rtp: added some commenting

stream/rtp/encoder.go

@@ -40,11 +40,11 @@ const (
 	timestampFreq  = 90000 // Hz
 	mtsSize        = 188
 	bufferSize     = 1000
-	maxMtsPerRtp   = 7
-	bufferCap      = 7 * 188
 	sendLength     = 7 * 188
 )
 
+// Encoder implements io writer and provides functionality to wrap data into
+// rtp packets
 type Encoder struct {
 	dst           io.Writer
 	ssrc          uint32
@@ -63,10 +63,12 @@ func NewEncoder(dst io.Writer, fps int) *Encoder {
 		ssrc:          rand.Uint32(),
 		frameInterval: time.Duration(float64(time.Second) / float64(fps)),
 		fps:           fps,
-		buffer:        make([]byte, 0, bufferCap),
+		buffer:        make([]byte, 0, sendLength),
 	}
 }
 
+// Write provides an interface between a prior encoder and this rtp encoder,
+// so that multiple layers of packetization can occur.
 func (e *Encoder) Write(data []byte) (int, error) {
 	e.buffer = append(e.buffer, data...)
 	for len(e.buffer) >= sendLength {

stream/rtp/rtp.go

@@ -36,6 +36,7 @@ const (
 	rtpVer = 2
 )
 
+// Pkt provides fields consistent with RFC3550 definition of an rtp packet
 type Pkt struct {
 	V       byte   // Version (currently 2)
 	P       byte   // Padding indicator (0 => padding, 1 => padding)
@@ -50,6 +51,7 @@ type Pkt struct {
 	Padding byte   // No of bytes of padding
 }
 
+// Bytes provides a byte slice of the packet
 func (p *Pkt) Bytes() []byte {
 	if p.V == 0 {
 		p.V = rtpVer