Re: XMP metadata schema yields invalid PDF/A - luigi scarso via ntg-context

From: luigi scarso via ntg-context <ntg-context@ntg.nl>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Cc: luigi scarso <luigi.scarso@gmail.com>
Subject: Re: XMP metadata schema yields invalid PDF/A
Date: Sat, 5 Feb 2022 00:37:44 +0100	[thread overview]
Message-ID: <CAG5iGsBY04sQj=sJoopH5F1ru=Qr-xK5OgzvFNkuhab1D+TU9w@mail.gmail.com> (raw)
In-Reply-To: <Yf2klQY+WSfK62y2@karl-ThinkPad-P50>

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On Fri, Feb 4, 2022 at 11:11 PM Karl Pettersson via ntg-context <
ntg-context@ntg.nl> wrote:

> On Fri, Feb 04, 2022 at 10:25:27PM +0100, Hans Hagen via ntg-context wrote:
> > On 2/4/2022 7:29 PM, Karl Pettersson via ntg-context wrote:
> > > Hi
> > >
> > > PDF/A files generated using ConTeXt fail validation with veraPDF, and
> > > the reason seems to be that the dc:description metadata is defined with
> > > the wrong type in the embedded XMP extension schema.
> > >
> > >
> https://tex.stackexchange.com/questions/632380/generate-pdf-a-with-context
> > >
> > > https://github.com/veraPDF/veraPDF-library/issues/1224
> > >
> > > I can reproduce the problem using TeX Live 2021 (MkIV 2021.03.05). The
> > > definition seems to be controlled by this code.
> > >
> > >
> https://source.contextgarden.net/tex/context/base/mkiv/lpdf-pua.xml?search=rdf#l81
> > so "dc:description" is not permitted? it is mentioned in
> >
> >
> https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http://purl.org/dc/elements/1.1/description
> >
> > (btw it never failed before)
>
> The description element is permitted, but the problem seems to be that
> its valueType is defined as Text in the embedded schema, while the
> metadata element in the PDF has an embedded <rdf:Alt><rdf:li
> xml:lang="x-default"> structure.
>
>
> https://github.com/veraPDF/veraPDF-library/issues/1224#issuecomment-1029932963
>
> (I suppose the reference to "title" in the issue comment should be
> "description".)
>
> Validating with veraPDF <1.20 does not raise the error. The validation
> seems to have changed for redefined types in that version.
>
>
> https://github.com/veraPDF/veraPDF-library/blob/integration/RELEASENOTES.md#validation

I am missing something here... true
<dc:description>FOO</dc:description>
makes a valid pdf 3a with verapdf 1.20.1.
But dc:description is like dc:title, so where we are redefining
dc:description as Text ?

-- 
luigi

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