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=r... so "dc:description" is not permitted? it is mentioned in

https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http://pur...

(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 structure. https://github.com/veraPDF/veraPDF-library/issues/1224#issuecomment-10299329... (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#...

Hans

----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl ----------------------------------------------------------------- ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

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-- Karl Pettersson Uppsala, Sweden https://static-dust.klpn.se/

On Sat, Feb 05, 2022 at 12:37:44AM +0100, luigi scarso via ntg-context wrote:

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=r... so "dc:description" is not permitted? it is mentioned in

https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http://pur...

...

(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 structure.

https://github.com/veraPDF/veraPDF-library/issues/1224#issuecomment-10299329...

(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#...

I am missing something here... true dc:descriptionFOO 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

Attach metadata xml for the non-validating and validating example (extraced with `pdfinfo -meta | xmllint format -`) in the Github issue. Here is a reference to the description element. Note that only description seems to be redefined, not title. https://source.contextgarden.net/tex/context/base/mkiv/lpdf-pua.xml#l81

___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________

-- Karl Pettersson Uppsala, Sweden https://static-dust.klpn.se/

On Sat, Feb 05, 2022 at 09:59:44AM +0100, luigi scarso wrote:

it's not redefined -- it's dropped. And this is ok. You can also check with dc:descriptionFOO dc:title rdf:Alt TITLE and again it's valid. But https://www.iso.org/obp/ui/#iso:std:iso:19005:-1:ed-1:v2:cor:1:v1:en and https://www.iso.org/obp/ui/#iso:std:iso:19005:-1:ed-1:v2:cor:2:v1:en:tab:1 suggest that dc:description and dc:title are of the same type, which is coherent with XMPSpecificationPart1.pdf as in https://github.com/adobe/XMP-Toolkit-SDK/tree/main/docs

I.e. these are correct -- but Subject must agree with dc:description dc:description rdf:Alt dc:title rdf:Alt TITLE

At least, this is what I understand.

From what I understand, ConTeXt applies a custom Dublin Core schema containing just a redefinition of dc:description, which is not coherent with how dc:description is written by the application.

This patch to lpdf-pda.xml removes the validation error.

-- luigi

-- Karl Pettersson, Sweden Uppsala https://static-dust.klpn.se/

On Sat, Feb 5, 2022 at 1:28 PM Karl Pettersson wrote:

...

From what I understand, ConTeXt applies a custom Dublin Core schema containing just a redefinition of dc:description, which is not coherent with how dc:description is written by the application.

This patch to lpdf-pda.xml removes the validation error.

Sorry, diff the other way round according to diff original new.

indeed.. Ok, now I see. Need to check some things . -- luigi

On Sat, Feb 05, 2022 at 03:18:08PM +0100, luigi scarso wrote:

Following https://www.pdfa.org/wp-content/until2016_uploads/2011/08/pdfa_metadata-2b.p... I think we should replace pdfaProperty:valueTypeText with pdfaProperty:valueTypeLang Alt

-- luigi

Yes, if a custom schema is needed at all (from what I can see, the XML does not embed any type definition for dc:title, for example). -- Karl Pettersson Uppsala, Sweden https://static-dust.klpn.se/