vendor.github.com.pion.webrtc.v3.rtpsender.go Maven / Gradle / Ivy
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// SPDX-FileCopyrightText: 2023 The Pion community
// SPDX-License-Identifier: MIT
//go:build !js
// +build !js
package webrtc
import (
"fmt"
"io"
"sync"
"time"
"github.com/pion/interceptor"
"github.com/pion/randutil"
"github.com/pion/rtcp"
"github.com/pion/rtp"
"github.com/pion/webrtc/v3/internal/util"
)
type trackEncoding struct {
track TrackLocal
srtpStream *srtpWriterFuture
rtcpInterceptor interceptor.RTCPReader
streamInfo interceptor.StreamInfo
context *baseTrackLocalContext
ssrc SSRC
}
// RTPSender allows an application to control how a given Track is encoded and transmitted to a remote peer
type RTPSender struct {
trackEncodings []*trackEncoding
transport *DTLSTransport
payloadType PayloadType
kind RTPCodecType
// nolint:godox
// TODO(sgotti) remove this when in future we'll avoid replacing
// a transceiver sender since we can just check the
// transceiver negotiation status
negotiated bool
// A reference to the associated api object
api *API
id string
rtpTransceiver *RTPTransceiver
mu sync.RWMutex
sendCalled, stopCalled chan struct{}
}
// NewRTPSender constructs a new RTPSender
func (api *API) NewRTPSender(track TrackLocal, transport *DTLSTransport) (*RTPSender, error) {
if track == nil {
return nil, errRTPSenderTrackNil
} else if transport == nil {
return nil, errRTPSenderDTLSTransportNil
}
id, err := randutil.GenerateCryptoRandomString(32, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
if err != nil {
return nil, err
}
r := &RTPSender{
transport: transport,
api: api,
sendCalled: make(chan struct{}),
stopCalled: make(chan struct{}),
id: id,
kind: track.Kind(),
}
r.addEncoding(track)
return r, nil
}
func (r *RTPSender) isNegotiated() bool {
r.mu.RLock()
defer r.mu.RUnlock()
return r.negotiated
}
func (r *RTPSender) setNegotiated() {
r.mu.Lock()
defer r.mu.Unlock()
r.negotiated = true
}
func (r *RTPSender) setRTPTransceiver(rtpTransceiver *RTPTransceiver) {
r.mu.Lock()
defer r.mu.Unlock()
r.rtpTransceiver = rtpTransceiver
}
// Transport returns the currently-configured *DTLSTransport or nil
// if one has not yet been configured
func (r *RTPSender) Transport() *DTLSTransport {
r.mu.RLock()
defer r.mu.RUnlock()
return r.transport
}
func (r *RTPSender) getParameters() RTPSendParameters {
var encodings []RTPEncodingParameters
for _, trackEncoding := range r.trackEncodings {
var rid string
if trackEncoding.track != nil {
rid = trackEncoding.track.RID()
}
encodings = append(encodings, RTPEncodingParameters{
RTPCodingParameters: RTPCodingParameters{
RID: rid,
SSRC: trackEncoding.ssrc,
PayloadType: r.payloadType,
},
})
}
sendParameters := RTPSendParameters{
RTPParameters: r.api.mediaEngine.getRTPParametersByKind(
r.kind,
[]RTPTransceiverDirection{RTPTransceiverDirectionSendonly},
),
Encodings: encodings,
}
if r.rtpTransceiver != nil {
sendParameters.Codecs = r.rtpTransceiver.getCodecs()
} else {
sendParameters.Codecs = r.api.mediaEngine.getCodecsByKind(r.kind)
}
return sendParameters
}
// GetParameters describes the current configuration for the encoding and
// transmission of media on the sender's track.
func (r *RTPSender) GetParameters() RTPSendParameters {
r.mu.RLock()
defer r.mu.RUnlock()
return r.getParameters()
}
// AddEncoding adds an encoding to RTPSender. Used by simulcast senders.
func (r *RTPSender) AddEncoding(track TrackLocal) error {
r.mu.Lock()
defer r.mu.Unlock()
if track == nil {
return errRTPSenderTrackNil
}
if track.RID() == "" {
return errRTPSenderRidNil
}
if r.hasStopped() {
return errRTPSenderStopped
}
if r.hasSent() {
return errRTPSenderSendAlreadyCalled
}
var refTrack TrackLocal
if len(r.trackEncodings) != 0 {
refTrack = r.trackEncodings[0].track
}
if refTrack == nil || refTrack.RID() == "" {
return errRTPSenderNoBaseEncoding
}
if refTrack.ID() != track.ID() || refTrack.StreamID() != track.StreamID() || refTrack.Kind() != track.Kind() {
return errRTPSenderBaseEncodingMismatch
}
for _, encoding := range r.trackEncodings {
if encoding.track == nil {
continue
}
if encoding.track.RID() == track.RID() {
return errRTPSenderRIDCollision
}
}
r.addEncoding(track)
return nil
}
func (r *RTPSender) addEncoding(track TrackLocal) {
ssrc := SSRC(randutil.NewMathRandomGenerator().Uint32())
trackEncoding := &trackEncoding{
track: track,
srtpStream: &srtpWriterFuture{ssrc: ssrc},
ssrc: ssrc,
}
trackEncoding.srtpStream.rtpSender = r
trackEncoding.rtcpInterceptor = r.api.interceptor.BindRTCPReader(
interceptor.RTPReaderFunc(func(in []byte, a interceptor.Attributes) (n int, attributes interceptor.Attributes, err error) {
n, err = trackEncoding.srtpStream.Read(in)
return n, a, err
}),
)
r.trackEncodings = append(r.trackEncodings, trackEncoding)
}
// Track returns the RTCRtpTransceiver track, or nil
func (r *RTPSender) Track() TrackLocal {
r.mu.RLock()
defer r.mu.RUnlock()
if len(r.trackEncodings) == 0 {
return nil
}
return r.trackEncodings[0].track
}
// ReplaceTrack replaces the track currently being used as the sender's source with a new TrackLocal.
// The new track must be of the same media kind (audio, video, etc) and switching the track should not
// require negotiation.
func (r *RTPSender) ReplaceTrack(track TrackLocal) error {
r.mu.Lock()
defer r.mu.Unlock()
if track != nil && r.kind != track.Kind() {
return ErrRTPSenderNewTrackHasIncorrectKind
}
// cannot replace simulcast envelope
if track != nil && len(r.trackEncodings) > 1 {
return ErrRTPSenderNewTrackHasIncorrectEnvelope
}
var replacedTrack TrackLocal
var context *baseTrackLocalContext
for _, e := range r.trackEncodings {
replacedTrack = e.track
context = e.context
if r.hasSent() && replacedTrack != nil {
if err := replacedTrack.Unbind(context); err != nil {
return err
}
}
if !r.hasSent() || track == nil {
e.track = track
}
}
if !r.hasSent() || track == nil {
return nil
}
// If we reach this point in the routine, there is only 1 track encoding
codec, err := track.Bind(&baseTrackLocalContext{
id: context.ID(),
params: r.api.mediaEngine.getRTPParametersByKind(track.Kind(), []RTPTransceiverDirection{RTPTransceiverDirectionSendonly}),
ssrc: context.SSRC(),
writeStream: context.WriteStream(),
rtcpInterceptor: context.RTCPReader(),
})
if err != nil {
// Re-bind the original track
if _, reBindErr := replacedTrack.Bind(context); reBindErr != nil {
return reBindErr
}
return err
}
// Codec has changed
if r.payloadType != codec.PayloadType {
context.params.Codecs = []RTPCodecParameters{codec}
}
r.trackEncodings[0].track = track
return nil
}
// Send Attempts to set the parameters controlling the sending of media.
func (r *RTPSender) Send(parameters RTPSendParameters) error {
r.mu.Lock()
defer r.mu.Unlock()
switch {
case r.hasSent():
return errRTPSenderSendAlreadyCalled
case r.trackEncodings[0].track == nil:
return errRTPSenderTrackRemoved
}
for idx, trackEncoding := range r.trackEncodings {
writeStream := &interceptorToTrackLocalWriter{}
trackEncoding.context = &baseTrackLocalContext{
id: r.id,
params: r.api.mediaEngine.getRTPParametersByKind(trackEncoding.track.Kind(), []RTPTransceiverDirection{RTPTransceiverDirectionSendonly}),
ssrc: parameters.Encodings[idx].SSRC,
writeStream: writeStream,
rtcpInterceptor: trackEncoding.rtcpInterceptor,
}
codec, err := trackEncoding.track.Bind(trackEncoding.context)
if err != nil {
return err
}
trackEncoding.context.params.Codecs = []RTPCodecParameters{codec}
trackEncoding.streamInfo = *createStreamInfo(
r.id,
parameters.Encodings[idx].SSRC,
codec.PayloadType,
codec.RTPCodecCapability,
parameters.HeaderExtensions,
)
srtpStream := trackEncoding.srtpStream
rtpInterceptor := r.api.interceptor.BindLocalStream(
&trackEncoding.streamInfo,
interceptor.RTPWriterFunc(func(header *rtp.Header, payload []byte, attributes interceptor.Attributes) (int, error) {
return srtpStream.WriteRTP(header, payload)
}),
)
writeStream.interceptor.Store(rtpInterceptor)
}
close(r.sendCalled)
return nil
}
// Stop irreversibly stops the RTPSender
func (r *RTPSender) Stop() error {
r.mu.Lock()
if stopped := r.hasStopped(); stopped {
r.mu.Unlock()
return nil
}
close(r.stopCalled)
r.mu.Unlock()
if !r.hasSent() {
return nil
}
if err := r.ReplaceTrack(nil); err != nil {
return err
}
errs := []error{}
for _, trackEncoding := range r.trackEncodings {
r.api.interceptor.UnbindLocalStream(&trackEncoding.streamInfo)
errs = append(errs, trackEncoding.srtpStream.Close())
}
return util.FlattenErrs(errs)
}
// Read reads incoming RTCP for this RTPSender
func (r *RTPSender) Read(b []byte) (n int, a interceptor.Attributes, err error) {
select {
case <-r.sendCalled:
return r.trackEncodings[0].rtcpInterceptor.Read(b, a)
case <-r.stopCalled:
return 0, nil, io.ErrClosedPipe
}
}
// ReadRTCP is a convenience method that wraps Read and unmarshals for you.
func (r *RTPSender) 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
}
// ReadSimulcast reads incoming RTCP for this RTPSender for given rid
func (r *RTPSender) ReadSimulcast(b []byte, rid string) (n int, a interceptor.Attributes, err error) {
select {
case <-r.sendCalled:
for _, t := range r.trackEncodings {
if t.track != nil && t.track.RID() == rid {
return t.rtcpInterceptor.Read(b, a)
}
}
return 0, nil, fmt.Errorf("%w: %s", errRTPSenderNoTrackForRID, rid)
case <-r.stopCalled:
return 0, nil, io.ErrClosedPipe
}
}
// ReadSimulcastRTCP is a convenience method that wraps ReadSimulcast and unmarshal for you
func (r *RTPSender) 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
}
// SetReadDeadline sets the deadline for the Read operation.
// Setting to zero means no deadline.
func (r *RTPSender) SetReadDeadline(t time.Time) error {
return r.trackEncodings[0].srtpStream.SetReadDeadline(t)
}
// SetReadDeadlineSimulcast sets the max amount of time the RTCP stream for a given rid will block before returning. 0 is forever.
func (r *RTPSender) SetReadDeadlineSimulcast(deadline time.Time, rid string) error {
r.mu.RLock()
defer r.mu.RUnlock()
for _, t := range r.trackEncodings {
if t.track != nil && t.track.RID() == rid {
return t.srtpStream.SetReadDeadline(deadline)
}
}
return fmt.Errorf("%w: %s", errRTPSenderNoTrackForRID, rid)
}
// hasSent tells if data has been ever sent for this instance
func (r *RTPSender) hasSent() bool {
select {
case <-r.sendCalled:
return true
default:
return false
}
}
// hasStopped tells if stop has been called
func (r *RTPSender) hasStopped() bool {
select {
case <-r.stopCalled:
return true
default:
return false
}
}