diff options
Diffstat (limited to 'media/webrtc/signaling/src/jsep/JsepTrack.cpp')
| -rw-r--r-- | media/webrtc/signaling/src/jsep/JsepTrack.cpp | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/media/webrtc/signaling/src/jsep/JsepTrack.cpp b/media/webrtc/signaling/src/jsep/JsepTrack.cpp new file mode 100644 index 000000000..1b045d8ec --- /dev/null +++ b/media/webrtc/signaling/src/jsep/JsepTrack.cpp @@ -0,0 +1,531 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "signaling/src/jsep/JsepTrack.h" +#include "signaling/src/jsep/JsepCodecDescription.h" +#include "signaling/src/jsep/JsepTrackEncoding.h" + +#include <algorithm> + +namespace mozilla +{ +void +JsepTrack::GetNegotiatedPayloadTypes(std::vector<uint16_t>* payloadTypes) +{ + if (!mNegotiatedDetails) { + return; + } + + for (const auto* encoding : mNegotiatedDetails->mEncodings.values) { + GetPayloadTypes(encoding->GetCodecs(), payloadTypes); + } + + // Prune out dupes + std::sort(payloadTypes->begin(), payloadTypes->end()); + auto newEnd = std::unique(payloadTypes->begin(), payloadTypes->end()); + payloadTypes->erase(newEnd, payloadTypes->end()); +} + +/* static */ +void +JsepTrack::GetPayloadTypes( + const std::vector<JsepCodecDescription*>& codecs, + std::vector<uint16_t>* payloadTypes) +{ + for (JsepCodecDescription* codec : codecs) { + uint16_t pt; + if (!codec->GetPtAsInt(&pt)) { + MOZ_ASSERT(false); + continue; + } + payloadTypes->push_back(pt); + } +} + +void +JsepTrack::EnsureNoDuplicatePayloadTypes( + std::vector<JsepCodecDescription*>* codecs) +{ + std::set<uint16_t> uniquePayloadTypes; + + for (JsepCodecDescription* codec : *codecs) { + // We assume there are no dupes in negotiated codecs; unnegotiated codecs + // need to change if there is a clash. + if (!codec->mEnabled) { + continue; + } + + // Disable, and only re-enable if we can ensure it has a unique pt. + codec->mEnabled = false; + + uint16_t currentPt; + if (!codec->GetPtAsInt(¤tPt)) { + MOZ_ASSERT(false); + continue; + } + + if (!uniquePayloadTypes.count(currentPt)) { + codec->mEnabled = true; + uniquePayloadTypes.insert(currentPt); + continue; + } + + // |codec| cannot use its current payload type. Try to find another. + for (uint16_t freePt = 96; freePt <= 127; ++freePt) { + // Not super efficient, but readability is probably more important. + if (!uniquePayloadTypes.count(freePt)) { + uniquePayloadTypes.insert(freePt); + codec->mEnabled = true; + std::ostringstream os; + os << freePt; + codec->mDefaultPt = os.str(); + break; + } + } + } +} + +void +JsepTrack::PopulateCodecs(const std::vector<JsepCodecDescription*>& prototype) +{ + for (const JsepCodecDescription* prototypeCodec : prototype) { + if (prototypeCodec->mType == mType) { + mPrototypeCodecs.values.push_back(prototypeCodec->Clone()); + mPrototypeCodecs.values.back()->mDirection = mDirection; + } + } + + EnsureNoDuplicatePayloadTypes(&mPrototypeCodecs.values); +} + +void +JsepTrack::AddToOffer(SdpMediaSection* offer) const +{ + AddToMsection(mPrototypeCodecs.values, offer); + if (mDirection == sdp::kSend) { + AddToMsection(mJsEncodeConstraints, sdp::kSend, offer); + } +} + +void +JsepTrack::AddToAnswer(const SdpMediaSection& offer, + SdpMediaSection* answer) const +{ + // We do not modify mPrototypeCodecs here, since we're only creating an + // answer. Once offer/answer concludes, we will update mPrototypeCodecs. + PtrVector<JsepCodecDescription> codecs; + codecs.values = GetCodecClones(); + NegotiateCodecs(offer, &codecs.values); + if (codecs.values.empty()) { + return; + } + + AddToMsection(codecs.values, answer); + + if (mDirection == sdp::kSend) { + std::vector<JsConstraints> constraints; + std::vector<SdpRidAttributeList::Rid> rids; + GetRids(offer, sdp::kRecv, &rids); + NegotiateRids(rids, &constraints); + AddToMsection(constraints, sdp::kSend, answer); + } +} + +void +JsepTrack::AddToMsection(const std::vector<JsepCodecDescription*>& codecs, + SdpMediaSection* msection) const +{ + MOZ_ASSERT(msection->GetMediaType() == mType); + MOZ_ASSERT(!codecs.empty()); + + for (const JsepCodecDescription* codec : codecs) { + codec->AddToMediaSection(*msection); + } + + if (mDirection == sdp::kSend) { + if (msection->GetMediaType() != SdpMediaSection::kApplication) { + msection->SetSsrcs(mSsrcs, mCNAME); + msection->AddMsid(mStreamId, mTrackId); + } + msection->SetSending(true); + } else { + msection->SetReceiving(true); + } +} + +// Updates the |id| values in |constraintsList| with the rid values in |rids|, +// where necessary. +void +JsepTrack::NegotiateRids(const std::vector<SdpRidAttributeList::Rid>& rids, + std::vector<JsConstraints>* constraintsList) const +{ + for (const SdpRidAttributeList::Rid& rid : rids) { + if (!FindConstraints(rid.id, *constraintsList)) { + // Pair up the first JsConstraints with an empty id, if it exists. + JsConstraints* constraints = FindConstraints("", *constraintsList); + if (constraints) { + constraints->rid = rid.id; + } + } + } +} + +/* static */ +void +JsepTrack::AddToMsection(const std::vector<JsConstraints>& constraintsList, + sdp::Direction direction, + SdpMediaSection* msection) +{ + UniquePtr<SdpSimulcastAttribute> simulcast(new SdpSimulcastAttribute); + UniquePtr<SdpRidAttributeList> rids(new SdpRidAttributeList); + for (const JsConstraints& constraints : constraintsList) { + if (!constraints.rid.empty()) { + SdpRidAttributeList::Rid rid; + rid.id = constraints.rid; + rid.direction = direction; + rids->mRids.push_back(rid); + + SdpSimulcastAttribute::Version version; + version.choices.push_back(constraints.rid); + if (direction == sdp::kSend) { + simulcast->sendVersions.push_back(version); + } else { + simulcast->recvVersions.push_back(version); + } + } + } + + if (!rids->mRids.empty()) { + msection->GetAttributeList().SetAttribute(simulcast.release()); + msection->GetAttributeList().SetAttribute(rids.release()); + } +} + +void +JsepTrack::GetRids(const SdpMediaSection& msection, + sdp::Direction direction, + std::vector<SdpRidAttributeList::Rid>* rids) const +{ + rids->clear(); + if (!msection.GetAttributeList().HasAttribute( + SdpAttribute::kSimulcastAttribute)) { + return; + } + + const SdpSimulcastAttribute& simulcast( + msection.GetAttributeList().GetSimulcast()); + + const SdpSimulcastAttribute::Versions* versions = nullptr; + switch (direction) { + case sdp::kSend: + versions = &simulcast.sendVersions; + break; + case sdp::kRecv: + versions = &simulcast.recvVersions; + break; + } + + if (!versions->IsSet()) { + return; + } + + if (versions->type != SdpSimulcastAttribute::Versions::kRid) { + // No support for PT-based simulcast, yet. + return; + } + + for (const SdpSimulcastAttribute::Version& version : *versions) { + if (!version.choices.empty()) { + // We validate that rids are present (and sane) elsewhere. + rids->push_back(*msection.FindRid(version.choices[0])); + } + } +} + +JsepTrack::JsConstraints* +JsepTrack::FindConstraints(const std::string& id, + std::vector<JsConstraints>& constraintsList) const +{ + for (JsConstraints& constraints : constraintsList) { + if (constraints.rid == id) { + return &constraints; + } + } + return nullptr; +} + +void +JsepTrack::CreateEncodings( + const SdpMediaSection& remote, + const std::vector<JsepCodecDescription*>& negotiatedCodecs, + JsepTrackNegotiatedDetails* negotiatedDetails) +{ + std::vector<SdpRidAttributeList::Rid> rids; + GetRids(remote, sdp::kRecv, &rids); // Get rids we will send + NegotiateRids(rids, &mJsEncodeConstraints); + if (rids.empty()) { + // Add dummy value with an empty id to make sure we get a single unicast + // stream. + rids.push_back(SdpRidAttributeList::Rid()); + } + + // For each rid in the remote, make sure we have an encoding, and configure + // that encoding appropriately. + for (size_t i = 0; i < rids.size(); ++i) { + if (i == negotiatedDetails->mEncodings.values.size()) { + negotiatedDetails->mEncodings.values.push_back(new JsepTrackEncoding); + } + + JsepTrackEncoding* encoding = negotiatedDetails->mEncodings.values[i]; + + for (const JsepCodecDescription* codec : negotiatedCodecs) { + if (rids[i].HasFormat(codec->mDefaultPt)) { + encoding->AddCodec(*codec); + } + } + + encoding->mRid = rids[i].id; + // If we end up supporting params for rid, we would handle that here. + + // Incorporate the corresponding JS encoding constraints, if they exist + for (const JsConstraints& jsConstraints : mJsEncodeConstraints) { + if (jsConstraints.rid == rids[i].id) { + encoding->mConstraints = jsConstraints.constraints; + } + } + + encoding->UpdateMaxBitrate(remote); + } +} + +std::vector<JsepCodecDescription*> +JsepTrack::GetCodecClones() const +{ + std::vector<JsepCodecDescription*> clones; + for (const JsepCodecDescription* codec : mPrototypeCodecs.values) { + clones.push_back(codec->Clone()); + } + return clones; +} + +static bool +CompareCodec(const JsepCodecDescription* lhs, const JsepCodecDescription* rhs) +{ + return lhs->mStronglyPreferred && !rhs->mStronglyPreferred; +} + +void +JsepTrack::NegotiateCodecs( + const SdpMediaSection& remote, + std::vector<JsepCodecDescription*>* codecs, + std::map<std::string, std::string>* formatChanges) const +{ + PtrVector<JsepCodecDescription> unnegotiatedCodecs; + std::swap(unnegotiatedCodecs.values, *codecs); + + // Outer loop establishes the remote side's preference + for (const std::string& fmt : remote.GetFormats()) { + for (size_t i = 0; i < unnegotiatedCodecs.values.size(); ++i) { + JsepCodecDescription* codec = unnegotiatedCodecs.values[i]; + if (!codec || !codec->mEnabled || !codec->Matches(fmt, remote)) { + continue; + } + + std::string originalFormat = codec->mDefaultPt; + if(codec->Negotiate(fmt, remote)) { + codecs->push_back(codec); + unnegotiatedCodecs.values[i] = nullptr; + if (formatChanges) { + (*formatChanges)[originalFormat] = codec->mDefaultPt; + } + break; + } + } + } + + // Find the (potential) red codec and ulpfec codec or telephone-event + JsepVideoCodecDescription* red = nullptr; + JsepVideoCodecDescription* ulpfec = nullptr; + JsepAudioCodecDescription* dtmf = nullptr; + // We can safely cast here since JsepTrack has a MediaType and only codecs + // that match that MediaType (kAudio or kVideo) are added. + for (auto codec : *codecs) { + if (codec->mName == "red") { + red = static_cast<JsepVideoCodecDescription*>(codec); + } + else if (codec->mName == "ulpfec") { + ulpfec = static_cast<JsepVideoCodecDescription*>(codec); + } + else if (codec->mName == "telephone-event") { + dtmf = static_cast<JsepAudioCodecDescription*>(codec); + } + } + // if we have a red codec remove redundant encodings that don't exist + if (red) { + // Since we could have an externally specified redundant endcodings + // list, we shouldn't simply rebuild the redundant encodings list + // based on the current list of codecs. + std::vector<uint8_t> unnegotiatedEncodings; + std::swap(unnegotiatedEncodings, red->mRedundantEncodings); + for (auto redundantPt : unnegotiatedEncodings) { + std::string pt = std::to_string(redundantPt); + for (auto codec : *codecs) { + if (pt == codec->mDefaultPt) { + red->mRedundantEncodings.push_back(redundantPt); + break; + } + } + } + } + // Video FEC is indicated by the existence of the red and ulpfec + // codecs and not an attribute on the particular video codec (like in + // a rtcpfb attr). If we see both red and ulpfec codecs, we enable FEC + // on all the other codecs. + if (red && ulpfec) { + for (auto codec : *codecs) { + if (codec->mName != "red" && codec->mName != "ulpfec") { + JsepVideoCodecDescription* videoCodec = + static_cast<JsepVideoCodecDescription*>(codec); + videoCodec->EnableFec(); + } + } + } + + // Dtmf support is indicated by the existence of the telephone-event + // codec, and not an attribute on the particular audio codec (like in a + // rtcpfb attr). If we see the telephone-event codec, we enabled dtmf + // support on all the other audio codecs. + if (dtmf) { + for (auto codec : *codecs) { + JsepAudioCodecDescription* audioCodec = + static_cast<JsepAudioCodecDescription*>(codec); + audioCodec->mDtmfEnabled = true; + } + } + + // Make sure strongly preferred codecs are up front, overriding the remote + // side's preference. + std::stable_sort(codecs->begin(), codecs->end(), CompareCodec); + + // TODO(bug 814227): Remove this once we're ready to put multiple codecs in an + // answer. For now, remove all but the first codec unless the red codec + // exists, and then we include the others per RFC 5109, section 14.2. + // Note: now allows keeping the telephone-event codec, if it appears, as the + // last codec in the list. + if (!codecs->empty() && !red) { + int newSize = dtmf ? 2 : 1; + for (size_t i = 1; i < codecs->size(); ++i) { + if (!dtmf || dtmf != (*codecs)[i]) { + delete (*codecs)[i]; + (*codecs)[i] = nullptr; + } + } + if (dtmf) { + (*codecs)[newSize-1] = dtmf; + } + codecs->resize(newSize); + } +} + +void +JsepTrack::Negotiate(const SdpMediaSection& answer, + const SdpMediaSection& remote) +{ + PtrVector<JsepCodecDescription> negotiatedCodecs; + negotiatedCodecs.values = GetCodecClones(); + + std::map<std::string, std::string> formatChanges; + NegotiateCodecs(remote, + &negotiatedCodecs.values, + &formatChanges); + + // Use |formatChanges| to update mPrototypeCodecs + size_t insertPos = 0; + for (size_t i = 0; i < mPrototypeCodecs.values.size(); ++i) { + if (formatChanges.count(mPrototypeCodecs.values[i]->mDefaultPt)) { + // Update the payload type to what was negotiated + mPrototypeCodecs.values[i]->mDefaultPt = + formatChanges[mPrototypeCodecs.values[i]->mDefaultPt]; + // Move this negotiated codec up front + std::swap(mPrototypeCodecs.values[insertPos], + mPrototypeCodecs.values[i]); + ++insertPos; + } + } + + EnsureNoDuplicatePayloadTypes(&mPrototypeCodecs.values); + + UniquePtr<JsepTrackNegotiatedDetails> negotiatedDetails = + MakeUnique<JsepTrackNegotiatedDetails>(); + + CreateEncodings(remote, negotiatedCodecs.values, negotiatedDetails.get()); + + if (answer.GetAttributeList().HasAttribute(SdpAttribute::kExtmapAttribute)) { + for (auto& extmapAttr : answer.GetAttributeList().GetExtmap().mExtmaps) { + negotiatedDetails->mExtmap[extmapAttr.extensionname] = extmapAttr; + } + } + + if (mDirection == sdp::kRecv) { + mSsrcs.clear(); + if (remote.GetAttributeList().HasAttribute(SdpAttribute::kSsrcAttribute)) { + for (auto& ssrcAttr : remote.GetAttributeList().GetSsrc().mSsrcs) { + AddSsrc(ssrcAttr.ssrc); + } + } + } + + mNegotiatedDetails = Move(negotiatedDetails); +} + +// When doing bundle, if all else fails we can try to figure out which m-line a +// given RTP packet belongs to by looking at the payload type field. This only +// works, however, if that payload type appeared in only one m-section. +// We figure that out here. +/* static */ +void +JsepTrack::SetUniquePayloadTypes(const std::vector<RefPtr<JsepTrack>>& tracks) +{ + // Maps to track details if no other track contains the payload type, + // otherwise maps to nullptr. + std::map<uint16_t, JsepTrackNegotiatedDetails*> payloadTypeToDetailsMap; + + for (const RefPtr<JsepTrack>& track : tracks) { + if (track->GetMediaType() == SdpMediaSection::kApplication) { + continue; + } + + auto* details = track->GetNegotiatedDetails(); + if (!details) { + // Can happen if negotiation fails on a track + continue; + } + + std::vector<uint16_t> payloadTypesForTrack; + track->GetNegotiatedPayloadTypes(&payloadTypesForTrack); + + for (uint16_t pt : payloadTypesForTrack) { + if (payloadTypeToDetailsMap.count(pt)) { + // Found in more than one track, not unique + payloadTypeToDetailsMap[pt] = nullptr; + } else { + payloadTypeToDetailsMap[pt] = details; + } + } + } + + for (auto ptAndDetails : payloadTypeToDetailsMap) { + uint16_t uniquePt = ptAndDetails.first; + MOZ_ASSERT(uniquePt <= UINT8_MAX); + auto trackDetails = ptAndDetails.second; + + if (trackDetails) { + trackDetails->mUniquePayloadTypes.push_back( + static_cast<uint8_t>(uniquePt)); + } + } +} + +} // namespace mozilla + |