New Track API

The Pion WebRTC API has been dramatically redesigned. The design docs
are located here [0]

You can also read the release notes [1] on how to migrate your
application.

[0] https://github.com/pion/webrtc-v3-design
[1] https://github.com/pion/webrtc/wiki/Release-WebRTC@v3.0.0

track_local.go

@@ -0,0 +1,68 @@
+package webrtc
+
+import "github.com/pion/rtp"
+
+// TrackLocalWriter is the Writer for outbound RTP Packets
+type TrackLocalWriter interface {
+	// WriteRTP encrypts a RTP packet and writes to the connection
+	WriteRTP(header *rtp.Header, payload []byte) (int, error)
+
+	// Write encrypts and writes a full RTP packet
+	Write(b []byte) (int, error)
+}
+
+// TrackLocalContext is the Context passed when a TrackLocal has been Binded/Unbinded from a PeerConnection
+type TrackLocalContext struct {
+	id          string
+	codecs      []RTPCodecParameters
+	ssrc        SSRC
+	writeStream TrackLocalWriter
+}
+
+// CodecParameters returns the negotiated RTPCodecParameters. These are the codecs supported by both
+// PeerConnections and the SSRC/PayloadTypes
+func (t *TrackLocalContext) CodecParameters() []RTPCodecParameters {
+	return t.codecs
+}
+
+// SSRC requires the negotiated SSRC of this track
+// This track may have multiple if RTX is enabled
+func (t *TrackLocalContext) SSRC() SSRC {
+	return t.ssrc
+}
+
+// WriteStream returns the WriteStream for this TrackLocal. The implementer writes the outbound
+// media packets to it
+func (t *TrackLocalContext) WriteStream() TrackLocalWriter {
+	return t.writeStream
+}
+
+// ID is a unique identifier that is used for both Bind/Unbind
+func (t *TrackLocalContext) ID() string {
+	return t.id
+}
+
+// TrackLocal is an interface that controls how the user can send media
+// The user can provide their own TrackLocal implementatiosn, or use
+// the implementations in pkg/media
+type TrackLocal interface {
+	// Bind should implement the way how the media data flows from the Track to the PeerConnection
+	// This will be called internally after signaling is complete and the list of available
+	// codecs has been determined
+	Bind(TrackLocalContext) error
+
+	// Unbind should implement the teardown logic when the track is no longer needed. This happens
+	// because a track has been stopped.
+	Unbind(TrackLocalContext) error
+
+	// ID is the unique identifier for this Track. This should be unique for the
+	// stream, but doesn't have to globally unique. A common example would be 'audio' or 'video'
+	// and StreamID would be 'desktop' or 'webcam'
+	ID() string
+
+	// StreamID is the group this track belongs too. This must be unique
+	StreamID() string
+
+	// Kind controls if this TrackLocal is audio or video
+	Kind() RTPCodecType
+}