Move more functions from PeerConnection to SdpOfferAnswer
These are functions that are called only from SdpOfferAnswer,
or that logically belong in the SdpOfferAnswer class.
Bug: webrtc:11995
Change-Id: I92136ee84e20e50957814c21b041ca152a2acca4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/186268
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32271}
diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 2b258cd..4196359 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -149,30 +149,6 @@
return true;
}
-// Add options to |[audio/video]_media_description_options| from |senders|.
-void AddPlanBRtpSenderOptions(
- const std::vector<rtc::scoped_refptr<
- RtpSenderProxyWithInternal<RtpSenderInternal>>>& senders,
- cricket::MediaDescriptionOptions* audio_media_description_options,
- cricket::MediaDescriptionOptions* video_media_description_options,
- int num_sim_layers) {
- for (const auto& sender : senders) {
- if (sender->media_type() == cricket::MEDIA_TYPE_AUDIO) {
- if (audio_media_description_options) {
- audio_media_description_options->AddAudioSender(
- sender->id(), sender->internal()->stream_ids());
- }
- } else {
- RTC_DCHECK(sender->media_type() == cricket::MEDIA_TYPE_VIDEO);
- if (video_media_description_options) {
- video_media_description_options->AddVideoSender(
- sender->id(), sender->internal()->stream_ids(), {},
- SimulcastLayerList(), num_sim_layers);
- }
- }
- }
-}
-
// Add options to |session_options| from |rtp_data_channels|.
void AddRtpDataChannelOptions(
const std::map<std::string, rtc::scoped_refptr<RtpDataChannel>>&
@@ -445,17 +421,6 @@
return cname;
}
-// From |rtc_options|, fill parts of |session_options| shared by all generated
-// m= sectionss (in other words, nothing that involves a map/array).
-void ExtractSharedMediaSessionOptions(
- const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
- cricket::MediaSessionOptions* session_options) {
- session_options->vad_enabled = rtc_options.voice_activity_detection;
- session_options->bundle_enabled = rtc_options.use_rtp_mux;
- session_options->raw_packetization_for_video =
- rtc_options.raw_packetization_for_video;
-}
-
PeerConnection::PeerConnection(PeerConnectionFactory* factory,
std::unique_ptr<RtcEventLog> event_log,
std::unique_ptr<Call> call)
@@ -1348,6 +1313,7 @@
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
PeerConnection::GetSendersInternal() const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
all_senders;
for (const auto& transceiver : transceivers_.List()) {
@@ -1698,9 +1664,11 @@
continue;
}
const ContentInfo* local_content =
- FindMediaSectionForTransceiver(transceiver, local_description());
+ sdp_handler_.FindMediaSectionForTransceiver(transceiver,
+ local_description());
const ContentInfo* remote_content =
- FindMediaSectionForTransceiver(transceiver, remote_description());
+ sdp_handler_.FindMediaSectionForTransceiver(transceiver,
+ remote_description());
if ((local_content && local_content->rejected) ||
(remote_content && remote_content->rejected)) {
RTC_LOG(LS_INFO) << "Dissociating transceiver"
@@ -1721,64 +1689,6 @@
}
}
-// The SDP parser used to populate these values by default for the 'content
-// name' if an a=mid line was absent.
-static absl::string_view GetDefaultMidForPlanB(cricket::MediaType media_type) {
- switch (media_type) {
- case cricket::MEDIA_TYPE_AUDIO:
- return cricket::CN_AUDIO;
- case cricket::MEDIA_TYPE_VIDEO:
- return cricket::CN_VIDEO;
- case cricket::MEDIA_TYPE_DATA:
- return cricket::CN_DATA;
- }
- RTC_NOTREACHED();
- return "";
-}
-
-void PeerConnection::FillInMissingRemoteMids(
- cricket::SessionDescription* new_remote_description) {
- RTC_DCHECK_RUN_ON(signaling_thread());
- RTC_DCHECK(new_remote_description);
- const cricket::ContentInfos no_infos;
- const cricket::ContentInfos& local_contents =
- (local_description() ? local_description()->description()->contents()
- : no_infos);
- const cricket::ContentInfos& remote_contents =
- (remote_description() ? remote_description()->description()->contents()
- : no_infos);
- for (size_t i = 0; i < new_remote_description->contents().size(); ++i) {
- cricket::ContentInfo& content = new_remote_description->contents()[i];
- if (!content.name.empty()) {
- continue;
- }
- std::string new_mid;
- absl::string_view source_explanation;
- if (IsUnifiedPlan()) {
- if (i < local_contents.size()) {
- new_mid = local_contents[i].name;
- source_explanation = "from the matching local media section";
- } else if (i < remote_contents.size()) {
- new_mid = remote_contents[i].name;
- source_explanation = "from the matching previous remote media section";
- } else {
- new_mid = mid_generator_();
- source_explanation = "generated just now";
- }
- } else {
- new_mid = std::string(
- GetDefaultMidForPlanB(content.media_description()->type()));
- source_explanation = "to match pre-existing behavior";
- }
- RTC_DCHECK(!new_mid.empty());
- content.name = new_mid;
- new_remote_description->transport_infos()[i].content_name = new_mid;
- RTC_LOG(LS_INFO) << "SetRemoteDescription: Remote media section at i=" << i
- << " is missing an a=mid line. Filling in the value '"
- << new_mid << "' " << source_explanation << ".";
- }
-}
-
void PeerConnection::SetRemoteDescription(
SetSessionDescriptionObserver* observer,
SessionDescriptionInterface* desc_ptr) {
@@ -1839,48 +1749,6 @@
return transceivers_.FindByMLineIndex(mline_index);
}
-rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
-PeerConnection::FindAvailableTransceiverToReceive(
- cricket::MediaType media_type) const {
- RTC_DCHECK_RUN_ON(signaling_thread());
- RTC_DCHECK(IsUnifiedPlan());
- // From JSEP section 5.10 (Applying a Remote Description):
- // If the m= section is sendrecv or recvonly, and there are RtpTransceivers of
- // the same type that were added to the PeerConnection by addTrack and are not
- // associated with any m= section and are not stopped, find the first such
- // RtpTransceiver.
- for (auto transceiver : transceivers_.List()) {
- if (transceiver->media_type() == media_type &&
- transceiver->internal()->created_by_addtrack() && !transceiver->mid() &&
- !transceiver->stopped()) {
- return transceiver;
- }
- }
- return nullptr;
-}
-
-const cricket::ContentInfo* PeerConnection::FindMediaSectionForTransceiver(
- rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- transceiver,
- const SessionDescriptionInterface* sdesc) const {
- RTC_DCHECK_RUN_ON(signaling_thread());
- RTC_DCHECK(transceiver);
- RTC_DCHECK(sdesc);
- if (IsUnifiedPlan()) {
- if (!transceiver->internal()->mid()) {
- // This transceiver is not associated with a media section yet.
- return nullptr;
- }
- return sdesc->description()->GetContentByName(
- *transceiver->internal()->mid());
- } else {
- // Plan B only allows at most one audio and one video section, so use the
- // first media section of that type.
- return cricket::GetFirstMediaContent(sdesc->description()->contents(),
- transceiver->media_type());
- }
-}
-
PeerConnectionInterface::RTCConfiguration PeerConnection::GetConfiguration() {
RTC_DCHECK_RUN_ON(signaling_thread());
return configuration_;
@@ -2687,465 +2555,6 @@
MSG_CREATE_SESSIONDESCRIPTION_FAILED, msg);
}
-void PeerConnection::GetOptionsForOffer(
- const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- RTC_DCHECK_RUN_ON(signaling_thread());
- ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
-
- if (IsUnifiedPlan()) {
- GetOptionsForUnifiedPlanOffer(offer_answer_options, session_options);
- } else {
- GetOptionsForPlanBOffer(offer_answer_options, session_options);
- }
-
- // Intentionally unset the data channel type for RTP data channel with the
- // second condition. Otherwise the RTP data channels would be successfully
- // negotiated by default and the unit tests in WebRtcDataBrowserTest will fail
- // when building with chromium. We want to leave RTP data channels broken, so
- // people won't try to use them.
- if (data_channel_controller_.HasRtpDataChannels() ||
- data_channel_type() != cricket::DCT_RTP) {
- session_options->data_channel_type = data_channel_type();
- }
-
- // Apply ICE restart flag and renomination flag.
- bool ice_restart =
- offer_answer_options.ice_restart || sdp_handler_.HasNewIceCredentials();
- for (auto& options : session_options->media_description_options) {
- options.transport_options.ice_restart = ice_restart;
- options.transport_options.enable_ice_renomination =
- configuration_.enable_ice_renomination;
- }
-
- session_options->rtcp_cname = rtcp_cname_;
- session_options->crypto_options = GetCryptoOptions();
- session_options->pooled_ice_credentials =
- network_thread()->Invoke<std::vector<cricket::IceParameters>>(
- RTC_FROM_HERE,
- rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
- port_allocator_.get()));
- session_options->offer_extmap_allow_mixed =
- configuration_.offer_extmap_allow_mixed;
-
- // Allow fallback for using obsolete SCTP syntax.
- // Note that the default in |session_options| is true, while
- // the default in |options| is false.
- session_options->use_obsolete_sctp_sdp =
- offer_answer_options.use_obsolete_sctp_sdp;
-}
-
-void PeerConnection::GetOptionsForPlanBOffer(
- const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- // Figure out transceiver directional preferences.
- bool send_audio = !GetAudioTransceiver()->internal()->senders().empty();
- bool send_video = !GetVideoTransceiver()->internal()->senders().empty();
-
- // By default, generate sendrecv/recvonly m= sections.
- bool recv_audio = true;
- bool recv_video = true;
-
- // By default, only offer a new m= section if we have media to send with it.
- bool offer_new_audio_description = send_audio;
- bool offer_new_video_description = send_video;
- bool offer_new_data_description = data_channel_controller_.HasDataChannels();
-
- // The "offer_to_receive_X" options allow those defaults to be overridden.
- if (offer_answer_options.offer_to_receive_audio !=
- RTCOfferAnswerOptions::kUndefined) {
- recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
- offer_new_audio_description =
- offer_new_audio_description ||
- (offer_answer_options.offer_to_receive_audio > 0);
- }
- if (offer_answer_options.offer_to_receive_video !=
- RTCOfferAnswerOptions::kUndefined) {
- recv_video = (offer_answer_options.offer_to_receive_video > 0);
- offer_new_video_description =
- offer_new_video_description ||
- (offer_answer_options.offer_to_receive_video > 0);
- }
-
- absl::optional<size_t> audio_index;
- absl::optional<size_t> video_index;
- absl::optional<size_t> data_index;
- // If a current description exists, generate m= sections in the same order,
- // using the first audio/video/data section that appears and rejecting
- // extraneous ones.
- if (local_description()) {
- GenerateMediaDescriptionOptions(
- local_description(),
- RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
- RtpTransceiverDirectionFromSendRecv(send_video, recv_video),
- &audio_index, &video_index, &data_index, session_options);
- }
-
- // Add audio/video/data m= sections to the end if needed.
- if (!audio_index && offer_new_audio_description) {
- cricket::MediaDescriptionOptions options(
- cricket::MEDIA_TYPE_AUDIO, cricket::CN_AUDIO,
- RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio), false);
- options.header_extensions =
- channel_manager()->GetSupportedAudioRtpHeaderExtensions();
- session_options->media_description_options.push_back(options);
- audio_index = session_options->media_description_options.size() - 1;
- }
- if (!video_index && offer_new_video_description) {
- cricket::MediaDescriptionOptions options(
- cricket::MEDIA_TYPE_VIDEO, cricket::CN_VIDEO,
- RtpTransceiverDirectionFromSendRecv(send_video, recv_video), false);
- options.header_extensions =
- channel_manager()->GetSupportedVideoRtpHeaderExtensions();
- session_options->media_description_options.push_back(options);
- video_index = session_options->media_description_options.size() - 1;
- }
- if (!data_index && offer_new_data_description) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForActiveData(cricket::CN_DATA));
- data_index = session_options->media_description_options.size() - 1;
- }
-
- cricket::MediaDescriptionOptions* audio_media_description_options =
- !audio_index ? nullptr
- : &session_options->media_description_options[*audio_index];
- cricket::MediaDescriptionOptions* video_media_description_options =
- !video_index ? nullptr
- : &session_options->media_description_options[*video_index];
-
- AddPlanBRtpSenderOptions(GetSendersInternal(),
- audio_media_description_options,
- video_media_description_options,
- offer_answer_options.num_simulcast_layers);
-}
-
-static cricket::MediaDescriptionOptions
-GetMediaDescriptionOptionsForTransceiver(
- rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- transceiver,
- const std::string& mid,
- bool is_create_offer) {
- // NOTE: a stopping transceiver should be treated as a stopped one in
- // createOffer as specified in
- // https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
- bool stopped =
- is_create_offer ? transceiver->stopping() : transceiver->stopped();
- cricket::MediaDescriptionOptions media_description_options(
- transceiver->media_type(), mid, transceiver->direction(), stopped);
- media_description_options.codec_preferences =
- transceiver->codec_preferences();
- media_description_options.header_extensions =
- transceiver->HeaderExtensionsToOffer();
- // This behavior is specified in JSEP. The gist is that:
- // 1. The MSID is included if the RtpTransceiver's direction is sendonly or
- // sendrecv.
- // 2. If the MSID is included, then it must be included in any subsequent
- // offer/answer exactly the same until the RtpTransceiver is stopped.
- if (stopped || (!RtpTransceiverDirectionHasSend(transceiver->direction()) &&
- !transceiver->internal()->has_ever_been_used_to_send())) {
- return media_description_options;
- }
-
- cricket::SenderOptions sender_options;
- sender_options.track_id = transceiver->sender()->id();
- sender_options.stream_ids = transceiver->sender()->stream_ids();
-
- // The following sets up RIDs and Simulcast.
- // RIDs are included if Simulcast is requested or if any RID was specified.
- RtpParameters send_parameters =
- transceiver->internal()->sender_internal()->GetParametersInternal();
- bool has_rids = std::any_of(send_parameters.encodings.begin(),
- send_parameters.encodings.end(),
- [](const RtpEncodingParameters& encoding) {
- return !encoding.rid.empty();
- });
-
- std::vector<RidDescription> send_rids;
- SimulcastLayerList send_layers;
- for (const RtpEncodingParameters& encoding : send_parameters.encodings) {
- if (encoding.rid.empty()) {
- continue;
- }
- send_rids.push_back(RidDescription(encoding.rid, RidDirection::kSend));
- send_layers.AddLayer(SimulcastLayer(encoding.rid, !encoding.active));
- }
-
- if (has_rids) {
- sender_options.rids = send_rids;
- }
-
- sender_options.simulcast_layers = send_layers;
- // When RIDs are configured, we must set num_sim_layers to 0 to.
- // Otherwise, num_sim_layers must be 1 because either there is no
- // simulcast, or simulcast is acheived by munging the SDP.
- sender_options.num_sim_layers = has_rids ? 0 : 1;
- media_description_options.sender_options.push_back(sender_options);
-
- return media_description_options;
-}
-
-// Returns the ContentInfo at mline index |i|, or null if none exists.
-static const ContentInfo* GetContentByIndex(
- const SessionDescriptionInterface* sdesc,
- size_t i) {
- if (!sdesc) {
- return nullptr;
- }
- const ContentInfos& contents = sdesc->description()->contents();
- return (i < contents.size() ? &contents[i] : nullptr);
-}
-
-void PeerConnection::GetOptionsForUnifiedPlanOffer(
- const RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- // Rules for generating an offer are dictated by JSEP sections 5.2.1 (Initial
- // Offers) and 5.2.2 (Subsequent Offers).
- RTC_DCHECK_EQ(session_options->media_description_options.size(), 0);
- const ContentInfos no_infos;
- const ContentInfos& local_contents =
- (local_description() ? local_description()->description()->contents()
- : no_infos);
- const ContentInfos& remote_contents =
- (remote_description() ? remote_description()->description()->contents()
- : no_infos);
- // The mline indices that can be recycled. New transceivers should reuse these
- // slots first.
- std::queue<size_t> recycleable_mline_indices;
- // First, go through each media section that exists in either the local or
- // remote description and generate a media section in this offer for the
- // associated transceiver. If a media section can be recycled, generate a
- // default, rejected media section here that can be later overwritten.
- for (size_t i = 0;
- i < std::max(local_contents.size(), remote_contents.size()); ++i) {
- // Either |local_content| or |remote_content| is non-null.
- const ContentInfo* local_content =
- (i < local_contents.size() ? &local_contents[i] : nullptr);
- const ContentInfo* current_local_content =
- GetContentByIndex(current_local_description(), i);
- const ContentInfo* remote_content =
- (i < remote_contents.size() ? &remote_contents[i] : nullptr);
- const ContentInfo* current_remote_content =
- GetContentByIndex(current_remote_description(), i);
- bool had_been_rejected =
- (current_local_content && current_local_content->rejected) ||
- (current_remote_content && current_remote_content->rejected);
- const std::string& mid =
- (local_content ? local_content->name : remote_content->name);
- cricket::MediaType media_type =
- (local_content ? local_content->media_description()->type()
- : remote_content->media_description()->type());
- if (media_type == cricket::MEDIA_TYPE_AUDIO ||
- media_type == cricket::MEDIA_TYPE_VIDEO) {
- // A media section is considered eligible for recycling if it is marked as
- // rejected in either the current local or current remote description.
- auto transceiver = GetAssociatedTransceiver(mid);
- if (!transceiver) {
- // No associated transceiver. The media section has been stopped.
- recycleable_mline_indices.push(i);
- session_options->media_description_options.push_back(
- cricket::MediaDescriptionOptions(media_type, mid,
- RtpTransceiverDirection::kInactive,
- /*stopped=*/true));
- } else {
- // NOTE: a stopping transceiver should be treated as a stopped one in
- // createOffer as specified in
- // https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
- if (had_been_rejected && transceiver->stopping()) {
- session_options->media_description_options.push_back(
- cricket::MediaDescriptionOptions(
- transceiver->media_type(), mid,
- RtpTransceiverDirection::kInactive,
- /*stopped=*/true));
- recycleable_mline_indices.push(i);
- } else {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForTransceiver(
- transceiver, mid,
- /*is_create_offer=*/true));
- // CreateOffer shouldn't really cause any state changes in
- // PeerConnection, but we need a way to match new transceivers to new
- // media sections in SetLocalDescription and JSEP specifies this is
- // done by recording the index of the media section generated for the
- // transceiver in the offer.
- transceiver->internal()->set_mline_index(i);
- }
- }
- } else {
- RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
- if (had_been_rejected) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForRejectedData(mid));
- } else {
- RTC_CHECK(GetDataMid());
- if (mid == *GetDataMid()) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForActiveData(mid));
- } else {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForRejectedData(mid));
- }
- }
- }
- }
-
- // Next, look for transceivers that are newly added (that is, are not stopped
- // and not associated). Reuse media sections marked as recyclable first,
- // otherwise append to the end of the offer. New media sections should be
- // added in the order they were added to the PeerConnection.
- for (const auto& transceiver : transceivers_.List()) {
- if (transceiver->mid() || transceiver->stopping()) {
- continue;
- }
- size_t mline_index;
- if (!recycleable_mline_indices.empty()) {
- mline_index = recycleable_mline_indices.front();
- recycleable_mline_indices.pop();
- session_options->media_description_options[mline_index] =
- GetMediaDescriptionOptionsForTransceiver(
- transceiver, mid_generator_(), /*is_create_offer=*/true);
- } else {
- mline_index = session_options->media_description_options.size();
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForTransceiver(
- transceiver, mid_generator_(), /*is_create_offer=*/true));
- }
- // See comment above for why CreateOffer changes the transceiver's state.
- transceiver->internal()->set_mline_index(mline_index);
- }
- // Lastly, add a m-section if we have local data channels and an m section
- // does not already exist.
- if (!GetDataMid() && data_channel_controller_.HasDataChannels()) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForActiveData(mid_generator_()));
- }
-}
-
-void PeerConnection::GetOptionsForAnswer(
- const RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- RTC_DCHECK_RUN_ON(signaling_thread());
- ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
-
- if (IsUnifiedPlan()) {
- GetOptionsForUnifiedPlanAnswer(offer_answer_options, session_options);
- } else {
- GetOptionsForPlanBAnswer(offer_answer_options, session_options);
- }
-
- // Intentionally unset the data channel type for RTP data channel. Otherwise
- // the RTP data channels would be successfully negotiated by default and the
- // unit tests in WebRtcDataBrowserTest will fail when building with chromium.
- // We want to leave RTP data channels broken, so people won't try to use them.
- if (data_channel_controller_.HasRtpDataChannels() ||
- data_channel_type() != cricket::DCT_RTP) {
- session_options->data_channel_type = data_channel_type();
- }
-
- // Apply ICE renomination flag.
- for (auto& options : session_options->media_description_options) {
- options.transport_options.enable_ice_renomination =
- configuration_.enable_ice_renomination;
- }
-
- session_options->rtcp_cname = rtcp_cname_;
- session_options->crypto_options = GetCryptoOptions();
- session_options->pooled_ice_credentials =
- network_thread()->Invoke<std::vector<cricket::IceParameters>>(
- RTC_FROM_HERE,
- rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
- port_allocator_.get()));
-}
-
-void PeerConnection::GetOptionsForPlanBAnswer(
- const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- // Figure out transceiver directional preferences.
- bool send_audio = !GetAudioTransceiver()->internal()->senders().empty();
- bool send_video = !GetVideoTransceiver()->internal()->senders().empty();
-
- // By default, generate sendrecv/recvonly m= sections. The direction is also
- // restricted by the direction in the offer.
- bool recv_audio = true;
- bool recv_video = true;
-
- // The "offer_to_receive_X" options allow those defaults to be overridden.
- if (offer_answer_options.offer_to_receive_audio !=
- RTCOfferAnswerOptions::kUndefined) {
- recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
- }
- if (offer_answer_options.offer_to_receive_video !=
- RTCOfferAnswerOptions::kUndefined) {
- recv_video = (offer_answer_options.offer_to_receive_video > 0);
- }
-
- absl::optional<size_t> audio_index;
- absl::optional<size_t> video_index;
- absl::optional<size_t> data_index;
-
- // Generate m= sections that match those in the offer.
- // Note that mediasession.cc will handle intersection our preferred
- // direction with the offered direction.
- GenerateMediaDescriptionOptions(
- remote_description(),
- RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
- RtpTransceiverDirectionFromSendRecv(send_video, recv_video), &audio_index,
- &video_index, &data_index, session_options);
-
- cricket::MediaDescriptionOptions* audio_media_description_options =
- !audio_index ? nullptr
- : &session_options->media_description_options[*audio_index];
- cricket::MediaDescriptionOptions* video_media_description_options =
- !video_index ? nullptr
- : &session_options->media_description_options[*video_index];
-
- AddPlanBRtpSenderOptions(GetSendersInternal(),
- audio_media_description_options,
- video_media_description_options,
- offer_answer_options.num_simulcast_layers);
-}
-
-void PeerConnection::GetOptionsForUnifiedPlanAnswer(
- const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options) {
- // Rules for generating an answer are dictated by JSEP sections 5.3.1 (Initial
- // Answers) and 5.3.2 (Subsequent Answers).
- RTC_DCHECK(remote_description());
- RTC_DCHECK(remote_description()->GetType() == SdpType::kOffer);
- for (const ContentInfo& content :
- remote_description()->description()->contents()) {
- cricket::MediaType media_type = content.media_description()->type();
- if (media_type == cricket::MEDIA_TYPE_AUDIO ||
- media_type == cricket::MEDIA_TYPE_VIDEO) {
- auto transceiver = GetAssociatedTransceiver(content.name);
- if (transceiver) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForTransceiver(
- transceiver, content.name,
- /*is_create_offer=*/false));
- } else {
- // This should only happen with rejected transceivers.
- RTC_DCHECK(content.rejected);
- session_options->media_description_options.push_back(
- cricket::MediaDescriptionOptions(media_type, content.name,
- RtpTransceiverDirection::kInactive,
- /*stopped=*/true));
- }
- } else {
- RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
- // Reject all data sections if data channels are disabled.
- // Reject a data section if it has already been rejected.
- // Reject all data sections except for the first one.
- if (data_channel_type() == cricket::DCT_NONE || content.rejected ||
- content.name != *GetDataMid()) {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForRejectedData(content.name));
- } else {
- session_options->media_description_options.push_back(
- GetMediaDescriptionOptionsForActiveData(content.name));
- }
- }
- }
-}
void PeerConnection::GenerateMediaDescriptionOptions(
const SessionDescriptionInterface* session_desc,
@@ -3155,6 +2564,7 @@
absl::optional<size_t>* video_index,
absl::optional<size_t>* data_index,
cricket::MediaSessionOptions* session_options) {
+ RTC_DCHECK_RUN_ON(signaling_thread());
for (const cricket::ContentInfo& content :
session_desc->description()->contents()) {
if (IsAudioContent(&content)) {
@@ -3209,6 +2619,7 @@
cricket::MediaDescriptionOptions
PeerConnection::GetMediaDescriptionOptionsForActiveData(
const std::string& mid) const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
// Direction for data sections is meaningless, but legacy endpoints might
// expect sendrecv.
cricket::MediaDescriptionOptions options(cricket::MEDIA_TYPE_DATA, mid,
@@ -3222,6 +2633,7 @@
cricket::MediaDescriptionOptions
PeerConnection::GetMediaDescriptionOptionsForRejectedData(
const std::string& mid) const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
cricket::MediaDescriptionOptions options(cricket::MEDIA_TYPE_DATA, mid,
RtpTransceiverDirection::kInactive,
/*stopped=*/true);
@@ -3511,6 +2923,7 @@
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
PeerConnection::GetAudioTransceiver() const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
// This method only works with Plan B SDP, where there is a single
// audio/video transceiver.
RTC_DCHECK(!IsUnifiedPlan());
@@ -3525,6 +2938,7 @@
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
PeerConnection::GetVideoTransceiver() const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
// This method only works with Plan B SDP, where there is a single
// audio/video transceiver.
RTC_DCHECK(!IsUnifiedPlan());
@@ -3839,7 +3253,7 @@
for (const auto& transceiver : transceivers_.List()) {
cricket::ChannelInterface* channel = transceiver->internal()->channel();
const ContentInfo* content =
- FindMediaSectionForTransceiver(transceiver, sdesc);
+ sdp_handler_.FindMediaSectionForTransceiver(transceiver, sdesc);
if (!channel || !content) {
continue;
}
@@ -3888,7 +3302,7 @@
// Push down the new SDP media section for each audio/video transceiver.
for (const auto& transceiver : transceivers_.List()) {
const ContentInfo* content_info =
- FindMediaSectionForTransceiver(transceiver, sdesc);
+ sdp_handler_.FindMediaSectionForTransceiver(transceiver, sdesc);
cricket::ChannelInterface* channel = transceiver->internal()->channel();
if (!channel || !content_info || content_info->rejected) {
continue;
@@ -4596,30 +4010,6 @@
return content->media_description()->rtcp_mux();
}
-bool PeerConnection::ExpectSetLocalDescription(SdpType type) {
- PeerConnectionInterface::SignalingState state = signaling_state();
- if (type == SdpType::kOffer) {
- return (state == PeerConnectionInterface::kStable) ||
- (state == PeerConnectionInterface::kHaveLocalOffer);
- } else {
- RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
- return (state == PeerConnectionInterface::kHaveRemoteOffer) ||
- (state == PeerConnectionInterface::kHaveLocalPrAnswer);
- }
-}
-
-bool PeerConnection::ExpectSetRemoteDescription(SdpType type) {
- PeerConnectionInterface::SignalingState state = signaling_state();
- if (type == SdpType::kOffer) {
- return (state == PeerConnectionInterface::kStable) ||
- (state == PeerConnectionInterface::kHaveRemoteOffer);
- } else {
- RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
- return (state == PeerConnectionInterface::kHaveLocalOffer) ||
- (state == PeerConnectionInterface::kHaveRemotePrAnswer);
- }
-}
-
const char* PeerConnection::SessionErrorToString(SessionError error) const {
switch (error) {
case SessionError::kNone:
@@ -5068,6 +4458,7 @@
}
CryptoOptions PeerConnection::GetCryptoOptions() {
+ RTC_DCHECK_RUN_ON(signaling_thread());
// TODO(bugs.webrtc.org/9891) - Remove PeerConnectionFactory::CryptoOptions
// after it has been removed.
return configuration_.crypto_options.has_value()
diff --git a/pc/peer_connection.h b/pc/peer_connection.h
index e57920d..e5a7ae8 100644
--- a/pc/peer_connection.h
+++ b/pc/peer_connection.h
@@ -412,15 +412,15 @@
RTC_RUN_ON(signaling_thread());
std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
- GetSendersInternal() const RTC_RUN_ON(signaling_thread());
+ GetSendersInternal() const;
std::vector<
rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>>
GetReceiversInternal() const RTC_RUN_ON(signaling_thread());
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- GetAudioTransceiver() const RTC_RUN_ON(signaling_thread());
+ GetAudioTransceiver() const;
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- GetVideoTransceiver() const RTC_RUN_ON(signaling_thread());
+ GetVideoTransceiver() const;
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetFirstAudioTransceiver() const RTC_RUN_ON(signaling_thread());
@@ -560,20 +560,6 @@
rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
GetTransceiverByMLineIndex(size_t mline_index) const;
- // Returns an RtpTransciever, if available, that can be used to receive the
- // given media type according to JSEP rules.
- rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- FindAvailableTransceiverToReceive(cricket::MediaType media_type) const;
-
- // Returns the media section in the given session description that is
- // associated with the RtpTransceiver. Returns null if none found or this
- // RtpTransceiver is not associated. Logic varies depending on the
- // SdpSemantics specified in the configuration.
- const cricket::ContentInfo* FindMediaSectionForTransceiver(
- rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
- transceiver,
- const SessionDescriptionInterface* sdesc) const;
-
// Runs the algorithm **process the removal of a remote track** specified in
// the WebRTC specification.
// This method will update the following lists:
@@ -595,21 +581,6 @@
void OnNegotiationNeeded();
- // Returns a MediaSessionOptions struct with options decided by |options|,
- // the local MediaStreams and DataChannels.
- void GetOptionsForOffer(const PeerConnectionInterface::RTCOfferAnswerOptions&
- offer_answer_options,
- cricket::MediaSessionOptions* session_options);
- void GetOptionsForPlanBOffer(
- const PeerConnectionInterface::RTCOfferAnswerOptions&
- offer_answer_options,
- cricket::MediaSessionOptions* session_options)
- RTC_RUN_ON(signaling_thread());
- void GetOptionsForUnifiedPlanOffer(
- const PeerConnectionInterface::RTCOfferAnswerOptions&
- offer_answer_options,
- cricket::MediaSessionOptions* session_options)
- RTC_RUN_ON(signaling_thread());
RTCError HandleLegacyOfferOptions(const RTCOfferAnswerOptions& options);
void RemoveRecvDirectionFromReceivingTransceiversOfType(
@@ -620,21 +591,6 @@
GetReceivingTransceiversOfType(cricket::MediaType media_type)
RTC_RUN_ON(signaling_thread());
- // Returns a MediaSessionOptions struct with options decided by
- // |constraints|, the local MediaStreams and DataChannels.
- void GetOptionsForAnswer(const RTCOfferAnswerOptions& offer_answer_options,
- cricket::MediaSessionOptions* session_options);
- void GetOptionsForPlanBAnswer(
- const PeerConnectionInterface::RTCOfferAnswerOptions&
- offer_answer_options,
- cricket::MediaSessionOptions* session_options)
- RTC_RUN_ON(signaling_thread());
- void GetOptionsForUnifiedPlanAnswer(
- const PeerConnectionInterface::RTCOfferAnswerOptions&
- offer_answer_options,
- cricket::MediaSessionOptions* session_options)
- RTC_RUN_ON(signaling_thread());
-
// Generates MediaDescriptionOptions for the |session_opts| based on existing
// local description or remote description.
void GenerateMediaDescriptionOptions(
@@ -644,18 +600,17 @@
absl::optional<size_t>* audio_index,
absl::optional<size_t>* video_index,
absl::optional<size_t>* data_index,
- cricket::MediaSessionOptions* session_options)
- RTC_RUN_ON(signaling_thread());
+ cricket::MediaSessionOptions* session_options);
// Generates the active MediaDescriptionOptions for the local data channel
// given the specified MID.
cricket::MediaDescriptionOptions GetMediaDescriptionOptionsForActiveData(
- const std::string& mid) const RTC_RUN_ON(signaling_thread());
+ const std::string& mid) const;
// Generates the rejected MediaDescriptionOptions for the local data channel
// given the specified MID.
cricket::MediaDescriptionOptions GetMediaDescriptionOptionsForRejectedData(
- const std::string& mid) const RTC_RUN_ON(signaling_thread());
+ const std::string& mid) const;
// Returns the MID for the data section associated with either the
// RtpDataChannel or SCTP data channel, if it has been set. If no data
@@ -732,12 +687,6 @@
return configuration_.sdp_semantics == SdpSemantics::kUnifiedPlan;
}
- // The offer/answer machinery assumes the media section MID is present and
- // unique. To support legacy end points that do not supply a=mid lines, this
- // method will modify the session description to add MIDs generated according
- // to the SDP semantics.
- void FillInMissingRemoteMids(cricket::SessionDescription* remote_description);
-
// Return the RtpSender with the given track attached.
rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>
FindSenderForTrack(MediaStreamTrackInterface* track) const
@@ -893,12 +842,6 @@
bool ValidateBundleSettings(const cricket::SessionDescription* desc);
bool HasRtcpMuxEnabled(const cricket::ContentInfo* content);
- // Check if a call to SetLocalDescription is acceptable with a session
- // description of the given type.
- bool ExpectSetLocalDescription(SdpType type);
- // Check if a call to SetRemoteDescription is acceptable with a session
- // description of the given type.
- bool ExpectSetRemoteDescription(SdpType type);
// Verifies a=setup attribute as per RFC 5763.
bool ValidateDtlsSetupAttribute(const cricket::SessionDescription* desc,
SdpType type);
@@ -1004,7 +947,7 @@
// Returns the CryptoOptions for this PeerConnection. This will always
// return the RTCConfiguration.crypto_options if set and will only default
// back to the PeerConnectionFactory settings if nothing was set.
- CryptoOptions GetCryptoOptions() RTC_RUN_ON(signaling_thread());
+ CryptoOptions GetCryptoOptions();
// Returns rtp transport, result can not be nullptr.
RtpTransportInternal* GetRtpTransport(const std::string& mid)
diff --git a/pc/sdp_offer_answer.cc b/pc/sdp_offer_answer.cc
index 03d3001..b150ce9 100644
--- a/pc/sdp_offer_answer.cc
+++ b/pc/sdp_offer_answer.cc
@@ -10,6 +10,9 @@
#include "pc/sdp_offer_answer.h"
+#include <algorithm>
+#include <queue>
+
#include "api/media_stream_proxy.h"
#include "api/uma_metrics.h"
#include "pc/media_stream.h"
@@ -40,6 +43,9 @@
namespace {
+typedef webrtc::PeerConnectionInterface::RTCOfferAnswerOptions
+ RTCOfferAnswerOptions;
+
// Error messages
const char kInvalidSdp[] = "Invalid session description.";
const char kInvalidCandidates[] = "Description contains invalid candidates.";
@@ -494,6 +500,132 @@
return sender->DisableEncodingLayers(disabled_layers);
}
+// The SDP parser used to populate these values by default for the 'content
+// name' if an a=mid line was absent.
+static absl::string_view GetDefaultMidForPlanB(cricket::MediaType media_type) {
+ switch (media_type) {
+ case cricket::MEDIA_TYPE_AUDIO:
+ return cricket::CN_AUDIO;
+ case cricket::MEDIA_TYPE_VIDEO:
+ return cricket::CN_VIDEO;
+ case cricket::MEDIA_TYPE_DATA:
+ return cricket::CN_DATA;
+ }
+ RTC_NOTREACHED();
+ return "";
+}
+
+// Add options to |[audio/video]_media_description_options| from |senders|.
+void AddPlanBRtpSenderOptions(
+ const std::vector<rtc::scoped_refptr<
+ RtpSenderProxyWithInternal<RtpSenderInternal>>>& senders,
+ cricket::MediaDescriptionOptions* audio_media_description_options,
+ cricket::MediaDescriptionOptions* video_media_description_options,
+ int num_sim_layers) {
+ for (const auto& sender : senders) {
+ if (sender->media_type() == cricket::MEDIA_TYPE_AUDIO) {
+ if (audio_media_description_options) {
+ audio_media_description_options->AddAudioSender(
+ sender->id(), sender->internal()->stream_ids());
+ }
+ } else {
+ RTC_DCHECK(sender->media_type() == cricket::MEDIA_TYPE_VIDEO);
+ if (video_media_description_options) {
+ video_media_description_options->AddVideoSender(
+ sender->id(), sender->internal()->stream_ids(), {},
+ SimulcastLayerList(), num_sim_layers);
+ }
+ }
+ }
+}
+
+static cricket::MediaDescriptionOptions
+GetMediaDescriptionOptionsForTransceiver(
+ rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
+ transceiver,
+ const std::string& mid,
+ bool is_create_offer) {
+ // NOTE: a stopping transceiver should be treated as a stopped one in
+ // createOffer as specified in
+ // https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
+ bool stopped =
+ is_create_offer ? transceiver->stopping() : transceiver->stopped();
+ cricket::MediaDescriptionOptions media_description_options(
+ transceiver->media_type(), mid, transceiver->direction(), stopped);
+ media_description_options.codec_preferences =
+ transceiver->codec_preferences();
+ media_description_options.header_extensions =
+ transceiver->HeaderExtensionsToOffer();
+ // This behavior is specified in JSEP. The gist is that:
+ // 1. The MSID is included if the RtpTransceiver's direction is sendonly or
+ // sendrecv.
+ // 2. If the MSID is included, then it must be included in any subsequent
+ // offer/answer exactly the same until the RtpTransceiver is stopped.
+ if (stopped || (!RtpTransceiverDirectionHasSend(transceiver->direction()) &&
+ !transceiver->internal()->has_ever_been_used_to_send())) {
+ return media_description_options;
+ }
+
+ cricket::SenderOptions sender_options;
+ sender_options.track_id = transceiver->sender()->id();
+ sender_options.stream_ids = transceiver->sender()->stream_ids();
+
+ // The following sets up RIDs and Simulcast.
+ // RIDs are included if Simulcast is requested or if any RID was specified.
+ RtpParameters send_parameters =
+ transceiver->internal()->sender_internal()->GetParametersInternal();
+ bool has_rids = std::any_of(send_parameters.encodings.begin(),
+ send_parameters.encodings.end(),
+ [](const RtpEncodingParameters& encoding) {
+ return !encoding.rid.empty();
+ });
+
+ std::vector<RidDescription> send_rids;
+ SimulcastLayerList send_layers;
+ for (const RtpEncodingParameters& encoding : send_parameters.encodings) {
+ if (encoding.rid.empty()) {
+ continue;
+ }
+ send_rids.push_back(RidDescription(encoding.rid, RidDirection::kSend));
+ send_layers.AddLayer(SimulcastLayer(encoding.rid, !encoding.active));
+ }
+
+ if (has_rids) {
+ sender_options.rids = send_rids;
+ }
+
+ sender_options.simulcast_layers = send_layers;
+ // When RIDs are configured, we must set num_sim_layers to 0 to.
+ // Otherwise, num_sim_layers must be 1 because either there is no
+ // simulcast, or simulcast is acheived by munging the SDP.
+ sender_options.num_sim_layers = has_rids ? 0 : 1;
+ media_description_options.sender_options.push_back(sender_options);
+
+ return media_description_options;
+}
+
+// Returns the ContentInfo at mline index |i|, or null if none exists.
+static const ContentInfo* GetContentByIndex(
+ const SessionDescriptionInterface* sdesc,
+ size_t i) {
+ if (!sdesc) {
+ return nullptr;
+ }
+ const ContentInfos& contents = sdesc->description()->contents();
+ return (i < contents.size() ? &contents[i] : nullptr);
+}
+
+// From |rtc_options|, fill parts of |session_options| shared by all generated
+// m= sectionss (in other words, nothing that involves a map/array).
+void ExtractSharedMediaSessionOptions(
+ const PeerConnectionInterface::RTCOfferAnswerOptions& rtc_options,
+ cricket::MediaSessionOptions* session_options) {
+ session_options->vad_enabled = rtc_options.voice_activity_detection;
+ session_options->bundle_enabled = rtc_options.use_rtp_mux;
+ session_options->raw_packetization_for_video =
+ rtc_options.raw_packetization_for_video;
+}
+
} // namespace
// Used by parameterless SetLocalDescription() to create an offer or answer.
@@ -964,7 +1096,7 @@
}
const ContentInfo* content =
- pc_->FindMediaSectionForTransceiver(transceiver, local_description());
+ FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
@@ -1041,7 +1173,7 @@
continue;
}
const ContentInfo* content =
- pc_->FindMediaSectionForTransceiver(transceiver, local_description());
+ FindMediaSectionForTransceiver(transceiver, local_description());
if (!content) {
continue;
}
@@ -1316,8 +1448,8 @@
std::vector<rtc::scoped_refptr<MediaStreamInterface>> added_streams;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> removed_streams;
for (const auto& transceiver : pc_->transceivers_.List()) {
- const ContentInfo* content = pc_->FindMediaSectionForTransceiver(
- transceiver, remote_description());
+ const ContentInfo* content =
+ FindMediaSectionForTransceiver(transceiver, remote_description());
if (!content) {
continue;
}
@@ -1668,7 +1800,7 @@
}
cricket::MediaSessionOptions session_options;
- pc_->GetOptionsForOffer(options, &session_options);
+ GetOptionsForOffer(options, &session_options);
webrtc_session_desc_factory_->CreateOffer(observer, options, session_options);
}
@@ -1753,7 +1885,7 @@
}
cricket::MediaSessionOptions session_options;
- pc_->GetOptionsForAnswer(options, &session_options);
+ GetOptionsForAnswer(options, &session_options);
webrtc_session_desc_factory_->CreateAnswer(observer, session_options);
}
@@ -1808,7 +1940,7 @@
// Handle remote descriptions missing a=mid lines for interop with legacy end
// points.
- pc_->FillInMissingRemoteMids(desc->description());
+ FillInMissingRemoteMids(desc->description());
RTCError error = ValidateSessionDescription(desc.get(), cricket::CS_REMOTE);
if (!error.ok()) {
@@ -2539,9 +2671,8 @@
}
SdpType type = sdesc->GetType();
- if ((source == cricket::CS_LOCAL && !pc_->ExpectSetLocalDescription(type)) ||
- (source == cricket::CS_REMOTE &&
- !pc_->ExpectSetRemoteDescription(type))) {
+ if ((source == cricket::CS_LOCAL && !ExpectSetLocalDescription(type)) ||
+ (source == cricket::CS_REMOTE && !ExpectSetRemoteDescription(type))) {
LOG_AND_RETURN_ERROR(
RTCErrorType::INVALID_STATE,
"Called in wrong state: " + GetSignalingStateString(signaling_state()));
@@ -2759,7 +2890,7 @@
if (!transceiver &&
RtpTransceiverDirectionHasRecv(media_desc->direction()) &&
!media_desc->HasSimulcast()) {
- transceiver = pc_->FindAvailableTransceiverToReceive(media_desc->type());
+ transceiver = FindAvailableTransceiverToReceive(media_desc->type());
}
// If no RtpTransceiver was found in the previous step, create one with a
// recvonly direction.
@@ -2918,4 +3049,501 @@
return RTCError::OK();
}
+bool SdpOfferAnswerHandler::ExpectSetLocalDescription(SdpType type) {
+ PeerConnectionInterface::SignalingState state = signaling_state();
+ if (type == SdpType::kOffer) {
+ return (state == PeerConnectionInterface::kStable) ||
+ (state == PeerConnectionInterface::kHaveLocalOffer);
+ } else {
+ RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
+ return (state == PeerConnectionInterface::kHaveRemoteOffer) ||
+ (state == PeerConnectionInterface::kHaveLocalPrAnswer);
+ }
+}
+
+bool SdpOfferAnswerHandler::ExpectSetRemoteDescription(SdpType type) {
+ PeerConnectionInterface::SignalingState state = signaling_state();
+ if (type == SdpType::kOffer) {
+ return (state == PeerConnectionInterface::kStable) ||
+ (state == PeerConnectionInterface::kHaveRemoteOffer);
+ } else {
+ RTC_DCHECK(type == SdpType::kPrAnswer || type == SdpType::kAnswer);
+ return (state == PeerConnectionInterface::kHaveLocalOffer) ||
+ (state == PeerConnectionInterface::kHaveRemotePrAnswer);
+ }
+}
+
+void SdpOfferAnswerHandler::FillInMissingRemoteMids(
+ cricket::SessionDescription* new_remote_description) {
+ RTC_DCHECK_RUN_ON(signaling_thread());
+ RTC_DCHECK(new_remote_description);
+ const cricket::ContentInfos no_infos;
+ const cricket::ContentInfos& local_contents =
+ (local_description() ? local_description()->description()->contents()
+ : no_infos);
+ const cricket::ContentInfos& remote_contents =
+ (remote_description() ? remote_description()->description()->contents()
+ : no_infos);
+ for (size_t i = 0; i < new_remote_description->contents().size(); ++i) {
+ cricket::ContentInfo& content = new_remote_description->contents()[i];
+ if (!content.name.empty()) {
+ continue;
+ }
+ std::string new_mid;
+ absl::string_view source_explanation;
+ if (IsUnifiedPlan()) {
+ if (i < local_contents.size()) {
+ new_mid = local_contents[i].name;
+ source_explanation = "from the matching local media section";
+ } else if (i < remote_contents.size()) {
+ new_mid = remote_contents[i].name;
+ source_explanation = "from the matching previous remote media section";
+ } else {
+ new_mid = pc_->mid_generator()->GenerateString();
+ source_explanation = "generated just now";
+ }
+ } else {
+ new_mid = std::string(
+ GetDefaultMidForPlanB(content.media_description()->type()));
+ source_explanation = "to match pre-existing behavior";
+ }
+ RTC_DCHECK(!new_mid.empty());
+ content.name = new_mid;
+ new_remote_description->transport_infos()[i].content_name = new_mid;
+ RTC_LOG(LS_INFO) << "SetRemoteDescription: Remote media section at i=" << i
+ << " is missing an a=mid line. Filling in the value '"
+ << new_mid << "' " << source_explanation << ".";
+ }
+}
+
+rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
+SdpOfferAnswerHandler::FindAvailableTransceiverToReceive(
+ cricket::MediaType media_type) const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
+ RTC_DCHECK(IsUnifiedPlan());
+ // From JSEP section 5.10 (Applying a Remote Description):
+ // If the m= section is sendrecv or recvonly, and there are RtpTransceivers of
+ // the same type that were added to the PeerConnection by addTrack and are not
+ // associated with any m= section and are not stopped, find the first such
+ // RtpTransceiver.
+ for (auto transceiver : pc_->transceivers_.List()) {
+ if (transceiver->media_type() == media_type &&
+ transceiver->internal()->created_by_addtrack() && !transceiver->mid() &&
+ !transceiver->stopped()) {
+ return transceiver;
+ }
+ }
+ return nullptr;
+}
+
+const cricket::ContentInfo*
+SdpOfferAnswerHandler::FindMediaSectionForTransceiver(
+ rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
+ transceiver,
+ const SessionDescriptionInterface* sdesc) const {
+ RTC_DCHECK_RUN_ON(signaling_thread());
+ RTC_DCHECK(transceiver);
+ RTC_DCHECK(sdesc);
+ if (IsUnifiedPlan()) {
+ if (!transceiver->internal()->mid()) {
+ // This transceiver is not associated with a media section yet.
+ return nullptr;
+ }
+ return sdesc->description()->GetContentByName(
+ *transceiver->internal()->mid());
+ } else {
+ // Plan B only allows at most one audio and one video section, so use the
+ // first media section of that type.
+ return cricket::GetFirstMediaContent(sdesc->description()->contents(),
+ transceiver->media_type());
+ }
+}
+
+void SdpOfferAnswerHandler::GetOptionsForOffer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ RTC_DCHECK_RUN_ON(signaling_thread());
+ ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
+
+ if (IsUnifiedPlan()) {
+ GetOptionsForUnifiedPlanOffer(offer_answer_options, session_options);
+ } else {
+ GetOptionsForPlanBOffer(offer_answer_options, session_options);
+ }
+
+ // Intentionally unset the data channel type for RTP data channel with the
+ // second condition. Otherwise the RTP data channels would be successfully
+ // negotiated by default and the unit tests in WebRtcDataBrowserTest will fail
+ // when building with chromium. We want to leave RTP data channels broken, so
+ // people won't try to use them.
+ if (pc_->data_channel_controller()->HasRtpDataChannels() ||
+ pc_->data_channel_type() != cricket::DCT_RTP) {
+ session_options->data_channel_type = pc_->data_channel_type();
+ }
+
+ // Apply ICE restart flag and renomination flag.
+ bool ice_restart = offer_answer_options.ice_restart || HasNewIceCredentials();
+ for (auto& options : session_options->media_description_options) {
+ options.transport_options.ice_restart = ice_restart;
+ options.transport_options.enable_ice_renomination =
+ pc_->configuration()->enable_ice_renomination;
+ }
+
+ session_options->rtcp_cname = pc_->rtcp_cname_;
+ session_options->crypto_options = pc_->GetCryptoOptions();
+ session_options->pooled_ice_credentials =
+ pc_->network_thread()->Invoke<std::vector<cricket::IceParameters>>(
+ RTC_FROM_HERE,
+ rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
+ pc_->port_allocator_.get()));
+ session_options->offer_extmap_allow_mixed =
+ pc_->configuration()->offer_extmap_allow_mixed;
+
+ // Allow fallback for using obsolete SCTP syntax.
+ // Note that the default in |session_options| is true, while
+ // the default in |options| is false.
+ session_options->use_obsolete_sctp_sdp =
+ offer_answer_options.use_obsolete_sctp_sdp;
+}
+
+void SdpOfferAnswerHandler::GetOptionsForPlanBOffer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ // Figure out transceiver directional preferences.
+ bool send_audio = !pc_->GetAudioTransceiver()->internal()->senders().empty();
+ bool send_video = !pc_->GetVideoTransceiver()->internal()->senders().empty();
+
+ // By default, generate sendrecv/recvonly m= sections.
+ bool recv_audio = true;
+ bool recv_video = true;
+
+ // By default, only offer a new m= section if we have media to send with it.
+ bool offer_new_audio_description = send_audio;
+ bool offer_new_video_description = send_video;
+ bool offer_new_data_description =
+ pc_->data_channel_controller()->HasDataChannels();
+
+ // The "offer_to_receive_X" options allow those defaults to be overridden.
+ if (offer_answer_options.offer_to_receive_audio !=
+ PeerConnectionInterface::RTCOfferAnswerOptions::kUndefined) {
+ recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
+ offer_new_audio_description =
+ offer_new_audio_description ||
+ (offer_answer_options.offer_to_receive_audio > 0);
+ }
+ if (offer_answer_options.offer_to_receive_video !=
+ RTCOfferAnswerOptions::kUndefined) {
+ recv_video = (offer_answer_options.offer_to_receive_video > 0);
+ offer_new_video_description =
+ offer_new_video_description ||
+ (offer_answer_options.offer_to_receive_video > 0);
+ }
+
+ absl::optional<size_t> audio_index;
+ absl::optional<size_t> video_index;
+ absl::optional<size_t> data_index;
+ // If a current description exists, generate m= sections in the same order,
+ // using the first audio/video/data section that appears and rejecting
+ // extraneous ones.
+ if (local_description()) {
+ pc_->GenerateMediaDescriptionOptions(
+ local_description(),
+ RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
+ RtpTransceiverDirectionFromSendRecv(send_video, recv_video),
+ &audio_index, &video_index, &data_index, session_options);
+ }
+
+ // Add audio/video/data m= sections to the end if needed.
+ if (!audio_index && offer_new_audio_description) {
+ cricket::MediaDescriptionOptions options(
+ cricket::MEDIA_TYPE_AUDIO, cricket::CN_AUDIO,
+ RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio), false);
+ options.header_extensions =
+ pc_->channel_manager()->GetSupportedAudioRtpHeaderExtensions();
+ session_options->media_description_options.push_back(options);
+ audio_index = session_options->media_description_options.size() - 1;
+ }
+ if (!video_index && offer_new_video_description) {
+ cricket::MediaDescriptionOptions options(
+ cricket::MEDIA_TYPE_VIDEO, cricket::CN_VIDEO,
+ RtpTransceiverDirectionFromSendRecv(send_video, recv_video), false);
+ options.header_extensions =
+ pc_->channel_manager()->GetSupportedVideoRtpHeaderExtensions();
+ session_options->media_description_options.push_back(options);
+ video_index = session_options->media_description_options.size() - 1;
+ }
+ if (!data_index && offer_new_data_description) {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForActiveData(cricket::CN_DATA));
+ data_index = session_options->media_description_options.size() - 1;
+ }
+
+ cricket::MediaDescriptionOptions* audio_media_description_options =
+ !audio_index ? nullptr
+ : &session_options->media_description_options[*audio_index];
+ cricket::MediaDescriptionOptions* video_media_description_options =
+ !video_index ? nullptr
+ : &session_options->media_description_options[*video_index];
+
+ AddPlanBRtpSenderOptions(pc_->GetSendersInternal(),
+ audio_media_description_options,
+ video_media_description_options,
+ offer_answer_options.num_simulcast_layers);
+}
+
+void SdpOfferAnswerHandler::GetOptionsForUnifiedPlanOffer(
+ const RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ // Rules for generating an offer are dictated by JSEP sections 5.2.1 (Initial
+ // Offers) and 5.2.2 (Subsequent Offers).
+ RTC_DCHECK_EQ(session_options->media_description_options.size(), 0);
+ const ContentInfos no_infos;
+ const ContentInfos& local_contents =
+ (local_description() ? local_description()->description()->contents()
+ : no_infos);
+ const ContentInfos& remote_contents =
+ (remote_description() ? remote_description()->description()->contents()
+ : no_infos);
+ // The mline indices that can be recycled. New transceivers should reuse these
+ // slots first.
+ std::queue<size_t> recycleable_mline_indices;
+ // First, go through each media section that exists in either the local or
+ // remote description and generate a media section in this offer for the
+ // associated transceiver. If a media section can be recycled, generate a
+ // default, rejected media section here that can be later overwritten.
+ for (size_t i = 0;
+ i < std::max(local_contents.size(), remote_contents.size()); ++i) {
+ // Either |local_content| or |remote_content| is non-null.
+ const ContentInfo* local_content =
+ (i < local_contents.size() ? &local_contents[i] : nullptr);
+ const ContentInfo* current_local_content =
+ GetContentByIndex(current_local_description(), i);
+ const ContentInfo* remote_content =
+ (i < remote_contents.size() ? &remote_contents[i] : nullptr);
+ const ContentInfo* current_remote_content =
+ GetContentByIndex(current_remote_description(), i);
+ bool had_been_rejected =
+ (current_local_content && current_local_content->rejected) ||
+ (current_remote_content && current_remote_content->rejected);
+ const std::string& mid =
+ (local_content ? local_content->name : remote_content->name);
+ cricket::MediaType media_type =
+ (local_content ? local_content->media_description()->type()
+ : remote_content->media_description()->type());
+ if (media_type == cricket::MEDIA_TYPE_AUDIO ||
+ media_type == cricket::MEDIA_TYPE_VIDEO) {
+ // A media section is considered eligible for recycling if it is marked as
+ // rejected in either the current local or current remote description.
+ auto transceiver = pc_->GetAssociatedTransceiver(mid);
+ if (!transceiver) {
+ // No associated transceiver. The media section has been stopped.
+ recycleable_mline_indices.push(i);
+ session_options->media_description_options.push_back(
+ cricket::MediaDescriptionOptions(media_type, mid,
+ RtpTransceiverDirection::kInactive,
+ /*stopped=*/true));
+ } else {
+ // NOTE: a stopping transceiver should be treated as a stopped one in
+ // createOffer as specified in
+ // https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer.
+ if (had_been_rejected && transceiver->stopping()) {
+ session_options->media_description_options.push_back(
+ cricket::MediaDescriptionOptions(
+ transceiver->media_type(), mid,
+ RtpTransceiverDirection::kInactive,
+ /*stopped=*/true));
+ recycleable_mline_indices.push(i);
+ } else {
+ session_options->media_description_options.push_back(
+ GetMediaDescriptionOptionsForTransceiver(
+ transceiver, mid,
+ /*is_create_offer=*/true));
+ // CreateOffer shouldn't really cause any state changes in
+ // PeerConnection, but we need a way to match new transceivers to new
+ // media sections in SetLocalDescription and JSEP specifies this is
+ // done by recording the index of the media section generated for the
+ // transceiver in the offer.
+ transceiver->internal()->set_mline_index(i);
+ }
+ }
+ } else {
+ RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
+ if (had_been_rejected) {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForRejectedData(mid));
+ } else {
+ RTC_CHECK(pc_->GetDataMid());
+ if (mid == *(pc_->GetDataMid())) {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForActiveData(mid));
+ } else {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForRejectedData(mid));
+ }
+ }
+ }
+ }
+
+ // Next, look for transceivers that are newly added (that is, are not stopped
+ // and not associated). Reuse media sections marked as recyclable first,
+ // otherwise append to the end of the offer. New media sections should be
+ // added in the order they were added to the PeerConnection.
+ for (const auto& transceiver : pc_->transceivers_.List()) {
+ if (transceiver->mid() || transceiver->stopping()) {
+ continue;
+ }
+ size_t mline_index;
+ if (!recycleable_mline_indices.empty()) {
+ mline_index = recycleable_mline_indices.front();
+ recycleable_mline_indices.pop();
+ session_options->media_description_options[mline_index] =
+ GetMediaDescriptionOptionsForTransceiver(
+ transceiver, pc_->mid_generator()->GenerateString(),
+ /*is_create_offer=*/true);
+ } else {
+ mline_index = session_options->media_description_options.size();
+ session_options->media_description_options.push_back(
+ GetMediaDescriptionOptionsForTransceiver(
+ transceiver, pc_->mid_generator()->GenerateString(),
+ /*is_create_offer=*/true));
+ }
+ // See comment above for why CreateOffer changes the transceiver's state.
+ transceiver->internal()->set_mline_index(mline_index);
+ }
+ // Lastly, add a m-section if we have local data channels and an m section
+ // does not already exist.
+ if (!pc_->GetDataMid() && pc_->data_channel_controller()->HasDataChannels()) {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForActiveData(
+ pc_->mid_generator()->GenerateString()));
+ }
+}
+
+void SdpOfferAnswerHandler::GetOptionsForAnswer(
+ const RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ RTC_DCHECK_RUN_ON(signaling_thread());
+ ExtractSharedMediaSessionOptions(offer_answer_options, session_options);
+
+ if (IsUnifiedPlan()) {
+ GetOptionsForUnifiedPlanAnswer(offer_answer_options, session_options);
+ } else {
+ GetOptionsForPlanBAnswer(offer_answer_options, session_options);
+ }
+
+ // Intentionally unset the data channel type for RTP data channel. Otherwise
+ // the RTP data channels would be successfully negotiated by default and the
+ // unit tests in WebRtcDataBrowserTest will fail when building with chromium.
+ // We want to leave RTP data channels broken, so people won't try to use them.
+ if (pc_->data_channel_controller()->HasRtpDataChannels() ||
+ pc_->data_channel_type() != cricket::DCT_RTP) {
+ session_options->data_channel_type = pc_->data_channel_type();
+ }
+
+ // Apply ICE renomination flag.
+ for (auto& options : session_options->media_description_options) {
+ options.transport_options.enable_ice_renomination =
+ pc_->configuration()->enable_ice_renomination;
+ }
+
+ session_options->rtcp_cname = pc_->rtcp_cname_;
+ session_options->crypto_options = pc_->GetCryptoOptions();
+ session_options->pooled_ice_credentials =
+ pc_->network_thread()->Invoke<std::vector<cricket::IceParameters>>(
+ RTC_FROM_HERE,
+ rtc::Bind(&cricket::PortAllocator::GetPooledIceCredentials,
+ pc_->port_allocator_.get()));
+}
+
+void SdpOfferAnswerHandler::GetOptionsForPlanBAnswer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ // Figure out transceiver directional preferences.
+ bool send_audio = !pc_->GetAudioTransceiver()->internal()->senders().empty();
+ bool send_video = !pc_->GetVideoTransceiver()->internal()->senders().empty();
+
+ // By default, generate sendrecv/recvonly m= sections. The direction is also
+ // restricted by the direction in the offer.
+ bool recv_audio = true;
+ bool recv_video = true;
+
+ // The "offer_to_receive_X" options allow those defaults to be overridden.
+ if (offer_answer_options.offer_to_receive_audio !=
+ RTCOfferAnswerOptions::kUndefined) {
+ recv_audio = (offer_answer_options.offer_to_receive_audio > 0);
+ }
+ if (offer_answer_options.offer_to_receive_video !=
+ RTCOfferAnswerOptions::kUndefined) {
+ recv_video = (offer_answer_options.offer_to_receive_video > 0);
+ }
+
+ absl::optional<size_t> audio_index;
+ absl::optional<size_t> video_index;
+ absl::optional<size_t> data_index;
+
+ // Generate m= sections that match those in the offer.
+ // Note that mediasession.cc will handle intersection our preferred
+ // direction with the offered direction.
+ pc_->GenerateMediaDescriptionOptions(
+ remote_description(),
+ RtpTransceiverDirectionFromSendRecv(send_audio, recv_audio),
+ RtpTransceiverDirectionFromSendRecv(send_video, recv_video), &audio_index,
+ &video_index, &data_index, session_options);
+
+ cricket::MediaDescriptionOptions* audio_media_description_options =
+ !audio_index ? nullptr
+ : &session_options->media_description_options[*audio_index];
+ cricket::MediaDescriptionOptions* video_media_description_options =
+ !video_index ? nullptr
+ : &session_options->media_description_options[*video_index];
+
+ AddPlanBRtpSenderOptions(pc_->GetSendersInternal(),
+ audio_media_description_options,
+ video_media_description_options,
+ offer_answer_options.num_simulcast_layers);
+}
+
+void SdpOfferAnswerHandler::GetOptionsForUnifiedPlanAnswer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions& offer_answer_options,
+ cricket::MediaSessionOptions* session_options) {
+ // Rules for generating an answer are dictated by JSEP sections 5.3.1 (Initial
+ // Answers) and 5.3.2 (Subsequent Answers).
+ RTC_DCHECK(remote_description());
+ RTC_DCHECK(remote_description()->GetType() == SdpType::kOffer);
+ for (const ContentInfo& content :
+ remote_description()->description()->contents()) {
+ cricket::MediaType media_type = content.media_description()->type();
+ if (media_type == cricket::MEDIA_TYPE_AUDIO ||
+ media_type == cricket::MEDIA_TYPE_VIDEO) {
+ auto transceiver = pc_->GetAssociatedTransceiver(content.name);
+ if (transceiver) {
+ session_options->media_description_options.push_back(
+ GetMediaDescriptionOptionsForTransceiver(
+ transceiver, content.name,
+ /*is_create_offer=*/false));
+ } else {
+ // This should only happen with rejected transceivers.
+ RTC_DCHECK(content.rejected);
+ session_options->media_description_options.push_back(
+ cricket::MediaDescriptionOptions(media_type, content.name,
+ RtpTransceiverDirection::kInactive,
+ /*stopped=*/true));
+ }
+ } else {
+ RTC_CHECK_EQ(cricket::MEDIA_TYPE_DATA, media_type);
+ // Reject all data sections if data channels are disabled.
+ // Reject a data section if it has already been rejected.
+ // Reject all data sections except for the first one.
+ if (pc_->data_channel_type() == cricket::DCT_NONE || content.rejected ||
+ content.name != *(pc_->GetDataMid())) {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForRejectedData(content.name));
+ } else {
+ session_options->media_description_options.push_back(
+ pc_->GetMediaDescriptionOptionsForActiveData(content.name));
+ }
+ }
+ }
+}
+
} // namespace webrtc
diff --git a/pc/sdp_offer_answer.h b/pc/sdp_offer_answer.h
index 780dd93..b84c8bd 100644
--- a/pc/sdp_offer_answer.h
+++ b/pc/sdp_offer_answer.h
@@ -131,6 +131,15 @@
bool IceRestartPending(const std::string& content_name) const;
void UpdateNegotiationNeeded();
+ // Returns the media section in the given session description that is
+ // associated with the RtpTransceiver. Returns null if none found or this
+ // RtpTransceiver is not associated. Logic varies depending on the
+ // SdpSemantics specified in the configuration.
+ const cricket::ContentInfo* FindMediaSectionForTransceiver(
+ rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
+ transceiver,
+ const SessionDescriptionInterface* sdesc) const;
+
private:
class ImplicitCreateSessionDescriptionObserver;
friend class ImplicitCreateSessionDescriptionObserver;
@@ -253,6 +262,55 @@
const cricket::ContentInfo& content,
const cricket::ContentGroup* bundle_group)
RTC_RUN_ON(signaling_thread());
+ // Check if a call to SetLocalDescription is acceptable with a session
+ // description of the given type.
+ bool ExpectSetLocalDescription(SdpType type);
+ // Check if a call to SetRemoteDescription is acceptable with a session
+ // description of the given type.
+ bool ExpectSetRemoteDescription(SdpType type);
+
+ // The offer/answer machinery assumes the media section MID is present and
+ // unique. To support legacy end points that do not supply a=mid lines, this
+ // method will modify the session description to add MIDs generated according
+ // to the SDP semantics.
+ void FillInMissingRemoteMids(cricket::SessionDescription* remote_description);
+
+ // Returns an RtpTransciever, if available, that can be used to receive the
+ // given media type according to JSEP rules.
+ rtc::scoped_refptr<RtpTransceiverProxyWithInternal<RtpTransceiver>>
+ FindAvailableTransceiverToReceive(cricket::MediaType media_type) const;
+
+ // Returns a MediaSessionOptions struct with options decided by |options|,
+ // the local MediaStreams and DataChannels.
+ void GetOptionsForOffer(const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options);
+ void GetOptionsForPlanBOffer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options)
+ RTC_RUN_ON(signaling_thread());
+ void GetOptionsForUnifiedPlanOffer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options)
+ RTC_RUN_ON(signaling_thread());
+
+ // Returns a MediaSessionOptions struct with options decided by
+ // |constraints|, the local MediaStreams and DataChannels.
+ void GetOptionsForAnswer(const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options);
+ void GetOptionsForPlanBAnswer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options)
+ RTC_RUN_ON(signaling_thread());
+ void GetOptionsForUnifiedPlanAnswer(
+ const PeerConnectionInterface::RTCOfferAnswerOptions&
+ offer_answer_options,
+ cricket::MediaSessionOptions* session_options)
+ RTC_RUN_ON(signaling_thread());
// ===================================================================
