Support emsg version 1

box_types.go

@@ -8,6 +8,7 @@ import (
 	"strconv"
 
 	"github.com/abema/go-mp4/bitio"
+	"github.com/abema/go-mp4/util"
 )
 
 /*************************** co64 ****************************/
@@ -260,7 +261,7 @@ func (elst *Elst) GetFieldLength(name string) uint {
 func BoxTypeEmsg() BoxType { return StrToBoxType("emsg") }
 
 func init() {
-	AddBoxDef(&Emsg{}, 0)
+	AddBoxDef(&Emsg{}, 0, 1)
 }
 
 // Emsg is ISOBMFF emsg box type
@@ -269,12 +270,59 @@ type Emsg struct {
 	SchemeIdUri           string `mp4:"string"`
 	Value                 string `mp4:"string"`
 	Timescale             uint32 `mp4:"size=32"`
-	PresentationTimeDelta uint32 `mp4:"size=32"`
+	PresentationTimeDelta uint32 `mp4:"size=32,ver=0"`
+	PresentationTime      uint64 `mp4:"size=64,ver=1"`
 	EventDuration         uint32 `mp4:"size=32"`
 	Id                    uint32 `mp4:"size=32"`
 	MessageData           []byte `mp4:"size=8,string"`
 }
 
+func (emsg *Emsg) OnReadField(name string, r bitio.ReadSeeker, leftBits uint64) (rbits uint64, override bool, err error) {
+	if emsg.GetVersion() == 0 {
+		return
+	}
+	switch name {
+	case "SchemeIdUri", "Value":
+		override = true
+		return
+	case "MessageData":
+		emsg.SchemeIdUri, err = util.ReadString(r)
+		if err != nil {
+			return
+		}
+		emsg.Value, err = util.ReadString(r)
+		if err != nil {
+			return
+		}
+		rbits += uint64(len(emsg.SchemeIdUri)+len(emsg.Value)+2) * 8
+		return
+	default:
+		return
+	}
+}
+
+func (emsg *Emsg) OnWriteField(name string, w bitio.Writer) (wbits uint64, override bool, err error) {
+	if emsg.GetVersion() == 0 {
+		return
+	}
+	switch name {
+	case "SchemeIdUri", "Value":
+		override = true
+		return
+	case "MessageData":
+		if err = util.WriteString(w, emsg.SchemeIdUri); err != nil {
+			return
+		}
+		if err = util.WriteString(w, emsg.Value); err != nil {
+			return
+		}
+		wbits += uint64(len(emsg.SchemeIdUri)+len(emsg.Value)+2) * 8
+		return
+	default:
+		return
+	}
+}
+
 // GetType returns the BoxType
 func (*Emsg) GetType() BoxType {
 	return BoxTypeEmsg()

box_types_test.go

@@ -241,7 +241,7 @@ func TestBoxTypes(t *testing.T) {
 				`{SegmentDurationV1=144115188075855882 MediaTimeV1=144115188075855883 MediaRateInteger=524}]`,
 		},
 		{
-			name: "emsg",
+			name: "emsg: version 0",
 			src: &Emsg{
 				FullBox: FullBox{
 					Version: 0,
@@ -276,6 +276,42 @@ func TestBoxTypes(t *testing.T) {
 				`Id=43981 ` +
 				`MessageData="abema"`,
 		},
+		{
+			name: "emsg: version 1",
+			src: &Emsg{
+				FullBox: FullBox{
+					Version: 1,
+					Flags:   [3]byte{0x00, 0x00, 0x00},
+				},
+				SchemeIdUri:      "urn:test",
+				Value:            "foo",
+				Timescale:        1000,
+				PresentationTime: 123,
+				EventDuration:    3000,
+				Id:               0xabcd,
+				MessageData:      []byte("abema"),
+			},
+			dst: &Emsg{},
+			bin: []byte{
+				1,                // version
+				0x00, 0x00, 0x00, // flags
+				0x00, 0x00, 0x03, 0xe8, // timescale
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7b, // presentation time
+				0x00, 0x00, 0x0b, 0xb8, // event duration
+				0x00, 0x00, 0xab, 0xcd, // id
+				0x75, 0x72, 0x6e, 0x3a, 0x74, 0x65, 0x73, 0x74, 0x00, // scheme id uri
+				0x66, 0x6f, 0x6f, 0x00, // value
+				0x61, 0x62, 0x65, 0x6d, 0x61, // message data
+			},
+			str: `Version=1 Flags=0x000000 ` +
+				`SchemeIdUri="urn:test" ` +
+				`Value="foo" ` +
+				`Timescale=1000 ` +
+				`PresentationTime=123 ` +
+				`EventDuration=3000 ` +
+				`Id=43981 ` +
+				`MessageData="abema"`,
+		},
 		{
 			name: "esds",
 			src: &Esds{

util/io.go

@@ -0,0 +1,30 @@
+package util
+
+import (
+	"bytes"
+	"io"
+)
+
+func ReadString(r io.Reader) (string, error) {
+	b := make([]byte, 1)
+	buf := bytes.NewBuffer(nil)
+	for {
+		if _, err := r.Read(b); err != nil {
+			return "", err
+		}
+		if b[0] == 0 {
+			return buf.String(), nil
+		}
+		buf.Write(b)
+	}
+}
+
+func WriteString(w io.Writer, s string) error {
+	if _, err := w.Write([]byte(s)); err != nil {
+		return err
+	}
+	if _, err := w.Write([]byte{0}); err != nil {
+		return err
+	}
+	return nil
+}

util/io_test.go

@@ -0,0 +1,41 @@
+package util
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestReadString(t *testing.T) {
+	r := bytes.NewReader([]byte{
+		'f', 'i', 'r', 's', 't', 0,
+		's', 'e', 'c', 'o', 'n', 'd', 0,
+		't', 'h', 'i', 'r', 'd', 0,
+	})
+	s, err := ReadString(r)
+	require.NoError(t, err)
+	assert.Equal(t, "first", s)
+	s, err = ReadString(r)
+	require.NoError(t, err)
+	assert.Equal(t, "second", s)
+	s, err = ReadString(r)
+	require.NoError(t, err)
+	assert.Equal(t, "third", s)
+	_, err = ReadString(r)
+	assert.Equal(t, io.EOF, err)
+}
+
+func TestWriteString(t *testing.T) {
+	w := bytes.NewBuffer(nil)
+	require.NoError(t, WriteString(w, "first"))
+	require.NoError(t, WriteString(w, "second"))
+	require.NoError(t, WriteString(w, "third"))
+	assert.Equal(t, []byte{
+		'f', 'i', 'r', 's', 't', 0,
+		's', 'e', 'c', 'o', 'n', 'd', 0,
+		't', 'h', 'i', 'r', 'd', 0,
+	}, w.Bytes())
+}