forked from pion/webrtc
/
rtpreceiver.go
165 lines (137 loc) · 3.22 KB
/
rtpreceiver.go
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// +build !js
package webrtc
import (
"fmt"
"io"
"sync"
"github.com/pion/rtcp"
"github.com/pion/srtp"
)
// RTPReceiver allows an application to inspect the receipt of a Track
type RTPReceiver struct {
kind RTPCodecType
transport *DTLSTransport
track *Track
closed, received chan interface{}
mu sync.RWMutex
rtpReadStream *srtp.ReadStreamSRTP
rtcpReadStream *srtp.ReadStreamSRTCP
// 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, fmt.Errorf("DTLSTransport must not be nil")
}
return &RTPReceiver{
kind: kind,
transport: transport,
api: api,
closed: make(chan interface{}),
received: make(chan interface{}),
}, nil
}
// 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
}
// Track returns the RTCRtpTransceiver track
func (r *RTPReceiver) Track() *Track {
r.mu.RLock()
defer r.mu.RUnlock()
return r.track
}
// Receive initialize the track and starts all the transports
func (r *RTPReceiver) Receive(parameters RTPReceiveParameters) error {
r.mu.Lock()
defer r.mu.Unlock()
select {
case <-r.received:
return fmt.Errorf("Receive has already been called")
default:
}
defer close(r.received)
r.track = &Track{
kind: r.kind,
ssrc: parameters.Encodings.SSRC,
receiver: r,
}
srtpSession, err := r.transport.getSRTPSession()
if err != nil {
return err
}
r.rtpReadStream, err = srtpSession.OpenReadStream(parameters.Encodings.SSRC)
if err != nil {
return err
}
srtcpSession, err := r.transport.getSRTCPSession()
if err != nil {
return err
}
r.rtcpReadStream, err = srtcpSession.OpenReadStream(parameters.Encodings.SSRC)
if err != nil {
return err
}
return nil
}
// Read reads incoming RTCP for this RTPReceiver
func (r *RTPReceiver) Read(b []byte) (n int, err error) {
select {
case <-r.received:
return r.rtcpReadStream.Read(b)
case <-r.closed:
return 0, io.ErrClosedPipe
}
}
// ReadRTCP is a convenience method that wraps Read and unmarshals for you
func (r *RTPReceiver) ReadRTCP() ([]rtcp.Packet, error) {
b := make([]byte, receiveMTU)
i, err := r.Read(b)
if err != nil {
return nil, err
}
return rtcp.Unmarshal(b[:i])
}
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()
select {
case <-r.closed:
return nil
default:
}
select {
case <-r.received:
if r.rtcpReadStream != nil {
if err := r.rtcpReadStream.Close(); err != nil {
return err
}
}
if r.rtpReadStream != nil {
if err := r.rtpReadStream.Close(); err != nil {
return err
}
}
default:
}
close(r.closed)
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) (n int, err error) {
<-r.received
return r.rtpReadStream.Read(b)
}