New integration of common/ and undefined/ subpackages

- common/type.go: Add FormatFromType() .
- Renamed common/type_encode.go to common/value_encoder.go .

v2/common/type.go

@@ -3,6 +3,7 @@ package exifcommon
 import (
     "errors"
     "fmt"
+    "reflect"
     "strconv"
     "strings"
 
@@ -93,6 +94,22 @@ func (tagType TagTypePrimitive) Size() int {
     }
 }
 
+// IsValid returns true if tagType is a valid type.
+func (tagType TagTypePrimitive) IsValid() bool {
+
+    // TODO(dustin): Add test
+
+    return tagType == TypeByte ||
+        tagType == TypeAscii ||
+        tagType == TypeAsciiNoNul ||
+        tagType == TypeShort ||
+        tagType == TypeLong ||
+        tagType == TypeRational ||
+        tagType == TypeSignedLong ||
+        tagType == TypeSignedRational ||
+        tagType == TypeUndefined
+}
+
 var (
     // TODO(dustin): Rename TypeNames() to typeNames() and add getter.
     TypeNames = map[TagTypePrimitive]string{
@@ -108,7 +125,7 @@ var (
         TypeAsciiNoNul: "_ASCII_NO_NUL",
     }
 
-    TypeNamesR = map[string]TagTypePrimitive{}
+    typeNamesR = map[string]TagTypePrimitive{}
 )
 
 type Rational struct {
@@ -123,14 +140,134 @@ type SignedRational struct {
 
 // Format returns a stringified value for the given encoding. Automatically
 // parses. Automatically calculates count based on type size.
-func Format(rawBytes []byte, tagType TagTypePrimitive, justFirst bool, byteOrder binary.ByteOrder) (value string, err error) {
+func FormatFromType(value interface{}, justFirst bool) (phrase string, err error) {
     defer func() {
         if state := recover(); state != nil {
             err = log.Wrap(state.(error))
         }
     }()
 
-    // TODO(dustin): !! Add tests
+    // TODO(dustin): !! Add test
+
+    switch t := value.(type) {
+    case []byte:
+        return DumpBytesToString(t), nil
+    case string:
+        return t, nil
+    case []uint16:
+        if len(t) == 0 {
+            return "", nil
+        }
+
+        if justFirst == true {
+            var valueSuffix string
+            if len(t) > 1 {
+                valueSuffix = "..."
+            }
+
+            return fmt.Sprintf("%v%s", t[0], valueSuffix), nil
+        }
+
+        return fmt.Sprintf("%v", t), nil
+    case []uint32:
+        if len(t) == 0 {
+            return "", nil
+        }
+
+        if justFirst == true {
+            var valueSuffix string
+            if len(t) > 1 {
+                valueSuffix = "..."
+            }
+
+            return fmt.Sprintf("%v%s", t[0], valueSuffix), nil
+        }
+
+        return fmt.Sprintf("%v", t), nil
+    case []Rational:
+        if len(t) == 0 {
+            return "", nil
+        }
+
+        parts := make([]string, len(t))
+        for i, r := range t {
+            parts[i] = fmt.Sprintf("%d/%d", r.Numerator, r.Denominator)
+
+            if justFirst == true {
+                break
+            }
+        }
+
+        if justFirst == true {
+            var valueSuffix string
+            if len(t) > 1 {
+                valueSuffix = "..."
+            }
+
+            return fmt.Sprintf("%v%s", parts[0], valueSuffix), nil
+        }
+
+        return fmt.Sprintf("%v", parts), nil
+    case []int32:
+        if len(t) == 0 {
+            return "", nil
+        }
+
+        if justFirst == true {
+            var valueSuffix string
+            if len(t) > 1 {
+                valueSuffix = "..."
+            }
+
+            return fmt.Sprintf("%v%s", t[0], valueSuffix), nil
+        }
+
+        return fmt.Sprintf("%v", t), nil
+    case []SignedRational:
+        if len(t) == 0 {
+            return "", nil
+        }
+
+        parts := make([]string, len(t))
+        for i, r := range t {
+            parts[i] = fmt.Sprintf("%d/%d", r.Numerator, r.Denominator)
+
+            if justFirst == true {
+                break
+            }
+        }
+
+        if justFirst == true {
+            var valueSuffix string
+            if len(t) > 1 {
+                valueSuffix = "..."
+            }
+
+            return fmt.Sprintf("%v%s", parts[0], valueSuffix), nil
+        }
+
+        return fmt.Sprintf("%v", parts), nil
+    default:
+        // Affects only "unknown" values, in general.
+        log.Panicf("type can not be formatted into string: %v", reflect.TypeOf(value).Name())
+
+        // Never called.
+        return "", nil
+    }
+}
+
+// TODO(dustin): Rename Format() to FormatFromBytes()
+
+// Format returns a stringified value for the given encoding. Automatically
+// parses. Automatically calculates count based on type size.
+func Format(rawBytes []byte, tagType TagTypePrimitive, justFirst bool, byteOrder binary.ByteOrder) (phrase string, err error) {
+    defer func() {
+        if state := recover(); state != nil {
+            err = log.Wrap(state.(error))
+        }
+    }()
+
+    // TODO(dustin): !! Add test
 
     typeSize := tagType.Size()
 
@@ -144,109 +281,61 @@ func Format(rawBytes []byte, tagType TagTypePrimitive, justFirst bool, byteOrder
 
     // Truncate the items if it's not bytes or a string and we just want the first.
 
-    valueSuffix := ""
+    var value interface{}
-    if justFirst == true && unitCount > 1 && tagType != TypeByte && tagType != TypeAscii && tagType != TypeAsciiNoNul {
-        unitCount = 1
-        valueSuffix = "..."
-    }
 
-    if tagType == TypeByte {
+    switch tagType {
-        items, err := parser.ParseBytes(rawBytes, unitCount)
+    case TypeByte:
+        var err error
+
+        value, err = parser.ParseBytes(rawBytes, unitCount)
         log.PanicIf(err)
+    case TypeAscii:
+        var err error
 
-        return DumpBytesToString(items), nil
+        value, err = parser.ParseAscii(rawBytes, unitCount)
-    } else if tagType == TypeAscii {
-        phrase, err := parser.ParseAscii(rawBytes, unitCount)
         log.PanicIf(err)
+    case TypeAsciiNoNul:
+        var err error
 
-        return phrase, nil
+        value, err = parser.ParseAsciiNoNul(rawBytes, unitCount)
-    } else if tagType == TypeAsciiNoNul {
-        phrase, err := parser.ParseAsciiNoNul(rawBytes, unitCount)
         log.PanicIf(err)
+    case TypeShort:
+        var err error
 
-        return phrase, nil
+        value, err = parser.ParseShorts(rawBytes, unitCount, byteOrder)
-    } else if tagType == TypeShort {
-        items, err := parser.ParseShorts(rawBytes, unitCount, byteOrder)
         log.PanicIf(err)
+    case TypeLong:
+        var err error
 
-        if len(items) > 0 {
+        value, err = parser.ParseLongs(rawBytes, unitCount, byteOrder)
-            if justFirst == true {
-                return fmt.Sprintf("%v%s", items[0], valueSuffix), nil
-            } else {
-                return fmt.Sprintf("%v", items), nil
-            }
-        } else {
-            return "", nil
-        }
-    } else if tagType == TypeLong {
-        items, err := parser.ParseLongs(rawBytes, unitCount, byteOrder)
         log.PanicIf(err)
+    case TypeRational:
+        var err error
 
-        if len(items) > 0 {
+        value, err = parser.ParseRationals(rawBytes, unitCount, byteOrder)
-            if justFirst == true {
-                return fmt.Sprintf("%v%s", items[0], valueSuffix), nil
-            } else {
-                return fmt.Sprintf("%v", items), nil
-            }
-        } else {
-            return "", nil
-        }
-    } else if tagType == TypeRational {
-        items, err := parser.ParseRationals(rawBytes, unitCount, byteOrder)
         log.PanicIf(err)
+    case TypeSignedLong:
+        var err error
 
-        if len(items) > 0 {
+        value, err = parser.ParseSignedLongs(rawBytes, unitCount, byteOrder)
-            parts := make([]string, len(items))
-            for i, r := range items {
-                parts[i] = fmt.Sprintf("%d/%d", r.Numerator, r.Denominator)
-            }
-
-            if justFirst == true {
-                return fmt.Sprintf("%v%s", parts[0], valueSuffix), nil
-            } else {
-                return fmt.Sprintf("%v", parts), nil
-            }
-        } else {
-            return "", nil
-        }
-    } else if tagType == TypeSignedLong {
-        items, err := parser.ParseSignedLongs(rawBytes, unitCount, byteOrder)
         log.PanicIf(err)
+    case TypeSignedRational:
+        var err error
 
-        if len(items) > 0 {
+        value, err = parser.ParseSignedRationals(rawBytes, unitCount, byteOrder)
-            if justFirst == true {
-                return fmt.Sprintf("%v%s", items[0], valueSuffix), nil
-            } else {
-                return fmt.Sprintf("%v", items), nil
-            }
-        } else {
-            return "", nil
-        }
-    } else if tagType == TypeSignedRational {
-        items, err := parser.ParseSignedRationals(rawBytes, unitCount, byteOrder)
         log.PanicIf(err)
-
+    default:
-        parts := make([]string, len(items))
-        for i, r := range items {
-            parts[i] = fmt.Sprintf("%d/%d", r.Numerator, r.Denominator)
-        }
-
-        if len(items) > 0 {
-            if justFirst == true {
-                return fmt.Sprintf("%v%s", parts[0], valueSuffix), nil
-            } else {
-                return fmt.Sprintf("%v", parts), nil
-            }
-        } else {
-            return "", nil
-        }
-    } else {
         // Affects only "unknown" values, in general.
         log.Panicf("value of type [%s] can not be formatted into string", tagType.String())
 
         // Never called.
         return "", nil
     }
+
+    phrase, err = FormatFromType(value, justFirst)
+    log.PanicIf(err)
+
+    return phrase, nil
 }
 
 // TranslateStringToType converts user-provided strings to properly-typed
@@ -323,8 +412,15 @@ func TranslateStringToType(tagType TagTypePrimitive, valueString string) (value
     return nil, nil
 }
 
+// GetTypeByName returns the `TagTypePrimitive` for the given type name.
+// Returns (0) if not valid.
+func GetTypeByName(typeName string) (tagType TagTypePrimitive, found bool) {
+    tagType, found = typeNamesR[typeName]
+    return tagType, found
+}
+
 func init() {
     for typeId, typeName := range TypeNames {
-        TypeNamesR[typeName] = typeId
+        typeNamesR[typeName] = typeId
     }
 }

v2/common/utility.go

@@ -7,6 +7,7 @@ import (
     "github.com/dsoprea/go-logging"
 )
 
+// DumpBytes prints a list of hex-encoded bytes.
 func DumpBytes(data []byte) {
     fmt.Printf("DUMP: ")
     for _, x := range data {
@@ -16,6 +17,8 @@ func DumpBytes(data []byte) {
     fmt.Printf("\n")
 }
 
+// DumpBytesClause prints a list like DumpBytes(), but encapsulated in
+// "[]byte { ... }".
 func DumpBytesClause(data []byte) {
     fmt.Printf("DUMP: ")
 
@@ -32,6 +35,7 @@ func DumpBytesClause(data []byte) {
     fmt.Printf(" }\n")
 }
 
+// DumpBytesToString returns a stringified list of hex-encoded bytes.
 func DumpBytesToString(data []byte) string {
     b := new(bytes.Buffer)
 
@@ -48,6 +52,7 @@ func DumpBytesToString(data []byte) string {
     return b.String()
 }
 
+// DumpBytesClauseToString returns a comma-separated list of hex-encoded bytes.
 func DumpBytesClauseToString(data []byte) string {
     b := new(bytes.Buffer)
 

v2/common/utility_test.go

@@ -0,0 +1,28 @@
+package exifcommon
+
+import (
+	"testing"
+	// "github.com/dsoprea/go-logging"
+)
+
+func TestDumpBytes(t *testing.T) {
+	DumpBytes([]byte{1, 2, 3, 4})
+}
+
+func TestDumpBytesClause(t *testing.T) {
+	DumpBytesClause([]byte{1, 2, 3, 4})
+}
+
+func TestDumpBytesToString(t *testing.T) {
+	s := DumpBytesToString([]byte{1, 2, 3, 4})
+	if s != "01 02 03 04" {
+		t.Fatalf("String not correct: [%s]", s)
+	}
+}
+
+func TestDumpBytesClauseToString(t *testing.T) {
+	s := DumpBytesClauseToString([]byte{1, 2, 3, 4})
+	if s != "0x01, 0x02, 0x03, 0x04" {
+		t.Fatalf("Stringified clause is not correct: [%s]", s)
+	}
+}

v2/common/value_context.go

@@ -32,7 +32,7 @@ type ValueContext struct {
 // TODO(dustin): We can update newValueContext() to derive `valueOffset` itself (from `rawValueOffset`).
 
 // newValueContext returns a new ValueContext struct.
-func newValueContext(ifdPath string, tagId uint16, unitCount, valueOffset uint32, rawValueOffset, addressableData []byte, tagType TagTypePrimitive, byteOrder binary.ByteOrder) *ValueContext {
+func NewValueContext(ifdPath string, tagId uint16, unitCount, valueOffset uint32, rawValueOffset, addressableData []byte, tagType TagTypePrimitive, byteOrder binary.ByteOrder) *ValueContext {
 	return &ValueContext{
 		unitCount:       unitCount,
 		valueOffset:     valueOffset,
@@ -138,6 +138,14 @@ func (vc *ValueContext) readRawEncoded() (rawBytes []byte, err error) {
 	}
 }
 
+// ReadRawEncoded returns the encoded bytes for the value that we represent.
+func (vc *ValueContext) ReadRawEncoded() (rawBytes []byte, err error) {
+
+	// TODO(dustin): Remove this method and rename readRawEncoded in its place.
+
+	return vc.readRawEncoded()
+}
+
 // Format returns a string representation for the value.
 //
 // Where the type is not ASCII, `justFirst` indicates whether to just stringify

v2/common/value_context_test.go

@@ -11,7 +11,7 @@ import (
 func TestNewValueContext(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
 
 	if vc.ifdPath != "aa/bb" {
 		t.Fatalf("ifdPath not correct: [%s]", vc.ifdPath)
@@ -48,7 +48,7 @@ func TestValueContext_SetUndefinedValueType__ErrorWhenNotUndefined(t *testing.T)
 
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
 
 	vc.SetUndefinedValueType(TypeLong)
 }
@@ -56,7 +56,7 @@ func TestValueContext_SetUndefinedValueType__ErrorWhenNotUndefined(t *testing.T)
 func TestValueContext_SetUndefinedValueType__Ok(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	vc.SetUndefinedValueType(TypeLong)
 
@@ -72,7 +72,7 @@ func TestValueContext_SetUndefinedValueType__Ok(t *testing.T) {
 func TestValueContext_effectiveValueType(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	vc.SetUndefinedValueType(TypeLong)
 
@@ -88,7 +88,7 @@ func TestValueContext_effectiveValueType(t *testing.T) {
 func TestValueContext_UnitCount(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if vc.UnitCount() != 11 {
 		t.Fatalf("UnitCount() not correct: (%d)", vc.UnitCount())
@@ -98,7 +98,7 @@ func TestValueContext_UnitCount(t *testing.T) {
 func TestValueContext_ValueOffset(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if vc.ValueOffset() != 22 {
 		t.Fatalf("ValueOffset() not correct: (%d)", vc.ValueOffset())
@@ -108,7 +108,7 @@ func TestValueContext_ValueOffset(t *testing.T) {
 func TestValueContext_RawValueOffset(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if bytes.Equal(vc.RawValueOffset(), rawValueOffset) != true {
 		t.Fatalf("RawValueOffset() not correct: %v", vc.RawValueOffset())
@@ -118,7 +118,7 @@ func TestValueContext_RawValueOffset(t *testing.T) {
 func TestValueContext_AddressableData(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if bytes.Equal(vc.AddressableData(), addressableData) != true {
 		t.Fatalf("AddressableData() not correct: %v", vc.AddressableData())
@@ -128,7 +128,7 @@ func TestValueContext_AddressableData(t *testing.T) {
 func TestValueContext_ByteOrder(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if vc.ByteOrder() != TestDefaultByteOrder {
 		t.Fatalf("ByteOrder() not correct: %v", vc.ByteOrder())
@@ -138,7 +138,7 @@ func TestValueContext_ByteOrder(t *testing.T) {
 func TestValueContext_IfdPath(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if vc.IfdPath() != "aa/bb" {
 		t.Fatalf("IfdPath() not correct: [%s]", vc.IfdPath())
@@ -148,7 +148,7 @@ func TestValueContext_IfdPath(t *testing.T) {
 func TestValueContext_TagId(t *testing.T) {
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, 11, 22, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	if vc.TagId() != 0x1234 {
 		t.Fatalf("TagId() not correct: (%d)", vc.TagId())
@@ -159,7 +159,7 @@ func TestValueContext_isEmbedded__True(t *testing.T) {
 	unitCount := uint32(4)
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, unitCount, 22, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, 22, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	if vc.isEmbedded() != true {
 		t.Fatalf("isEmbedded() not correct: %v", vc.isEmbedded())
@@ -170,7 +170,7 @@ func TestValueContext_isEmbedded__False(t *testing.T) {
 	unitCount := uint32(5)
 	rawValueOffset := []byte{0, 0, 0, 22}
 	addressableData := []byte{1, 2, 3, 4}
-	vc := newValueContext("aa/bb", 0x1234, unitCount, 22, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, 22, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	if vc.isEmbedded() != false {
 		t.Fatalf("isEmbedded() not correct: %v", vc.isEmbedded())
@@ -186,7 +186,7 @@ func TestValueContext_readRawEncoded__IsEmbedded(t *testing.T) {
 	valueOffset := uint32(0)
 
 	addressableData := []byte{}
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	recovered, err := vc.readRawEncoded()
 	log.PanicIf(err)
@@ -208,7 +208,7 @@ func TestValueContext_readRawEncoded__IsRelative(t *testing.T) {
 	addressableData := []byte{1, 2, 3, 4}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	recovered, err := vc.readRawEncoded()
 	log.PanicIf(err)
@@ -228,7 +228,7 @@ func TestValueContext_Format__Byte(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -248,7 +248,7 @@ func TestValueContext_Format__Ascii(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -268,7 +268,7 @@ func TestValueContext_Format__AsciiNoNul(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -288,7 +288,7 @@ func TestValueContext_Format__Short(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -308,7 +308,7 @@ func TestValueContext_Format__Long(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -332,7 +332,7 @@ func TestValueContext_Format__Rational(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -352,7 +352,7 @@ func TestValueContext_Format__SignedLong(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -376,7 +376,7 @@ func TestValueContext_Format__SignedRational(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -409,7 +409,7 @@ func TestValueContext_Format__Undefined__NoEffectiveType(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	value, err := vc.Format()
 	log.PanicIf(err)
@@ -429,7 +429,7 @@ func TestValueContext_Format__Undefined__HasEffectiveType(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeUndefined, TestDefaultByteOrder)
 
 	vc.SetUndefinedValueType(TypeAscii)
 
@@ -451,7 +451,7 @@ func TestValueContext_FormatFirst__Bytes(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	value, err := vc.FormatFirst()
 	log.PanicIf(err)
@@ -471,7 +471,7 @@ func TestValueContext_FormatFirst__String(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
 
 	value, err := vc.FormatFirst()
 	log.PanicIf(err)
@@ -491,7 +491,7 @@ func TestValueContext_FormatFirst__List(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
 
 	value, err := vc.FormatFirst()
 	log.PanicIf(err)
@@ -511,7 +511,7 @@ func TestValueContext_ReadBytes(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	value, err := vc.ReadBytes()
 	log.PanicIf(err)
@@ -531,7 +531,7 @@ func TestValueContext_ReadAscii(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
 
 	value, err := vc.ReadAscii()
 	log.PanicIf(err)
@@ -551,7 +551,7 @@ func TestValueContext_ReadAsciiNoNul(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
 
 	value, err := vc.ReadAsciiNoNul()
 	log.PanicIf(err)
@@ -571,7 +571,7 @@ func TestValueContext_ReadShorts(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
 
 	value, err := vc.ReadShorts()
 	log.PanicIf(err)
@@ -591,7 +591,7 @@ func TestValueContext_ReadLongs(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
 
 	value, err := vc.ReadLongs()
 	log.PanicIf(err)
@@ -615,7 +615,7 @@ func TestValueContext_ReadRationals(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
 
 	value, err := vc.ReadRationals()
 	log.PanicIf(err)
@@ -640,7 +640,7 @@ func TestValueContext_ReadSignedLongs(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
 
 	value, err := vc.ReadSignedLongs()
 	log.PanicIf(err)
@@ -664,7 +664,7 @@ func TestValueContext_ReadSignedRationals(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
 
 	value, err := vc.ReadSignedRationals()
 	log.PanicIf(err)
@@ -689,7 +689,7 @@ func TestValueContext_Values__Byte(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeByte, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -709,7 +709,7 @@ func TestValueContext_Values__Ascii(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAscii, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -729,7 +729,7 @@ func TestValueContext_Values__AsciiNoNul(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeAsciiNoNul, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -749,7 +749,7 @@ func TestValueContext_Values__Short(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeShort, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -769,7 +769,7 @@ func TestValueContext_Values__Long(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeLong, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -793,7 +793,7 @@ func TestValueContext_Values__Rational(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeRational, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -818,7 +818,7 @@ func TestValueContext_Values__SignedLong(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedLong, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)
@@ -842,7 +842,7 @@ func TestValueContext_Values__SignedRational(t *testing.T) {
 	addressableData := []byte{0, 0, 0, 0}
 	addressableData = append(addressableData, data...)
 
-	vc := newValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
+	vc := NewValueContext("aa/bb", 0x1234, unitCount, valueOffset, rawValueOffset, addressableData, TypeSignedRational, TestDefaultByteOrder)
 
 	value, err := vc.Values()
 	log.PanicIf(err)

v2/common/value_encoder.go

@@ -187,8 +187,6 @@ func (ve *ValueEncoder) Encode(value interface{}) (ed EncodedData, err error) {
         }
     }()
 
-    // TODO(dustin): This is redundant with EncodeWithType. Refactor one to use the other.
-
     switch value.(type) {
     case []byte:
         ed, err = ve.encodeBytes(value.([]byte))

v2/exif.go

@@ -177,7 +177,7 @@ func ParseExifHeader(data []byte) (eh ExifHeader, err error) {
 }
 
 // Visit recursively invokes a callback for every tag.
-func Visit(rootIfdName string, ifdMapping *IfdMapping, tagIndex *TagIndex, exifData []byte, visitor RawTagVisitor) (eh ExifHeader, err error) {
+func Visit(rootIfdName string, ifdMapping *IfdMapping, tagIndex *TagIndex, exifData []byte, visitor RawTagWalk) (eh ExifHeader, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/exif_test.go

@@ -11,13 +11,28 @@ import (
 	"io/ioutil"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
+	"github.com/dsoprea/go-exif/v2/undefined"
 )
 
+type innerVisitorCall func(fqIfdPath string, ifdIndex int, tagId uint16, tagType exifcommon.TagTypePrimitive, valueContext *exifcommon.ValueContext) (err error)
+
+type visitorWrapper struct {
+	f innerVisitorCall
+}
+
+func (vw *visitorWrapper) Visit(fqIfdPath string, ifdIndex int, tagId uint16, tagType exifcommon.TagTypePrimitive, valueContext *exifcommon.ValueContext) (err error) {
+	return vw.f(fqIfdPath, ifdIndex, tagId, tagType, valueContext)
+}
+
 func TestVisit(t *testing.T) {
 	defer func() {
 		if state := recover(); state != nil {
 			err := log.Wrap(state.(error))
-			log.PrintErrorf(err, "Exif failure.")
+			log.PrintError(err)
+
+			t.Fatalf("Test failure.")
 		}
 	}()
 
@@ -56,7 +71,7 @@ func TestVisit(t *testing.T) {
 
 	tags := make([]string, 0)
 
-	visitor := func(fqIfdPath string, ifdIndex int, tagId uint16, tagType TagType, valueContext ValueContext) (err error) {
+	visitor := func(fqIfdPath string, ifdIndex int, tagId uint16, tagType exifcommon.TagTypePrimitive, valueContext *exifcommon.ValueContext) (err error) {
 		defer func() {
 			if state := recover(); state != nil {
 				err = log.Wrap(state.(error))
@@ -78,10 +93,10 @@ func TestVisit(t *testing.T) {
 		}
 
 		valueString := ""
-		if tagType.Type() == TypeUndefined {
+		if tagType == exifcommon.TypeUndefined {
-			value, err := valueContext.Undefined()
+			value, err := exifundefined.Decode(fqIfdPath, tagId, valueContext, valueContext.ByteOrder())
 			if err != nil {
-				if err == ErrUnhandledUnknownTypedTag {
+				if err == exifcommon.ErrUnhandledUnknownTypedTag {
 					valueString = "!UNDEFINED!"
 				} else {
 					log.Panic(err)
@@ -90,17 +105,23 @@ func TestVisit(t *testing.T) {
 
 			valueString = fmt.Sprintf("%v", value)
 		} else {
+			var err error
+
 			valueString, err = valueContext.FormatFirst()
 			log.PanicIf(err)
 		}
 
-		description := fmt.Sprintf("IFD-PATH=[%s] ID=(0x%04x) NAME=[%s] COUNT=(%d) TYPE=[%s] VALUE=[%s]", ifdPath, tagId, it.Name, valueContext.UnitCount(), tagType.Name(), valueString)
+		description := fmt.Sprintf("IFD-PATH=[%s] ID=(0x%04x) NAME=[%s] COUNT=(%d) TYPE=[%s] VALUE=[%s]", ifdPath, tagId, it.Name, valueContext.UnitCount(), tagType.String(), valueString)
 		tags = append(tags, description)
 
 		return nil
 	}
 
-	_, err = Visit(IfdStandard, im, ti, data[foundAt:], visitor)
+	vw := &visitorWrapper{
+		f: visitor,
+	}
+
+	_, err = Visit(exifcommon.IfdStandard, im, ti, data[foundAt:], vw)
 	log.PanicIf(err)
 
 	expected := []string{
@@ -124,7 +145,7 @@ func TestVisit(t *testing.T) {
 		"IFD-PATH=[IFD/Exif] ID=(0x9000) NAME=[ExifVersion] COUNT=(4) TYPE=[UNDEFINED] VALUE=[0230]",
 		"IFD-PATH=[IFD/Exif] ID=(0x9003) NAME=[DateTimeOriginal] COUNT=(20) TYPE=[ASCII] VALUE=[2017:12:02 08:18:50]",
 		"IFD-PATH=[IFD/Exif] ID=(0x9004) NAME=[DateTimeDigitized] COUNT=(20) TYPE=[ASCII] VALUE=[2017:12:02 08:18:50]",
-		"IFD-PATH=[IFD/Exif] ID=(0x9101) NAME=[ComponentsConfiguration] COUNT=(4) TYPE=[UNDEFINED] VALUE=[ComponentsConfiguration<ID=[YCBCR] BYTES=[1 2 3 0]>]",
+		"IFD-PATH=[IFD/Exif] ID=(0x9101) NAME=[ComponentsConfiguration] COUNT=(4) TYPE=[UNDEFINED] VALUE=[Exif9101ComponentsConfiguration<ID=[YCBCR] BYTES=[1 2 3 0]>]",
 		"IFD-PATH=[IFD/Exif] ID=(0x9201) NAME=[ShutterSpeedValue] COUNT=(1) TYPE=[SRATIONAL] VALUE=[614400/65536]",
 		"IFD-PATH=[IFD/Exif] ID=(0x9202) NAME=[ApertureValue] COUNT=(1) TYPE=[RATIONAL] VALUE=[262144/65536]",
 		"IFD-PATH=[IFD/Exif] ID=(0x9204) NAME=[ExposureBiasValue] COUNT=(1) TYPE=[SRATIONAL] VALUE=[0/1]",
@@ -213,7 +234,9 @@ func TestCollect(t *testing.T) {
 	defer func() {
 		if state := recover(); state != nil {
 			err := log.Wrap(state.(error))
-			log.PrintErrorf(err, "Exif failure.")
+			log.PrintError(err)
+
+			t.Fatalf("Test failure.")
 		}
 	}()
 
@@ -259,52 +282,52 @@ func TestCollect(t *testing.T) {
 		t.Fatalf("Root IFD chain not terminated correctly (2).")
 	}
 
-	if rootIfd.IfdPath != IfdPathStandard {
+	if rootIfd.IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("Root IFD is not labeled correctly: [%s]", rootIfd.IfdPath)
-	} else if rootIfd.NextIfd.IfdPath != IfdPathStandard {
+	} else if rootIfd.NextIfd.IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("Root IFD sibling is not labeled correctly: [%s]", rootIfd.IfdPath)
-	} else if rootIfd.Children[0].IfdPath != IfdPathStandardExif {
+	} else if rootIfd.Children[0].IfdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("Root IFD child (0) is not labeled correctly: [%s]", rootIfd.Children[0].IfdPath)
-	} else if rootIfd.Children[1].IfdPath != IfdPathStandardGps {
+	} else if rootIfd.Children[1].IfdPath != exifcommon.IfdPathStandardGps {
 		t.Fatalf("Root IFD child (1) is not labeled correctly: [%s]", rootIfd.Children[1].IfdPath)
-	} else if rootIfd.Children[0].Children[0].IfdPath != IfdPathStandardExifIop {
+	} else if rootIfd.Children[0].Children[0].IfdPath != exifcommon.IfdPathStandardExifIop {
 		t.Fatalf("Exif IFD child is not an IOP IFD: [%s]", rootIfd.Children[0].Children[0].IfdPath)
 	}
 
-	if lookup[IfdPathStandard][0].IfdPath != IfdPathStandard {
+	if lookup[exifcommon.IfdPathStandard][0].IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("Lookup for standard IFD not correct.")
-	} else if lookup[IfdPathStandard][1].IfdPath != IfdPathStandard {
+	} else if lookup[exifcommon.IfdPathStandard][1].IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("Lookup for standard IFD not correct.")
 	}
 
-	if lookup[IfdPathStandardExif][0].IfdPath != IfdPathStandardExif {
+	if lookup[exifcommon.IfdPathStandardExif][0].IfdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("Lookup for EXIF IFD not correct.")
 	}
 
-	if lookup[IfdPathStandardGps][0].IfdPath != IfdPathStandardGps {
+	if lookup[exifcommon.IfdPathStandardGps][0].IfdPath != exifcommon.IfdPathStandardGps {
 		t.Fatalf("Lookup for GPS IFD not correct.")
 	}
 
-	if lookup[IfdPathStandardExifIop][0].IfdPath != IfdPathStandardExifIop {
+	if lookup[exifcommon.IfdPathStandardExifIop][0].IfdPath != exifcommon.IfdPathStandardExifIop {
 		t.Fatalf("Lookup for IOP IFD not correct.")
 	}
 
 	foundExif := 0
 	foundGps := 0
-	for _, ite := range lookup[IfdPathStandard][0].Entries {
+	for _, ite := range lookup[exifcommon.IfdPathStandard][0].Entries {
-		if ite.ChildIfdPath == IfdPathStandardExif {
+		if ite.ChildIfdPath == exifcommon.IfdPathStandardExif {
 			foundExif++
 
-			if ite.TagId != IfdExifId {
+			if ite.TagId != exifcommon.IfdExifId {
-				t.Fatalf("EXIF IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, IfdExifId)
+				t.Fatalf("EXIF IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, exifcommon.IfdExifId)
 			}
 		}
 
-		if ite.ChildIfdPath == IfdPathStandardGps {
+		if ite.ChildIfdPath == exifcommon.IfdPathStandardGps {
 			foundGps++
 
-			if ite.TagId != IfdGpsId {
+			if ite.TagId != exifcommon.IfdGpsId {
-				t.Fatalf("GPS IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, IfdGpsId)
+				t.Fatalf("GPS IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, exifcommon.IfdGpsId)
 			}
 		}
 	}
@@ -316,12 +339,12 @@ func TestCollect(t *testing.T) {
 	}
 
 	foundIop := 0
-	for _, ite := range lookup[IfdPathStandardExif][0].Entries {
+	for _, ite := range lookup[exifcommon.IfdPathStandardExif][0].Entries {
-		if ite.ChildIfdPath == IfdPathStandardExifIop {
+		if ite.ChildIfdPath == exifcommon.IfdPathStandardExifIop {
 			foundIop++
 
-			if ite.TagId != IfdIopId {
+			if ite.TagId != exifcommon.IfdIopId {
-				t.Fatalf("IOP IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, IfdIopId)
+				t.Fatalf("IOP IFD tag-ID mismatch: (0x%04x) != (0x%04x)", ite.TagId, exifcommon.IfdIopId)
 			}
 		}
 	}
@@ -343,13 +366,13 @@ func TestParseExifHeader(t *testing.T) {
 }
 
 func TestExif_BuildAndParseExifHeader(t *testing.T) {
-	headerBytes, err := BuildExifHeader(TestDefaultByteOrder, 0x11223344)
+	headerBytes, err := BuildExifHeader(exifcommon.TestDefaultByteOrder, 0x11223344)
 	log.PanicIf(err)
 
 	eh, err := ParseExifHeader(headerBytes)
 	log.PanicIf(err)
 
-	if eh.ByteOrder != TestDefaultByteOrder {
+	if eh.ByteOrder != exifcommon.TestDefaultByteOrder {
 		t.Fatalf("Byte-order of EXIF header not correct.")
 	} else if eh.FirstIfdOffset != 0x11223344 {
 		t.Fatalf("First IFD offset not correct.")
@@ -357,7 +380,7 @@ func TestExif_BuildAndParseExifHeader(t *testing.T) {
 }
 
 func ExampleBuildExifHeader() {
-	headerBytes, err := BuildExifHeader(TestDefaultByteOrder, 0x11223344)
+	headerBytes, err := BuildExifHeader(exifcommon.TestDefaultByteOrder, 0x11223344)
 	log.PanicIf(err)
 
 	eh, err := ParseExifHeader(headerBytes)

v2/ifd.go

@@ -6,6 +6,8 @@ import (
 	"strings"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 var (
@@ -363,16 +365,16 @@ func LoadStandardIfds(im *IfdMapping) (err error) {
 		}
 	}()
 
-	err = im.Add([]uint16{}, IfdRootId, IfdStandard)
+	err = im.Add([]uint16{}, exifcommon.IfdRootId, exifcommon.IfdStandard)
 	log.PanicIf(err)
 
-	err = im.Add([]uint16{IfdRootId}, IfdExifId, IfdExif)
+	err = im.Add([]uint16{exifcommon.IfdRootId}, exifcommon.IfdExifId, exifcommon.IfdExif)
 	log.PanicIf(err)
 
-	err = im.Add([]uint16{IfdRootId, IfdExifId}, IfdIopId, IfdIop)
+	err = im.Add([]uint16{exifcommon.IfdRootId, exifcommon.IfdExifId}, exifcommon.IfdIopId, exifcommon.IfdIop)
 	log.PanicIf(err)
 
-	err = im.Add([]uint16{IfdRootId}, IfdGpsId, IfdGps)
+	err = im.Add([]uint16{exifcommon.IfdRootId}, exifcommon.IfdGpsId, exifcommon.IfdGps)
 	log.PanicIf(err)
 
 	return nil

v2/ifd_builder.go

@@ -13,6 +13,9 @@ import (
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
+	"github.com/dsoprea/go-exif/v2/undefined"
 )
 
 var (
@@ -94,7 +97,7 @@ type BuilderTag struct {
 	ifdPath string
 
 	tagId  uint16
-	typeId TagTypePrimitive
+	typeId exifcommon.TagTypePrimitive
 
 	// value is either a value that can be encoded, an IfdBuilder instance (for
 	// child IFDs), or an IfdTagEntry instance representing an existing,
@@ -106,7 +109,7 @@ type BuilderTag struct {
 	byteOrder binary.ByteOrder
 }
 
-func NewBuilderTag(ifdPath string, tagId uint16, typeId TagTypePrimitive, value *IfdBuilderTagValue, byteOrder binary.ByteOrder) *BuilderTag {
+func NewBuilderTag(ifdPath string, tagId uint16, typeId exifcommon.TagTypePrimitive, value *IfdBuilderTagValue, byteOrder binary.ByteOrder) *BuilderTag {
 	return &BuilderTag{
 		ifdPath:   ifdPath,
 		tagId:     tagId,
@@ -120,7 +123,7 @@ func NewChildIfdBuilderTag(ifdPath string, tagId uint16, value *IfdBuilderTagVal
 	return &BuilderTag{
 		ifdPath: ifdPath,
 		tagId:   tagId,
-		typeId:  TypeLong,
+		typeId:  exifcommon.TypeLong,
 		value:   value,
 	}
 }
@@ -135,13 +138,13 @@ func (bt *BuilderTag) String() string {
 	if bt.value.IsBytes() == true {
 		var err error
 
-		valueString, err = Format(bt.value.Bytes(), bt.typeId, false, bt.byteOrder)
+		valueString, err = exifcommon.Format(bt.value.Bytes(), bt.typeId, false, bt.byteOrder)
 		log.PanicIf(err)
 	} else {
 		valueString = fmt.Sprintf("%v", bt.value)
 	}
 
-	return fmt.Sprintf("BuilderTag<IFD-PATH=[%s] TAG-ID=(0x%04x) TAG-TYPE=[%s] VALUE=[%s]>", bt.ifdPath, bt.tagId, TypeNames[bt.typeId], valueString)
+	return fmt.Sprintf("BuilderTag<IFD-PATH=[%s] TAG-ID=(0x%04x) TAG-TYPE=[%s] VALUE=[%s]>", bt.ifdPath, bt.tagId, bt.typeId.String(), valueString)
 }
 
 func (bt *BuilderTag) SetValue(byteOrder binary.ByteOrder, value interface{}) (err error) {
@@ -153,19 +156,24 @@ func (bt *BuilderTag) SetValue(byteOrder binary.ByteOrder, value interface{}) (e
 
 	// TODO(dustin): !! Add test.
 
-	tt := NewTagType(bt.typeId, byteOrder)
+	var ed exifcommon.EncodedData
-	ve := NewValueEncoder(byteOrder)
+	if bt.typeId == exifcommon.TypeUndefined {
+		encodeable := value.(exifundefined.EncodeableValue)
 
-	var ed EncodedData
+		encoded, unitCount, err := exifundefined.Encode(encodeable, byteOrder)
-	if bt.typeId == TypeUndefined {
-		var err error
-
-		ed, err = EncodeUndefined(bt.ifdPath, bt.tagId, value)
 		log.PanicIf(err)
+
+		ed = exifcommon.EncodedData{
+			Type:      exifcommon.TypeUndefined,
+			Encoded:   encoded,
+			UnitCount: unitCount,
+		}
 	} else {
+		ve := exifcommon.NewValueEncoder(byteOrder)
+
 		var err error
 
-		ed, err = ve.EncodeWithType(tt, value)
+		ed, err = ve.Encode(value)
 		log.PanicIf(err)
 	}
 
@@ -177,30 +185,29 @@ func (bt *BuilderTag) SetValue(byteOrder binary.ByteOrder, value interface{}) (e
 // NewStandardBuilderTag constructs a `BuilderTag` instance. The type is looked
 // up. `ii` is the type of IFD that owns this tag.
 func NewStandardBuilderTag(ifdPath string, it *IndexedTag, byteOrder binary.ByteOrder, value interface{}) *BuilderTag {
-	typeId := it.Type
+	var rawBytes []byte
-	tt := NewTagType(typeId, byteOrder)
+	if it.Type == exifcommon.TypeUndefined {
+		encodeable := value.(exifundefined.EncodeableValue)
 
-	ve := NewValueEncoder(byteOrder)
-
-	var ed EncodedData
-	if it.Type == TypeUndefined {
 		var err error
 
-		ed, err = EncodeUndefined(ifdPath, it.Id, value)
+		rawBytes, _, err = exifundefined.Encode(encodeable, byteOrder)
 		log.PanicIf(err)
 	} else {
-		var err error
+		ve := exifcommon.NewValueEncoder(byteOrder)
 
-		ed, err = ve.EncodeWithType(tt, value)
+		ed, err := ve.Encode(value)
 		log.PanicIf(err)
+
+		rawBytes = ed.Encoded
 	}
 
-	tagValue := NewIfdBuilderTagValueFromBytes(ed.Encoded)
+	tagValue := NewIfdBuilderTagValueFromBytes(rawBytes)
 
 	return NewBuilderTag(
 		ifdPath,
 		it.Id,
-		typeId,
+		it.Type,
 		tagValue,
 		byteOrder)
 }
@@ -288,7 +295,7 @@ func NewIfdBuilderWithExistingIfd(ifd *Ifd) (ib *IfdBuilder) {
 	var ifdTagId uint16
 
 	// There is no tag-ID for the root IFD. It will never be a child IFD.
-	if ifdPath != IfdPathStandard {
+	if ifdPath != exifcommon.IfdPathStandard {
 		mi, err := ifd.ifdMapping.GetWithPath(ifdPath)
 		log.PanicIf(err)
 
@@ -523,7 +530,7 @@ func (ib *IfdBuilder) SetThumbnail(data []byte) (err error) {
 		}
 	}()
 
-	if ib.ifdPath != IfdPathStandard {
+	if ib.ifdPath != exifcommon.IfdPathStandard {
 		log.Panicf("thumbnails can only go into a root Ifd (and only the second one)")
 	}
 
@@ -540,7 +547,7 @@ func (ib *IfdBuilder) SetThumbnail(data []byte) (err error) {
 		NewBuilderTag(
 			ib.ifdPath,
 			ThumbnailOffsetTagId,
-			TypeLong,
+			exifcommon.TypeLong,
 			ibtvfb,
 			ib.byteOrder)
 
@@ -1113,13 +1120,15 @@ func (ib *IfdBuilder) AddTagsFromExisting(ifd *Ifd, itevr *IfdTagEntryValueResol
 
 			var rawBytes []byte
 
-			if ite.TagType == TypeUndefined {
+			if ite.TagType == exifcommon.TypeUndefined {
-				// It's an undefined-type value. Try to process, or skip if
+				// It's an undefined-type value. Try to process (or skip if
-				// we don't know how to.
+				// we don't know how to), and encode back to bytes. This is the
+				// cleanest way of using what we already have to both determine
+				// if we support this tag and producing the bytes for it.
 
-				undefinedInterface, err := valueContext.Undefined()
+				value, err := exifundefined.Decode(ite.IfdPath, ite.TagId, valueContext, ib.byteOrder)
 				if err != nil {
-					if err == ErrUnhandledUnknownTypedTag {
+					if err == exifcommon.ErrUnhandledUnknownTypedTag {
 						// It's an undefined-type tag that we don't handle. If
 						// we don't know how to handle it, we can't know how
 						// many bytes it is and we must skip it.
@@ -1129,19 +1138,14 @@ func (ib *IfdBuilder) AddTagsFromExisting(ifd *Ifd, itevr *IfdTagEntryValueResol
 					log.Panic(err)
 				}
 
-				undefined, ok := undefinedInterface.(UnknownTagValue)
+				rawBytes, _, err = exifundefined.Encode(value, ib.byteOrder)
-				if ok != true {
-					log.Panicf("unexpected value returned from undefined-value processor")
-				}
-
-				rawBytes, err = undefined.ValueBytes()
 				log.PanicIf(err)
 			} else {
 				// It's a value with a standard type.
 
 				var err error
 
-				rawBytes, err = valueContext.readRawEncoded()
+				rawBytes, err = valueContext.ReadRawEncoded()
 				log.PanicIf(err)
 			}
 

v2/ifd_builder_encode.go

@@ -8,6 +8,8 @@ import (
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 const (
@@ -219,8 +221,8 @@ func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *BuilderTag, bw *
 
 	if bt.value.IsBytes() == true {
 		effectiveType := bt.typeId
-		if bt.typeId == TypeUndefined {
+		if bt.typeId == exifcommon.TypeUndefined {
-			effectiveType = TypeByte
+			effectiveType = exifcommon.TypeByte
 		}
 
 		// It's a non-unknown value.Calculate the count of values of

v2/ifd_builder_encode_test.go

@@ -7,11 +7,13 @@ import (
 	"testing"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 func Test_ByteWriter_writeAsBytes_uint8(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.writeAsBytes(uint8(0x12))
 	log.PanicIf(err)
@@ -23,7 +25,7 @@ func Test_ByteWriter_writeAsBytes_uint8(t *testing.T) {
 
 func Test_ByteWriter_writeAsBytes_uint16(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.writeAsBytes(uint16(0x1234))
 	log.PanicIf(err)
@@ -35,7 +37,7 @@ func Test_ByteWriter_writeAsBytes_uint16(t *testing.T) {
 
 func Test_ByteWriter_writeAsBytes_uint32(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.writeAsBytes(uint32(0x12345678))
 	log.PanicIf(err)
@@ -47,7 +49,7 @@ func Test_ByteWriter_writeAsBytes_uint32(t *testing.T) {
 
 func Test_ByteWriter_WriteUint16(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.WriteUint16(uint16(0x1234))
 	log.PanicIf(err)
@@ -59,7 +61,7 @@ func Test_ByteWriter_WriteUint16(t *testing.T) {
 
 func Test_ByteWriter_WriteUint32(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.WriteUint32(uint32(0x12345678))
 	log.PanicIf(err)
@@ -71,7 +73,7 @@ func Test_ByteWriter_WriteUint32(t *testing.T) {
 
 func Test_ByteWriter_WriteFourBytes(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.WriteFourBytes([]byte{0x11, 0x22, 0x33, 0x44})
 	log.PanicIf(err)
@@ -83,7 +85,7 @@ func Test_ByteWriter_WriteFourBytes(t *testing.T) {
 
 func Test_ByteWriter_WriteFourBytes_TooMany(t *testing.T) {
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	err := bw.WriteFourBytes([]byte{0x11, 0x22, 0x33, 0x44, 0x55})
 	if err == nil {
@@ -194,15 +196,15 @@ func Test_IfdByteEncoder_encodeTagToBytes_bytes_embedded1(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandardGps, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardGps, exifcommon.TestDefaultByteOrder)
 
 	it, err := ti.Get(ib.ifdPath, uint16(0x0000))
 	log.PanicIf(err)
 
-	bt := NewStandardBuilderTag(IfdPathStandardGps, it, TestDefaultByteOrder, []uint8{uint8(0x12)})
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandardGps, it, exifcommon.TestDefaultByteOrder, []uint8{uint8(0x12)})
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	addressableOffset := uint32(0x1234)
 	ida := newIfdDataAllocator(addressableOffset)
@@ -228,15 +230,15 @@ func Test_IfdByteEncoder_encodeTagToBytes_bytes_embedded2(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandardGps, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardGps, exifcommon.TestDefaultByteOrder)
 
 	it, err := ti.Get(ib.ifdPath, uint16(0x0000))
 	log.PanicIf(err)
 
-	bt := NewStandardBuilderTag(IfdPathStandardGps, it, TestDefaultByteOrder, []uint8{uint8(0x12), uint8(0x34), uint8(0x56), uint8(0x78)})
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandardGps, it, exifcommon.TestDefaultByteOrder, []uint8{uint8(0x12), uint8(0x34), uint8(0x56), uint8(0x78)})
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	addressableOffset := uint32(0x1234)
 	ida := newIfdDataAllocator(addressableOffset)
@@ -262,10 +264,10 @@ func Test_IfdByteEncoder_encodeTagToBytes_bytes_allocated(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandardGps, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardGps, exifcommon.TestDefaultByteOrder)
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	addressableOffset := uint32(0x1234)
 	ida := newIfdDataAllocator(addressableOffset)
@@ -273,7 +275,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_bytes_allocated(t *testing.T) {
 	it, err := ti.Get(ib.ifdPath, uint16(0x0000))
 	log.PanicIf(err)
 
-	bt := NewStandardBuilderTag(IfdPathStandardGps, it, TestDefaultByteOrder, []uint8{uint8(0x12), uint8(0x34), uint8(0x56), uint8(0x78), uint8(0x9a)})
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandardGps, it, exifcommon.TestDefaultByteOrder, []uint8{uint8(0x12), uint8(0x34), uint8(0x56), uint8(0x78), uint8(0x9a)})
 
 	childIfdBlock, err := ibe.encodeTagToBytes(ib, bt, bw, ida, uint32(0))
 	log.PanicIf(err)
@@ -290,7 +292,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_bytes_allocated(t *testing.T) {
 
 	// Test that another allocation encodes to the new offset.
 
-	bt = NewStandardBuilderTag(IfdPathStandardGps, it, TestDefaultByteOrder, []uint8{uint8(0xbc), uint8(0xde), uint8(0xf0), uint8(0x12), uint8(0x34)})
+	bt = NewStandardBuilderTag(exifcommon.IfdPathStandardGps, it, exifcommon.TestDefaultByteOrder, []uint8{uint8(0xbc), uint8(0xde), uint8(0xf0), uint8(0x12), uint8(0x34)})
 
 	childIfdBlock, err = ibe.encodeTagToBytes(ib, bt, bw, ida, uint32(0))
 	log.PanicIf(err)
@@ -321,17 +323,17 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withoutAllocate(t *testing.T
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	addressableOffset := uint32(0x1234)
 	ida := newIfdDataAllocator(addressableOffset)
 
-	childIb := NewIfdBuilder(im, ti, IfdPathStandardExif, TestDefaultByteOrder)
+	childIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardExif, exifcommon.TestDefaultByteOrder)
 	tagValue := NewIfdBuilderTagValueFromIfdBuilder(childIb)
-	bt := NewChildIfdBuilderTag(IfdPathStandard, IfdExifId, tagValue)
+	bt := NewChildIfdBuilderTag(exifcommon.IfdPathStandard, exifcommon.IfdExifId, tagValue)
 
 	nextIfdOffsetToWrite := uint32(0)
 	childIfdBlock, err := ibe.encodeTagToBytes(ib, bt, bw, ida, nextIfdOffsetToWrite)
@@ -365,12 +367,12 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	childIb := NewIfdBuilder(im, ti, IfdPathStandardExif, TestDefaultByteOrder)
+	childIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardExif, exifcommon.TestDefaultByteOrder)
 
 	childIbTestTag := &BuilderTag{
-		ifdPath: IfdPathStandardExif,
+		ifdPath: exifcommon.IfdPathStandardExif,
 		tagId:   0x8822,
-		typeId:  TypeShort,
+		typeId:  exifcommon.TypeShort,
 		value:   NewIfdBuilderTagValueFromBytes([]byte{0x12, 0x34}),
 	}
 
@@ -379,7 +381,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 	// Formally compose the tag that refers to it.
 
 	tagValue := NewIfdBuilderTagValueFromIfdBuilder(childIb)
-	bt := NewChildIfdBuilderTag(IfdPathStandard, IfdExifId, tagValue)
+	bt := NewChildIfdBuilderTag(exifcommon.IfdPathStandard, exifcommon.IfdExifId, tagValue)
 
 	// Encode the tag. Since we've actually provided an offset at which we can
 	// allocate data, the child-IFD will automatically be encoded, allocated,
@@ -388,10 +390,10 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 
 	ibe := NewIfdByteEncoder()
 
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	// addressableOffset is the offset of where large data can be allocated
 	// (which follows the IFD table/block). Large, in that it can't be stored
@@ -420,14 +422,14 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 		t.Fatalf("Child IFD is not the right size: (%d)", len(childIfdBlock))
 	}
 
-	iteV, err := ParseOneTag(im, ti, fmt.Sprintf("%s%d", IfdPathStandard, 0), IfdPathStandard, TestDefaultByteOrder, tagBytes, false)
+	iteV, err := ParseOneTag(im, ti, fmt.Sprintf("%s%d", exifcommon.IfdPathStandard, 0), exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder, tagBytes, false)
 	log.PanicIf(err)
 
-	if iteV.TagId != IfdExifId {
+	if iteV.TagId != exifcommon.IfdExifId {
 		t.Fatalf("IFD first tag-ID not correct: (0x%02x)", iteV.TagId)
 	} else if iteV.TagIndex != 0 {
 		t.Fatalf("IFD first tag index not correct: (%d)", iteV.TagIndex)
-	} else if iteV.TagType != TypeLong {
+	} else if iteV.TagType != exifcommon.TypeLong {
 		t.Fatalf("IFD first tag type not correct: (%d)", iteV.TagType)
 	} else if iteV.UnitCount != 1 {
 		t.Fatalf("IFD first tag unit-count not correct: (%d)", iteV.UnitCount)
@@ -435,15 +437,15 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 		t.Fatalf("IFD's child-IFD offset (as offset) is not correct: (%d) != (%d)", iteV.ValueOffset, nextIfdOffsetToWrite)
 	} else if bytes.Compare(iteV.RawValueOffset, []byte{0x0, 0x0, 0x07, 0xd0}) != 0 {
 		t.Fatalf("IFD's child-IFD offset (as raw bytes) is not correct: [%x]", iteV.RawValueOffset)
-	} else if iteV.ChildIfdPath != IfdPathStandardExif {
+	} else if iteV.ChildIfdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("IFD first tag IFD-name name not correct: [%s]", iteV.ChildIfdPath)
-	} else if iteV.IfdPath != IfdPathStandard {
+	} else if iteV.IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("IFD first tag parent IFD not correct: %v", iteV.IfdPath)
 	}
 
 	// Validate the child's raw IFD bytes.
 
-	childNextIfdOffset, childEntries, err := ParseOneIfd(im, ti, "IFD0/Exif0", "IFD/Exif", TestDefaultByteOrder, childIfdBlock, nil, false)
+	childNextIfdOffset, childEntries, err := ParseOneIfd(im, ti, "IFD0/Exif0", "IFD/Exif", exifcommon.TestDefaultByteOrder, childIfdBlock, nil, false)
 	log.PanicIf(err)
 
 	if childNextIfdOffset != uint32(0) {
@@ -458,7 +460,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 		t.Fatalf("Child IFD first tag-ID not correct: (0x%02x)", ite.TagId)
 	} else if ite.TagIndex != 0 {
 		t.Fatalf("Child IFD first tag index not correct: (%d)", ite.TagIndex)
-	} else if ite.TagType != TypeShort {
+	} else if ite.TagType != exifcommon.TypeShort {
 		t.Fatalf("Child IFD first tag type not correct: (%d)", ite.TagType)
 	} else if ite.UnitCount != 1 {
 		t.Fatalf("Child IFD first tag unit-count not correct: (%d)", ite.UnitCount)
@@ -468,7 +470,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_childIfd__withAllocate(t *testing.T) {
 		t.Fatalf("Child IFD first tag value value (as raw bytes) not correct: [%v]", ite.RawValueOffset)
 	} else if ite.ChildIfdPath != "" {
 		t.Fatalf("Child IFD first tag IFD-name name not empty: [%s]", ite.ChildIfdPath)
-	} else if ite.IfdPath != IfdPathStandardExif {
+	} else if ite.IfdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("Child IFD first tag parent IFD not correct: %v", ite.IfdPath)
 	}
 }
@@ -495,16 +497,16 @@ func Test_IfdByteEncoder_encodeTagToBytes_simpleTag_allocate(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	it, err := ib.tagIndex.Get(ib.ifdPath, uint16(0x000b))
 	log.PanicIf(err)
 
 	valueString := "testvalue"
-	bt := NewStandardBuilderTag(IfdPathStandard, it, TestDefaultByteOrder, valueString)
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandard, it, exifcommon.TestDefaultByteOrder, valueString)
 
 	b := new(bytes.Buffer)
-	bw := NewByteWriter(b, TestDefaultByteOrder)
+	bw := NewByteWriter(b, exifcommon.TestDefaultByteOrder)
 
 	// addressableOffset is the offset of where large data can be allocated
 	// (which follows the IFD table/block). Large, in that it can't be stored
@@ -529,14 +531,14 @@ func Test_IfdByteEncoder_encodeTagToBytes_simpleTag_allocate(t *testing.T) {
 		t.Fatalf("Child IFD not have been allocated.")
 	}
 
-	ite, err := ParseOneTag(im, ti, fmt.Sprintf("%s%d", IfdPathStandard, 0), IfdPathStandard, TestDefaultByteOrder, tagBytes, false)
+	ite, err := ParseOneTag(im, ti, fmt.Sprintf("%s%d", exifcommon.IfdPathStandard, 0), exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder, tagBytes, false)
 	log.PanicIf(err)
 
 	if ite.TagId != 0x000b {
 		t.Fatalf("Tag-ID not correct: (0x%02x)", ite.TagId)
 	} else if ite.TagIndex != 0 {
 		t.Fatalf("Tag index not correct: (%d)", ite.TagIndex)
-	} else if ite.TagType != TypeAscii {
+	} else if ite.TagType != exifcommon.TypeAscii {
 		t.Fatalf("Tag type not correct: (%d)", ite.TagType)
 	} else if ite.UnitCount != (uint32(len(valueString) + 1)) {
 		t.Fatalf("Tag unit-count not correct: (%d)", ite.UnitCount)
@@ -546,7 +548,7 @@ func Test_IfdByteEncoder_encodeTagToBytes_simpleTag_allocate(t *testing.T) {
 		t.Fatalf("Tag's value (as raw bytes) is not correct: [%x]", ite.RawValueOffset)
 	} else if ite.ChildIfdPath != "" {
 		t.Fatalf("Tag's IFD-name should be empty: [%s]", ite.ChildIfdPath)
-	} else if ite.IfdPath != IfdPathStandard {
+	} else if ite.IfdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("Tag's parent IFD is not correct: %v", ite.IfdPath)
 	}
 
@@ -617,7 +619,7 @@ func Test_IfdByteEncoder_encodeIfdToBytes_simple(t *testing.T) {
 	}
 
 	if bytes.Compare(tableAndAllocated, expectedIfdAndDataBytes) != 0 {
-		t.Fatalf("IFD table and allocated data not correct: %v", DumpBytesClauseToString(tableAndAllocated))
+		t.Fatalf("IFD table and allocated data not correct: %v", exifcommon.DumpBytesClauseToString(tableAndAllocated))
 	}
 }
 
@@ -655,7 +657,7 @@ func Test_IfdByteEncoder_encodeIfdToBytes_fullExif(t *testing.T) {
 
 	b := new(bytes.Buffer)
 
-	headerBytes, err := BuildExifHeader(TestDefaultByteOrder, ExifDefaultFirstIfdOffset)
+	headerBytes, err := BuildExifHeader(exifcommon.TestDefaultByteOrder, ExifDefaultFirstIfdOffset)
 	log.PanicIf(err)
 
 	_, err = b.Write(headerBytes)
@@ -693,7 +695,7 @@ func Test_IfdByteEncoder_EncodeToExifPayload(t *testing.T) {
 
 	b := new(bytes.Buffer)
 
-	headerBytes, err := BuildExifHeader(TestDefaultByteOrder, ExifDefaultFirstIfdOffset)
+	headerBytes, err := BuildExifHeader(exifcommon.TestDefaultByteOrder, ExifDefaultFirstIfdOffset)
 	log.PanicIf(err)
 
 	_, err = b.Write(headerBytes)
@@ -737,7 +739,7 @@ func Test_IfdByteEncoder_EncodeToExif_WithChildAndSibling(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddStandard(0x000b, "asciivalue")
 	log.PanicIf(err)
@@ -747,7 +749,7 @@ func Test_IfdByteEncoder_EncodeToExif_WithChildAndSibling(t *testing.T) {
 
 	// Add a child IB right in the middle.
 
-	childIb := NewIfdBuilder(im, ti, IfdPathStandardExif, TestDefaultByteOrder)
+	childIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardExif, exifcommon.TestDefaultByteOrder)
 
 	err = childIb.AddStandardWithName("ISOSpeedRatings", []uint16{0x1122})
 	log.PanicIf(err)
@@ -764,7 +766,7 @@ func Test_IfdByteEncoder_EncodeToExif_WithChildAndSibling(t *testing.T) {
 	// Add another child IB, just to ensure a little more punishment and make
 	// sure we're managing our allocation offsets correctly.
 
-	childIb2 := NewIfdBuilder(im, ti, IfdPathStandardGps, TestDefaultByteOrder)
+	childIb2 := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardGps, exifcommon.TestDefaultByteOrder)
 
 	err = childIb2.AddStandardWithName("GPSAltitudeRef", []uint8{0x11, 0x22})
 	log.PanicIf(err)
@@ -772,13 +774,13 @@ func Test_IfdByteEncoder_EncodeToExif_WithChildAndSibling(t *testing.T) {
 	err = ib.AddChildIb(childIb2)
 	log.PanicIf(err)
 
-	err = ib.AddStandard(0x013e, []Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
+	err = ib.AddStandard(0x013e, []exifcommon.Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
 	log.PanicIf(err)
 
 	// Link to another IB (sibling relationship). The root/standard IFD may
 	// occur twice in some JPEGs (for thumbnail or FlashPix images).
 
-	nextIb := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	nextIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = nextIb.AddStandard(0x0101, []uint32{0x11223344})
 	log.PanicIf(err)
@@ -852,7 +854,7 @@ func ExampleIfdByteEncoder_EncodeToExif() {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddStandardWithName("ProcessingSoftware", "asciivalue")
 	log.PanicIf(err)
@@ -866,10 +868,10 @@ func ExampleIfdByteEncoder_EncodeToExif() {
 	err = ib.AddStandardWithName("ImageWidth", []uint32{0x44556677})
 	log.PanicIf(err)
 
-	err = ib.AddStandardWithName("WhitePoint", []Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
+	err = ib.AddStandardWithName("WhitePoint", []exifcommon.Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
 	log.PanicIf(err)
 
-	err = ib.AddStandardWithName("ShutterSpeedValue", []SignedRational{{Numerator: 0x11112222, Denominator: 0x33334444}})
+	err = ib.AddStandardWithName("ShutterSpeedValue", []exifcommon.SignedRational{{Numerator: 0x11112222, Denominator: 0x33334444}})
 	log.PanicIf(err)
 
 	// Encode it.
@@ -889,7 +891,7 @@ func ExampleIfdByteEncoder_EncodeToExif() {
 	addressableData := exifData[ExifAddressableAreaStart:]
 
 	for i, e := range index.RootIfd.Entries {
-		value, err := e.Value(addressableData, TestDefaultByteOrder)
+		value, err := e.Value(addressableData, exifcommon.TestDefaultByteOrder)
 		log.PanicIf(err)
 
 		fmt.Printf("%d: %s [%v]\n", i, e, value)

v2/ifd_builder_test.go

@@ -7,6 +7,8 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/dsoprea/go-exif/v2/common"
+	"github.com/dsoprea/go-exif/v2/undefined"
 	"github.com/dsoprea/go-logging"
 )
 
@@ -17,11 +19,11 @@ func TestIfdBuilder_Add(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -30,8 +32,8 @@ func TestIfdBuilder_Add(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -40,8 +42,8 @@ func TestIfdBuilder_Add(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -52,8 +54,8 @@ func TestIfdBuilder_Add(t *testing.T) {
 	originalBytes := []byte{0x11, 0x22, 0x33}
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x44,
 		value:   NewIfdBuilderTagValueFromBytes([]byte(originalBytes)),
 	}
@@ -61,11 +63,11 @@ func TestIfdBuilder_Add(t *testing.T) {
 	err = ib.Add(bt)
 	log.PanicIf(err)
 
-	if ib.ifdPath != IfdPathStandard {
+	if ib.ifdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("IFD name not correct.")
 	} else if ib.ifdTagId != 0 {
 		t.Fatalf("IFD tag-ID not correct.")
-	} else if ib.byteOrder != TestDefaultByteOrder {
+	} else if ib.byteOrder != exifcommon.TestDefaultByteOrder {
 		t.Fatalf("IFD byte-order not correct.")
 	} else if len(ib.tags) != 4 {
 		t.Fatalf("IFD tag-count not correct.")
@@ -110,8 +112,8 @@ func TestIfdBuilder_SetNextIb(t *testing.T) {
 
 	ti := NewTagIndex()
 
-	ib1 := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib1 := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
-	ib2 := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib2 := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	if ib1.nextIb != nil {
 		t.Fatalf("Next-IFD for IB1 not initially terminal.")
@@ -134,11 +136,11 @@ func TestIfdBuilder_AddChildIb(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -146,13 +148,13 @@ func TestIfdBuilder_AddChildIb(t *testing.T) {
 	err = ib.Add(bt)
 	log.PanicIf(err)
 
-	ibChild := NewIfdBuilder(im, ti, IfdPathStandardExif, TestDefaultByteOrder)
+	ibChild := NewIfdBuilder(im, ti, exifcommon.IfdPathStandardExif, exifcommon.TestDefaultByteOrder)
 	err = ib.AddChildIb(ibChild)
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -193,7 +195,7 @@ func TestIfdBuilder_AddTagsFromExisting(t *testing.T) {
 	_, index, err := Collect(im, ti, exifData)
 	log.PanicIf(err)
 
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddTagsFromExisting(index.RootIfd, nil, nil, nil)
 	log.PanicIf(err)
@@ -229,7 +231,7 @@ func TestIfdBuilder_AddTagsFromExisting__Includes(t *testing.T) {
 	_, index, err := Collect(im, ti, exifData)
 	log.PanicIf(err)
 
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddTagsFromExisting(index.RootIfd, nil, []uint16{0x00ff}, nil)
 	log.PanicIf(err)
@@ -262,7 +264,7 @@ func TestIfdBuilder_AddTagsFromExisting__Excludes(t *testing.T) {
 	_, index, err := Collect(im, ti, exifData)
 	log.PanicIf(err)
 
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddTagsFromExisting(index.RootIfd, nil, nil, []uint16{0xff})
 	log.PanicIf(err)
@@ -291,11 +293,11 @@ func TestIfdBuilder_FindN__First_1(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -304,8 +306,8 @@ func TestIfdBuilder_FindN__First_1(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -314,8 +316,8 @@ func TestIfdBuilder_FindN__First_1(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -347,11 +349,11 @@ func TestIfdBuilder_FindN__First_2_1Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -360,8 +362,8 @@ func TestIfdBuilder_FindN__First_2_1Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -370,8 +372,8 @@ func TestIfdBuilder_FindN__First_2_1Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -403,11 +405,11 @@ func TestIfdBuilder_FindN__First_2_2Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -416,8 +418,8 @@ func TestIfdBuilder_FindN__First_2_2Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -426,8 +428,8 @@ func TestIfdBuilder_FindN__First_2_2Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -436,8 +438,8 @@ func TestIfdBuilder_FindN__First_2_2Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -446,8 +448,8 @@ func TestIfdBuilder_FindN__First_2_2Returned(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string5")),
 	}
@@ -486,11 +488,11 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -499,8 +501,8 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -509,8 +511,8 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -519,8 +521,8 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -529,8 +531,8 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string5")),
 	}
@@ -539,8 +541,8 @@ func TestIfdBuilder_FindN__Middle_WithDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string6")),
 	}
@@ -572,11 +574,11 @@ func TestIfdBuilder_FindN__Middle_NoDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -585,8 +587,8 @@ func TestIfdBuilder_FindN__Middle_NoDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -595,8 +597,8 @@ func TestIfdBuilder_FindN__Middle_NoDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -605,8 +607,8 @@ func TestIfdBuilder_FindN__Middle_NoDuplicates(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -638,7 +640,7 @@ func TestIfdBuilder_FindN__Miss(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	found, err := ib.FindN(0x11, 1)
 	log.PanicIf(err)
@@ -655,11 +657,11 @@ func TestIfdBuilder_Find__Hit(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -668,8 +670,8 @@ func TestIfdBuilder_Find__Hit(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -678,8 +680,8 @@ func TestIfdBuilder_Find__Hit(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -688,8 +690,8 @@ func TestIfdBuilder_Find__Hit(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -719,11 +721,11 @@ func TestIfdBuilder_Find__Miss(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -732,8 +734,8 @@ func TestIfdBuilder_Find__Miss(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -742,8 +744,8 @@ func TestIfdBuilder_Find__Miss(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -752,8 +754,8 @@ func TestIfdBuilder_Find__Miss(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -776,11 +778,11 @@ func TestIfdBuilder_Replace(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -789,8 +791,8 @@ func TestIfdBuilder_Replace(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -799,8 +801,8 @@ func TestIfdBuilder_Replace(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -818,8 +820,8 @@ func TestIfdBuilder_Replace(t *testing.T) {
 	}
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x99,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -844,11 +846,11 @@ func TestIfdBuilder_ReplaceN(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -857,8 +859,8 @@ func TestIfdBuilder_ReplaceN(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -867,8 +869,8 @@ func TestIfdBuilder_ReplaceN(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -886,8 +888,8 @@ func TestIfdBuilder_ReplaceN(t *testing.T) {
 	}
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0xA9,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -912,11 +914,11 @@ func TestIfdBuilder_DeleteFirst(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -925,8 +927,8 @@ func TestIfdBuilder_DeleteFirst(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -935,8 +937,8 @@ func TestIfdBuilder_DeleteFirst(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -945,8 +947,8 @@ func TestIfdBuilder_DeleteFirst(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -1014,11 +1016,11 @@ func TestIfdBuilder_DeleteN(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -1027,8 +1029,8 @@ func TestIfdBuilder_DeleteN(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -1037,8 +1039,8 @@ func TestIfdBuilder_DeleteN(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -1047,8 +1049,8 @@ func TestIfdBuilder_DeleteN(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -1116,11 +1118,11 @@ func TestIfdBuilder_DeleteN_Two(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -1129,8 +1131,8 @@ func TestIfdBuilder_DeleteN_Two(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -1139,8 +1141,8 @@ func TestIfdBuilder_DeleteN_Two(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -1149,8 +1151,8 @@ func TestIfdBuilder_DeleteN_Two(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -1202,11 +1204,11 @@ func TestIfdBuilder_DeleteAll(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	bt := &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x11,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string")),
 	}
@@ -1215,8 +1217,8 @@ func TestIfdBuilder_DeleteAll(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string2")),
 	}
@@ -1225,8 +1227,8 @@ func TestIfdBuilder_DeleteAll(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x22,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string3")),
 	}
@@ -1235,8 +1237,8 @@ func TestIfdBuilder_DeleteAll(t *testing.T) {
 	log.PanicIf(err)
 
 	bt = &BuilderTag{
-		ifdPath: IfdPathStandard,
+		ifdPath: exifcommon.IfdPathStandard,
-		typeId:  TypeByte,
+		typeId:  exifcommon.TypeByte,
 		tagId:   0x33,
 		value:   NewIfdBuilderTagValueFromBytes([]byte("test string4")),
 	}
@@ -1486,15 +1488,69 @@ func TestIfdBuilder_CreateIfdBuilderFromExistingChain_RealData(t *testing.T) {
 			t.Fatalf("Tag-type not as expected: %d != %d  ITE=%s", recoveredIte.TagType, originalIte.TagType, recoveredIte)
 		}
 
+		var originalValueBytes []byte
+
+		if originalIte.TagType == exifcommon.TypeUndefined {
+			var err error
+
+			valueContext :=
+				newValueContextFromTag(
+					originalIte,
+					originalIndex.RootIfd.addressableData,
+					originalIndex.RootIfd.ByteOrder)
+
+			value, err := exifundefined.Decode(
+				originalIte.IfdPath,
+				originalIte.TagId,
+				valueContext,
+				originalIndex.RootIfd.ByteOrder)
+
+			log.PanicIf(err)
+
+			originalValueBytes, _, err = exifundefined.Encode(value, originalIndex.RootIfd.ByteOrder)
+		} else {
+			var err error
+
 			// TODO(dustin): We're always accessing the addressable-data using the root-IFD. It shouldn't matter, but we'd rather access it from our specific IFD.
-		originalValueBytes, err := originalIte.ValueBytes(originalIndex.RootIfd.addressableData, originalIndex.RootIfd.ByteOrder)
+			originalValueBytes, err = originalIte.ValueBytes(originalIndex.RootIfd.addressableData, originalIndex.RootIfd.ByteOrder)
+			log.PanicIf(err)
+		}
+
+		var recoveredValueBytes []byte
+
+		if recoveredIte.TagType == exifcommon.TypeUndefined {
+			var err error
+
+			valueContext :=
+				newValueContextFromTag(
+					recoveredIte,
+					recoveredIndex.RootIfd.addressableData,
+					recoveredIndex.RootIfd.ByteOrder)
+
+			value, err := exifundefined.Decode(
+				recoveredIte.IfdPath,
+				recoveredIte.TagId,
+				valueContext,
+				recoveredIndex.RootIfd.ByteOrder)
+
 			log.PanicIf(err)
 
-		recoveredValueBytes, err := recoveredIte.ValueBytes(recoveredIndex.RootIfd.addressableData, recoveredIndex.RootIfd.ByteOrder)
+			recoveredValueBytes, _, err = exifundefined.Encode(value, recoveredIndex.RootIfd.ByteOrder)
-		log.PanicIf(err)
+		} else {
+			var err error
 
-		if bytes.Compare(originalValueBytes, recoveredValueBytes) != 0 {
+			recoveredValueBytes, err = recoveredIte.ValueBytes(recoveredIndex.RootIfd.addressableData, recoveredIndex.RootIfd.ByteOrder)
-			t.Fatalf("bytes of tag content not correct: %s != %s", originalIte, recoveredIte)
+			log.PanicIf(err)
+		}
+
+		if bytes.Compare(recoveredValueBytes, originalValueBytes) != 0 {
+			fmt.Printf("ACTUAL: %s\n", originalIte)
+			exifcommon.DumpBytes(recoveredValueBytes)
+
+			fmt.Printf("EXPECTED: %s\n", recoveredIte)
+			exifcommon.DumpBytes(originalValueBytes)
+
+			t.Fatalf("Bytes of tag content not correct.")
 		}
 	}
 }
@@ -1529,8 +1585,8 @@ func TestIfdBuilder_CreateIfdBuilderFromExistingChain_RealData(t *testing.T) {
 // 	ucBt, err := exifBt.value.Ib().FindTagWithName("UserComment")
 // 	log.PanicIf(err)
 
-// 	uc := TagUnknownType_9298_UserComment{
+// 	uc := exifundefined.Tag9286UserComment{
-// 		EncodingType:  TagUnknownType_9298_UserComment_Encoding_ASCII,
+// 		EncodingType:  TagUndefinedType_9286_UserComment_Encoding_ASCII,
 // 		EncodingBytes: []byte("TEST COMMENT"),
 // 	}
 
@@ -1687,8 +1743,8 @@ func ExampleBuilderTag_SetValue() {
 	// its type-specific struct.
 
 	// TODO(dustin): !! Add an example for setting a non-unknown value, too.
-	uc := TagUnknownType_9298_UserComment{
+	uc := exifundefined.Tag9286UserComment{
-		EncodingType:  TagUnknownType_9298_UserComment_Encoding_ASCII,
+		EncodingType:  exifundefined.TagUndefinedType_9286_UserComment_Encoding_ASCII,
 		EncodingBytes: []byte("TEST COMMENT"),
 	}
 
@@ -1793,19 +1849,19 @@ func TestIfdBuilder_CreateIfdBuilderWithExistingIfd(t *testing.T) {
 	err := LoadStandardIfds(im)
 	log.PanicIf(err)
 
-	mi, err := im.GetWithPath(IfdPathStandardGps)
+	mi, err := im.GetWithPath(exifcommon.IfdPathStandardGps)
 	log.PanicIf(err)
 
 	tagId := mi.TagId
 
 	parentIfd := &Ifd{
-		IfdPath:  IfdPathStandard,
+		IfdPath:  exifcommon.IfdPathStandard,
 		tagIndex: ti,
 	}
 
 	ifd := &Ifd{
-		IfdPath:   IfdPathStandardGps,
+		IfdPath:   exifcommon.IfdPathStandardGps,
-		ByteOrder: TestDefaultByteOrder,
+		ByteOrder: exifcommon.TestDefaultByteOrder,
 		Offset:    0x123,
 		ParentIfd: parentIfd,
 
@@ -1829,12 +1885,12 @@ func TestIfdBuilder_CreateIfdBuilderWithExistingIfd(t *testing.T) {
 func TestNewStandardBuilderTag__OneUnit(t *testing.T) {
 	ti := NewTagIndex()
 
-	it, err := ti.Get(IfdPathStandardExif, uint16(0x8833))
+	it, err := ti.Get(exifcommon.IfdPathStandardExif, uint16(0x8833))
 	log.PanicIf(err)
 
-	bt := NewStandardBuilderTag(IfdPathStandardExif, it, TestDefaultByteOrder, []uint32{uint32(0x1234)})
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandardExif, it, exifcommon.TestDefaultByteOrder, []uint32{uint32(0x1234)})
 
-	if bt.ifdPath != IfdPathStandardExif {
+	if bt.ifdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("II in BuilderTag not correct")
 	} else if bt.tagId != 0x8833 {
 		t.Fatalf("tag-ID not correct")
@@ -1846,12 +1902,12 @@ func TestNewStandardBuilderTag__OneUnit(t *testing.T) {
 func TestNewStandardBuilderTag__TwoUnits(t *testing.T) {
 	ti := NewTagIndex()
 
-	it, err := ti.Get(IfdPathStandardExif, uint16(0x8833))
+	it, err := ti.Get(exifcommon.IfdPathStandardExif, uint16(0x8833))
 	log.PanicIf(err)
 
-	bt := NewStandardBuilderTag(IfdPathStandardExif, it, TestDefaultByteOrder, []uint32{uint32(0x1234), uint32(0x5678)})
+	bt := NewStandardBuilderTag(exifcommon.IfdPathStandardExif, it, exifcommon.TestDefaultByteOrder, []uint32{uint32(0x1234), uint32(0x5678)})
 
-	if bt.ifdPath != IfdPathStandardExif {
+	if bt.ifdPath != exifcommon.IfdPathStandardExif {
 		t.Fatalf("II in BuilderTag not correct")
 	} else if bt.tagId != 0x8833 {
 		t.Fatalf("tag-ID not correct")
@@ -1869,7 +1925,7 @@ func TestIfdBuilder_AddStandardWithName(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddStandardWithName("ProcessingSoftware", "some software")
 	log.PanicIf(err)
@@ -1880,7 +1936,7 @@ func TestIfdBuilder_AddStandardWithName(t *testing.T) {
 
 	bt := ib.tags[0]
 
-	if bt.ifdPath != IfdPathStandard {
+	if bt.ifdPath != exifcommon.IfdPathStandard {
 		t.Fatalf("II not correct: %s", bt.ifdPath)
 	} else if bt.tagId != 0x000b {
 		t.Fatalf("Tag-ID not correct: (0x%04x)", bt.tagId)
@@ -1900,7 +1956,7 @@ func TestGetOrCreateIbFromRootIb__Noop(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	rootIb := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	rootIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	ib, err := GetOrCreateIbFromRootIb(rootIb, "IFD")
 	log.PanicIf(err)
@@ -1921,7 +1977,7 @@ func TestGetOrCreateIbFromRootIb__FqNoop(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	rootIb := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	rootIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	ib, err := GetOrCreateIbFromRootIb(rootIb, "IFD0")
 	log.PanicIf(err)
@@ -1942,7 +1998,7 @@ func TestGetOrCreateIbFromRootIb_InvalidChild(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	rootIb := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	rootIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	_, err = GetOrCreateIbFromRootIb(rootIb, "IFD/Invalid")
 	if err == nil {
@@ -1966,7 +2022,7 @@ func TestGetOrCreateIbFromRootIb__Child(t *testing.T) {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	rootIb := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	rootIb := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	lines := rootIb.DumpToStrings()
 	expected := []string{

v2/ifd_enumerate.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"reflect"
 	"strconv"
 	"strings"
 	"time"
@@ -12,6 +11,9 @@ import (
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
+	"github.com/dsoprea/go-exif/v2/undefined"
 )
 
 var (
@@ -159,7 +161,7 @@ func (ie *IfdEnumerate) parseTag(fqIfdPath string, tagPosition int, ite *IfdTagE
 	tagTypeRaw, _, err := ite.getUint16()
 	log.PanicIf(err)
 
-	tagType := TagTypePrimitive(tagTypeRaw)
+	tagType := exifcommon.TagTypePrimitive(tagTypeRaw)
 
 	unitCount, _, err := ite.getUint32()
 	log.PanicIf(err)
@@ -167,7 +169,7 @@ func (ie *IfdEnumerate) parseTag(fqIfdPath string, tagPosition int, ite *IfdTagE
 	valueOffset, rawValueOffset, err := ite.getUint32()
 	log.PanicIf(err)
 
-	if _, found := TypeNames[tagType]; found == false {
+	if tagType.IsValid() == false {
 		log.Panic(ErrTagTypeNotValid)
 	}
 
@@ -210,7 +212,7 @@ func (ie *IfdEnumerate) parseTag(fqIfdPath string, tagPosition int, ite *IfdTagE
 	return tag, nil
 }
 
-func (ie *IfdEnumerate) GetValueContext(ite *IfdTagEntry) *ValueContext {
+func (ie *IfdEnumerate) GetValueContext(ite *IfdTagEntry) *exifcommon.ValueContext {
 
 	// TODO(dustin): Add test
 
@@ -229,120 +231,56 @@ func (ie *IfdEnumerate) resolveTagValue(ite *IfdTagEntry) (valueBytes []byte, is
 		}
 	}()
 
-	addressableData := ie.exifData[ExifAddressableAreaStart:]
+	valueContext := ie.GetValueContext(ite)
 
 	// Return the exact bytes of the unknown-type value. Returning a string
 	// (`ValueString`) is easy because we can just pass everything to
 	// `Sprintf()`. Returning the raw, typed value (`Value`) is easy
 	// (obviously). However, here, in order to produce the list of bytes, we
 	// need to coerce whatever `Undefined()` returns.
-	if ite.TagType == TypeUndefined {
+	if ite.TagType == exifcommon.TypeUndefined {
-		valueContext := ie.GetValueContext(ite)
+		value, err := exifundefined.Decode(ite.IfdPath, ite.TagId, valueContext, ie.byteOrder)
-
-		value, err := valueContext.Undefined()
 		if err != nil {
-			if err == ErrUnhandledUnknownTypedTag {
+			if err == exifcommon.ErrUnhandledUnknownTypedTag {
-				valueBytes = []byte(UnparseableUnknownTagValuePlaceholder)
+				return nil, true, nil
-				return valueBytes, true, nil
 			}
 
 			log.Panic(err)
-		} else {
-			switch value.(type) {
-			case []byte:
-				return value.([]byte), false, nil
-			case TagUnknownType_UnknownValue:
-				b := []byte(value.(TagUnknownType_UnknownValue))
-				return b, false, nil
-			case string:
-				return []byte(value.(string)), false, nil
-			case UnknownTagValue:
-				valueBytes, err := value.(UnknownTagValue).ValueBytes()
-				log.PanicIf(err)
-
-				return valueBytes, false, nil
-			default:
-				// TODO(dustin): !! Finish translating the rest of the types (make reusable and replace into other similar implementations?)
-				log.Panicf("can not produce bytes for unknown-type tag (0x%04x) (1): [%s]", ite.TagId, reflect.TypeOf(value))
 		}
-		}
-	} else {
-		originalType := NewTagType(ite.TagType, ie.byteOrder)
-		byteCount := uint32(originalType.Type().Size()) * ite.UnitCount
 
-		tt := NewTagType(TypeByte, ie.byteOrder)
+		encodeable := value.(exifundefined.EncodeableValue)
 
-		if tt.valueIsEmbedded(byteCount) == true {
+		valueBytes, _, err = exifundefined.Encode(encodeable, ie.byteOrder)
-			iteLogger.Debugf(nil, "Reading BYTE value (ITE; embedded).")
-
-			// In this case, the bytes normally used for the offset are actually
-			// data.
-			valueBytes, err = tt.ParseBytes(ite.RawValueOffset, byteCount)
 		log.PanicIf(err)
 	} else {
-			iteLogger.Debugf(nil, "Reading BYTE value (ITE; at offset).")
+		var err error
 
-			valueBytes, err = tt.ParseBytes(addressableData[ite.ValueOffset:], byteCount)
+		valueBytes, err = valueContext.ReadRawEncoded()
 		log.PanicIf(err)
 	}
-	}
 
 	return valueBytes, false, nil
 }
 
-// RawTagVisitorPtr is an optional callback that can get hit for every tag we parse
+// RawTagWalk is an optional callback that can get hit for every tag we parse
 // through. `addressableData` is the byte array startign after the EXIF header
 // (where the offsets of all IFDs and values are calculated from).
 //
 // This was reimplemented as an interface to allow for simpler change management
 // in the future.
 type RawTagWalk interface {
-	Visit(fqIfdPath string, ifdIndex int, tagId uint16, tagType TagType, valueContext *ValueContext) (err error)
+	Visit(fqIfdPath string, ifdIndex int, tagId uint16, tagType exifcommon.TagTypePrimitive, valueContext *exifcommon.ValueContext) (err error)
 }
 
-type RawTagWalkLegacyWrapper struct {
-	legacyVisitor RawTagVisitor
-}
-
-func (rtwlw RawTagWalkLegacyWrapper) Visit(fqIfdPath string, ifdIndex int, tagId uint16, tagType TagType, valueContext *ValueContext) (err error) {
-	return rtwlw.legacyVisitor(fqIfdPath, ifdIndex, tagId, tagType, *valueContext)
-}
-
-// RawTagVisitor is an optional callback that can get hit for every tag we parse
-// through. `addressableData` is the byte array startign after the EXIF header
-// (where the offsets of all IFDs and values are calculated from).
-//
-// DEPRECATED(dustin): Use a RawTagWalk instead.
-type RawTagVisitor func(fqIfdPath string, ifdIndex int, tagId uint16, tagType TagType, valueContext ValueContext) (err error)
-
 // ParseIfd decodes the IFD block that we're currently sitting on the first
 // byte of.
-func (ie *IfdEnumerate) ParseIfd(fqIfdPath string, ifdIndex int, ite *IfdTagEnumerator, visitor interface{}, doDescend bool, resolveValues bool) (nextIfdOffset uint32, entries []*IfdTagEntry, thumbnailData []byte, err error) {
+func (ie *IfdEnumerate) ParseIfd(fqIfdPath string, ifdIndex int, ite *IfdTagEnumerator, visitor RawTagWalk, doDescend bool, resolveValues bool) (nextIfdOffset uint32, entries []*IfdTagEntry, thumbnailData []byte, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
 		}
 	}()
 
-	var visitorWrapper RawTagWalk
-
-	if visitor != nil {
-		var ok bool
-
-		visitorWrapper, ok = visitor.(RawTagWalk)
-		if ok == false {
-			// Legacy usage.
-
-			// `ok` can be `true` but `legacyVisitor` can still be `nil` (when
-			// passed as nil).
-			if legacyVisitor, ok := visitor.(RawTagVisitor); ok == true && legacyVisitor != nil {
-				visitorWrapper = RawTagWalkLegacyWrapper{
-					legacyVisitor: legacyVisitor,
-				}
-			}
-		}
-	}
-
 	tagCount, _, err := ite.getUint16()
 	log.PanicIf(err)
 
@@ -373,12 +311,10 @@ func (ie *IfdEnumerate) ParseIfd(fqIfdPath string, ifdIndex int, ite *IfdTagEnum
 			continue
 		}
 
-		if visitorWrapper != nil {
+		if visitor != nil {
-			tt := NewTagType(tag.TagType, ie.byteOrder)
-
 			valueContext := ie.GetValueContext(tag)
 
-			err := visitorWrapper.Visit(fqIfdPath, ifdIndex, tag.TagId, tt, valueContext)
+			err := visitor.Visit(fqIfdPath, ifdIndex, tag.TagId, tag.TagType, valueContext)
 			log.PanicIf(err)
 		}
 
@@ -430,7 +366,7 @@ func (ie *IfdEnumerate) parseThumbnail(offsetIte, lengthIte *IfdTagEntry) (thumb
 	length := vList[0]
 
 	// The tag is official a LONG type, but it's actually an offset to a blob of bytes.
-	offsetIte.TagType = TypeByte
+	offsetIte.TagType = exifcommon.TypeByte
 	offsetIte.UnitCount = length
 
 	thumbnailData, err = offsetIte.ValueBytes(addressableData, ie.byteOrder)
@@ -440,7 +376,7 @@ func (ie *IfdEnumerate) parseThumbnail(offsetIte, lengthIte *IfdTagEntry) (thumb
 }
 
 // Scan enumerates the different EXIF's IFD blocks.
-func (ie *IfdEnumerate) scan(fqIfdName string, ifdOffset uint32, visitor interface{}, resolveValues bool) (err error) {
+func (ie *IfdEnumerate) scan(fqIfdName string, ifdOffset uint32, visitor RawTagWalk, resolveValues bool) (err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -466,7 +402,7 @@ func (ie *IfdEnumerate) scan(fqIfdName string, ifdOffset uint32, visitor interfa
 
 // Scan enumerates the different EXIF blocks (called IFDs). `rootIfdName` will
 // be "IFD" in the TIFF standard.
-func (ie *IfdEnumerate) Scan(rootIfdName string, ifdOffset uint32, visitor RawTagVisitor, resolveValue bool) (err error) {
+func (ie *IfdEnumerate) Scan(rootIfdName string, ifdOffset uint32, visitor RawTagWalk, resolveValue bool) (err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -717,8 +653,8 @@ func (ifd *Ifd) printTagTree(populateValues bool, index, level int, nextLink boo
 
 				value, err = ifd.TagValue(tag)
 				if err != nil {
-					if err == ErrUnhandledUnknownTypedTag {
+					if err == exifcommon.ErrUnhandledUnknownTypedTag {
-						value = UnparseableUnknownTagValuePlaceholder
+						value = exifundefined.UnparseableUnknownTagValuePlaceholder
 					} else {
 						log.Panic(err)
 					}
@@ -863,8 +799,8 @@ func (ifd *Ifd) GpsInfo() (gi *GpsInfo, err error) {
 
 	gi = new(GpsInfo)
 
-	if ifd.IfdPath != IfdPathStandardGps {
+	if ifd.IfdPath != exifcommon.IfdPathStandardGps {
-		log.Panicf("GPS can only be read on GPS IFD: [%s] != [%s]", ifd.IfdPath, IfdPathStandardGps)
+		log.Panicf("GPS can only be read on GPS IFD: [%s] != [%s]", ifd.IfdPath, exifcommon.IfdPathStandardGps)
 	}
 
 	if tags, found := ifd.EntriesByTagId[TagVersionId]; found == false {
@@ -926,7 +862,7 @@ func (ifd *Ifd) GpsInfo() (gi *GpsInfo, err error) {
 
 	// Parse location.
 
-	latitudeRaw := latitudeValue.([]Rational)
+	latitudeRaw := latitudeValue.([]exifcommon.Rational)
 
 	gi.Latitude = GpsDegrees{
 		Orientation: latitudeRefValue.(string)[0],
@@ -935,7 +871,7 @@ func (ifd *Ifd) GpsInfo() (gi *GpsInfo, err error) {
 		Seconds:     float64(latitudeRaw[2].Numerator) / float64(latitudeRaw[2].Denominator),
 	}
 
-	longitudeRaw := longitudeValue.([]Rational)
+	longitudeRaw := longitudeValue.([]exifcommon.Rational)
 
 	gi.Longitude = GpsDegrees{
 		Orientation: longitudeRefValue.(string)[0],
@@ -956,7 +892,7 @@ func (ifd *Ifd) GpsInfo() (gi *GpsInfo, err error) {
 		altitudeRefValue, err := ifd.TagValue(altitudeRefTags[0])
 		log.PanicIf(err)
 
-		altitudeRaw := altitudeValue.([]Rational)
+		altitudeRaw := altitudeValue.([]exifcommon.Rational)
 		altitude := int(altitudeRaw[0].Numerator / altitudeRaw[0].Denominator)
 		if altitudeRefValue.([]byte)[0] == 1 {
 			altitude *= -1
@@ -984,7 +920,7 @@ func (ifd *Ifd) GpsInfo() (gi *GpsInfo, err error) {
 			timestampValue, err := ifd.TagValue(timestampTags[0])
 			log.PanicIf(err)
 
-			timestampRaw := timestampValue.([]Rational)
+			timestampRaw := timestampValue.([]exifcommon.Rational)
 
 			hour := int(timestampRaw[0].Numerator / timestampRaw[0].Denominator)
 			minute := int(timestampRaw[1].Numerator / timestampRaw[1].Denominator)
@@ -1023,7 +959,7 @@ func (ifd *Ifd) EnumerateTagsRecursively(visitor ParsedTagVisitor) (err error) {
 	return nil
 }
 
-func (ifd *Ifd) GetValueContext(ite *IfdTagEntry) *ValueContext {
+func (ifd *Ifd) GetValueContext(ite *IfdTagEntry) *exifcommon.ValueContext {
 	return newValueContextFromTag(
 		ite,
 		ifd.addressableData,
@@ -1068,9 +1004,9 @@ func (ie *IfdEnumerate) Collect(rootIfdOffset uint32, resolveValues bool) (index
 
 	queue := []QueuedIfd{
 		{
-			Name:      IfdStandard,
+			Name:      exifcommon.IfdStandard,
-			IfdPath:   IfdStandard,
+			IfdPath:   exifcommon.IfdStandard,
-			FqIfdPath: IfdStandard,
+			FqIfdPath: exifcommon.IfdStandard,
 
 			TagId: 0xffff,
 
@@ -1258,7 +1194,7 @@ func (ie *IfdEnumerate) setChildrenIndex(ifd *Ifd) (err error) {
 
 // ParseOneIfd is a hack to use an IE to parse a raw IFD block. Can be used for
 // testing.
-func ParseOneIfd(ifdMapping *IfdMapping, tagIndex *TagIndex, fqIfdPath, ifdPath string, byteOrder binary.ByteOrder, ifdBlock []byte, visitor RawTagVisitor, resolveValues bool) (nextIfdOffset uint32, entries []*IfdTagEntry, err error) {
+func ParseOneIfd(ifdMapping *IfdMapping, tagIndex *TagIndex, fqIfdPath, ifdPath string, byteOrder binary.ByteOrder, ifdBlock []byte, visitor RawTagWalk, resolveValues bool) (nextIfdOffset uint32, entries []*IfdTagEntry, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -1308,8 +1244,8 @@ func FindIfdFromRootIfd(rootIfd *Ifd, ifdPath string) (ifd *Ifd, err error) {
 
 	if len(lineage) == 0 {
 		log.Panicf("IFD path must be non-empty.")
-	} else if lineage[0].Name != IfdStandard {
+	} else if lineage[0].Name != exifcommon.IfdStandard {
-		log.Panicf("First IFD path item must be [%s].", IfdStandard)
+		log.Panicf("First IFD path item must be [%s].", exifcommon.IfdStandard)
 	}
 
 	desiredRootIndex := lineage[0].Index

v2/ifd_enumerate_test.go

@@ -11,15 +11,17 @@ import (
 	"io/ioutil"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 func TestIfdTagEntry_ValueBytes(t *testing.T) {
 	byteOrder := binary.BigEndian
-	ve := NewValueEncoder(byteOrder)
+	ve := exifcommon.NewValueEncoder(byteOrder)
 
 	original := []byte("original text")
 
-	ed, err := ve.encodeBytes(original)
+	ed, err := ve.Encode(original)
 	log.PanicIf(err)
 
 	// Now, pass the raw encoded value as if it was the entire addressable area
@@ -27,7 +29,7 @@ func TestIfdTagEntry_ValueBytes(t *testing.T) {
 	// value happened to be recorded at the beginning.
 
 	ite := IfdTagEntry{
-		TagType:     TypeByte,
+		TagType:     exifcommon.TypeByte,
 		UnitCount:   uint32(len(original)),
 		ValueOffset: 0,
 	}
@@ -264,7 +266,7 @@ func TestIfd_GpsInfo(t *testing.T) {
 	_, index, err := Collect(im, ti, rawExif)
 	log.PanicIf(err)
 
-	ifd, err := index.RootIfd.ChildWithIfdPath(IfdPathStandardGps)
+	ifd, err := index.RootIfd.ChildWithIfdPath(exifcommon.IfdPathStandardGps)
 	log.PanicIf(err)
 
 	gi, err := ifd.GpsInfo()
@@ -482,7 +484,7 @@ func ExampleIfd_GpsInfo() {
 	_, index, err := Collect(im, ti, rawExif)
 	log.PanicIf(err)
 
-	ifd, err := index.RootIfd.ChildWithIfdPath(IfdPathStandardGps)
+	ifd, err := index.RootIfd.ChildWithIfdPath(exifcommon.IfdPathStandardGps)
 	log.PanicIf(err)
 
 	gi, err := ifd.GpsInfo()

v2/ifd_tag_entry.go

@@ -2,11 +2,13 @@ package exif
 
 import (
 	"fmt"
-	"reflect"
 
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
+	"github.com/dsoprea/go-exif/v2/undefined"
 )
 
 var (
@@ -16,7 +18,7 @@ var (
 type IfdTagEntry struct {
 	TagId          uint16
 	TagIndex       int
-	TagType        TagTypePrimitive
+	TagType        exifcommon.TagTypePrimitive
 	UnitCount      uint32
 	ValueOffset    uint32
 	RawValueOffset []byte
@@ -44,7 +46,7 @@ type IfdTagEntry struct {
 }
 
 func (ite *IfdTagEntry) String() string {
-	return fmt.Sprintf("IfdTagEntry<TAG-IFD-PATH=[%s] TAG-ID=(0x%04x) TAG-TYPE=[%s] UNIT-COUNT=(%d)>", ite.IfdPath, ite.TagId, TypeNames[ite.TagType], ite.UnitCount)
+	return fmt.Sprintf("IfdTagEntry<TAG-IFD-PATH=[%s] TAG-ID=(0x%04x) TAG-TYPE=[%s] UNIT-COUNT=(%d)>", ite.IfdPath, ite.TagId, ite.TagType.String(), ite.UnitCount)
 }
 
 // TODO(dustin): TODO(dustin): Stop exporting IfdPath and TagId.
@@ -60,7 +62,7 @@ func (ite *IfdTagEntry) String() string {
 // }
 
 // ValueString renders a string from whatever the value in this tag is.
-func (ite *IfdTagEntry) ValueString(addressableData []byte, byteOrder binary.ByteOrder) (value string, err error) {
+func (ite *IfdTagEntry) ValueString(addressableData []byte, byteOrder binary.ByteOrder) (phrase string, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -73,17 +75,23 @@ func (ite *IfdTagEntry) ValueString(addressableData []byte, byteOrder binary.Byt
 			addressableData,
 			byteOrder)
 
-	if ite.TagType == TypeUndefined {
+	if ite.TagType == exifcommon.TypeUndefined {
-		valueRaw, err := valueContext.Undefined()
+		var err error
+
+		value, err := exifundefined.Decode(ite.IfdPath, ite.TagId, valueContext, byteOrder)
 		log.PanicIf(err)
 
-		value = fmt.Sprintf("%v", valueRaw)
+		s := value.(fmt.Stringer)
+
+		phrase = s.String()
 	} else {
-		value, err = valueContext.Format()
+		var err error
+
+		phrase, err = valueContext.Format()
 		log.PanicIf(err)
 	}
 
-	return value, nil
+	return phrase, nil
 }
 
 // ValueBytes renders a specific list of bytes from the value in this tag.
@@ -94,60 +102,33 @@ func (ite *IfdTagEntry) ValueBytes(addressableData []byte, byteOrder binary.Byte
 		}
 	}()
 
-	// Return the exact bytes of the unknown-type value. Returning a string
-	// (`ValueString`) is easy because we can just pass everything to
-	// `Sprintf()`. Returning the raw, typed value (`Value`) is easy
-	// (obviously). However, here, in order to produce the list of bytes, we
-	// need to coerce whatever `Undefined()` returns.
-	if ite.TagType == TypeUndefined {
 	valueContext :=
 		newValueContextFromTag(
 			ite,
 			addressableData,
 			byteOrder)
 
-		value, err := valueContext.Undefined()
+	// Return the exact bytes of the unknown-type value. Returning a string
+	// (`ValueString`) is easy because we can just pass everything to
+	// `Sprintf()`. Returning the raw, typed value (`Value`) is easy
+	// (obviously). However, here, in order to produce the list of bytes, we
+	// need to coerce whatever `Undefined()` returns.
+	if ite.TagType == exifcommon.TypeUndefined {
+		value, err := exifundefined.Decode(ite.IfdPath, ite.TagId, valueContext, byteOrder)
 		log.PanicIf(err)
 
-		switch value.(type) {
+		ve := exifcommon.NewValueEncoder(byteOrder)
-		case []byte:
+
-			return value.([]byte), nil
+		ed, err := ve.Encode(value)
-		case TagUnknownType_UnknownValue:
-			b := []byte(value.(TagUnknownType_UnknownValue))
-			return b, nil
-		case string:
-			return []byte(value.(string)), nil
-		case UnknownTagValue:
-			valueBytes, err := value.(UnknownTagValue).ValueBytes()
 		log.PanicIf(err)
 
-			return valueBytes, nil
+		return ed.Encoded, nil
-		default:
-			// TODO(dustin): !! Finish translating the rest of the types (make reusable and replace into other similar implementations?)
-			log.Panicf("can not produce bytes for unknown-type tag (0x%04x) (2): [%s]", ite.TagId, reflect.TypeOf(value))
-		}
-	}
-
-	originalType := NewTagType(ite.TagType, byteOrder)
-	byteCount := uint32(originalType.Type().Size()) * ite.UnitCount
-
-	tt := NewTagType(TypeByte, byteOrder)
-
-	if tt.valueIsEmbedded(byteCount) == true {
-		iteLogger.Debugf(nil, "Reading BYTE value (ITE; embedded).")
-
-		// In this case, the bytes normally used for the offset are actually
-		// data.
-		value, err = tt.ParseBytes(ite.RawValueOffset, byteCount)
-		log.PanicIf(err)
 	} else {
-		iteLogger.Debugf(nil, "Reading BYTE value (ITE; at offset).")
+		rawBytes, err := valueContext.ReadRawEncoded()
-
-		value, err = tt.ParseBytes(addressableData[ite.ValueOffset:], byteCount)
 		log.PanicIf(err)
-	}
 
-	return value, nil
+		return rawBytes, nil
+	}
 }
 
 // Value returns the specific, parsed, typed value from the tag.
@@ -164,13 +145,15 @@ func (ite *IfdTagEntry) Value(addressableData []byte, byteOrder binary.ByteOrder
 			addressableData,
 			byteOrder)
 
-	if ite.TagType == TypeUndefined {
+	if ite.TagType == exifcommon.TypeUndefined {
-		value, err = valueContext.Undefined()
+		var err error
+
+		value, err = exifundefined.Decode(ite.IfdPath, ite.TagId, valueContext, byteOrder)
 		log.PanicIf(err)
 	} else {
-		tt := NewTagType(ite.TagType, byteOrder)
+		var err error
 
-		value, err = tt.Resolve(valueContext)
+		value, err = valueContext.Values()
 		log.PanicIf(err)
 	}
 
@@ -206,7 +189,7 @@ func (itevr *IfdTagEntryValueResolver) ValueBytes(ite *IfdTagEntry) (value []byt
 		itevr.addressableData,
 		itevr.byteOrder)
 
-	rawBytes, err := valueContext.readRawEncoded()
+	rawBytes, err := valueContext.ReadRawEncoded()
 	log.PanicIf(err)
 
 	return rawBytes, nil

v2/ifd_tag_entry_test.go

@@ -2,25 +2,28 @@ package exif
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 func TestIfdTagEntry_ValueString_Allocated(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      6,
 		ValueOffset:    0x0,
 		RawValueOffset: []byte{0x0, 0x0, 0x0, 0x0},
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
 	data := []byte{0x11, 0x22, 0x33, 0x44, 0x55, 0x66}
 
-	value, err := ite.ValueString(data, TestDefaultByteOrder)
+	value, err := ite.ValueString(data, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	expected := "11 22 33 44 55 66"
@@ -35,14 +38,14 @@ func TestIfdTagEntry_ValueString_Embedded(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      4,
 		ValueOffset:    0,
 		RawValueOffset: data,
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
-	value, err := ite.ValueString(nil, TestDefaultByteOrder)
+	value, err := ite.ValueString(nil, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	expected := "11 22 33 44"
@@ -51,20 +54,29 @@ func TestIfdTagEntry_ValueString_Embedded(t *testing.T) {
 	}
 }
 
-func TestIfdTagEntry_ValueString_Unknown(t *testing.T) {
+func TestIfdTagEntry_ValueString_Undefined(t *testing.T) {
+	defer func() {
+		if state := recover(); state != nil {
+			err := log.Wrap(state.(error))
+			log.PrintError(err)
+
+			t.Fatalf("Test failure.")
+		}
+	}()
+
 	data := []uint8{'0', '2', '3', '0'}
 
 	ite := IfdTagEntry{
 		TagId:          0x9000,
 		TagIndex:       0,
-		TagType:        TypeUndefined,
+		TagType:        exifcommon.TypeUndefined,
 		UnitCount:      4,
 		ValueOffset:    0x0,
 		RawValueOffset: data,
-		IfdPath:        IfdPathStandardExif,
+		IfdPath:        exifcommon.IfdPathStandardExif,
 	}
 
-	value, err := ite.ValueString(nil, TestDefaultByteOrder)
+	value, err := ite.ValueString(nil, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	expected := "0230"
@@ -77,16 +89,16 @@ func TestIfdTagEntry_ValueBytes_Allocated(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      6,
 		ValueOffset:    0x0,
 		RawValueOffset: []byte{0x0, 0x0, 0x0, 0x0},
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
 	data := []byte{0x11, 0x22, 0x33, 0x44, 0x55, 0x66}
 
-	value, err := ite.ValueBytes(data, TestDefaultByteOrder)
+	value, err := ite.ValueBytes(data, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	if bytes.Compare(value, data) != 0 {
@@ -100,14 +112,14 @@ func TestIfdTagEntry_ValueBytes_Embedded(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      4,
 		ValueOffset:    0x0,
 		RawValueOffset: data,
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
-	value, err := ite.ValueBytes(nil, TestDefaultByteOrder)
+	value, err := ite.ValueBytes(nil, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	if bytes.Compare(value, data) != 0 {
@@ -121,14 +133,14 @@ func TestIfdTagEntry_Value_Normal(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      4,
 		ValueOffset:    0x0,
 		RawValueOffset: data,
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
-	value, err := ite.Value(nil, TestDefaultByteOrder)
+	value, err := ite.Value(nil, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
 	if bytes.Compare(value.([]byte), data) != 0 {
@@ -136,29 +148,27 @@ func TestIfdTagEntry_Value_Normal(t *testing.T) {
 	}
 }
 
-func TestIfdTagEntry_Value_Unknown(t *testing.T) {
+func TestIfdTagEntry_Value_Undefined(t *testing.T) {
 	data := []uint8{'0', '2', '3', '0'}
 
 	ite := IfdTagEntry{
 		TagId:          0x9000,
 		TagIndex:       0,
-		TagType:        TypeUndefined,
+		TagType:        exifcommon.TypeUndefined,
 		UnitCount:      4,
 		ValueOffset:    0x0,
 		RawValueOffset: data,
-		IfdPath:        IfdPathStandardExif,
+		IfdPath:        exifcommon.IfdPathStandardExif,
 	}
 
-	value, err := ite.Value(nil, TestDefaultByteOrder)
+	value, err := ite.Value(nil, exifcommon.TestDefaultByteOrder)
 	log.PanicIf(err)
 
-	gs := value.(TagUnknownType_GeneralString)
+	s := value.(fmt.Stringer)
+	recovered := []byte(s.String())
 
-	vb, err := gs.ValueBytes()
+	if bytes.Compare(recovered, data) != 0 {
-	log.PanicIf(err)
+		t.Fatalf("Value not expected: [%s] != [%s]", recovered, data)
-
-	if bytes.Compare(vb, data) != 0 {
-		t.Fatalf("Value not expected: [%s] != [%s]", value, data)
 	}
 }
 
@@ -166,11 +176,11 @@ func TestIfdTagEntry_String(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      6,
 		ValueOffset:    0x0,
 		RawValueOffset: []byte{0x0, 0x0, 0x0, 0x0},
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
 	expected := "IfdTagEntry<TAG-IFD-PATH=[IFD] TAG-ID=(0x0001) TAG-TYPE=[BYTE] UNIT-COUNT=(6)>"
@@ -185,21 +195,21 @@ func TestIfdTagEntryValueResolver_ValueBytes(t *testing.T) {
 	ite := IfdTagEntry{
 		TagId:          0x1,
 		TagIndex:       0,
-		TagType:        TypeByte,
+		TagType:        exifcommon.TypeByte,
 		UnitCount:      uint32(len(allocatedData)),
 		ValueOffset:    0x8,
 		RawValueOffset: []byte{0x0, 0x0, 0x0, 0x0},
-		IfdPath:        IfdPathStandard,
+		IfdPath:        exifcommon.IfdPathStandard,
 	}
 
-	headerBytes, err := BuildExifHeader(TestDefaultByteOrder, uint32(0))
+	headerBytes, err := BuildExifHeader(exifcommon.TestDefaultByteOrder, uint32(0))
 	log.PanicIf(err)
 
 	exifData := make([]byte, len(headerBytes)+len(allocatedData))
 	copy(exifData[0:], headerBytes)
 	copy(exifData[len(headerBytes):], allocatedData)
 
-	itevr := NewIfdTagEntryValueResolver(exifData, TestDefaultByteOrder)
+	itevr := NewIfdTagEntryValueResolver(exifData, exifcommon.TestDefaultByteOrder)
 
 	value, err := itevr.ValueBytes(&ite)
 	log.PanicIf(err)

v2/ifd_test.go

@@ -7,6 +7,8 @@ import (
 	"testing"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 func TestIfdMapping_Add(t *testing.T) {
@@ -106,12 +108,12 @@ func TestIfdMapping_Get(t *testing.T) {
 	err := LoadStandardIfds(im)
 	log.PanicIf(err)
 
-	mi, err := im.Get([]uint16{IfdRootId, IfdExifId, IfdIopId})
+	mi, err := im.Get([]uint16{exifcommon.IfdRootId, exifcommon.IfdExifId, exifcommon.IfdIopId})
 	log.PanicIf(err)
 
-	if mi.ParentTagId != IfdExifId {
+	if mi.ParentTagId != exifcommon.IfdExifId {
 		t.Fatalf("Parent tag-ID not correct")
-	} else if mi.TagId != IfdIopId {
+	} else if mi.TagId != exifcommon.IfdIopId {
 		t.Fatalf("Tag-ID not correct")
 	} else if mi.Name != "Iop" {
 		t.Fatalf("name not correct")
@@ -129,9 +131,9 @@ func TestIfdMapping_GetWithPath(t *testing.T) {
 	mi, err := im.GetWithPath("IFD/Exif/Iop")
 	log.PanicIf(err)
 
-	if mi.ParentTagId != IfdExifId {
+	if mi.ParentTagId != exifcommon.IfdExifId {
 		t.Fatalf("Parent tag-ID not correct")
-	} else if mi.TagId != IfdIopId {
+	} else if mi.TagId != exifcommon.IfdIopId {
 		t.Fatalf("Tag-ID not correct")
 	} else if mi.Name != "Iop" {
 		t.Fatalf("name not correct")

v2/tags.go

@@ -5,6 +5,8 @@ import (
 
 	"github.com/dsoprea/go-logging"
 	"gopkg.in/yaml.v2"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 const (
@@ -59,7 +61,7 @@ type IndexedTag struct {
 	Id      uint16
 	Name    string
 	IfdPath string
-	Type    TagTypePrimitive
+	Type    exifcommon.TagTypePrimitive
 }
 
 func (it *IndexedTag) String() string {
@@ -203,7 +205,7 @@ func LoadStandardTags(ti *TagIndex) (err error) {
 				continue
 			}
 
-			tagTypeId, found := TypeNamesR[tagTypeName]
+			tagTypeId, found := exifcommon.GetTypeByName(tagTypeName)
 			if found == false {
 				log.Panicf("type [%s] for [%s] not valid", tagTypeName, tagName)
 				continue

v2/tags_test.go

@@ -4,15 +4,17 @@ import (
 	"testing"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 func TestGet(t *testing.T) {
 	ti := NewTagIndex()
 
-	it, err := ti.Get(IfdPathStandard, 0x10f)
+	it, err := ti.Get(exifcommon.IfdPathStandard, 0x10f)
 	log.PanicIf(err)
 
-	if it.Is(IfdPathStandard, 0x10f) == false || it.IsName(IfdPathStandard, "Make") == false {
+	if it.Is(exifcommon.IfdPathStandard, 0x10f) == false || it.IsName(exifcommon.IfdPathStandard, "Make") == false {
 		t.Fatalf("tag info not correct")
 	}
 }
@@ -20,10 +22,10 @@ func TestGet(t *testing.T) {
 func TestGetWithName(t *testing.T) {
 	ti := NewTagIndex()
 
-	it, err := ti.GetWithName(IfdPathStandard, "Make")
+	it, err := ti.GetWithName(exifcommon.IfdPathStandard, "Make")
 	log.PanicIf(err)
 
-	if it.Is(IfdPathStandard, 0x10f) == false || it.Is(IfdPathStandard, 0x10f) == false {
+	if it.Is(exifcommon.IfdPathStandard, 0x10f) == false {
 		t.Fatalf("tag info not correct")
 	}
 }

v2/testing_common.go

@@ -9,6 +9,8 @@ import (
 	"io/ioutil"
 
 	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
 var (
@@ -32,7 +34,7 @@ func getExifSimpleTestIb() *IfdBuilder {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddStandard(0x000b, "asciivalue")
 	log.PanicIf(err)
@@ -43,7 +45,7 @@ func getExifSimpleTestIb() *IfdBuilder {
 	err = ib.AddStandard(0x0100, []uint32{0x33445566})
 	log.PanicIf(err)
 
-	err = ib.AddStandard(0x013e, []Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
+	err = ib.AddStandard(0x013e, []exifcommon.Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
 	log.PanicIf(err)
 
 	return ib
@@ -63,7 +65,7 @@ func getExifSimpleTestIbBytes() []byte {
 	log.PanicIf(err)
 
 	ti := NewTagIndex()
-	ib := NewIfdBuilder(im, ti, IfdPathStandard, TestDefaultByteOrder)
+	ib := NewIfdBuilder(im, ti, exifcommon.IfdPathStandard, exifcommon.TestDefaultByteOrder)
 
 	err = ib.AddStandard(0x000b, "asciivalue")
 	log.PanicIf(err)
@@ -74,7 +76,7 @@ func getExifSimpleTestIbBytes() []byte {
 	err = ib.AddStandard(0x0100, []uint32{0x33445566})
 	log.PanicIf(err)
 
-	err = ib.AddStandard(0x013e, []Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
+	err = ib.AddStandard(0x013e, []exifcommon.Rational{{Numerator: 0x11112222, Denominator: 0x33334444}})
 	log.PanicIf(err)
 
 	ibe := NewIfdByteEncoder()
@@ -103,7 +105,7 @@ func validateExifSimpleTestIb(exifData []byte, t *testing.T) {
 	eh, index, err := Collect(im, ti, exifData)
 	log.PanicIf(err)
 
-	if eh.ByteOrder != TestDefaultByteOrder {
+	if eh.ByteOrder != exifcommon.TestDefaultByteOrder {
 		t.Fatalf("EXIF byte-order is not correct: %v", eh.ByteOrder)
 	} else if eh.FirstIfdOffset != ExifDefaultFirstIfdOffset {
 		t.Fatalf("EXIF first IFD-offset not correct: (0x%02x)", eh.FirstIfdOffset)
@@ -115,9 +117,9 @@ func validateExifSimpleTestIb(exifData []byte, t *testing.T) {
 
 	ifd := index.RootIfd
 
-	if ifd.ByteOrder != TestDefaultByteOrder {
+	if ifd.ByteOrder != exifcommon.TestDefaultByteOrder {
 		t.Fatalf("IFD byte-order not correct.")
-	} else if ifd.IfdPath != IfdStandard {
+	} else if ifd.IfdPath != exifcommon.IfdStandard {
 		t.Fatalf("IFD name not correct.")
 	} else if ifd.Index != 0 {
 		t.Fatalf("IFD index not zero: (%d)", ifd.Index)
@@ -142,7 +144,7 @@ func validateExifSimpleTestIb(exifData []byte, t *testing.T) {
 		{tagId: 0x000b, value: "asciivalue"},
 		{tagId: 0x00ff, value: []uint16{0x1122}},
 		{tagId: 0x0100, value: []uint32{0x33445566}},
-		{tagId: 0x013e, value: []Rational{{Numerator: 0x11112222, Denominator: 0x33334444}}},
+		{tagId: 0x013e, value: []exifcommon.Rational{{Numerator: 0x11112222, Denominator: 0x33334444}}},
 	}
 
 	for i, e := range ifd.Entries {
@@ -150,7 +152,7 @@ func validateExifSimpleTestIb(exifData []byte, t *testing.T) {
 			t.Fatalf("Tag-ID for entry (%d) not correct: (0x%02x) != (0x%02x)", i, e.TagId, expected[i].tagId)
 		}
 
-		value, err := e.Value(addressableData, TestDefaultByteOrder)
+		value, err := e.Value(addressableData, exifcommon.TestDefaultByteOrder)
 		log.PanicIf(err)
 
 		if reflect.DeepEqual(value, expected[i].value) != true {

v2/undefined/accessor.go

@@ -1,8 +1,6 @@
 package exifundefined
 
 import (
-	"reflect"
-
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
@@ -10,14 +8,14 @@ import (
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
-func Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+func Encode(value EncodeableValue, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
 		}
 	}()
 
-	encoderName := reflect.TypeOf(value).Name()
+	encoderName := value.EncoderName()
 
 	encoder, found := encoders[encoderName]
 	if found == false {
@@ -31,7 +29,7 @@ func Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unit
 }
 
 // UndefinedValue knows how to resolve the value for most unknown-type tags.
-func Decode(ifdPath string, tagId uint16, valueContext *exifcommon.ValueContext, byteOrder binary.ByteOrder) (value interface{}, err error) {
+func Decode(ifdPath string, tagId uint16, valueContext *exifcommon.ValueContext, byteOrder binary.ByteOrder) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_8828_oecf.go

@@ -1,6 +1,8 @@
 package exifundefined
 
 import (
+	"fmt"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
@@ -13,10 +15,18 @@ type Tag8828Oecf struct {
 	Values      []exifcommon.SignedRational
 }
 
+func (oecf Tag8828Oecf) String() string {
+	return fmt.Sprintf("Tag8828Oecf<COLUMNS=(%d) ROWS=(%d)>", oecf.Columns, oecf.Rows)
+}
+
+func (oecf Tag8828Oecf) EncoderName() string {
+	return "Codec8828Oecf"
+}
+
 type Codec8828Oecf struct {
 }
 
-func (Codec8828Oecf) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec8828Oecf) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_9000_exif_version.go

@@ -1,15 +1,44 @@
 package exifundefined
 
 import (
+	"encoding/binary"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
+type Tag9000ExifVersion struct {
+	string
+}
+
+func (Tag9000ExifVersion) EncoderName() string {
+	return "Codec9000ExifVersion"
+}
+
+func (ev Tag9000ExifVersion) String() string {
+	return ev.string
+}
+
 type Codec9000ExifVersion struct {
 }
 
-func (Codec9000ExifVersion) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec9000ExifVersion) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	s, ok := value.(Tag9000ExifVersion)
+	if ok == false {
+		log.Panicf("can only encode a Tag9000ExifVersion")
+	}
+
+	return []byte(s.string), uint32(len(s.string)), nil
+}
+
+func (Codec9000ExifVersion) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -21,10 +50,14 @@ func (Codec9000ExifVersion) Decode(valueContext *exifcommon.ValueContext) (value
 	valueString, err := valueContext.ReadAsciiNoNul()
 	log.PanicIf(err)
 
-	return TagUndefinedGeneralString(valueString), nil
+	return Tag9000ExifVersion{valueString}, nil
 }
 
 func init() {
+	registerEncoder(
+		Tag9000ExifVersion{},
+		Codec9000ExifVersion{})
+
 	registerDecoder(
 		exifcommon.IfdPathStandardExif,
 		0x9000,

v2/undefined/exif_9101_components_configuration.go

@@ -55,6 +55,10 @@ type TagExif9101ComponentsConfiguration struct {
 	ConfigurationBytes []byte
 }
 
+func (TagExif9101ComponentsConfiguration) EncoderName() string {
+	return "CodecExif9101ComponentsConfiguration"
+}
+
 func (cc TagExif9101ComponentsConfiguration) String() string {
 	return fmt.Sprintf("Exif9101ComponentsConfiguration<ID=[%s] BYTES=%v>", TagUndefinedType_9101_ComponentsConfiguration_Names[cc.ConfigurationId], cc.ConfigurationBytes)
 }
@@ -79,7 +83,7 @@ func (CodecExif9101ComponentsConfiguration) Encode(value interface{}, byteOrder
 	return cc.ConfigurationBytes, uint32(len(cc.ConfigurationBytes)), nil
 }
 
-func (CodecExif9101ComponentsConfiguration) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecExif9101ComponentsConfiguration) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_927C_maker_note.go

@@ -17,6 +17,10 @@ type Tag927CMakerNote struct {
     MakerNoteBytes []byte
 }
 
+func (Tag927CMakerNote) EncoderName() string {
+    return "Codec927CMakerNote"
+}
+
 func (mn Tag927CMakerNote) String() string {
     parts := make([]string, 20)
     for i, c := range mn.MakerNoteType {
@@ -53,7 +57,7 @@ func (Codec927CMakerNote) Encode(value interface{}, byteOrder binary.ByteOrder)
     return mn.MakerNoteBytes, uint32(len(mn.MakerNoteBytes)), nil
 }
 
-func (Codec927CMakerNote) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec927CMakerNote) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
     defer func() {
         if state := recover(); state != nil {
             err = log.Wrap(state.(error))

v2/undefined/exif_9286_user_comment.go

@@ -43,6 +43,10 @@ type Tag9286UserComment struct {
     EncodingBytes []byte
 }
 
+func (Tag9286UserComment) EncoderName() string {
+    return "Codec9286UserComment"
+}
+
 func (uc Tag9286UserComment) String() string {
     var valuePhrase string
 
@@ -85,7 +89,7 @@ func (Codec9286UserComment) Encode(value interface{}, byteOrder binary.ByteOrder
     return encoded, uint32(len(encoded)), nil
 }
 
-func (Codec9286UserComment) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec9286UserComment) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
     defer func() {
         if state := recover(); state != nil {
             err = log.Wrap(state.(error))

v2/undefined/exif_A000_flashpix_version.go

@@ -1,15 +1,44 @@
 package exifundefined
 
 import (
+	"encoding/binary"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
+type TagA000FlashpixVersion struct {
+	string
+}
+
+func (TagA000FlashpixVersion) EncoderName() string {
+	return "CodecA000FlashpixVersion"
+}
+
+func (fv TagA000FlashpixVersion) String() string {
+	return fv.string
+}
+
 type CodecA000FlashpixVersion struct {
 }
 
-func (CodecA000FlashpixVersion) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecA000FlashpixVersion) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	s, ok := value.(TagA000FlashpixVersion)
+	if ok == false {
+		log.Panicf("can only encode a TagA000FlashpixVersion")
+	}
+
+	return []byte(s.string), uint32(len(s.string)), nil
+}
+
+func (CodecA000FlashpixVersion) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -21,10 +50,14 @@ func (CodecA000FlashpixVersion) Decode(valueContext *exifcommon.ValueContext) (v
 	valueString, err := valueContext.ReadAsciiNoNul()
 	log.PanicIf(err)
 
-	return TagUndefinedGeneralString(valueString), nil
+	return TagA000FlashpixVersion{valueString}, nil
 }
 
 func init() {
+	registerEncoder(
+		TagA000FlashpixVersion{},
+		CodecA000FlashpixVersion{})
+
 	registerDecoder(
 		exifcommon.IfdPathStandardExif,
 		0xa000,

v2/undefined/exif_A20C_spatial_frequency_response.go

@@ -2,6 +2,7 @@ package exifundefined
 
 import (
 	"bytes"
+	"fmt"
 
 	"encoding/binary"
 
@@ -17,6 +18,14 @@ type TagA20CSpatialFrequencyResponse struct {
 	Values      []exifcommon.Rational
 }
 
+func (TagA20CSpatialFrequencyResponse) EncoderName() string {
+	return "CodecA20CSpatialFrequencyResponse"
+}
+
+func (sfr TagA20CSpatialFrequencyResponse) String() string {
+	return fmt.Sprintf("CodecA20CSpatialFrequencyResponse<COLUMNS=(%d) ROWS=(%d)>", sfr.Columns, sfr.Rows)
+}
+
 type CodecA20CSpatialFrequencyResponse struct {
 }
 
@@ -69,7 +78,7 @@ func (CodecA20CSpatialFrequencyResponse) Encode(value interface{}, byteOrder bin
 	return encoded, uint32(len(encoded)), nil
 }
 
-func (CodecA20CSpatialFrequencyResponse) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecA20CSpatialFrequencyResponse) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -141,11 +150,11 @@ func (CodecA20CSpatialFrequencyResponse) Decode(valueContext *exifcommon.ValueCo
 
 func init() {
 	registerEncoder(
-		TagA302CfaPattern{},
+		TagA20CSpatialFrequencyResponse{},
-		CodecA302CfaPattern{})
+		CodecA20CSpatialFrequencyResponse{})
 
 	registerDecoder(
 		exifcommon.IfdPathStandardExif,
-		0xa302,
+		0xa20c,
-		CodecA302CfaPattern{})
+		CodecA20CSpatialFrequencyResponse{})
 }

v2/undefined/exif_A300_file_source.go

@@ -1,6 +1,8 @@
 package exifundefined
 
 import (
+	"fmt"
+
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
@@ -10,6 +12,14 @@ import (
 
 type TagExifA300FileSource uint32
 
+func (TagExifA300FileSource) EncoderName() string {
+	return "CodecExifA300FileSource"
+}
+
+func (af TagExifA300FileSource) String() string {
+	return fmt.Sprintf("%d", af)
+}
+
 const (
 	TagUndefinedType_A300_SceneType_Others                   TagExifA300FileSource = 0
 	TagUndefinedType_A300_SceneType_ScannerOfTransparentType TagExifA300FileSource = 1
@@ -42,7 +52,7 @@ func (CodecExifA300FileSource) Encode(value interface{}, byteOrder binary.ByteOr
 	return ed.Encoded, uint32(int(ed.UnitCount)), nil
 }
 
-func (CodecExifA300FileSource) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecExifA300FileSource) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_A301_scene_type.go

@@ -1,6 +1,8 @@
 package exifundefined
 
 import (
+	"fmt"
+
 	"encoding/binary"
 
 	"github.com/dsoprea/go-logging"
@@ -10,6 +12,14 @@ import (
 
 type TagExifA301SceneType uint32
 
+func (TagExifA301SceneType) EncoderName() string {
+	return "CodecExifA301SceneType"
+}
+
+func (st TagExifA301SceneType) String() string {
+	return fmt.Sprintf("%d", st)
+}
+
 const (
 	TagUndefinedType_A301_SceneType_DirectlyPhotographedImage TagExifA301SceneType = 1
 )
@@ -39,7 +49,7 @@ func (CodecExifA301SceneType) Encode(value interface{}, byteOrder binary.ByteOrd
 	return ed.Encoded, uint32(int(ed.UnitCount)), nil
 }
 
-func (CodecExifA301SceneType) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecExifA301SceneType) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_A302_cfa_pattern.go

@@ -2,6 +2,7 @@ package exifundefined
 
 import (
 	"bytes"
+	"fmt"
 
 	"encoding/binary"
 
@@ -16,6 +17,14 @@ type TagA302CfaPattern struct {
 	CfaValue         []byte
 }
 
+func (TagA302CfaPattern) EncoderName() string {
+	return "CodecA302CfaPattern"
+}
+
+func (cp TagA302CfaPattern) String() string {
+	return fmt.Sprintf("TagA302CfaPattern<HORZ-REPEAT=(%d) VERT-REPEAT=(%d)>", cp.HorizontalRepeat, cp.VerticalRepeat)
+}
+
 type CodecA302CfaPattern struct {
 }
 
@@ -51,7 +60,7 @@ func (CodecA302CfaPattern) Encode(value interface{}, byteOrder binary.ByteOrder)
 	return encoded, uint32(len(encoded)), nil
 }
 
-func (CodecA302CfaPattern) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (CodecA302CfaPattern) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))

v2/undefined/exif_iop_0002_interop_version.go

@@ -1,15 +1,44 @@
 package exifundefined
 
 import (
+	"encoding/binary"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
+type Tag0002InteropVersion struct {
+	string
+}
+
+func (Tag0002InteropVersion) EncoderName() string {
+	return "Codec0002InteropVersion"
+}
+
+func (iv Tag0002InteropVersion) String() string {
+	return iv.string
+}
+
 type Codec0002InteropVersion struct {
 }
 
-func (Codec0002InteropVersion) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec0002InteropVersion) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	s, ok := value.(Tag0002InteropVersion)
+	if ok == false {
+		log.Panicf("can only encode a Tag0002InteropVersion")
+	}
+
+	return []byte(s.string), uint32(len(s.string)), nil
+}
+
+func (Codec0002InteropVersion) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -21,10 +50,14 @@ func (Codec0002InteropVersion) Decode(valueContext *exifcommon.ValueContext) (va
 	valueString, err := valueContext.ReadAsciiNoNul()
 	log.PanicIf(err)
 
-	return TagUndefinedGeneralString(valueString), nil
+	return Tag0002InteropVersion{valueString}, nil
 }
 
 func init() {
+	registerEncoder(
+		Tag0002InteropVersion{},
+		Codec0002InteropVersion{})
+
 	registerDecoder(
 		exifcommon.IfdPathStandardExifIop,
 		0x0002,

v2/undefined/gps_001B_gps_processing_method.go

@@ -1,15 +1,44 @@
 package exifundefined
 
 import (
+	"encoding/binary"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
+type Tag001BGPSProcessingMethod struct {
+	string
+}
+
+func (Tag001BGPSProcessingMethod) EncoderName() string {
+	return "Codec001BGPSProcessingMethod"
+}
+
+func (gpm Tag001BGPSProcessingMethod) String() string {
+	return gpm.string
+}
+
 type Codec001BGPSProcessingMethod struct {
 }
 
-func (Codec001BGPSProcessingMethod) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec001BGPSProcessingMethod) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	s, ok := value.(Tag001BGPSProcessingMethod)
+	if ok == false {
+		log.Panicf("can only encode a Tag001BGPSProcessingMethod")
+	}
+
+	return []byte(s.string), uint32(len(s.string)), nil
+}
+
+func (Codec001BGPSProcessingMethod) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -21,10 +50,14 @@ func (Codec001BGPSProcessingMethod) Decode(valueContext *exifcommon.ValueContext
 	valueString, err := valueContext.ReadAsciiNoNul()
 	log.PanicIf(err)
 
-	return TagUndefinedGeneralString(valueString), nil
+	return Tag001BGPSProcessingMethod{valueString}, nil
 }
 
 func init() {
+	registerEncoder(
+		Tag001BGPSProcessingMethod{},
+		Codec001BGPSProcessingMethod{})
+
 	registerDecoder(
 		exifcommon.IfdPathStandardGps,
 		0x001b,

v2/undefined/gps_001C_gps_area_information.go

@@ -1,15 +1,44 @@
 package exifundefined
 
 import (
+	"encoding/binary"
+
 	"github.com/dsoprea/go-logging"
 
 	"github.com/dsoprea/go-exif/v2/common"
 )
 
+type Tag001CGPSAreaInformation struct {
+	string
+}
+
+func (Tag001CGPSAreaInformation) EncoderName() string {
+	return "Codec001CGPSAreaInformation"
+}
+
+func (gai Tag001CGPSAreaInformation) String() string {
+	return gai.string
+}
+
 type Codec001CGPSAreaInformation struct {
 }
 
-func (Codec001CGPSAreaInformation) Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error) {
+func (Codec001CGPSAreaInformation) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	s, ok := value.(Tag001CGPSAreaInformation)
+	if ok == false {
+		log.Panicf("can only encode a Tag001CGPSAreaInformation")
+	}
+
+	return []byte(s.string), uint32(len(s.string)), nil
+}
+
+func (Codec001CGPSAreaInformation) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
 	defer func() {
 		if state := recover(); state != nil {
 			err = log.Wrap(state.(error))
@@ -21,10 +50,14 @@ func (Codec001CGPSAreaInformation) Decode(valueContext *exifcommon.ValueContext)
 	valueString, err := valueContext.ReadAsciiNoNul()
 	log.PanicIf(err)
 
-	return TagUndefinedGeneralString(valueString), nil
+	return Tag001CGPSAreaInformation{valueString}, nil
 }
 
 func init() {
+	registerEncoder(
+		Tag001CGPSAreaInformation{},
+		Codec001CGPSAreaInformation{})
+
 	registerDecoder(
 		exifcommon.IfdPathStandardGps,
 		0x001c,

v2/undefined/registration.go

@@ -1,8 +1,6 @@
 package exifundefined
 
 import (
-	"reflect"
-
 	"github.com/dsoprea/go-logging"
 )
 
@@ -11,11 +9,11 @@ type UndefinedTagHandle struct {
 	TagId   uint16
 }
 
-func registerEncoder(entity interface{}, encoder UndefinedValueEncoder) {
+func registerEncoder(entity EncodeableValue, encoder UndefinedValueEncoder) {
-	typeName := reflect.TypeOf(entity).Name()
+	typeName := entity.EncoderName()
 
 	_, found := encoders[typeName]
-	if found != true {
+	if found == true {
 		log.Panicf("encoder already registered: %v", typeName)
 	}
 
@@ -29,7 +27,7 @@ func registerDecoder(ifdPath string, tagId uint16, decoder UndefinedValueDecoder
 	}
 
 	_, found := decoders[uth]
-	if found != true {
+	if found == true {
 		log.Panicf("decoder already registered: %v", uth)
 	}
 

v2/undefined/type.go

@@ -22,24 +22,19 @@ type UndefinedValueEncoder interface {
 	Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error)
 }
 
+type EncodeableValue interface {
+	EncoderName() string
+}
+
 // UndefinedValueEncoder knows how to decode an undefined-type tag's value from
 // bytes.
 type UndefinedValueDecoder interface {
-	Decode(valueContext *exifcommon.ValueContext) (value interface{}, err error)
+	Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error)
 }
 
-// TODO(dustin): Rename `UnknownTagValue` to `UndefinedTagValue`.
+type TagUndefinedType_UnknownValue []byte
-// OBSOLETE(dustin): Use a `UndefinedValueEncoder` instead of an `UnknownTagValue`.
 
-type UnknownTagValue interface {
+func (tutuv TagUndefinedType_UnknownValue) String() string {
-	ValueBytes() ([]byte, error)
-}
-
-// TODO(dustin): Rename `TagUnknownType_UnknownValue` to `TagUndefinedType_UnknownValue`.
-
-type TagUnknownType_UnknownValue []byte
-
-func (tutuv TagUnknownType_UnknownValue) String() string {
 	parts := make([]string, len(tutuv))
 	for i, c := range tutuv {
 		parts[i] = fmt.Sprintf("%02x", c)
@@ -54,5 +49,3 @@ func (tutuv TagUnknownType_UnknownValue) String() string {
 
 	return fmt.Sprintf("Unknown<DATA=[%s] LEN=(%d) SHA1=[%020x]>", strings.Join(parts, " "), len(tutuv), digest)
 }
-
-type TagUndefinedGeneralString string

v2/utility.go

@@ -1,13 +1,15 @@
 package exif
 
 import (
-    "bytes"
     "fmt"
     "strconv"
     "strings"
     "time"
 
     "github.com/dsoprea/go-logging"
+
+    "github.com/dsoprea/go-exif/v2/common"
+    "github.com/dsoprea/go-exif/v2/undefined"
 )
 
 // ParseExifFullTimestamp parses dates like "2018:11:30 13:01:49" into a UTC
@@ -75,7 +77,7 @@ type ExifTag struct {
     TagId   uint16 `json:"id"`
     TagName string `json:"name"`
 
-    TagTypeId   TagTypePrimitive `json:"type_id"`
+    TagTypeId   exifcommon.TagTypePrimitive `json:"type_id"`
     TagTypeName string                      `json:"type_name"`
     Value       interface{}                 `json:"value"`
     ValueBytes  []byte                      `json:"value_bytes"`
@@ -126,15 +128,15 @@ func GetFlatExifData(exifData []byte) (exifTags []ExifTag, err error) {
 
             value, err := ifd.TagValue(ite)
             if err != nil {
-                if err == ErrUnhandledUnknownTypedTag {
+                if err == exifcommon.ErrUnhandledUnknownTypedTag {
-                    value = UnparseableUnknownTagValuePlaceholder
+                    value = exifundefined.UnparseableUnknownTagValuePlaceholder
                 } else {
                     log.Panic(err)
                 }
             }
 
             valueBytes, err := ifd.TagValueBytes(ite)
-            if err != nil && err != ErrUnhandledUnknownTypedTag {
+            if err != nil && err != exifcommon.ErrUnhandledUnknownTypedTag {
                 log.Panic(err)
             }
 
@@ -143,7 +145,7 @@ func GetFlatExifData(exifData []byte) (exifTags []ExifTag, err error) {
                 TagId:        ite.TagId,
                 TagName:      tagName,
                 TagTypeId:    ite.TagType,
-                TagTypeName:  TypeNames[ite.TagType],
+                TagTypeName:  ite.TagType.String(),
                 Value:        value,
                 ValueBytes:   valueBytes,
                 ChildIfdPath: ite.ChildIfdPath,

v2/utility_test.go

@@ -1,80 +1,13 @@
 package exif
 
 import (
-    "io/ioutil"
-
     "fmt"
-    "os"
     "testing"
     "time"
 
     "github.com/dsoprea/go-logging"
 )
 
-func TestDumpBytes(t *testing.T) {
-    f, err := ioutil.TempFile(os.TempDir(), "utilitytest")
-    log.PanicIf(err)
-
-    defer os.Remove(f.Name())
-
-    originalStdout := os.Stdout
-    os.Stdout = f
-
-    DumpBytes([]byte{0x11, 0x22})
-
-    os.Stdout = originalStdout
-
-    _, err = f.Seek(0, 0)
-    log.PanicIf(err)
-
-    content, err := ioutil.ReadAll(f)
-    log.PanicIf(err)
-
-    if string(content) != "DUMP: 11 22 \n" {
-        t.Fatalf("content not correct: [%s]", string(content))
-    }
-}
-
-func TestDumpBytesClause(t *testing.T) {
-    f, err := ioutil.TempFile(os.TempDir(), "utilitytest")
-    log.PanicIf(err)
-
-    defer os.Remove(f.Name())
-
-    originalStdout := os.Stdout
-    os.Stdout = f
-
-    DumpBytesClause([]byte{0x11, 0x22})
-
-    os.Stdout = originalStdout
-
-    _, err = f.Seek(0, 0)
-    log.PanicIf(err)
-
-    content, err := ioutil.ReadAll(f)
-    log.PanicIf(err)
-
-    if string(content) != "DUMP: []byte { 0x11, 0x22 }\n" {
-        t.Fatalf("content not correct: [%s]", string(content))
-    }
-}
-
-func TestDumpBytesToString(t *testing.T) {
-    s := DumpBytesToString([]byte{0x12, 0x34, 0x56})
-
-    if s != "12 34 56" {
-        t.Fatalf("result not expected")
-    }
-}
-
-func TestDumpBytesClauseToString(t *testing.T) {
-    s := DumpBytesClauseToString([]byte{0x12, 0x34, 0x56})
-
-    if s != "0x12, 0x34, 0x56" {
-        t.Fatalf("result not expected")
-    }
-}
-
 func TestParseExifFullTimestamp(t *testing.T) {
     timestamp, err := ParseExifFullTimestamp("2018:11:30 13:01:49")
     log.PanicIf(err)

v2/value_context.go

@@ -2,10 +2,12 @@ package exif
 
 import (
 	"encoding/binary"
+
+	"github.com/dsoprea/go-exif/v2/common"
 )
 
-func newValueContextFromTag(ite *IfdTagEntry, addressableData []byte, byteOrder binary.ByteOrder) *ValueContext {
+func newValueContextFromTag(ite *IfdTagEntry, addressableData []byte, byteOrder binary.ByteOrder) *exifcommon.ValueContext {
-	return newValueContext(
+	return exifcommon.NewValueContext(
 		ite.IfdPath,
 		ite.TagId,
 		ite.UnitCount,