Set CSRC as a empty (not nil) slice by default

Allows packetizer marshal / unmarshal to be consistent

Resolves pion#79

packet.go

@@ -33,7 +33,7 @@ type Header struct {
 // NOTE: Raw is populated by Marshal/Unmarshal and should not be modified
 type Packet struct {
 	Header
-	Raw     []byte
+	Raw         []byte
 	Payload     []byte
 	PaddingSize byte
 }

packetizer.go

@@ -69,6 +69,7 @@ func (p *packetizer) Packetize(payload []byte, samples uint32) []*Packet {
 				SequenceNumber: p.Sequencer.NextSequenceNumber(),
 				Timestamp:      p.Timestamp, // Figure out how to do timestamps
 				SSRC:           p.SSRC,
+				CSRC:           []uint32{},
 			},
 			Payload: pp,
 		}

packetizer_test.go

@@ -53,7 +53,7 @@ func TestPacketizer_AbsSendTime(t *testing.T) {
 			SequenceNumber:   1234,
 			Timestamp:        45678,
 			SSRC:             0x1234ABCD,
-			CSRC:             nil,
+			CSRC:             []uint32{},
 			ExtensionProfile: 0xBEDE,
 			Extensions: []Extension{
 				{
@@ -72,3 +72,81 @@ func TestPacketizer_AbsSendTime(t *testing.T) {
 		t.Errorf("Packetize failed\nexpected: %v\n     got: %v", expected, packets[0])
 	}
 }
+
+func TestPacketizer_Roundtrip(t *testing.T) {
+	multiplepayload := make([]byte, 128)
+	packetizer := NewPacketizer(100, 98, 0x1234ABCD, &codecs.G722Payloader{}, NewRandomSequencer(), 90000)
+	packets := packetizer.Packetize(multiplepayload, 1000)
+
+	rawPkts := make([][]byte, 0, 1400)
+	for _, pkt := range packets {
+		raw, err := pkt.Marshal()
+		if err != nil {
+			t.Errorf("Packet Marshal failed: %v", err)
+		}
+
+		rawPkts = append(rawPkts, raw)
+	}
+
+	for ndx, raw := range rawPkts {
+		expectedPkt := packets[ndx]
+		pkt := &Packet{}
+
+		err := pkt.Unmarshal(raw)
+		if err != nil {
+			t.Errorf("Packet Unmarshal failed: %v", err)
+		}
+
+		if len(raw) != pkt.MarshalSize() {
+			t.Errorf("Packet sizes don't match, expected %d but got %d", len(raw), pkt.MarshalSize())
+		}
+		if expectedPkt.MarshalSize() != pkt.MarshalSize() {
+			t.Errorf("Packet marshal sizes don't match, expected %d but got %d", expectedPkt.MarshalSize(), pkt.MarshalSize())
+		}
+
+		if expectedPkt.Version != pkt.Version {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.Version, pkt.Version)
+		}
+		if expectedPkt.Padding != pkt.Padding {
+			t.Errorf("Packet versions don't match, expected %t but got %t", expectedPkt.Padding, pkt.Padding)
+		}
+		if expectedPkt.Extension != pkt.Extension {
+			t.Errorf("Packet versions don't match, expected %v but got %v", expectedPkt.Extension, pkt.Extension)
+		}
+		if expectedPkt.Marker != pkt.Marker {
+			t.Errorf("Packet versions don't match, expected %v but got %v", expectedPkt.Marker, pkt.Marker)
+		}
+		if expectedPkt.PayloadType != pkt.PayloadType {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.PayloadType, pkt.PayloadType)
+		}
+		if expectedPkt.SequenceNumber != pkt.SequenceNumber {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.SequenceNumber, pkt.SequenceNumber)
+		}
+		if expectedPkt.Timestamp != pkt.Timestamp {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.Timestamp, pkt.Timestamp)
+		}
+		if expectedPkt.SSRC != pkt.SSRC {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.SSRC, pkt.SSRC)
+		}
+		if !reflect.DeepEqual(expectedPkt.CSRC, pkt.CSRC) {
+			t.Errorf("Packet versions don't match, expected %v but got %v", expectedPkt.CSRC, pkt.CSRC)
+		}
+		if expectedPkt.ExtensionProfile != pkt.ExtensionProfile {
+			t.Errorf("Packet versions don't match, expected %d but got %d", expectedPkt.ExtensionProfile, pkt.ExtensionProfile)
+		}
+		if !reflect.DeepEqual(expectedPkt.Extensions, pkt.Extensions) {
+			t.Errorf("Packet versions don't match, expected %v but got %v", expectedPkt.Extensions, pkt.Extensions)
+		}
+		if !reflect.DeepEqual(expectedPkt.Payload, pkt.Payload) {
+			t.Errorf("Packet versions don't match, expected %v but got %v", expectedPkt.Payload, pkt.Payload)
+		}
+
+		pkt.PayloadOffset = 0
+		pkt.PaddingSize = 0
+		pkt.Raw = nil
+
+		if !reflect.DeepEqual(expectedPkt, pkt) {
+			t.Errorf("Packets don't match, expected %v but got %v", expectedPkt, pkt)
+		}
+	}
+}