Fixes two issues in how we handle OfferToReceiveX for CreateOffer:

1. the options set in the first CreateOffer call should not affect the result of a second CreateOffer call, if SetLocalDescription is not called after the first CreateOffer. So the member var options_ of MediaStreamSignaling is removed to make each CreateOffer independent.
Instead, MediaSession is responsible to make sure that an m-line in the current local description is never removed from the newly created offer.

2. OfferToReceiveAudio used to default to true, i.e. always having m=audio line even if no audio track. This is changed so that by default m=audio is only added if there are any audio tracks.

BUG=2108
R=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/16309004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/talk@7068 4adac7df-926f-26a2-2b94-8c16560cd09d

5 files changed, 93 insertions, 98 deletions

diff --git a/app/webrtc/mediastreamsignaling.cc b/app/webrtc/mediastreamsignaling.cc
index c4a8281..9a22ad4 100644
--- a/app/webrtc/mediastreamsignaling.cc
+++ b/app/webrtc/mediastreamsignaling.cc
@@ -51,9 +51,9 @@ namespace webrtc {
 using rtc::scoped_ptr;
 using rtc::scoped_refptr;
 
-static bool ParseConstraints(
+static bool ParseConstraintsForAnswer(
     const MediaConstraintsInterface* constraints,
-    cricket::MediaSessionOptions* options, bool is_answer) {
+    cricket::MediaSessionOptions* options) {
   bool value;
   size_t mandatory_constraints_satisfied = 0;
 
@@ -82,7 +82,7 @@ static bool ParseConstraints(
     // kOfferToReceiveVideo defaults to false according to spec. But
     // if it is an answer and video is offered, we should still accept video
     // per default.
-    options->has_video |= is_answer;
+    options->has_video = true;
   }
 
   if (FindConstraint(constraints,
@@ -133,6 +133,55 @@ static bool IsValidOfferToReceiveMedia(int value) {
       (value <= Options::kMaxOfferToReceiveMedia);
 }
 
+// Add the stream and RTP data channel info to |session_options|.
+static void SetStreams(
+    cricket::MediaSessionOptions* session_options,
+    rtc::scoped_refptr<StreamCollection> streams,
+    const MediaStreamSignaling::RtpDataChannels& rtp_data_channels) {
+  session_options->streams.clear();
+  if (streams != NULL) {
+    for (size_t i = 0; i < streams->count(); ++i) {
+      MediaStreamInterface* stream = streams->at(i);
+
+      AudioTrackVector audio_tracks(stream->GetAudioTracks());
+
+      // For each audio track in the stream, add it to the MediaSessionOptions.
+      for (size_t j = 0; j < audio_tracks.size(); ++j) {
+        scoped_refptr<MediaStreamTrackInterface> track(audio_tracks[j]);
+        session_options->AddStream(
+            cricket::MEDIA_TYPE_AUDIO, track->id(), stream->label());
+      }
+
+      VideoTrackVector video_tracks(stream->GetVideoTracks());
+
+      // For each video track in the stream, add it to the MediaSessionOptions.
+      for (size_t j = 0; j < video_tracks.size(); ++j) {
+        scoped_refptr<MediaStreamTrackInterface> track(video_tracks[j]);
+        session_options->AddStream(
+            cricket::MEDIA_TYPE_VIDEO, track->id(), stream->label());
+      }
+    }
+  }
+
+  // Check for data channels.
+  MediaStreamSignaling::RtpDataChannels::const_iterator data_channel_it =
+      rtp_data_channels.begin();
+  for (; data_channel_it != rtp_data_channels.end(); ++data_channel_it) {
+    const DataChannel* channel = data_channel_it->second;
+    if (channel->state() == DataChannel::kConnecting ||
+        channel->state() == DataChannel::kOpen) {
+      // |streamid| and |sync_label| are both set to the DataChannel label
+      // here so they can be signaled the same way as MediaStreams and Tracks.
+      // For MediaStreams, the sync_label is the MediaStream label and the
+      // track label is the same as |streamid|.
+      const std::string& streamid = channel->label();
+      const std::string& sync_label = channel->label();
+      session_options->AddStream(
+          cricket::MEDIA_TYPE_DATA, streamid, sync_label);
+    }
+  }
+}
+
 // Factory class for creating remote MediaStreams and MediaStreamTracks.
 class RemoteMediaStreamFactory {
  public:
@@ -192,8 +241,6 @@ MediaStreamSignaling::MediaStreamSignaling(
                                                           channel_manager)),
       last_allocated_sctp_even_sid_(-2),
       last_allocated_sctp_odd_sid_(-1) {
-  options_.has_video = false;
-  options_.has_audio = false;
 }
 
 MediaStreamSignaling::~MediaStreamSignaling() {
@@ -377,40 +424,38 @@ bool MediaStreamSignaling::GetOptionsForOffer(
     return false;
   }
 
-  UpdateSessionOptions();
+  session_options->has_audio = false;
+  session_options->has_video = false;
+  SetStreams(session_options, local_streams_, rtp_data_channels_);
 
-  // |options.has_audio| and |options.has_video| can only change from false to
-  // true, but never change from true to false. This is to make sure
-  // CreateOffer / CreateAnswer doesn't remove a media content
-  // description that has been created.
-  if (rtc_options.offer_to_receive_audio > 0) {
-    options_.has_audio = true;
+  // If |offer_to_receive_[audio/video]| is undefined, respect the flags set
+  // from SetStreams. Otherwise, overwrite it based on |rtc_options|.
+  if (rtc_options.offer_to_receive_audio != RTCOfferAnswerOptions::kUndefined) {
+    session_options->has_audio = rtc_options.offer_to_receive_audio > 0;
   }
-  if (rtc_options.offer_to_receive_video > 0) {
-    options_.has_video = true;
+  if (rtc_options.offer_to_receive_video != RTCOfferAnswerOptions::kUndefined) {
+    session_options->has_video = rtc_options.offer_to_receive_video > 0;
   }
-  options_.vad_enabled = rtc_options.voice_activity_detection;
-  options_.transport_options.ice_restart = rtc_options.ice_restart;
-  options_.bundle_enabled = rtc_options.use_rtp_mux;
 
-  options_.bundle_enabled = EvaluateNeedForBundle(options_);
-  *session_options = options_;
+  session_options->vad_enabled = rtc_options.voice_activity_detection;
+  session_options->transport_options.ice_restart = rtc_options.ice_restart;
+  session_options->bundle_enabled = rtc_options.use_rtp_mux;
+
+  session_options->bundle_enabled = EvaluateNeedForBundle(*session_options);
   return true;
 }
 
 bool MediaStreamSignaling::GetOptionsForAnswer(
     const MediaConstraintsInterface* constraints,
     cricket::MediaSessionOptions* options) {
-  UpdateSessionOptions();
+  options->has_audio = false;
+  options->has_video = false;
+  SetStreams(options, local_streams_, rtp_data_channels_);
 
-  // Copy the |options_| to not let the flag MediaSessionOptions::has_audio and
-  // MediaSessionOptions::has_video affect subsequent offers.
-  cricket::MediaSessionOptions current_options = options_;
-  if (!ParseConstraints(constraints, &current_options, true)) {
+  if (!ParseConstraintsForAnswer(constraints, options)) {
     return false;
   }
-  current_options.bundle_enabled = EvaluateNeedForBundle(current_options);
-  *options = current_options;
+  options->bundle_enabled = EvaluateNeedForBundle(*options);
   return true;
 }
 
@@ -545,54 +590,6 @@ void MediaStreamSignaling::OnDataChannelClose() {
   }
 }
 
-void MediaStreamSignaling::UpdateSessionOptions() {
-  options_.streams.clear();
-  if (local_streams_ != NULL) {
-    for (size_t i = 0; i < local_streams_->count(); ++i) {
-      MediaStreamInterface* stream = local_streams_->at(i);
-
-      AudioTrackVector audio_tracks(stream->GetAudioTracks());
-      if (!audio_tracks.empty()) {
-        options_.has_audio = true;
-      }
-
-      // For each audio track in the stream, add it to the MediaSessionOptions.
-      for (size_t j = 0; j < audio_tracks.size(); ++j) {
-        scoped_refptr<MediaStreamTrackInterface> track(audio_tracks[j]);
-        options_.AddStream(cricket::MEDIA_TYPE_AUDIO, track->id(),
-                           stream->label());
-      }
-
-      VideoTrackVector video_tracks(stream->GetVideoTracks());
-      if (!video_tracks.empty()) {
-        options_.has_video = true;
-      }
-      // For each video track in the stream, add it to the MediaSessionOptions.
-      for (size_t j = 0; j < video_tracks.size(); ++j) {
-        scoped_refptr<MediaStreamTrackInterface> track(video_tracks[j]);
-        options_.AddStream(cricket::MEDIA_TYPE_VIDEO, track->id(),
-                           stream->label());
-      }
-    }
-  }
-
-  // Check for data channels.
-  RtpDataChannels::const_iterator data_channel_it = rtp_data_channels_.begin();
-  for (; data_channel_it != rtp_data_channels_.end(); ++data_channel_it) {
-    const DataChannel* channel = data_channel_it->second;
-    if (channel->state() == DataChannel::kConnecting ||
-        channel->state() == DataChannel::kOpen) {
-      // |streamid| and |sync_label| are both set to the DataChannel label
-      // here so they can be signaled the same way as MediaStreams and Tracks.
-      // For MediaStreams, the sync_label is the MediaStream label and the
-      // track label is the same as |streamid|.
-      const std::string& streamid = channel->label();
-      const std::string& sync_label = channel->label();
-      options_.AddStream(cricket::MEDIA_TYPE_DATA, streamid, sync_label);
-    }
-  }
-}
-
 void MediaStreamSignaling::UpdateRemoteStreamsList(
     const cricket::StreamParamsVec& streams,
     cricket::MediaType media_type,
diff --git a/app/webrtc/mediastreamsignaling.h b/app/webrtc/mediastreamsignaling.h
index 7f17971..d4b1be8 100644
--- a/app/webrtc/mediastreamsignaling.h
+++ b/app/webrtc/mediastreamsignaling.h
@@ -160,6 +160,9 @@ class MediaStreamSignalingObserver {
 
 class MediaStreamSignaling : public sigslot::has_slots<> {
  public:
+  typedef std::map<std::string, rtc::scoped_refptr<DataChannel> >
+      RtpDataChannels;
+
   MediaStreamSignaling(rtc::Thread* signaling_thread,
                        MediaStreamSignalingObserver* stream_observer,
                        cricket::ChannelManager* channel_manager);
@@ -289,8 +292,6 @@ class MediaStreamSignaling : public sigslot::has_slots<> {
   };
   typedef std::vector<TrackInfo> TrackInfos;
 
-  void UpdateSessionOptions();
-
   // Makes sure a MediaStream Track is created for each StreamParam in
   // |streams|. |media_type| is the type of the |streams| and can be either
   // audio or video.
@@ -378,7 +379,6 @@ class MediaStreamSignaling : public sigslot::has_slots<> {
   RemotePeerInfo remote_info_;
   rtc::Thread* signaling_thread_;
   DataChannelFactory* data_channel_factory_;
-  cricket::MediaSessionOptions options_;
   MediaStreamSignalingObserver* stream_observer_;
   rtc::scoped_refptr<StreamCollection> local_streams_;
   rtc::scoped_refptr<StreamCollection> remote_streams_;
@@ -392,8 +392,6 @@ class MediaStreamSignaling : public sigslot::has_slots<> {
   int last_allocated_sctp_even_sid_;
   int last_allocated_sctp_odd_sid_;
 
-  typedef std::map<std::string, rtc::scoped_refptr<DataChannel> >
-      RtpDataChannels;
   typedef std::vector<rtc::scoped_refptr<DataChannel> > SctpDataChannels;
 
   RtpDataChannels rtp_data_channels_;
diff --git a/app/webrtc/mediastreamsignaling_unittest.cc b/app/webrtc/mediastreamsignaling_unittest.cc
index fa83646..2ccfd8d 100644
--- a/app/webrtc/mediastreamsignaling_unittest.cc
+++ b/app/webrtc/mediastreamsignaling_unittest.cc
@@ -775,8 +775,10 @@ TEST_F(MediaStreamSignalingTest, MediaConstraintsInAnswer) {
   RTCOfferAnswerOptions default_rtc_options;
   EXPECT_TRUE(signaling_->GetOptionsForOffer(default_rtc_options,
                                              &updated_offer_options));
-  EXPECT_TRUE(updated_offer_options.has_audio);
-  EXPECT_TRUE(updated_offer_options.has_video);
+  // By default, |has_audio| or |has_video| are false if there is no media
+  // track.
+  EXPECT_FALSE(updated_offer_options.has_audio);
+  EXPECT_FALSE(updated_offer_options.has_video);
 }
 
 // This test verifies that the remote MediaStreams corresponding to a received
diff --git a/app/webrtc/peerconnection.cc b/app/webrtc/peerconnection.cc
index 201269a..9c2bf02 100644
--- a/app/webrtc/peerconnection.cc
+++ b/app/webrtc/peerconnection.cc
@@ -508,10 +508,6 @@ void PeerConnection::CreateOffer(CreateSessionDescriptionObserver* observer,
     return;
   }
   RTCOfferAnswerOptions options;
-  // Defaults to receiving audio and not receiving video.
-  options.offer_to_receive_audio =
-      RTCOfferAnswerOptions::kOfferToReceiveMediaTrue;
-  options.offer_to_receive_video = 0;
 
   bool value;
   size_t mandatory_constraints = 0;
diff --git a/app/webrtc/webrtcsession_unittest.cc b/app/webrtc/webrtcsession_unittest.cc
index 2f731a9..001156d 100644
--- a/app/webrtc/webrtcsession_unittest.cc
+++ b/app/webrtc/webrtcsession_unittest.cc
@@ -510,7 +510,7 @@ class WebRtcSessionTest : public testing::Test {
   }
 
   void VerifyAnswerFromNonCryptoOffer() {
-    // Create a SDP without Crypto.
+    // Create an SDP without Crypto.
     cricket::MediaSessionOptions options;
     options.has_video = true;
     JsepSessionDescription* offer(
@@ -1211,14 +1211,13 @@ TEST_F(WebRtcSessionTest, TestCreateSdesOfferReceiveSdesAnswer) {
             rtc::FromString<uint64>(offer->session_version()));
 
   SetLocalDescriptionWithoutError(offer);
+  EXPECT_EQ(0u, video_channel_->send_streams().size());
+  EXPECT_EQ(0u, voice_channel_->send_streams().size());
 
   mediastream_signaling_.SendAudioVideoStream2();
   answer = CreateRemoteAnswer(session_->local_description());
   SetRemoteDescriptionWithoutError(answer);
 
-  EXPECT_EQ(0u, video_channel_->send_streams().size());
-  EXPECT_EQ(0u, voice_channel_->send_streams().size());
-
   // Make sure the receive streams have not changed.
   ASSERT_EQ(1u, video_channel_->recv_streams().size());
   EXPECT_TRUE(kVideoTrack2 == video_channel_->recv_streams()[0].id);
@@ -1992,13 +1991,21 @@ TEST_F(WebRtcSessionTest, CreateOfferWithConstraints) {
 
   const cricket::ContentInfo* content =
       cricket::GetFirstAudioContent(offer->description());
-
   EXPECT_TRUE(content != NULL);
+
   content = cricket::GetFirstVideoContent(offer->description());
   EXPECT_TRUE(content != NULL);
 
-  // TODO(perkj): Should the direction be set to SEND_ONLY if
-  // The constraints is set to not receive audio or video but a track is added?
+  // Sets constraints to false and verifies that audio/video contents are
+  // removed.
+  options.offer_to_receive_audio = 0;
+  options.offer_to_receive_video = 0;
+  offer.reset(CreateOffer(options));
+
+  content = cricket::GetFirstAudioContent(offer->description());
+  EXPECT_TRUE(content == NULL);
+  content = cricket::GetFirstVideoContent(offer->description());
+  EXPECT_TRUE(content == NULL);
 }
 
 // Test that an answer can not be created if the last remote description is not
@@ -2037,8 +2044,7 @@ TEST_F(WebRtcSessionTest, CreateAudioAnswerWithoutConstraintsOrStreams) {
   Init(NULL);
   // Create a remote offer with audio only.
   cricket::MediaSessionOptions options;
-  options.has_audio = true;
-  options.has_video = false;
+
   rtc::scoped_ptr<JsepSessionDescription> offer(
       CreateRemoteOffer(options));
   ASSERT_TRUE(cricket::GetFirstVideoContent(offer->description()) == NULL);
@@ -2174,7 +2180,6 @@ TEST_F(WebRtcSessionTest, TestAVOfferWithAudioOnlyAnswer) {
   SessionDescriptionInterface* offer = CreateOffer();
 
   cricket::MediaSessionOptions options;
-  options.has_video = false;
   SessionDescriptionInterface* answer = CreateRemoteAnswer(offer, options);
 
   // SetLocalDescription and SetRemoteDescriptions takes ownership of offer
@@ -2887,7 +2892,6 @@ TEST_F(WebRtcSessionTest, TestCryptoAfterSetLocalDescriptionWithDisabled) {
 TEST_F(WebRtcSessionTest, TestCreateAnswerWithNewUfragAndPassword) {
   Init(NULL);
   cricket::MediaSessionOptions options;
-  options.has_audio = true;
   options.has_video = true;
   rtc::scoped_ptr<JsepSessionDescription> offer(
       CreateRemoteOffer(options));
@@ -2919,7 +2923,6 @@ TEST_F(WebRtcSessionTest, TestCreateAnswerWithNewUfragAndPassword) {
 TEST_F(WebRtcSessionTest, TestCreateAnswerWithOldUfragAndPassword) {
   Init(NULL);
   cricket::MediaSessionOptions options;
-  options.has_audio = true;
   options.has_video = true;
   rtc::scoped_ptr<JsepSessionDescription> offer(
       CreateRemoteOffer(options));
@@ -2985,7 +2988,6 @@ TEST_F(WebRtcSessionTest, TestIceStatesBundle) {
 TEST_F(WebRtcSessionTest, SetSdpFailedOnSessionError) {
   Init(NULL);
   cricket::MediaSessionOptions options;
-  options.has_audio = true;
   options.has_video = true;
 
   cricket::BaseSession::Error error_code = cricket::BaseSession::ERROR_CONTENT;