSdpStringWithStream1AudioTrackOnly[] =
     "a=sendrecv\r\n"
     "a=rtpmap:103 ISAC/16000\r\n"
     "a=ssrc:1 cname:stream1\r\n"
-    "a=ssrc:1 mslabel:stream1\r\n"
-    "a=ssrc:1 label:audiotrack0\r\n"
+    "a=ssrc:1 msid:stream1 audiotrack0\r\n"
     "a=rtcp-mux\r\n";
 
 // Reference SDP with two MediaStreams with label "stream1" and "stream2. Each
@@ -440,8 +435,6 @@ static const char kDtlsSdesFallbackSdp[] =
     "a=rtcp-mux\r\n"
     "a=mid:audio\r\n"
     "a=ssrc:1 cname:stream1\r\n"
-    "a=ssrc:1 mslabel:stream1\r\n"
-    "a=ssrc:1 label:audiotrack0\r\n"
     "a=ice-ufrag:e5785931\r\n"
     "a=ice-pwd:36fb7878390db89481c1d46daa4278d8\r\n"
     "a=rtpmap:0 pcmu/8000\r\n"
diff --git a/pc/webrtc_sdp.cc b/pc/webrtc_sdp.cc
index 7846e5e389..bd31e9249e 100644
--- a/pc/webrtc_sdp.cc
+++ b/pc/webrtc_sdp.cc
@@ -126,8 +126,6 @@ static const char kMediaStreamSemantic[] = "WMS";
 static const char kSsrcAttributeMsid[] = "msid";
 static const char kDefaultMsid[] = "default";
 static const char kNoStreamMsid[] = "-";
-static const char kSsrcAttributeMslabel[] = "mslabel";
-static const char kSSrcAttributeLabel[] = "label";
 static const char kAttributeSsrcGroup[] = "ssrc-group";
 static const char kAttributeCrypto[] = "crypto";
 static const char kAttributeCandidate[] = "candidate";
@@ -244,11 +242,6 @@ struct SsrcInfo {
   std::string cname;
   std::string stream_id;
   std::string track_id;
-
-  // For backward compatibility.
-  // TODO(ronghuawu): Remove below 2 fields once all the clients support msid.
-  std::string label;
-  std::string mslabel;
 };
 typedef std::vector<SsrcInfo> SsrcInfoVec;
 typedef std::vector<SsrcGroup> SsrcGroupVec;
@@ -702,12 +695,6 @@ void CreateTracksFromSsrcInfos(const SsrcInfoVec& ssrc_infos,
       // This is the case with Plan B SDP msid signaling.
       stream_ids.push_back(ssrc_info.stream_id);
       track_id = ssrc_info.track_id;
-    } else if (!ssrc_info.mslabel.empty()) {
-      // Since there's no a=msid or a=ssrc msid signaling, this is a sdp from
-      // an older version of client that doesn't support msid.
-      // In that case, we use the mslabel and label to construct the track.
-      stream_ids.push_back(ssrc_info.mslabel);
-      track_id = ssrc_info.label;
     } else {
       // Since no media streams isn't supported with older SDP signaling, we
       // use a default a stream id.
@@ -1716,15 +1703,6 @@ void BuildRtpContentAttributes(const MediaContentDescription* media_desc,
            << kSsrcAttributeMsid << kSdpDelimiterColon << stream_id
            << kSdpDelimiterSpace << track.id;
         AddLine(os.str(), message);
-
-        // TODO(ronghuawu): Remove below code which is for backward
-        // compatibility.
-        // draft-alvestrand-rtcweb-mid-01
-        // a=ssrc:<ssrc-id> mslabel:<value>
-        // The label isn't yet defined.
-        // a=ssrc:<ssrc-id> label:<value>
-        AddSsrcLine(ssrc, kSsrcAttributeMslabel, stream_id, message);
-        AddSsrcLine(ssrc, kSSrcAttributeLabel, track.id, message);
       }
     }
 
@@ -3488,14 +3466,8 @@ bool ParseSsrcAttribute(const std::string& line,
       ssrc_info.track_id = fields[1];
     }
     *msid_signaling |= cricket::kMsidSignalingSsrcAttribute;
-  } else if (attribute == kSsrcAttributeMslabel) {
-    // draft-alvestrand-rtcweb-mid-01
-    // mslabel:<value>
-    ssrc_info.mslabel = value;
-  } else if (attribute == kSSrcAttributeLabel) {
-    // The label isn't defined.
-    // label:<value>
-    ssrc_info.label = value;
+  } else {
+    RTC_LOG(LS_INFO) << "Ignored unknown ssrc-specific attribute: " << line;
   }
   return true;
 }
diff --git a/pc/webrtc_sdp_unittest.cc b/pc/webrtc_sdp_unittest.cc
index b849f01864..034e04e94a 100644
--- a/pc/webrtc_sdp_unittest.cc
+++ b/pc/webrtc_sdp_unittest.cc
@@ -184,8 +184,6 @@ static const char kSdpFullString[] =
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
     "a=ssrc:1 msid:local_stream_1 audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream_1\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n"
     "m=video 3457 RTP/SAVPF 120\r\n"
     "c=IN IP4 74.125.224.39\r\n"
     "a=rtcp:3456 IN IP4 74.125.224.39\r\n"
@@ -210,12 +208,8 @@ static const char kSdpFullString[] =
     "a=ssrc-group:FEC 2 3\r\n"
     "a=ssrc:2 cname:stream_1_cname\r\n"
     "a=ssrc:2 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:2 mslabel:local_stream_1\r\n"
-    "a=ssrc:2 label:video_track_id_1\r\n"
     "a=ssrc:3 cname:stream_1_cname\r\n"
-    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:3 mslabel:local_stream_1\r\n"
-    "a=ssrc:3 label:video_track_id_1\r\n";
+    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n";
 
 // SDP reference string without the candidates.
 static const char kSdpString[] =
@@ -240,8 +234,6 @@ static const char kSdpString[] =
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
     "a=ssrc:1 msid:local_stream_1 audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream_1\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n"
     "m=video 9 RTP/SAVPF 120\r\n"
     "c=IN IP4 0.0.0.0\r\n"
     "a=rtcp:9 IN IP4 0.0.0.0\r\n"
@@ -254,12 +246,8 @@ static const char kSdpString[] =
     "a=ssrc-group:FEC 2 3\r\n"
     "a=ssrc:2 cname:stream_1_cname\r\n"
     "a=ssrc:2 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:2 mslabel:local_stream_1\r\n"
-    "a=ssrc:2 label:video_track_id_1\r\n"
     "a=ssrc:3 cname:stream_1_cname\r\n"
-    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:3 mslabel:local_stream_1\r\n"
-    "a=ssrc:3 label:video_track_id_1\r\n";
+    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n";
 
 static const char kSdpRtpDataChannelString[] =
     "m=application 9 RTP/SAVPF 101\r\n"
@@ -273,9 +261,7 @@ static const char kSdpRtpDataChannelString[] =
     "inline:FvLcvU2P3ZWmQxgPAgcDu7Zl9vftYElFOjEzhWs5\r\n"
     "a=rtpmap:101 google-data/90000\r\n"
     "a=ssrc:10 cname:data_channel_cname\r\n"
-    "a=ssrc:10 msid:data_channel data_channeld0\r\n"
-    "a=ssrc:10 mslabel:data_channel\r\n"
-    "a=ssrc:10 label:data_channeld0\r\n";
+    "a=ssrc:10 msid:data_channel data_channeld0\r\n";
 
 // draft-ietf-mmusic-sctp-sdp-03
 static const char kSdpSctpDataChannelString[] =
@@ -350,9 +336,7 @@ static const char kSdpAudioString[] =
     "a=sendrecv\r\n"
     "a=rtpmap:111 opus/48000/2\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
-    "a=ssrc:1 msid:local_stream audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n";
+    "a=ssrc:1 msid:local_stream audio_track_id_1\r\n";
 
 static const char kSdpVideoString[] =
     "m=video 9 RTP/SAVPF 120\r\n"
@@ -363,9 +347,7 @@ static const char kSdpVideoString[] =
     "a=sendrecv\r\n"
     "a=rtpmap:120 VP8/90000\r\n"
     "a=ssrc:2 cname:stream_1_cname\r\n"
-    "a=ssrc:2 msid:local_stream video_track_id_1\r\n"
-    "a=ssrc:2 mslabel:local_stream\r\n"
-    "a=ssrc:2 label:video_track_id_1\r\n";
+    "a=ssrc:2 msid:local_stream video_track_id_1\r\n";
 
 // Reference sdp string using bundle-only.
 static const char kBundleOnlySdpFullString[] =
@@ -405,8 +387,6 @@ static const char kBundleOnlySdpFullString[] =
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
     "a=ssrc:1 msid:local_stream_1 audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream_1\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n"
     "m=video 0 RTP/SAVPF 120\r\n"
     "c=IN IP4 0.0.0.0\r\n"
     "a=rtcp:9 IN IP4 0.0.0.0\r\n"
@@ -419,12 +399,8 @@ static const char kBundleOnlySdpFullString[] =
     "a=ssrc-group:FEC 2 3\r\n"
     "a=ssrc:2 cname:stream_1_cname\r\n"
     "a=ssrc:2 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:2 mslabel:local_stream_1\r\n"
-    "a=ssrc:2 label:video_track_id_1\r\n"
     "a=ssrc:3 cname:stream_1_cname\r\n"
-    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:3 mslabel:local_stream_1\r\n"
-    "a=ssrc:3 label:video_track_id_1\r\n";
+    "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n";
 
 // Plan B SDP reference string, with 2 streams, 2 audio tracks and 3 video
 // tracks.
@@ -464,12 +440,8 @@ static const char kPlanBSdpFullString[] =
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
     "a=ssrc:1 msid:local_stream_1 audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream_1\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n"
     "a=ssrc:4 cname:stream_2_cname\r\n"
     "a=ssrc:4 msid:local_stream_2 audio_track_id_2\r\n"
-    "a=ssrc:4 mslabel:local_stream_2\r\n"
-    "a=ssrc:4 label:audio_track_id_2\r\n"
     "m=video 3457 RTP/SAVPF 120\r\n"
     "c=IN IP4 74.125.224.39\r\n"
     "a=rtcp:3456 IN IP4 74.125.224.39\r\n"
@@ -494,20 +466,12 @@ static const char kPlanBSdpFullString[] =
     "a=ssrc-group:FEC 2 3\r\n"
     "a=ssrc:2 cname:stream_1_cname\r\n"
     "a=ssrc:2 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:2 mslabel:local_stream_1\r\n"
-    "a=ssrc:2 label:video_track_id_1\r\n"
     "a=ssrc:3 cname:stream_1_cname\r\n"
     "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n"
-    "a=ssrc:3 mslabel:local_stream_1\r\n"
-    "a=ssrc:3 label:video_track_id_1\r\n"
     "a=ssrc:5 cname:stream_2_cname\r\n"
     "a=ssrc:5 msid:local_stream_2 video_track_id_2\r\n"
-    "a=ssrc:5 mslabel:local_stream_2\r\n"
-    "a=ssrc:5 label:video_track_id_2\r\n"
     "a=ssrc:6 cname:stream_2_cname\r\n"
-    "a=ssrc:6 msid:local_stream_2 video_track_id_3\r\n"
-    "a=ssrc:6 mslabel:local_stream_2\r\n"
-    "a=ssrc:6 label:video_track_id_3\r\n";
+    "a=ssrc:6 msid:local_stream_2 video_track_id_3\r\n";
 
 // Unified Plan SDP reference string, with 2 streams, 2 audio tracks and 3 video
 // tracks.
@@ -661,8 +625,6 @@ static const char kUnifiedPlanSdpFullStringWithSpecialMsid[] =
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:1 cname:stream_1_cname\r\n"
     "a=ssrc:1 msid:local_stream_1 audio_track_id_1\r\n"
-    "a=ssrc:1 mslabel:local_stream_1\r\n"
-    "a=ssrc:1 label:audio_track_id_1\r\n"
     // Audio track 2, with two stream ids.
     "m=audio 9 RTP/SAVPF 111 103 104\r\n"
     "c=IN IP4 0.0.0.0\r\n"
@@ -684,8 +646,6 @@ static const char kUnifiedPlanSdpFullStringWithSpecialMsid[] =
     // The support for Plan B msid signaling only includes the
     // first media stream id "local_stream_1."
     "a=ssrc:4 msid:local_stream_1 audio_track_id_2\r\n"
-    "a=ssrc:4 mslabel:local_stream_1\r\n"
-    "a=ssrc:4 label:audio_track_id_2\r\n"
     // Audio track 3, with no stream ids.
     "m=audio 9 RTP/SAVPF 111 103 104\r\n"
     "c=IN IP4 0.0.0.0\r\n"
@@ -703,9 +663,7 @@ static const char kUnifiedPlanSdpFullStringWithSpecialMsid[] =
     "a=rtpmap:103 ISAC/16000\r\n"
     "a=rtpmap:104 ISAC/32000\r\n"
     "a=ssrc:7 cname:stream_2_cname\r\n"
-    "a=ssrc:7 msid:- audio_track_id_3\r\n"
-    "a=ssrc:7 mslabel:-\r\n"
-    "a=ssrc:7 label:audio_track_id_3\r\n";
+    "a=ssrc:7 msid:- audio_track_id_3\r\n";
 
 // SDP string for unified plan without SSRCs
 static const char kUnifiedPlanSdpFullStringNoSsrc[] =
@@ -2749,21 +2707,6 @@ TEST_F(WebRtcSdpTest, DeserializeSessionDescriptionWithRejectedAudioVideo) {
   EXPECT_TRUE(TestDeserializeRejected(true, true));
 }
 
-// Tests that we can still handle the sdp uses mslabel and label instead of
-// msid for backward compatibility.
-TEST_F(WebRtcSdpTest, DeserializeSessionDescriptionWithoutMsid) {
-  jdesc_.description()->set_msid_supported(false);
-  JsepSessionDescription jdesc(kDummyType);
-  std::string sdp_without_msid = kSdpFullString;
-  Replace("msid", "xmsid", &sdp_without_msid);
-  // Deserialize
-  EXPECT_TRUE(SdpDeserialize(sdp_without_msid, &jdesc));
-  // Verify
-  EXPECT_TRUE(CompareSessionDescription(jdesc_, jdesc));
-  EXPECT_FALSE(jdesc.description()->msid_signaling() &
-               ~cricket::kMsidSignalingSsrcAttribute);
-}
-
 TEST_F(WebRtcSdpTest, DeserializeSessionDescriptionWithExtmapAllowMixed) {
   jdesc_.description()->set_extmap_allow_mixed(true);
   std::string sdp_with_extmap_allow_mixed = kSdpFullString;
@@ -3222,7 +3165,7 @@ TEST_F(WebRtcSdpTest, DeserializeSessionDescriptionWithoutEndLineBreak) {
   // Deserialize
   SdpParseError error;
   EXPECT_FALSE(webrtc::SdpDeserialize(sdp, &jdesc, &error));
-  const std::string lastline = "a=ssrc:3 label:video_track_id_1";
+  const std::string lastline = "a=ssrc:3 msid:local_stream_1 video_track_id_1";
   EXPECT_EQ(lastline, error.line);
   EXPECT_EQ("Invalid SDP line.", error.description);
 }
@@ -4344,15 +4287,16 @@ TEST_F(WebRtcSdpTest, DeserializeEmptySessionName) {
 
 // Simulcast malformed input test for invalid format.
 TEST_F(WebRtcSdpTest, DeserializeSimulcastNegative_EmptyAttribute) {
-  ExpectParseFailureWithNewLines("a=ssrc:3 label:video_track_id_1\r\n",
-                                 "a=simulcast:\r\n", "a=simulcast:");
+  ExpectParseFailureWithNewLines(
+      "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n", "a=simulcast:\r\n",
+      "a=simulcast:");
 }
 
 // Tests that duplicate simulcast entries in the SDP triggers a parse failure.
 TEST_F(WebRtcSdpTest, DeserializeSimulcastNegative_DuplicateAttribute) {
-  ExpectParseFailureWithNewLines("a=ssrc:3 label:video_track_id_1\r\n",
-                                 "a=simulcast:send 1\r\na=simulcast:recv 2\r\n",
-                                 "a=simulcast:");
+  ExpectParseFailureWithNewLines(
+      "a=ssrc:3 msid:local_stream_1 video_track_id_1\r\n",
+      "a=simulcast:send 1\r\na=simulcast:recv 2\r\n", "a=simulcast:");
 }
 
 // Validates that deserialization uses the a=simulcast: attribute
@@ -4690,3 +4634,13 @@ TEST_F(WebRtcSdpTest, DeserializeSessionDescriptionWithoutCname) {
                                 jdesc_.session_version()));
   EXPECT_TRUE(CompareSessionDescription(jdesc_, new_jdesc));
 }
+
+// This tests parsing of SDP with unknown ssrc-specific attributes.
+TEST_F(WebRtcSdpTest, ParseIgnoreUnknownSsrcSpecificAttribute) {
+  std::string sdp = kSdpString;
+  sdp += "a=ssrc:1 mslabel:something\r\n";
+
+  JsepSessionDescription output(kDummyType);
+  SdpParseError error;
+  ASSERT_TRUE(webrtc::SdpDeserialize(sdp, &output, &error));
+}