Merge pull request #361 from superseriousbusiness/media_refactorv0.2.0

Refactor media handler to allow async media resolution

1 files changed, 148 insertions, 0 deletions

diff --git a/vendor/github.com/dsoprea/go-exif/v3/undefined/exif_8828_oecf.go b/vendor/github.com/dsoprea/go-exif/v3/undefined/exif_8828_oecf.go
new file mode 100644
index 000000000..26f3675ab
--- /dev/null
+++ b/vendor/github.com/dsoprea/go-exif/v3/undefined/exif_8828_oecf.go
@@ -0,0 +1,148 @@
+package exifundefined
+
+import (
+	"bytes"
+	"fmt"
+
+	"encoding/binary"
+
+	"github.com/dsoprea/go-logging"
+
+	"github.com/dsoprea/go-exif/v3/common"
+)
+
+type Tag8828Oecf struct {
+	Columns     uint16
+	Rows        uint16
+	ColumnNames []string
+	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) Encode(value interface{}, byteOrder binary.ByteOrder) (encoded []byte, unitCount uint32, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	// TODO(dustin): Add test
+
+	oecf, ok := value.(Tag8828Oecf)
+	if ok == false {
+		log.Panicf("can only encode a Tag8828Oecf")
+	}
+
+	b := new(bytes.Buffer)
+
+	err = binary.Write(b, byteOrder, oecf.Columns)
+	log.PanicIf(err)
+
+	err = binary.Write(b, byteOrder, oecf.Rows)
+	log.PanicIf(err)
+
+	for _, name := range oecf.ColumnNames {
+		_, err := b.Write([]byte(name))
+		log.PanicIf(err)
+
+		_, err = b.Write([]byte{0})
+		log.PanicIf(err)
+	}
+
+	ve := exifcommon.NewValueEncoder(byteOrder)
+
+	ed, err := ve.Encode(oecf.Values)
+	log.PanicIf(err)
+
+	_, err = b.Write(ed.Encoded)
+	log.PanicIf(err)
+
+	return b.Bytes(), uint32(b.Len()), nil
+}
+
+func (Codec8828Oecf) Decode(valueContext *exifcommon.ValueContext) (value EncodeableValue, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	// TODO(dustin): Add test using known good data.
+
+	valueContext.SetUndefinedValueType(exifcommon.TypeByte)
+
+	valueBytes, err := valueContext.ReadBytes()
+	log.PanicIf(err)
+
+	oecf := Tag8828Oecf{}
+
+	oecf.Columns = valueContext.ByteOrder().Uint16(valueBytes[0:2])
+	oecf.Rows = valueContext.ByteOrder().Uint16(valueBytes[2:4])
+
+	columnNames := make([]string, oecf.Columns)
+
+	// startAt is where the current column name starts.
+	startAt := 4
+
+	// offset is our current position.
+	offset := startAt
+
+	currentColumnNumber := uint16(0)
+
+	for currentColumnNumber < oecf.Columns {
+		if valueBytes[offset] == 0 {
+			columnName := string(valueBytes[startAt:offset])
+			if len(columnName) == 0 {
+				log.Panicf("SFR column (%d) has zero length", currentColumnNumber)
+			}
+
+			columnNames[currentColumnNumber] = columnName
+			currentColumnNumber++
+
+			offset++
+			startAt = offset
+			continue
+		}
+
+		offset++
+	}
+
+	oecf.ColumnNames = columnNames
+
+	rawRationalBytes := valueBytes[offset:]
+
+	rationalSize := exifcommon.TypeSignedRational.Size()
+	if len(rawRationalBytes)%rationalSize > 0 {
+		log.Panicf("OECF signed-rationals not aligned: (%d) %% (%d) > 0", len(rawRationalBytes), rationalSize)
+	}
+
+	rationalCount := len(rawRationalBytes) / rationalSize
+
+	parser := new(exifcommon.Parser)
+
+	byteOrder := valueContext.ByteOrder()
+
+	items, err := parser.ParseSignedRationals(rawRationalBytes, uint32(rationalCount), byteOrder)
+	log.PanicIf(err)
+
+	oecf.Values = items
+
+	return oecf, nil
+}
+
+func init() {
+	registerDecoder(
+		exifcommon.IfdExifStandardIfdIdentity.UnindexedString(),
+		0x8828,
+		Codec8828Oecf{})
+}