Example #1
0
// Parse decodes all Canon makernote data found in x and adds it to x.
func (_ *canon) Parse(x *exif.Exif) error {
	m, err := x.Get(exif.MakerNote)
	if err != nil {
		return nil
	}

	mk, err := x.Get(exif.Make)
	if err != nil {
		return nil
	}

	if val, err := mk.StringVal(); err != nil || val != "Canon" {
		return nil
	}

	// Canon notes are a single IFD directory with no header.
	// Reader offsets need to be w.r.t. the original tiff structure.
	buf := bytes.NewReader(append(make([]byte, m.ValOffset), m.Val...))
	buf.Seek(int64(m.ValOffset), 0)

	mkNotesDir, _, err := tiff.DecodeDir(buf, x.Tiff.Order)
	if err != nil {
		return err
	}
	x.LoadTags(mkNotesDir, makerNoteCanonFields, false)
	return nil
}
Example #2
0
func loadSubDir(x *Exif, ptr FieldName, fieldMap map[uint16]FieldName) error {
	r := bytes.NewReader(x.Raw)

	tag, err := x.Get(ptr)
	if err != nil {
		return nil
	}
	offset, err := tag.Int64(0)
	if err != nil {
		return nil
	}

	_, err = r.Seek(offset, 0)
	if err != nil {
		return fmt.Errorf("exif: seek to sub-IFD %s failed: %v", ptr, err)
	}
	subDir, _, err := tiff.DecodeDir(r, x.Tiff.Order)
	if err != nil {
		return fmt.Errorf("exif: sub-IFD %s decode failed: %v", ptr, err)
	}
	x.LoadTags(subDir, fieldMap, false)
	return nil
}