Code review changes

Cache byte slice only

internal/packet/writer.go

@@ -112,8 +112,3 @@ func (w *Writer) Bytes() []byte {
 func (w *Writer) Reset() {
 	w.offset = 0
 }
-
-// Return original byte slice (for sync.Pool)
-func (w *Writer) Buffer() []byte {
-	return w.buffer
-}

internal/rtp/rtp.go

@@ -126,7 +126,8 @@ func newRTPWriter(out io.Writer, ssrc uint32, crypto *cryptoContext) *rtpWriter
 	}
 	w.cache.OnEvicted = func(key lru.Key, value interface{}) {
 		// Recycle retransmission buffers to put less pressure on GC
-		w.pool.Put(value.(*packet.Writer).Buffer())
+		b := value.([]byte)
+		w.pool.Put(b[0:cap(b)])
 	}
 
 	return w
@@ -163,7 +164,7 @@ func (w *rtpWriter) writePacket(payloadType byte, marker bool, timestamp uint32,
 	w.totalBytes += uint64(len(payload))
 
 	// Add packet to cache for retransmission in case of nack.
-	w.cache.Add(uint16(index), p)
+	w.cache.Add(uint16(index), p.Bytes())
 
 	_, err := w.out.Write(p.Bytes())
 	return err
@@ -173,8 +174,8 @@ func (w *rtpWriter) writePacket(payloadType byte, marker bool, timestamp uint32,
 func (w *rtpWriter) resend(sequenceNumber uint16) {
 	w.Lock()
 	defer w.Unlock()
-	if p, ok := w.cache.Get(sequenceNumber); ok {
-		if _, err := w.out.Write(p.(*packet.Writer).Bytes()); err != nil {
+	if b, ok := w.cache.Get(sequenceNumber); ok {
+		if _, err := w.out.Write(b.([]byte)); err != nil {
 			log.Error("Failed to retransmit: %s", err.Error())
 		}
 	} else {

peer_connection.go

@@ -168,11 +168,7 @@ func (pc *PeerConnection) createAnswer() (sdp.Session, error) {
 			// Parse payload type from attribute. Will bin by payload type.
 			pt = -1
 			switch attr.Key {
-			case "rtpmap":
-				fallthrough
-			case "fmtp":
-				fallthrough
-			case "rtcp-fb":
+			case "fmtp", "rtcp-fb", "rtpmap":
 				if _, err := fmt.Sscanf(
 					attr.Value, "%3d %s", &pt, &text,
 				); err != nil {