Remove unnecessary nil check

pkg/core/track.go

@@ -98,8 +98,7 @@ func NewSender(media *Media, codec *Codec) *Sender {
 	}
 	s.Input = func(packet *Packet) {
 		s.mu.Lock()
-		if s.buf != nil {
-			// unblocked write to channel
+		// unblock write to nil chan - OK, write to closed chan - panic
 		select {
 		case s.buf <- packet:
 			s.Bytes += len(packet.Payload)
@@ -107,9 +106,6 @@ func NewSender(media *Media, codec *Codec) *Sender {
 		default:
 			s.Drops++
 		}
-		} else {
-			s.Drops++
-		}
 		s.mu.Unlock()
 	}
 	s.Output = func(packet *Packet) {