status-go/vendor/github.com/pion/webrtc/v3/rtpreceiver.go

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2022-03-10 09:44:48 +00:00
//go:build !js
// +build !js
package webrtc
import (
"fmt"
"io"
"sync"
"time"
"github.com/pion/interceptor"
"github.com/pion/rtcp"
"github.com/pion/srtp/v2"
"github.com/pion/webrtc/v3/internal/util"
)
// trackStreams maintains a mapping of RTP/RTCP streams to a specific track
// a RTPReceiver may contain multiple streams if we are dealing with Simulcast
type trackStreams struct {
track *TrackRemote
streamInfo, repairStreamInfo *interceptor.StreamInfo
rtpReadStream *srtp.ReadStreamSRTP
rtpInterceptor interceptor.RTPReader
rtcpReadStream *srtp.ReadStreamSRTCP
rtcpInterceptor interceptor.RTCPReader
repairReadStream *srtp.ReadStreamSRTP
repairInterceptor interceptor.RTPReader
repairRtcpReadStream *srtp.ReadStreamSRTCP
repairRtcpInterceptor interceptor.RTCPReader
}
// RTPReceiver allows an application to inspect the receipt of a TrackRemote
type RTPReceiver struct {
kind RTPCodecType
transport *DTLSTransport
tracks []trackStreams
closed, received chan interface{}
mu sync.RWMutex
tr *RTPTransceiver
// A reference to the associated api object
api *API
}
// NewRTPReceiver constructs a new RTPReceiver
func (api *API) NewRTPReceiver(kind RTPCodecType, transport *DTLSTransport) (*RTPReceiver, error) {
if transport == nil {
return nil, errRTPReceiverDTLSTransportNil
}
r := &RTPReceiver{
kind: kind,
transport: transport,
api: api,
closed: make(chan interface{}),
received: make(chan interface{}),
tracks: []trackStreams{},
}
return r, nil
}
func (r *RTPReceiver) setRTPTransceiver(tr *RTPTransceiver) {
r.mu.Lock()
defer r.mu.Unlock()
r.tr = tr
}
// Transport returns the currently-configured *DTLSTransport or nil
// if one has not yet been configured
func (r *RTPReceiver) Transport() *DTLSTransport {
r.mu.RLock()
defer r.mu.RUnlock()
return r.transport
}
func (r *RTPReceiver) getParameters() RTPParameters {
parameters := r.api.mediaEngine.getRTPParametersByKind(r.kind, []RTPTransceiverDirection{RTPTransceiverDirectionRecvonly})
if r.tr != nil {
parameters.Codecs = r.tr.getCodecs()
}
return parameters
}
// GetParameters describes the current configuration for the encoding and
// transmission of media on the receiver's track.
func (r *RTPReceiver) GetParameters() RTPParameters {
r.mu.RLock()
defer r.mu.RUnlock()
return r.getParameters()
}
// Track returns the RtpTransceiver TrackRemote
func (r *RTPReceiver) Track() *TrackRemote {
r.mu.RLock()
defer r.mu.RUnlock()
if len(r.tracks) != 1 {
return nil
}
return r.tracks[0].track
}
// Tracks returns the RtpTransceiver tracks
// A RTPReceiver to support Simulcast may now have multiple tracks
func (r *RTPReceiver) Tracks() []*TrackRemote {
r.mu.RLock()
defer r.mu.RUnlock()
var tracks []*TrackRemote
for i := range r.tracks {
tracks = append(tracks, r.tracks[i].track)
}
return tracks
}
// configureReceive initialize the track
func (r *RTPReceiver) configureReceive(parameters RTPReceiveParameters) {
r.mu.Lock()
defer r.mu.Unlock()
for i := range parameters.Encodings {
t := trackStreams{
track: newTrackRemote(
r.kind,
parameters.Encodings[i].SSRC,
parameters.Encodings[i].RID,
r,
),
}
r.tracks = append(r.tracks, t)
}
}
// startReceive starts all the transports
func (r *RTPReceiver) startReceive(parameters RTPReceiveParameters) error {
r.mu.Lock()
defer r.mu.Unlock()
select {
case <-r.received:
return errRTPReceiverReceiveAlreadyCalled
default:
}
defer close(r.received)
globalParams := r.getParameters()
codec := RTPCodecCapability{}
if len(globalParams.Codecs) != 0 {
codec = globalParams.Codecs[0].RTPCodecCapability
}
for i := range parameters.Encodings {
if parameters.Encodings[i].RID != "" {
// RID based tracks will be set up in receiveForRid
continue
}
var t *trackStreams
for idx, ts := range r.tracks {
if ts.track != nil && parameters.Encodings[i].SSRC != 0 && ts.track.SSRC() == parameters.Encodings[i].SSRC {
t = &r.tracks[idx]
break
}
}
if t == nil {
return fmt.Errorf("%w: %d", errRTPReceiverWithSSRCTrackStreamNotFound, parameters.Encodings[i].SSRC)
}
if parameters.Encodings[i].SSRC != 0 {
t.streamInfo = createStreamInfo("", parameters.Encodings[i].SSRC, 0, codec, globalParams.HeaderExtensions)
var err error
if t.rtpReadStream, t.rtpInterceptor, t.rtcpReadStream, t.rtcpInterceptor, err = r.transport.streamsForSSRC(parameters.Encodings[i].SSRC, *t.streamInfo); err != nil {
return err
}
}
if rtxSsrc := parameters.Encodings[i].RTX.SSRC; rtxSsrc != 0 {
streamInfo := createStreamInfo("", rtxSsrc, 0, codec, globalParams.HeaderExtensions)
rtpReadStream, rtpInterceptor, rtcpReadStream, rtcpInterceptor, err := r.transport.streamsForSSRC(rtxSsrc, *streamInfo)
if err != nil {
return err
}
if err = r.receiveForRtx(rtxSsrc, "", streamInfo, rtpReadStream, rtpInterceptor, rtcpReadStream, rtcpInterceptor); err != nil {
return err
}
}
}
return nil
}
// Receive initialize the track and starts all the transports
func (r *RTPReceiver) Receive(parameters RTPReceiveParameters) error {
r.configureReceive(parameters)
return r.startReceive(parameters)
}
// Read reads incoming RTCP for this RTPReceiver
func (r *RTPReceiver) Read(b []byte) (n int, a interceptor.Attributes, err error) {
select {
case <-r.received:
return r.tracks[0].rtcpInterceptor.Read(b, a)
case <-r.closed:
return 0, nil, io.ErrClosedPipe
}
}
// ReadSimulcast reads incoming RTCP for this RTPReceiver for given rid
func (r *RTPReceiver) ReadSimulcast(b []byte, rid string) (n int, a interceptor.Attributes, err error) {
select {
case <-r.received:
for _, t := range r.tracks {
if t.track != nil && t.track.rid == rid {
return t.rtcpInterceptor.Read(b, a)
}
}
return 0, nil, fmt.Errorf("%w: %s", errRTPReceiverForRIDTrackStreamNotFound, rid)
case <-r.closed:
return 0, nil, io.ErrClosedPipe
}
}
// ReadRTCP is a convenience method that wraps Read and unmarshal for you.
// It also runs any configured interceptors.
func (r *RTPReceiver) ReadRTCP() ([]rtcp.Packet, interceptor.Attributes, error) {
b := make([]byte, r.api.settingEngine.getReceiveMTU())
i, attributes, err := r.Read(b)
if err != nil {
return nil, nil, err
}
pkts, err := rtcp.Unmarshal(b[:i])
if err != nil {
return nil, nil, err
}
return pkts, attributes, nil
}
// ReadSimulcastRTCP is a convenience method that wraps ReadSimulcast and unmarshal for you
func (r *RTPReceiver) ReadSimulcastRTCP(rid string) ([]rtcp.Packet, interceptor.Attributes, error) {
b := make([]byte, r.api.settingEngine.getReceiveMTU())
i, attributes, err := r.ReadSimulcast(b, rid)
if err != nil {
return nil, nil, err
}
pkts, err := rtcp.Unmarshal(b[:i])
return pkts, attributes, err
}
func (r *RTPReceiver) haveReceived() bool {
select {
case <-r.received:
return true
default:
return false
}
}
// Stop irreversibly stops the RTPReceiver
func (r *RTPReceiver) Stop() error {
r.mu.Lock()
defer r.mu.Unlock()
var err error
select {
case <-r.closed:
return err
default:
}
select {
case <-r.received:
for i := range r.tracks {
errs := []error{}
if r.tracks[i].rtcpReadStream != nil {
errs = append(errs, r.tracks[i].rtcpReadStream.Close())
}
if r.tracks[i].rtpReadStream != nil {
errs = append(errs, r.tracks[i].rtpReadStream.Close())
}
if r.tracks[i].repairReadStream != nil {
errs = append(errs, r.tracks[i].repairReadStream.Close())
}
if r.tracks[i].repairRtcpReadStream != nil {
errs = append(errs, r.tracks[i].repairRtcpReadStream.Close())
}
if r.tracks[i].streamInfo != nil {
r.api.interceptor.UnbindRemoteStream(r.tracks[i].streamInfo)
}
if r.tracks[i].repairStreamInfo != nil {
r.api.interceptor.UnbindRemoteStream(r.tracks[i].repairStreamInfo)
}
err = util.FlattenErrs(errs)
}
default:
}
close(r.closed)
return err
}
func (r *RTPReceiver) streamsForTrack(t *TrackRemote) *trackStreams {
for i := range r.tracks {
if r.tracks[i].track == t {
return &r.tracks[i]
}
}
return nil
}
// readRTP should only be called by a track, this only exists so we can keep state in one place
func (r *RTPReceiver) readRTP(b []byte, reader *TrackRemote) (n int, a interceptor.Attributes, err error) {
<-r.received
if t := r.streamsForTrack(reader); t != nil {
return t.rtpInterceptor.Read(b, a)
}
return 0, nil, fmt.Errorf("%w: %d", errRTPReceiverWithSSRCTrackStreamNotFound, reader.SSRC())
}
// receiveForRid is the sibling of Receive expect for RIDs instead of SSRCs
// It populates all the internal state for the given RID
func (r *RTPReceiver) receiveForRid(rid string, params RTPParameters, streamInfo *interceptor.StreamInfo, rtpReadStream *srtp.ReadStreamSRTP, rtpInterceptor interceptor.RTPReader, rtcpReadStream *srtp.ReadStreamSRTCP, rtcpInterceptor interceptor.RTCPReader) (*TrackRemote, error) {
r.mu.Lock()
defer r.mu.Unlock()
for i := range r.tracks {
if r.tracks[i].track.RID() == rid {
r.tracks[i].track.mu.Lock()
r.tracks[i].track.kind = r.kind
r.tracks[i].track.codec = params.Codecs[0]
r.tracks[i].track.params = params
r.tracks[i].track.ssrc = SSRC(streamInfo.SSRC)
r.tracks[i].track.mu.Unlock()
r.tracks[i].streamInfo = streamInfo
r.tracks[i].rtpReadStream = rtpReadStream
r.tracks[i].rtpInterceptor = rtpInterceptor
r.tracks[i].rtcpReadStream = rtcpReadStream
r.tracks[i].rtcpInterceptor = rtcpInterceptor
return r.tracks[i].track, nil
}
}
return nil, fmt.Errorf("%w: %s", errRTPReceiverForRIDTrackStreamNotFound, rid)
}
// receiveForRtx starts a routine that processes the repair stream
// These packets aren't exposed to the user yet, but we need to process them for
// TWCC
func (r *RTPReceiver) receiveForRtx(ssrc SSRC, rsid string, streamInfo *interceptor.StreamInfo, rtpReadStream *srtp.ReadStreamSRTP, rtpInterceptor interceptor.RTPReader, rtcpReadStream *srtp.ReadStreamSRTCP, rtcpInterceptor interceptor.RTCPReader) error {
var track *trackStreams
if ssrc != 0 && len(r.tracks) == 1 {
track = &r.tracks[0]
} else {
for i := range r.tracks {
if r.tracks[i].track.RID() == rsid {
track = &r.tracks[i]
}
}
}
if track == nil {
return fmt.Errorf("%w: ssrc(%d) rsid(%s)", errRTPReceiverForRIDTrackStreamNotFound, ssrc, rsid)
}
track.repairStreamInfo = streamInfo
track.repairReadStream = rtpReadStream
track.repairInterceptor = rtpInterceptor
track.repairRtcpReadStream = rtcpReadStream
track.repairRtcpInterceptor = rtcpInterceptor
go func() {
b := make([]byte, r.api.settingEngine.getReceiveMTU())
for {
if _, _, readErr := track.repairInterceptor.Read(b, nil); readErr != nil {
return
}
}
}()
return nil
}
// SetReadDeadline sets the max amount of time the RTCP stream will block before returning. 0 is forever.
func (r *RTPReceiver) SetReadDeadline(t time.Time) error {
r.mu.RLock()
defer r.mu.RUnlock()
if err := r.tracks[0].rtcpReadStream.SetReadDeadline(t); err != nil {
return err
}
return nil
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}
// SetReadDeadlineSimulcast sets the max amount of time the RTCP stream for a given rid will block before returning. 0 is forever.
func (r *RTPReceiver) SetReadDeadlineSimulcast(deadline time.Time, rid string) error {
r.mu.RLock()
defer r.mu.RUnlock()
for _, t := range r.tracks {
if t.track != nil && t.track.rid == rid {
return t.rtcpReadStream.SetReadDeadline(deadline)
}
}
return fmt.Errorf("%w: %s", errRTPReceiverForRIDTrackStreamNotFound, rid)
}
// setRTPReadDeadline sets the max amount of time the RTP stream will block before returning. 0 is forever.
// This should be fired by calling SetReadDeadline on the TrackRemote
func (r *RTPReceiver) setRTPReadDeadline(deadline time.Time, reader *TrackRemote) error {
r.mu.RLock()
defer r.mu.RUnlock()
if t := r.streamsForTrack(reader); t != nil {
return t.rtpReadStream.SetReadDeadline(deadline)
}
return fmt.Errorf("%w: %d", errRTPReceiverWithSSRCTrackStreamNotFound, reader.SSRC())
}