livekit/livekit/pkg/rtc/participant_sdp.go

408 lines
10 KiB
Go

// Copyright 2023 LiveKit, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package rtc
import (
"fmt"
"slices"
"strconv"
"strings"
"github.com/pion/sdp/v3"
"github.com/pion/webrtc/v4"
"github.com/livekit/livekit-server/pkg/rtc/types"
"github.com/livekit/livekit-server/pkg/sfu/mime"
"github.com/livekit/protocol/livekit"
"github.com/livekit/protocol/logger"
lksdp "github.com/livekit/protocol/sdp"
"github.com/livekit/protocol/utils"
)
func (p *ParticipantImpl) populateSdpCid(parsedOffer *sdp.SessionDescription) ([]*sdp.MediaDescription, []*sdp.MediaDescription) {
processUnmatch := func(unmatches []*sdp.MediaDescription, trackType livekit.TrackType) {
for _, unmatch := range unmatches {
streamID, ok := lksdp.ExtractStreamID(unmatch)
if !ok {
continue
}
sdpCodecs, err := lksdp.CodecsFromMediaDescription(unmatch)
if err != nil || len(sdpCodecs) == 0 {
p.pubLogger.Errorw(
"extract codecs from media section failed", err,
"media", unmatch,
"parsedOffer", parsedOffer,
)
continue
}
p.pendingTracksLock.Lock()
signalCid, info, _, migrated, _ := p.getPendingTrack(streamID, trackType, false)
if migrated {
p.pendingTracksLock.Unlock()
continue
}
if info == nil {
p.pendingTracksLock.Unlock()
// could be already published track and the unmatch could be a back up codec publish
numUnmatchedTracks := 0
var unmatchedTrack types.MediaTrack
var unmatchedSdpMimeType mime.MimeType
found := false
for _, sdpCodec := range sdpCodecs {
sdpMimeType := mime.NormalizeMimeTypeCodec(sdpCodec.Name).ToMimeType()
for _, publishedTrack := range p.GetPublishedTracks() {
if sigCid, sdpCid := publishedTrack.(*MediaTrack).GetCidsForMimeType(sdpMimeType); sigCid != "" && sdpCid == "" {
// a back up codec has a SDP cid match
if sigCid == streamID {
found = true
break
} else {
numUnmatchedTracks++
unmatchedTrack = publishedTrack
unmatchedSdpMimeType = sdpMimeType
}
}
}
if found {
break
}
}
if !found && unmatchedTrack != nil {
if numUnmatchedTracks != 1 {
p.pubLogger.Warnw(
"too many unmatched tracks", nil,
"media", unmatch,
"parsedOffer", parsedOffer,
)
}
unmatchedTrack.(*MediaTrack).UpdateCodecSdpCid(unmatchedSdpMimeType, streamID)
p.pubLogger.Debugw(
"published track SDP cid updated",
"trackID", unmatchedTrack.ID(),
"track", logger.Proto(unmatchedTrack.ToProto()),
)
}
continue
}
if len(info.Codecs) == 0 {
p.pendingTracksLock.Unlock()
p.pubLogger.Warnw(
"track without codecs", nil,
"trackID", info.Sid,
"pendingTrack", p.pendingTracks[signalCid],
"media", unmatch,
"parsedOffer", parsedOffer,
)
continue
}
found := false
updated := false
for _, sdpCodec := range sdpCodecs {
if mime.NormalizeMimeTypeCodec(sdpCodec.Name) == mime.GetMimeTypeCodec(info.Codecs[0].MimeType) {
// set SdpCid only if different from SignalCid
if streamID != info.Codecs[0].Cid {
info.Codecs[0].SdpCid = streamID
updated = true
}
found = true
break
}
if found {
break
}
}
if !found {
// not using SimulcastCodec, i. e. mime type not available till track publish
if len(info.Codecs) == 1 {
// set SdpCid only if different from SignalCid
if streamID != info.Codecs[0].Cid {
info.Codecs[0].SdpCid = streamID
updated = true
}
}
}
if updated {
p.pendingTracks[signalCid].trackInfos[0] = utils.CloneProto(info)
p.pubLogger.Debugw(
"pending track SDP cid updated",
"signalCid", signalCid,
"trackID", info.Sid,
"pendingTrack", p.pendingTracks[signalCid],
)
}
p.pendingTracksLock.Unlock()
}
}
unmatchAudios, err := p.TransportManager.GetUnmatchMediaForOffer(parsedOffer, "audio")
if err != nil {
p.pubLogger.Warnw("could not get unmatch audios", err)
return nil, nil
}
unmatchVideos, err := p.TransportManager.GetUnmatchMediaForOffer(parsedOffer, "video")
if err != nil {
p.pubLogger.Warnw("could not get unmatch videos", err)
return nil, nil
}
processUnmatch(unmatchAudios, livekit.TrackType_AUDIO)
processUnmatch(unmatchVideos, livekit.TrackType_VIDEO)
return unmatchAudios, unmatchVideos
}
func (p *ParticipantImpl) setCodecPreferencesForPublisher(
parsedOffer *sdp.SessionDescription,
unmatchAudios []*sdp.MediaDescription,
unmatchVideos []*sdp.MediaDescription,
) {
unprocessedUnmatchAudios := p.setCodecPreferencesForPublisherMedia(
parsedOffer,
unmatchAudios,
livekit.TrackType_AUDIO,
)
p.setCodecPreferencesOpusRedForPublisher(parsedOffer, unprocessedUnmatchAudios)
_ = p.setCodecPreferencesForPublisherMedia(
parsedOffer,
unmatchVideos,
livekit.TrackType_VIDEO,
)
}
func (p *ParticipantImpl) setCodecPreferencesForPublisherMedia(
parsedOffer *sdp.SessionDescription,
unmatches []*sdp.MediaDescription,
trackType livekit.TrackType,
) []*sdp.MediaDescription {
unprocessed := make([]*sdp.MediaDescription, 0, len(unmatches))
for _, unmatch := range unmatches {
var ti *livekit.TrackInfo
var mimeType string
mid := lksdp.GetMidValue(unmatch)
if mid == "" {
unprocessed = append(unprocessed, unmatch)
continue
}
transceiver := p.TransportManager.GetPublisherRTPTransceiver(mid)
if transceiver == nil {
unprocessed = append(unprocessed, unmatch)
continue
}
streamID, ok := lksdp.ExtractStreamID(unmatch)
if !ok {
unprocessed = append(unprocessed, unmatch)
continue
}
p.pendingTracksLock.RLock()
mt := p.getPublishedTrackBySdpCid(streamID)
if mt != nil {
ti = mt.ToProto()
} else {
_, ti, _, _, _ = p.getPendingTrack(streamID, trackType, false)
}
p.pendingTracksLock.RUnlock()
if ti == nil {
unprocessed = append(unprocessed, unmatch)
continue
}
for _, c := range ti.Codecs {
if c.Cid == streamID || c.SdpCid == streamID {
mimeType = c.MimeType
break
}
}
if mimeType == "" && len(ti.Codecs) > 0 {
mimeType = ti.Codecs[0].MimeType
}
if mimeType == "" {
unprocessed = append(unprocessed, unmatch)
continue
}
configureReceiverCodecs(
transceiver,
mimeType,
p.params.ClientInfo.ComplyWithCodecOrderInSDPAnswer(),
)
}
return unprocessed
}
func (p *ParticipantImpl) setCodecPreferencesOpusRedForPublisher(
parsedOffer *sdp.SessionDescription,
unmatchAudios []*sdp.MediaDescription,
) {
for _, unmatchAudio := range unmatchAudios {
mid := lksdp.GetMidValue(unmatchAudio)
if mid == "" {
continue
}
transceiver := p.TransportManager.GetPublisherRTPTransceiver(mid)
if transceiver == nil {
continue
}
streamID, ok := lksdp.ExtractStreamID(unmatchAudio)
if !ok {
continue
}
p.pendingTracksLock.RLock()
_, ti, _, _, _ := p.getPendingTrack(streamID, livekit.TrackType_AUDIO, false)
p.pendingTracksLock.RUnlock()
if ti == nil {
continue
}
codecs, err := lksdp.CodecsFromMediaDescription(unmatchAudio)
if err != nil {
p.pubLogger.Errorw(
"extract codecs from media section failed", err,
"media", unmatchAudio,
"parsedOffer", parsedOffer,
)
continue
}
var opusPayload uint8
for _, codec := range codecs {
if mime.IsMimeTypeCodecStringOpus(codec.Name) {
opusPayload = codec.PayloadType
break
}
}
if opusPayload == 0 {
continue
}
preferRED := IsRedEnabled(ti)
// if RED is enabled for this track, prefer RED codec in offer
for _, codec := range codecs {
// codec contain opus/red
if preferRED &&
mime.IsMimeTypeCodecStringRED(codec.Name) &&
strings.Contains(codec.Fmtp, strconv.FormatInt(int64(opusPayload), 10)) {
configureReceiverCodecs(transceiver, "audio/red", true)
break
}
}
}
}
// configure publisher answer for audio track's dtx and stereo settings
func (p *ParticipantImpl) configurePublisherAnswer(answer webrtc.SessionDescription) webrtc.SessionDescription {
offer := p.TransportManager.LastPublisherOffer()
parsedOffer, err := offer.Unmarshal()
if err != nil {
return answer
}
parsedAnswer, err := answer.Unmarshal()
if err != nil {
return answer
}
for _, m := range parsedAnswer.MediaDescriptions {
switch m.MediaName.Media {
case "audio":
_, ok := m.Attribute(sdp.AttrKeyInactive)
if ok {
continue
}
mid, ok := m.Attribute(sdp.AttrKeyMID)
if !ok {
continue
}
// find track info from offer's stream id
var ti *livekit.TrackInfo
for _, om := range parsedOffer.MediaDescriptions {
_, ok := om.Attribute(sdp.AttrKeyInactive)
if ok {
continue
}
omid, ok := om.Attribute(sdp.AttrKeyMID)
if ok && omid == mid {
streamID, ok := lksdp.ExtractStreamID(om)
if !ok {
continue
}
track, _ := p.getPublishedTrackBySdpCid(streamID).(*MediaTrack)
if track == nil {
p.pendingTracksLock.RLock()
_, ti, _, _, _ = p.getPendingTrack(streamID, livekit.TrackType_AUDIO, false)
p.pendingTracksLock.RUnlock()
} else {
ti = track.ToProto()
}
break
}
}
if ti == nil {
// no need to configure
continue
}
opusPT, err := parsedAnswer.GetPayloadTypeForCodec(sdp.Codec{Name: mime.MimeTypeCodecOpus.String()})
if err != nil {
p.pubLogger.Infow("failed to get opus payload type", "error", err, "trackID", ti.Sid)
continue
}
for i, attr := range m.Attributes {
if strings.HasPrefix(attr.String(), fmt.Sprintf("fmtp:%d", opusPT)) {
if !slices.Contains(ti.AudioFeatures, livekit.AudioTrackFeature_TF_NO_DTX) {
attr.Value += ";usedtx=1"
} else {
attr.Value = strings.ReplaceAll(attr.Value, ";usedtx=1", "")
}
if slices.Contains(ti.AudioFeatures, livekit.AudioTrackFeature_TF_STEREO) {
attr.Value += ";stereo=1;maxaveragebitrate=510000"
} else {
attr.Value = strings.ReplaceAll(attr.Value, ";stereo=1", "")
}
m.Attributes[i] = attr
}
}
default:
continue
}
}
bytes, err := parsedAnswer.Marshal()
if err != nil {
p.pubLogger.Infow("failed to marshal answer", "error", err)
return answer
}
answer.SDP = string(bytes)
return answer
}