Validate PDF/A files

[benjamingeer]

This is the only PDF/A validation library I found that looks serious and well-maintained:

https://verapdf.org/home/

[benjamingeer]

@mrivoal @loicjaouen @gfoo Lukas says we're not going to do this. You have to validate your own PDFs before putting them into Sipi. You could use https://verapdf.org/home/ for that.

[mrivoal]

I guess we could do that by ourselves now. But at some point (and I guess sooner than later), when a user can upload a PDF to Sipi using Salsah or KUIRL, his PDF should be validated somehow, isn't it?

So, the idea is that Sipi only hosts validated PDF/A?

[benjamingeer]

If I understood correctly, @lrosenth said each project is responsible for ensuring that its data is valid before upload/import. Perhaps a GUI could handle validation before submitting the file to Sipi.

[lrosenth]

Hi to all from Corsica... Validating a PDF/A is a complex process. I could imagine that I could use the ghostscript-library to di it, but it will be a lot of work. Acrobat allows to validate PDFs before upload. So I suggest for the moment its up to the user. Later - as i mentioned - we can add some validation... Lukas Von meinem iPhone gesendet Am 05.07.2019 um 09:58 schrieb Benjamin Geer <notifications@github.com<mailto:notifications@github.com>>: If I understood correctly, @lrosenth<https://github.com/lrosenth> said each project is responsible for ensuring that its data is valid before upload/import. Perhaps a GUI could handle validation before submitting the file to Sipi. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#285>, or mute the thread<https://github.com/notifications/unsubscribe-auth/ABJX3TCH3G77PDK5WUQESLDP535JHANCNFSM4G3265GA>.

[subotic]

I think that Sipi needs to do this. In the context of long-term preservation, this is a must-have. But as @lrosenth said, it will take a bit longer to actually implement.

[mrivoal]

Ok, fine. We will do our own PDF validation for now.

But at some point, Sipi should definitely check during the upload every file format we are going to accept.

[mrivoal]

@lrosenth : a question regarding the PDF formats we are willing to store and preserve though Sipi.

• Are we only going accept PDF/A or will we also accept other well formed and validated versions of PDF? I am asking because other archives (such as the CINES, in France) accept other versions of PDF, provided the file are validated against the declared format.

• If we only accept PDF/A , what is the prefered version of PDF/A we should accept? The CINES seems to prefer PDF/A 1a for archiving, but what do you think?

(As we are going to convert some 1200 PDF files for Lumières.Lausanne, let's choose the right version/format!)

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Here are the comments from the CINES on PDF/A versions:

Format	Commentaire
PDFA 1a	Basé sur PDF 1.4 mais plus restrictive : pas de dépendances externes, polices embarquées, pas de transparence, métadonnées XMP obligatoires. C'est le format d'archivage à privilégier bien que difficile à générer.
PDF 1.4	Basé sur PDF 1.4 - moins exigeant que 1a, structure logique du document non obligatoire. Bon format d'archivage si PDFA-1a trop compliqué à générer.
PDFA 2a	Basé sur PDF 1.7 - fichier PDF/A embarquable, structure logique obligatoire.
PDFA 2u	PDF adapté à l'accessibilité.
PDFA 2b	Basé sur PDF 1.7, identique à PDF/A-2b sans structure logique obligatoire.
PDFA 3a	Basé sur PDF 1.7 - fichier de n'importe quel format embarquable, structure logique obligatoire. Format axé sur l'accessibilité