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go-exif
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type.go: Created `TagTypePrimitive` alias for `uint16` 

Added a `Size()` method to it and decommissioned redundant
`TagTypeSize()` and `(TagType).Size()`.

- ifd_enumerate.go: Moved `ValueContext` definition to
  value_context.go .
pull/28/head
Dustin Oprea 2019-12-28 23:59:12 -05:00
parent 483dbacf14
commit a69c3987eb
10 changed files with 121 additions and 102 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
exif-read-tool/main.go
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@ -32,16 +32,16 @@ var (
) )
type IfdEntry struct { type IfdEntry struct {
IfdPath string `json:"ifd_path"` IfdPath string `json:"ifd_path"`
FqIfdPath string `json:"fq_ifd_path"` FqIfdPath string `json:"fq_ifd_path"`
IfdIndex int `json:"ifd_index"` IfdIndex int `json:"ifd_index"`
TagId uint16 `json:"tag_id"` TagId uint16 `json:"tag_id"`
TagName string `json:"tag_name"` TagName string `json:"tag_name"`
TagTypeId uint16 `json:"tag_type_id"` TagTypeId exif.TagTypePrimitive `json:"tag_type_id"`
TagTypeName string `json:"tag_type_name"` TagTypeName string `json:"tag_type_name"`
UnitCount uint32 `json:"unit_count"` UnitCount uint32 `json:"unit_count"`
Value interface{} `json:"value"` Value interface{} `json:"value"`
ValueString string `json:"value_string"` ValueString string `json:"value_string"`
} }
func main() { func main() {

4
ifd_builder.go
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@ -90,7 +90,7 @@ type BuilderTag struct {
ifdPath string ifdPath string
tagId uint16 tagId uint16
typeId uint16 typeId TagTypePrimitive
// value is either a value that can be encoded, an IfdBuilder instance (for // value is either a value that can be encoded, an IfdBuilder instance (for
// child IFDs), or an IfdTagEntry instance representing an existing, // child IFDs), or an IfdTagEntry instance representing an existing,
@ -102,7 +102,7 @@ type BuilderTag struct {
byteOrder binary.ByteOrder byteOrder binary.ByteOrder
} }
func NewBuilderTag(ifdPath string, tagId uint16, typeId uint16, value *IfdBuilderTagValue, byteOrder binary.ByteOrder) *BuilderTag { func NewBuilderTag(ifdPath string, tagId uint16, typeId TagTypePrimitive, value *IfdBuilderTagValue, byteOrder binary.ByteOrder) *BuilderTag {
return &BuilderTag{ return &BuilderTag{
ifdPath: ifdPath, ifdPath: ifdPath,
tagId: tagId, tagId: tagId,

4
ifd_builder_encode.go
View File

@ -212,7 +212,7 @@ func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *BuilderTag, bw *
// Works for both values and child IFDs (which have an official size of // Works for both values and child IFDs (which have an official size of
// LONG). // LONG).
err = bw.WriteUint16(bt.typeId) err = bw.WriteUint16(uint16(bt.typeId))
log.PanicIf(err) log.PanicIf(err)
// Write unit-count. // Write unit-count.
@ -226,7 +226,7 @@ func (ibe *IfdByteEncoder) encodeTagToBytes(ib *IfdBuilder, bt *BuilderTag, bw *
// It's a non-unknown value.Calculate the count of values of // It's a non-unknown value.Calculate the count of values of
// the type that we're writing and the raw bytes for the whole list. // the type that we're writing and the raw bytes for the whole list.
typeSize := uint32(TagTypeSize(effectiveType)) typeSize := uint32(effectiveType.Size())
valueBytes := bt.value.Bytes() valueBytes := bt.value.Bytes()

15
ifd_enumerate.go
View File

@ -145,15 +145,6 @@ func NewIfdEnumerate(ifdMapping *IfdMapping, tagIndex *TagIndex, exifData []byte
} }
} }
// ValueContext describes all of the parameters required to find and extract
// the actual tag value.
type ValueContext struct {
UnitCount uint32
ValueOffset uint32
RawValueOffset []byte
AddressableData []byte
}
func (ie *IfdEnumerate) getTagEnumerator(ifdOffset uint32) (ite *IfdTagEnumerator) { func (ie *IfdEnumerate) getTagEnumerator(ifdOffset uint32) (ite *IfdTagEnumerator) {
ite = NewIfdTagEnumerator( ite = NewIfdTagEnumerator(
ie.exifData[ExifAddressableAreaStart:], ie.exifData[ExifAddressableAreaStart:],
@ -173,9 +164,11 @@ func (ie *IfdEnumerate) parseTag(fqIfdPath string, tagPosition int, ite *IfdTagE
tagId, _, err := ite.getUint16() tagId, _, err := ite.getUint16()
log.PanicIf(err) log.PanicIf(err)
tagType, _, err := ite.getUint16() tagTypeRaw, _, err := ite.getUint16()
log.PanicIf(err) log.PanicIf(err)
tagType := TagTypePrimitive(tagTypeRaw)
unitCount, _, err := ite.getUint32() unitCount, _, err := ite.getUint32()
log.PanicIf(err) log.PanicIf(err)
@ -276,7 +269,7 @@ func (ie *IfdEnumerate) resolveTagValue(ite *IfdTagEntry) (valueBytes []byte, is
} }
} else { } else {
originalType := NewTagType(ite.TagType, ie.byteOrder) originalType := NewTagType(ite.TagType, ie.byteOrder)
byteCount := uint32(originalType.Size()) * ite.UnitCount byteCount := uint32(originalType.Type().Size()) * ite.UnitCount
tt := NewTagType(TypeByte, ie.byteOrder) tt := NewTagType(TypeByte, ie.byteOrder)

4
ifd_tag_entry.go
View File

@ -16,7 +16,7 @@ var (
type IfdTagEntry struct { type IfdTagEntry struct {
TagId uint16 TagId uint16
TagIndex int TagIndex int
TagType uint16 TagType TagTypePrimitive
UnitCount uint32 UnitCount uint32
ValueOffset uint32 ValueOffset uint32
RawValueOffset []byte RawValueOffset []byte
@ -121,7 +121,7 @@ func (ite IfdTagEntry) ValueBytes(addressableData []byte, byteOrder binary.ByteO
} }
originalType := NewTagType(ite.TagType, byteOrder) originalType := NewTagType(ite.TagType, byteOrder)
byteCount := uint32(originalType.Size()) * ite.UnitCount byteCount := uint32(originalType.Type().Size()) * ite.UnitCount
tt := NewTagType(TypeByte, byteOrder) tt := NewTagType(TypeByte, byteOrder)

2
tags.go
View File

@ -59,7 +59,7 @@ type IndexedTag struct {
Id uint16 Id uint16
Name string Name string
IfdPath string IfdPath string
Type uint16 Type TagTypePrimitive
} }
func (it *IndexedTag) String() string { func (it *IndexedTag) String() string {

126
type.go
View File

@ -12,18 +12,43 @@ import (
"github.com/dsoprea/go-logging" "github.com/dsoprea/go-logging"
) )
const ( type TagTypePrimitive uint16
TypeByte = uint16(1)
TypeAscii = uint16(2)
TypeShort = uint16(3)
TypeLong = uint16(4)
TypeRational = uint16(5)
TypeUndefined = uint16(7)
TypeSignedLong = uint16(9)
TypeSignedRational = uint16(10)
// Custom, for our purposes. func (tagType TagTypePrimitive) Size() int {
TypeAsciiNoNul = uint16(0xf0) if tagType == TypeByte {
return 1
} else if tagType == TypeAscii || tagType == TypeAsciiNoNul {
return 1
} else if tagType == TypeShort {
return 2
} else if tagType == TypeLong {
return 4
} else if tagType == TypeRational {
return 8
} else if tagType == TypeSignedLong {
return 4
} else if tagType == TypeSignedRational {
return 8
} else {
log.Panicf("can not determine tag-value size for type (%d): [%s]", tagType, TypeNames[tagType])
// Never called.
return 0
}
}
const (
TypeByte TagTypePrimitive = 1
TypeAscii = 2
TypeShort = 3
TypeLong = 4
TypeRational = 5
TypeUndefined = 7
TypeSignedLong = 9
TypeSignedRational = 10
// TypeAsciiNoNul is just a pseudo-type, for our own purposes.
TypeAsciiNoNul = 0xf0
) )
var ( var (
@ -32,7 +57,7 @@ var (
var ( var (
// TODO(dustin): Rename TypeNames() to typeNames() and add getter. // TODO(dustin): Rename TypeNames() to typeNames() and add getter.
TypeNames = map[uint16]string{ TypeNames = map[TagTypePrimitive]string{
TypeByte: "BYTE", TypeByte: "BYTE",
TypeAscii: "ASCII", TypeAscii: "ASCII",
TypeShort: "SHORT", TypeShort: "SHORT",
@ -45,7 +70,7 @@ var (
TypeAsciiNoNul: "_ASCII_NO_NUL", TypeAsciiNoNul: "_ASCII_NO_NUL",
} }
TypeNamesR = map[string]uint16{} TypeNamesR = map[string]TagTypePrimitive{}
) )
var ( var (
@ -74,12 +99,12 @@ type SignedRational struct {
} }
type TagType struct { type TagType struct {
tagType uint16 tagType TagTypePrimitive
name string name string
byteOrder binary.ByteOrder byteOrder binary.ByteOrder
} }
func NewTagType(tagType uint16, byteOrder binary.ByteOrder) TagType { func NewTagType(tagType TagTypePrimitive, byteOrder binary.ByteOrder) TagType {
name, found := TypeNames[tagType] name, found := TypeNames[tagType]
if found == false { if found == false {
log.Panicf("tag-type not valid: 0x%04x", tagType) log.Panicf("tag-type not valid: 0x%04x", tagType)
@ -100,7 +125,7 @@ func (tt TagType) Name() string {
return tt.name return tt.name
} }
func (tt TagType) Type() uint16 { func (tt TagType) Type() TagTypePrimitive {
return tt.tagType return tt.tagType
} }
@ -108,37 +133,20 @@ func (tt TagType) ByteOrder() binary.ByteOrder {
return tt.byteOrder return tt.byteOrder
} }
// DEPRECATED(dustin): `(TagTypePrimitive).Size()` should be used, directly.
func (tt TagType) Size() int { func (tt TagType) Size() int {
return TagTypeSize(tt.Type()) return tt.Type().Size()
} }
func TagTypeSize(tagType uint16) int { // DEPRECATED(dustin): `(TagTypePrimitive).Size()` should be used, directly.
if tagType == TypeByte { func TagTypeSize(tagType TagTypePrimitive) int {
return 1 return tagType.Size()
} else if tagType == TypeAscii || tagType == TypeAsciiNoNul {
return 1
} else if tagType == TypeShort {
return 2
} else if tagType == TypeLong {
return 4
} else if tagType == TypeRational {
return 8
} else if tagType == TypeSignedLong {
return 4
} else if tagType == TypeSignedRational {
return 8
} else {
log.Panicf("can not determine tag-value size for type (%d): [%s]", tagType, TypeNames[tagType])
// Never called.
return 0
}
} }
// valueIsEmbedded will return a boolean indicating whether the value should be // valueIsEmbedded will return a boolean indicating whether the value should be
// found directly within the IFD entry or an offset to somewhere else. // found directly within the IFD entry or an offset to somewhere else.
func (tt TagType) valueIsEmbedded(unitCount uint32) bool { func (tt TagType) valueIsEmbedded(unitCount uint32) bool {
return (tt.Size() * int(unitCount)) <= 4 return (tt.tagType.Size() * int(unitCount)) <= 4
} }
func (tt TagType) readRawEncoded(valueContext ValueContext) (rawBytes []byte, err error) { func (tt TagType) readRawEncoded(valueContext ValueContext) (rawBytes []byte, err error) {
@ -148,11 +156,13 @@ func (tt TagType) readRawEncoded(valueContext ValueContext) (rawBytes []byte, er
} }
}() }()
unitSizeRaw := uint32(tt.tagType.Size())
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := unitSizeRaw * valueContext.UnitCount
return valueContext.RawValueOffset[:byteLength], nil return valueContext.RawValueOffset[:byteLength], nil
} else { } else {
return valueContext.AddressableData[valueContext.ValueOffset : valueContext.ValueOffset+valueContext.UnitCount*uint32(tt.Size())], nil return valueContext.AddressableData[valueContext.ValueOffset : valueContext.ValueOffset+valueContext.UnitCount*unitSizeRaw], nil
} }
} }
@ -169,7 +179,7 @@ func (tt TagType) ParseBytes(data []byte, unitCount uint32) (value []uint8, err
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -192,7 +202,7 @@ func (tt TagType) ParseAscii(data []byte, unitCount uint32) (value string, err e
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -224,7 +234,7 @@ func (tt TagType) ParseAsciiNoNul(data []byte, unitCount uint32) (value string,
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -244,7 +254,7 @@ func (tt TagType) ParseShorts(data []byte, unitCount uint32) (value []uint16, er
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -273,7 +283,7 @@ func (tt TagType) ParseLongs(data []byte, unitCount uint32) (value []uint32, err
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -302,7 +312,7 @@ func (tt TagType) ParseRationals(data []byte, unitCount uint32) (value []Rationa
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -333,7 +343,7 @@ func (tt TagType) ParseSignedLongs(data []byte, unitCount uint32) (value []int32
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -366,7 +376,7 @@ func (tt TagType) ParseSignedRationals(data []byte, unitCount uint32) (value []S
count := int(unitCount) count := int(unitCount)
if len(data) < (tt.Size() * count) { if len(data) < (tt.tagType.Size() * count) {
log.Panic(ErrNotEnoughData) log.Panic(ErrNotEnoughData)
} }
@ -405,7 +415,7 @@ func (tt TagType) ReadByteValues(valueContext ValueContext) (value []byte, err e
// In this case, the bytes normally used for the offset are actually // In this case, the bytes normally used for the offset are actually
// data. // data.
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseBytes(rawValue, valueContext.UnitCount) value, err = tt.ParseBytes(rawValue, valueContext.UnitCount)
@ -430,7 +440,7 @@ func (tt TagType) ReadAsciiValue(valueContext ValueContext) (value string, err e
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading ASCII value (embedded).") typeLogger.Debugf(nil, "Reading ASCII value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseAscii(rawValue, valueContext.UnitCount) value, err = tt.ParseAscii(rawValue, valueContext.UnitCount)
@ -455,7 +465,7 @@ func (tt TagType) ReadAsciiNoNulValue(valueContext ValueContext) (value string,
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading ASCII value (no-nul; embedded).") typeLogger.Debugf(nil, "Reading ASCII value (no-nul; embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseAsciiNoNul(rawValue, valueContext.UnitCount) value, err = tt.ParseAsciiNoNul(rawValue, valueContext.UnitCount)
@ -480,7 +490,7 @@ func (tt TagType) ReadShortValues(valueContext ValueContext) (value []uint16, er
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading SHORT value (embedded).") typeLogger.Debugf(nil, "Reading SHORT value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseShorts(rawValue, valueContext.UnitCount) value, err = tt.ParseShorts(rawValue, valueContext.UnitCount)
@ -505,7 +515,7 @@ func (tt TagType) ReadLongValues(valueContext ValueContext) (value []uint32, err
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading LONG value (embedded).") typeLogger.Debugf(nil, "Reading LONG value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseLongs(rawValue, valueContext.UnitCount) value, err = tt.ParseLongs(rawValue, valueContext.UnitCount)
@ -530,7 +540,7 @@ func (tt TagType) ReadRationalValues(valueContext ValueContext) (value []Rationa
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading RATIONAL value (embedded).") typeLogger.Debugf(nil, "Reading RATIONAL value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseRationals(rawValue, valueContext.UnitCount) value, err = tt.ParseRationals(rawValue, valueContext.UnitCount)
@ -555,7 +565,7 @@ func (tt TagType) ReadSignedLongValues(valueContext ValueContext) (value []int32
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading SLONG value (embedded).") typeLogger.Debugf(nil, "Reading SLONG value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseSignedLongs(rawValue, valueContext.UnitCount) value, err = tt.ParseSignedLongs(rawValue, valueContext.UnitCount)
@ -580,7 +590,7 @@ func (tt TagType) ReadSignedRationalValues(valueContext ValueContext) (value []S
if tt.valueIsEmbedded(valueContext.UnitCount) == true { if tt.valueIsEmbedded(valueContext.UnitCount) == true {
typeLogger.Debugf(nil, "Reading SRATIONAL value (embedded).") typeLogger.Debugf(nil, "Reading SRATIONAL value (embedded).")
byteLength := uint32(tt.Size()) * valueContext.UnitCount byteLength := uint32(tt.tagType.Size()) * valueContext.UnitCount
rawValue := valueContext.RawValueOffset[:byteLength] rawValue := valueContext.RawValueOffset[:byteLength]
value, err = tt.ParseSignedRationals(rawValue, valueContext.UnitCount) value, err = tt.ParseSignedRationals(rawValue, valueContext.UnitCount)
@ -632,7 +642,7 @@ func (tt TagType) Format(rawBytes []byte, justFirst bool) (value string, err err
// TODO(dustin): !! Add tests // TODO(dustin): !! Add tests
typeId := tt.Type() typeId := tt.Type()
typeSize := TagTypeSize(typeId) typeSize := typeId.Size()
if len(rawBytes)%typeSize != 0 { if len(rawBytes)%typeSize != 0 {
log.Panicf("byte-count (%d) does not align for [%s] type with a size of (%d) bytes", len(rawBytes), TypeNames[typeId], typeSize) log.Panicf("byte-count (%d) does not align for [%s] type with a size of (%d) bytes", len(rawBytes), TypeNames[typeId], typeSize)

21
type_encode.go
View File

@ -1,8 +1,8 @@
package exif package exif
import ( import (
"reflect"
"bytes" "bytes"
"reflect"
"encoding/binary" "encoding/binary"
@ -13,15 +13,13 @@ var (
typeEncodeLogger = log.NewLogger("exif.type_encode") typeEncodeLogger = log.NewLogger("exif.type_encode")
) )
// EncodedData encapsulates the compound output of an encoding operation. // EncodedData encapsulates the compound output of an encoding operation.
type EncodedData struct { type EncodedData struct {
Type uint16 Type TagTypePrimitive
Encoded []byte Encoded []byte
UnitCount uint32 UnitCount uint32
} }
type ValueEncoder struct { type ValueEncoder struct {
byteOrder binary.ByteOrder byteOrder binary.ByteOrder
} }
@ -32,7 +30,6 @@ func NewValueEncoder(byteOrder binary.ByteOrder) *ValueEncoder {
} }
} }
func (ve *ValueEncoder) encodeBytes(value []uint8) (ed EncodedData, err error) { func (ve *ValueEncoder) encodeBytes(value []uint8) (ed EncodedData, err error) {
ed.Type = TypeByte ed.Type = TypeByte
ed.Encoded = []byte(value) ed.Encoded = []byte(value)
@ -81,10 +78,10 @@ func (ve *ValueEncoder) encodeShorts(value []uint16) (ed EncodedData, err error)
}() }()
ed.UnitCount = uint32(len(value)) ed.UnitCount = uint32(len(value))
ed.Encoded = make([]byte, ed.UnitCount * 2) ed.Encoded = make([]byte, ed.UnitCount*2)
for i := uint32(0); i < ed.UnitCount; i++ { for i := uint32(0); i < ed.UnitCount; i++ {
// TODO(dustin): We have a ton of duplication in how we handle the byte-orders and the inherent risk of accidentally doing something inconsistently. Move this to reusable code. // TODO(dustin): We have a ton of duplication in how we handle the byte-orders and the inherent risk of accidentally doing something inconsistently. Move this to reusable code.
if ve.byteOrder == binary.BigEndian { if ve.byteOrder == binary.BigEndian {
binary.BigEndian.PutUint16(ed.Encoded[i*2:(i+1)*2], value[i]) binary.BigEndian.PutUint16(ed.Encoded[i*2:(i+1)*2], value[i])
} else { } else {
@ -105,7 +102,7 @@ func (ve *ValueEncoder) encodeLongs(value []uint32) (ed EncodedData, err error)
}() }()
ed.UnitCount = uint32(len(value)) ed.UnitCount = uint32(len(value))
ed.Encoded = make([]byte, ed.UnitCount * 4) ed.Encoded = make([]byte, ed.UnitCount*4)
for i := uint32(0); i < ed.UnitCount; i++ { for i := uint32(0); i < ed.UnitCount; i++ {
if ve.byteOrder == binary.BigEndian { if ve.byteOrder == binary.BigEndian {
@ -128,7 +125,7 @@ func (ve *ValueEncoder) encodeRationals(value []Rational) (ed EncodedData, err e
}() }()
ed.UnitCount = uint32(len(value)) ed.UnitCount = uint32(len(value))
ed.Encoded = make([]byte, ed.UnitCount * 8) ed.Encoded = make([]byte, ed.UnitCount*8)
for i := uint32(0); i < ed.UnitCount; i++ { for i := uint32(0); i < ed.UnitCount; i++ {
if ve.byteOrder == binary.BigEndian { if ve.byteOrder == binary.BigEndian {
@ -154,7 +151,7 @@ func (ve *ValueEncoder) encodeSignedLongs(value []int32) (ed EncodedData, err er
ed.UnitCount = uint32(len(value)) ed.UnitCount = uint32(len(value))
b := bytes.NewBuffer(make([]byte, 0, 8 * ed.UnitCount)) b := bytes.NewBuffer(make([]byte, 0, 8*ed.UnitCount))
for i := uint32(0); i < ed.UnitCount; i++ { for i := uint32(0); i < ed.UnitCount; i++ {
if ve.byteOrder == binary.BigEndian { if ve.byteOrder == binary.BigEndian {
@ -181,7 +178,7 @@ func (ve *ValueEncoder) encodeSignedRationals(value []SignedRational) (ed Encode
ed.UnitCount = uint32(len(value)) ed.UnitCount = uint32(len(value))
b := bytes.NewBuffer(make([]byte, 0, 8 * ed.UnitCount)) b := bytes.NewBuffer(make([]byte, 0, 8*ed.UnitCount))
for i := uint32(0); i < ed.UnitCount; i++ { for i := uint32(0); i < ed.UnitCount; i++ {
if ve.byteOrder == binary.BigEndian { if ve.byteOrder == binary.BigEndian {

8
utility.go
View File

@ -132,10 +132,10 @@ type ExifTag struct {
TagId uint16 `json:"id"` TagId uint16 `json:"id"`
TagName string `json:"name"` TagName string `json:"name"`
TagTypeId uint16 `json:"type_id"` TagTypeId TagTypePrimitive `json:"type_id"`
TagTypeName string `json:"type_name"` TagTypeName string `json:"type_name"`
Value interface{} `json:"value"` Value interface{} `json:"value"`
ValueBytes []byte `json:"value_bytes"` ValueBytes []byte `json:"value_bytes"`
ChildIfdPath string `json:"child_ifd_path"` ChildIfdPath string `json:"child_ifd_path"`
} }

19
value_context.go Normal file
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package exif
// ValueContext describes all of the parameters required to find and extract
// the actual tag value.
type ValueContext struct {
UnitCount uint32
ValueOffset uint32
RawValueOffset []byte
AddressableData []byte
}
func newValueContext(unitCount, valueOffset uint32, rawValueOffset, addressableData []byte) ValueContext {
return ValueContext{
UnitCount: unitCount,
ValueOffset: valueOffset,
RawValueOffset: rawValueOffset,
AddressableData: addressableData,
}
}