[
https://issues.apache.org/jira/browse/TIKA-1678?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14627948#comment-14627948
]
Tim Allison commented on TIKA-1678:
-----------------------------------
Shouldn't have taken me this long, but, isn't that pseudo UTF-16? For example,
capital B shouldn't be {{\000B}}...shouldn't it be {{\0042}}. Or is there some
genuine alternate encoding?
> PDF metadata extraction fails to spot UTF-16 encoded title
> ----------------------------------------------------------
>
> Key: TIKA-1678
> URL: https://issues.apache.org/jira/browse/TIKA-1678
> Project: Tika
> Issue Type: Bug
> Components: metadata
> Affects Versions: 1.9
> Reporter: Andrew Jackson
> Priority: Minor
>
> When extracting metadata from PDFs, we see some odd behaviour for a minority
> of the documents. The PDF metadata can be encoded as UTF-18 octets, but is
> not always being decoded as such.
> A specific example is here:
> http://mqug.org.uk/downloads/201207/201207%20-%20TEC02%20-%20Introduction%20to%20Worklight.pdf
> Which contains this (literal file content):
> {noformat}
> 443 0 obj
> <</Type/Metadata
> /Subtype/XML/Length 1978>>stream
> <?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?>
> <?adobe-xap-filters esc="CRLF"?>
> <x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='XMP toolkit 2.9.1-13, framework
> 1.6'>
> <rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
> xmlns:iX='http://ns.adobe.com/iX/1.0/'>
> <rdf:Description rdf:about='ac9f232e-d341-11e1-0000-ba905bfc4694'
> xmlns:pdf='http://ns.adobe.com/pdf/1.3/'
> pdf:Producer='\376\377\000B\000u\000l\000l\000z\000i\000p\000
> \000P\000D\000F\000 \000P\000r\000i\000n\000t\000e\000r\000 \000/\000
> \000w\000w\000w\000.\000b\000u\000l\000l\000z\000i\000p\000.\000c\000o\000m\000
> \000/\000 \000F\000r\000e\000e\000w\000a\000r\000e\000
> \000E\000d\000i\000t\000i\000o\000n'/>
> <rdf:Description rdf:about='ac9f232e-d341-11e1-0000-ba905bfc4694'
> xmlns:xmp='http://ns.adobe.com/xap/1.0/'><xmp:ModifyDate>2012-07-18T15:38:01+01:00</xmp:ModifyDate>
> <xmp:CreateDate>2012-07-18T15:38:01+01:00</xmp:CreateDate>
> <xmp:CreatorTool>UnknownApplication</xmp:CreatorTool></rdf:Description>
> <rdf:Description rdf:about='ac9f232e-d341-11e1-0000-ba905bfc4694'
> xmlns:xapMM='http://ns.adobe.com/xap/1.0/mm/'
> xapMM:DocumentID='ac9f232e-d341-11e1-0000-ba905bfc4694'/>
> <rdf:Description rdf:about='ac9f232e-d341-11e1-0000-ba905bfc4694'
> xmlns:dc='http://purl.org/dc/elements/1.1/'
> dc:format='application/pdf'><dc:title><rdf:Alt><rdf:li
> xml:lang='x-default'>\376\377\000M\000i\000c\000r\000o\000s\000o\000f\000t\000
> \000P\000o\000w\000e\000r\000P\000o\000i\000n\000t\000 \000-\000
> \000I\000n\000t\000r\000o\000d\000u\000c\000t\000i\000o\000n\000
> \000t\000o\000 \000W\000o\000r\000k\000l\000i\000g\000h\000t\000
> \000\(\000S\000R\000D\000\)\000.\000p\000p\000t\000x</rdf:li></rdf:Alt></dc:title><dc:creator><rdf:Seq><rdf:li>\376\377\000T\000e\000t\000t\000i</rdf:li></rdf:Seq></dc:creator></rdf:Description>
> </rdf:RDF>
> </x:xmpmeta>
> <?xpacket end='w'?>
> endstream
> endobj
> 2 0 obj
> <</Producer(\376\377\000B\000u\000l\000l\000z\000i\000p\000
> \000P\000D\000F\000 \000P\000r\000i\000n\000t\000e\000r\000 \000/\000
> \000w\000w\000w\000.\000b\000u\000l\000l\000z\000i\000p\000.\000c\000o\000m\000
> \000/\000 \000F\000r\000e\000e\000w\000a\000r\000e\000
> \000E\000d\000i\000t\000i\000o\000n)
> /CreationDate(D:20120718153801+01'00')
> /ModDate(D:20120718153801+01'00')
> /Title(\376\377\000M\000i\000c\000r\000o\000s\000o\000f\000t\000
> \000P\000o\000w\000e\000r\000P\000o\000i\000n\000t\000 \000-\000
> \000I\000n\000t\000r\000o\000d\000u\000c\000t\000i\000o\000n\000
> \000t\000o\000 \000W\000o\000r\000k\000l\000i\000g\000h\000t\000
> \000\(\000S\000R\000D\000\)\000.\000p\000p\000t\000x)
> /Author(\376\377\000T\000e\000t\000t\000i)>>endobj
> {noformat}
> Presumably, embedding these UTF-16 octet sequences in the XMP RDF is an
> error, but the ones encoded in the actual PDF metadata fields should be
> extracted accurately.
> When extracted, we get:
> {noformat}
> ...
> dc:title: \376\377\000M\000i\000c\000r\000o\000s\000o\000f\000t\000
> \000P\000o\000w\000e\000r\000P\000o\000i\000n\000t\000 \000-\000
> \000I\000n\000t\000r\000o\000d\000u\000c\000t\000i\000o\000n\000
> \000t\000o\000 \000W\000o\000r\000k\000l\000i\000g\000h\000t\000
> \000\(\000S\000R\000D\000\)\000.\000p\000p\000t\000x
> title: \376\377\000M\000i\000c\000r\000o\000s\000o\000f\000t\000
> \000P\000o\000w\000e\000r\000P\000o\000i\000n\000t\000 \000-\000
> \000I\000n\000t\000r\000o\000d\000u\000c\000t\000i\000o\000n\000
> \000t\000o\000 \000W\000o\000r\000k\000l\000i\000g\000h\000t\000
> \000\(\000S\000R\000D\000\)\000.\000p\000p\000t\000x
> meta:author: \376\377\000T\000e\000t\000t\000i
> meta:author: Tetti
> ...
> {noformat}
> So, the author appears to be decoded correctly once, but the title is not. Is
> the XML dc:title being used to override the PDF title field? Or is one of the
> title fields being decoded incorrectly?
> (I accept that although this is a real PDF document from the web, it is also
> a malformed one, so maybe there is not much to be done here.)
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
