add fmp4/seekablebuffer

go.mod

@@ -4,7 +4,6 @@ go 1.19
 
 require (
 	github.com/abema/go-mp4 v1.1.1
-	github.com/aler9/writerseeker v1.1.0
 	github.com/asticode/go-astits v1.13.0
 	github.com/stretchr/testify v1.8.4
 )

go.sum

@@ -1,7 +1,5 @@
 github.com/abema/go-mp4 v1.1.1 h1:OfzkdMO6SWTBR1ltNSVwlTHatrAK9I3iYLQfkdEMMuc=
 github.com/abema/go-mp4 v1.1.1/go.mod h1:vPl9t5ZK7K0x68jh12/+ECWBCXoWuIDtNgPtU2f04ws=
-github.com/aler9/writerseeker v1.1.0 h1:t+Sm3tjp8scNlqyoa8obpeqwciMNOvdvsxjxEb3Sx3g=
-github.com/aler9/writerseeker v1.1.0/go.mod h1:QNCcjSKnLsYoTfMmXkEEfgbz6nNXWxKSaBY+hGJGWDA=
 github.com/asticode/go-astikit v0.30.0 h1:DkBkRQRIxYcknlaU7W7ksNfn4gMFsB0tqMJflxkRsZA=
 github.com/asticode/go-astikit v0.30.0/go.mod h1:h4ly7idim1tNhaVkdVBeXQZEE3L0xblP7fCWbgwipF0=
 github.com/asticode/go-astits v1.13.0 h1:XOgkaadfZODnyZRR5Y0/DWkA9vrkLLPLeeOvDwfKZ1c=

pkg/formats/fmp4/init_test.go

@@ -4,10 +4,10 @@ import (
 	"bytes"
 	"testing"
 
-	"github.com/aler9/writerseeker"
 	"github.com/stretchr/testify/require"
 
 	"github.com/bluenviron/mediacommon/pkg/codecs/mpeg4audio"
+	"github.com/bluenviron/mediacommon/pkg/formats/fmp4/seekablebuffer"
 )
 
 var testSPS = []byte{
@@ -2069,8 +2069,8 @@ func TestInitUnmarshalExternal(t *testing.T) {
 func TestInitMarshal(t *testing.T) {
 	for _, ca := range casesInit {
 		t.Run(ca.name, func(t *testing.T) {
-			buf := &writerseeker.WriterSeeker{}
-			err := ca.dec.Marshal(buf)
+			var buf seekablebuffer.Buffer
+			err := ca.dec.Marshal(&buf)
 			require.NoError(t, err)
 			require.Equal(t, ca.enc, buf.Bytes())
 		})
@@ -2120,8 +2120,8 @@ func TestInitMarshalEmptyParameters(t *testing.T) {
 				}},
 			}
 
-			buf := &writerseeker.WriterSeeker{}
-			err := i.Marshal(buf)
+			var buf seekablebuffer.Buffer
+			err := i.Marshal(&buf)
 			require.Error(t, err)
 		})
 	}

pkg/formats/fmp4/part.go

@@ -28,7 +28,13 @@ func (p *Part) Marshal(w io.WriteSeeker) error {
 		moof
 		- mfhd
 		- traf (video)
+		  - tfhd
+		  - tfdt
+		  - trun
 		- traf (audio)
+		  - tfhd
+		  - tfdt
+		  - trun
 		mdat
 	*/
 

pkg/formats/fmp4/parts_test.go

@@ -3,7 +3,7 @@ package fmp4
 import (
 	"testing"
 
-	"github.com/aler9/writerseeker"
+	"github.com/bluenviron/mediacommon/pkg/formats/fmp4/seekablebuffer"
 	"github.com/stretchr/testify/require"
 )
 
@@ -154,8 +154,8 @@ var casesParts = []struct {
 func TestPartsMarshal(t *testing.T) {
 	for _, ca := range casesParts {
 		t.Run(ca.name, func(t *testing.T) {
-			buf := &writerseeker.WriterSeeker{}
-			err := ca.parts.Marshal(buf)
+			var buf seekablebuffer.Buffer
+			err := ca.parts.Marshal(&buf)
 			require.NoError(t, err)
 			require.Equal(t, ca.enc, buf.Bytes())
 		})

pkg/formats/fmp4/seekablebuffer/seekablebuffer.go

@@ -0,0 +1,74 @@
+// Package seekablebuffer contains a bytes.Buffer with an additional Seek() method.
+package seekablebuffer
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+// Buffer is a bytes.Buffer with an additional Seek() method.
+type Buffer struct {
+	bytes.Buffer
+	pos int64
+}
+
+// Write implements io.Writer.
+func (b *Buffer) Write(p []byte) (int, error) {
+	n := 0
+
+	if b.pos < int64(b.Len()) {
+		n = copy(b.Bytes()[b.pos:], p)
+		p = p[n:]
+	}
+
+	if len(p) > 0 {
+		// Buffer.Write can't return an error.
+		nn, _ := b.Buffer.Write(p) //nolint:errcheck
+		n += nn
+	}
+
+	b.pos += int64(n)
+	return n, nil
+}
+
+// Read implements io.Reader.
+func (b *Buffer) Read(_ []byte) (int, error) {
+	return 0, fmt.Errorf("unimplemented")
+}
+
+// Seek implements io.Seeker.
+func (b *Buffer) Seek(offset int64, whence int) (int64, error) {
+	pos2 := int64(0)
+
+	switch whence {
+	case io.SeekStart:
+		pos2 = offset
+
+	case io.SeekCurrent:
+		pos2 = b.pos + offset
+
+	case io.SeekEnd:
+		pos2 = int64(b.Len()) + offset
+	}
+
+	if pos2 < 0 {
+		return 0, fmt.Errorf("negative position")
+	}
+
+	b.pos = pos2
+
+	diff := b.pos - int64(b.Len())
+	if diff > 0 {
+		// Buffer.Write can't return an error.
+		b.Buffer.Write(make([]byte, diff)) //nolint:errcheck
+	}
+
+	return pos2, nil
+}
+
+// Reset resets the buffer state.
+func (b *Buffer) Reset() {
+	b.Buffer.Reset()
+	b.pos = 0
+}

pkg/formats/fmp4/seekablebuffer/seekablebuffer_test.go

@@ -0,0 +1,61 @@
+package seekablebuffer
+
+import (
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuffer(t *testing.T) {
+	t.Run("seek start", func(t *testing.T) {
+		var b Buffer
+
+		_, err := b.Seek(-2, io.SeekStart)
+		require.Error(t, err)
+
+		n1, err := b.Seek(0, io.SeekStart)
+		require.NoError(t, err)
+		require.Equal(t, int64(0), n1)
+
+		n2, err := b.Write([]byte{1, 2, 3, 4})
+		require.NoError(t, err)
+		require.Equal(t, 4, n2)
+	})
+
+	t.Run("seek current", func(t *testing.T) {
+		var b Buffer
+
+		n2, err := b.Write([]byte{1, 2, 3, 4})
+		require.NoError(t, err)
+		require.Equal(t, 4, n2)
+
+		n1, err := b.Seek(-2, io.SeekCurrent)
+		require.NoError(t, err)
+		require.Equal(t, int64(2), n1)
+
+		n2, err = b.Write([]byte{1, 2, 3, 4})
+		require.NoError(t, err)
+		require.Equal(t, 4, n2)
+
+		require.Equal(t, []byte{1, 2, 1, 2, 3, 4}, b.Bytes())
+	})
+
+	t.Run("seek end", func(t *testing.T) {
+		var b Buffer
+
+		n2, err := b.Write([]byte{1, 2, 3, 4})
+		require.NoError(t, err)
+		require.Equal(t, 4, n2)
+
+		n1, err := b.Seek(2, io.SeekEnd)
+		require.NoError(t, err)
+		require.Equal(t, int64(6), n1)
+
+		n2, err = b.Write([]byte{1, 2, 3, 4})
+		require.NoError(t, err)
+		require.Equal(t, 4, n2)
+
+		require.Equal(t, []byte{1, 2, 3, 4, 0, 0, 1, 2, 3, 4}, b.Bytes())
+	})
+}