feat: new data reference box

Box.go

@@ -42,6 +42,12 @@ const (
 	BoxTypeMediaInformation = "minf"
 	// BoxTypeDataInformation Data Information Box
 	BoxTypeDataInformation = "dinf"
+	// BoxTypeDataReferenceBox Data Reference Box
+	BoxTypeDataReferenceBox = "dref"
+	// BoxTypeDataEntryUrlBox Data Entry URL Box
+	BoxTypeDataEntryUrlBox = "url "
+	// BoxTypeDataEntryUrnBox Data Entry URN Box
+	BoxTypeDataEntryUrnBox = "urn "
 	// BoxTypeMovieFragment Movie Fragment Box
 	BoxTypeMovieFragment = "moof"
 	// BoxTypeMovieFragmentHeader Movie Fragment Header Box

DataReferenceBox.go

@@ -0,0 +1,136 @@
+// Copyright 2024 Martin Riedl
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gomp4
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+// DataReferenceBox data reference box struct
+//
+// 8.7.2 Data Reference Box
+//
+// Box Types: ‘dref’
+// Container: Data Information Box (‘dinf’)
+// Mandatory: Yes
+// Quantity: Exactly one
+//
+// The data reference object contains a table of data references (normally URLs) that declare the
+// location(s) of the media data used within the presentation. The data reference index in the sample
+// description ties entries in this table to the samples in the track. A track may be split over several
+// sources in this way.
+//
+// If the flag is set indicating that the data is in the same file as this box, then no string (not even an empty
+// one) shall be supplied in the entry field.
+//
+// The entry_count in the DataReferenceBox shall be 1 or greater; each DataEntryBox within the
+// DataReferenceBox shall be either a DataEntryUrnBox or a DataEntryUrlBox.
+//
+// When a file that has data entries with the flag set indicating that the media data is in the same file, is
+// split into segments for transport, the value of this flag does not change, as the file is (logically)
+// reassembled after the transport operation.
+type DataReferenceBox struct {
+	*FullBox
+	// EntryCount is an integer that counts the actual entries
+	EntryCount uint32
+	ChildBoxes []interface{}
+}
+
+// ParseDataReferenceBox creates a new data reference box struct based on bytes
+func ParseDataReferenceBox(filePosition uint64, headerSize uint32, content []byte) (*DataReferenceBox, error) {
+	box := &DataReferenceBox{
+		FullBox: newFullBox(&Box{filePosition, headerSize}, content[0:4]),
+	}
+
+	// parse entry counter
+	box.EntryCount = binary.BigEndian.Uint32(content[4:8])
+
+	// parse child boxes
+	var err error
+	box.ChildBoxes, err = box.parseChildBoxes(filePosition, content[8:])
+	if err != nil {
+		return box, err
+	}
+
+	// validate entries amount
+	if len(box.ChildBoxes) != int(box.EntryCount) {
+		return box, fmt.Errorf("invalid amount of boxes at %d", filePosition)
+	}
+
+	return box, err
+}
+
+// DataEntryUrlBox data entry URL box struct
+//
+// Box Types: ‘url ‘
+// Container: Data Information Box (‘dref’)
+// Mandatory: Yes (at least one of ‘url ‘ or ‘urn ‘ shall be present)
+// Quantity: One or more
+type DataEntryUrlBox struct {
+	*FullBox
+	// Location is a URL, and is required in a URL entry and optional in a URN entry, where it gives a location to find
+	// the resource with the given name. If the
+	// self‐contained flag is set, the URL form is used and no string is present; the box terminates with
+	// the entry‐flags field. The URL type should be of a service that delivers a file (e.g. URLs of type file,
+	// http, ftp etc.), and which services ideally also permit random access. Relative URLs are
+	// permissible and are relative to the file containing the Movie Box that contains this data
+	// reference.
+	Location string
+}
+
+// ParseDataEntryUrlBox creates a data entry URL box struct based on bytes
+func ParseDataEntryUrlBox(filePosition uint64, headerSize uint32, content []byte) *DataEntryUrlBox {
+	box := &DataEntryUrlBox{
+		FullBox: newFullBox(&Box{filePosition, headerSize}, content[0:4]),
+	}
+
+	box.Location, _ = ParseStringNullTerminated(content[4:])
+
+	return box
+}
+
+// DataEntryUrnBox data entry URN box struct
+//
+// Box Types: ‘urn ‘
+// Container: Data Information Box (‘dref’)
+// Mandatory: Yes (at least one of ‘url ‘ or ‘urn ‘ shall be present)
+// Quantity: One or more
+type DataEntryUrnBox struct {
+	*FullBox
+	// Name is a URN, and is required in a URN entry.
+	Name string
+	// Location is a URL, and is required in a URL entry and optional in a URN entry, where it gives a location to find
+	// the resource with the given name. If the
+	// self‐contained flag is set, the URL form is used and no string is present; the box terminates with
+	// the entry‐flags field. The URL type should be of a service that delivers a file (e.g. URLs of type file,
+	// http, ftp etc.), and which services ideally also permit random access. Relative URLs are
+	// permissible and are relative to the file containing the Movie Box that contains this data
+	// reference.
+	Location string
+}
+
+// ParseDataEntryUrnBox creates a data entry URN box struct based on bytes
+func ParseDataEntryUrnBox(filePosition uint64, headerSize uint32, content []byte) *DataEntryUrnBox {
+	box := &DataEntryUrnBox{
+		FullBox: newFullBox(&Box{filePosition, headerSize}, content[0:4]),
+	}
+
+	name, endIndex := ParseStringNullTerminated(content[4:])
+	box.Name = name
+	box.Location, _ = ParseStringNullTerminated(content[4+endIndex:])
+
+	return box
+}

HandlerReferenceBox.go

@@ -65,7 +65,7 @@ func ParseHandlerReferenceBox(filePosition uint64, headerSize uint32, content []
 	position += 3 * 4
 
 	// parse name
-	box.Name = ParseStringNullTerminated(content[position:])
+	box.Name, _ = ParseStringNullTerminated(content[position:])
 
 	return box
 }

Parser.go

@@ -126,6 +126,12 @@ func parseNextBox(reader io.Reader, filePosition uint64) (box interface{}, endPo
 		box, err = ParseMediaInformationBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeDataInformation:
 		box, err = ParseDataInformationBox(filePosition, boxHeaderSize, boxContentBytes)
+	case BoxTypeDataReferenceBox:
+		box, err = ParseDataReferenceBox(filePosition, boxHeaderSize, boxContentBytes)
+	case BoxTypeDataEntryUrlBox:
+		box = ParseDataEntryUrlBox(filePosition, boxHeaderSize, boxContentBytes)
+	case BoxTypeDataEntryUrnBox:
+		box = ParseDataEntryUrnBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeMovieFragment:
 		box, err = ParseMovieFragmentBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeMovieFragmentHeader:

README.md

@@ -45,7 +45,7 @@ Implementation progress
 | 8.6.5 Edit Box                                     | edts           |      - |
 | 8.6.6 Edit List Box                                | elst           |      - |
 | 8.7.1 Data Information Box                         | dinf           |   100% |
-| 8.7.2 Data Reference Box                           | dref, url, urn |      - |
+| 8.7.2 Data Reference Box                           | dref, url, urn |   100% |
 | 8.7.3 Sample Size Boxes                            | stsz, stz2     |      - |
 | 8.7.4 Sample To Chunk Box                          | stsc           |      - |
 | 8.7.5 Chunk Offset Box                             | stco, co64     |      - |

String.go

@@ -18,11 +18,11 @@ import (
 	"bytes"
 )
 
-func ParseStringNullTerminated(b []byte) string {
+func ParseStringNullTerminated(b []byte) (string, int) {
 	endIndex := bytes.IndexByte(b, '\x00')
 	if endIndex == -1 {
-		return ""
+		return "", -1
 	}
 
-	return string(b[:endIndex])
+	return string(b[:endIndex]), endIndex
 }