func String(s []byte) []byte {
if s[0] == '<' {
r := hex.Decode(string(s[1 : len(s)-1]))
return r
}
if s[0] != '(' {
return s
}
r := make([]byte, len(s))
q := 0
for p := 1; p < len(s)-1; p++ {
if s[p] == '\\' {
p++
switch s[p] {
case 13:
if s[p+1] == 10 {
p++
}
q--
case 10:
q--
case 'n':
r[q] = 10
case 'r':
r[q] = 13
case 't':
r[q] = 9
case 'b':
r[q] = 8
case 'f':
r[q] = 12
case '0', '1', '2', '3', '4', '5', '6', '7':
a := s[p] - '0'
if s[p+1] >= '0' && s[p+1] <= '7' {
p++
a = (a << 3) + (s[p] - '0')
if s[p+1] >= '0' && s[p+1] <= '7' {
p++
a = (a << 3) + (s[p] - '0')
}
}
r[q] = a
default:
r[q] = s[p]
}
} else {
r[q] = s[p]
}
q++
}
return r[0:q]
}
// pd.DecodedStream() returns decoded contents of a stream.
func (pd *PdfReaderT) DecodedStream(reference []byte) (DictionaryT, []byte) {
dic, data := pd.Stream(reference)
if f, ok := dic["/Filter"]; ok {
filter := pd.ForcedArray(f)
var decos [][]byte
if d, ok := dic["/DecodeParams"]; ok {
decos = pd.ForcedArray(d)
} else {
decos = make([][]byte, len(filter))
}
for ff := range filter {
deco := pd.Dic(decos[ff])
switch string(filter[ff]) {
case "/FlateDecode":
data = fancy.ReadAndClose(zlib.NewInflater(fancy.SliceReader(data)))
case "/LZWDecode":
early := true
if deco != nil {
if s, ok := deco["/EarlyChange"]; ok {
early = pd.Num(s) == 1
}
}
data = lzw.Decode(data, early)
case "/ASCII85Decode":
ds := data
for len(ds) > 1 && ds[len(ds)-1] < 33 {
ds = ds[0 : len(ds)-1]
}
if len(ds) >= 2 && ds[len(ds)-1] == '>' && ds[len(ds)-2] == '~' {
ds = ds[0 : len(ds)-2]
}
data = fancy.ReadAll(ascii85.NewDecoder(fancy.SliceReader(ds)))
case "/ASCIIHexDecode":
data = hex.Decode(string(data))
default:
data = []byte{}
}
}
}
return dic, data
}