Preserving PDF files with multimedia content

Question

I am curious what other insitutions are doing for PDF files with embedded video or audio content? We migrate almost all of our PDF's to PDF/A. The PDF/A stadard does not allow for embedded content like this.

We have discussed normalizing the file to ensure long term usability but not to PDF/A or extracting the embedded content and handling them seperately. But this takes them out of their original presentation.

Are there other options?

Thanks.

Answer 1

In addition to Euan's answer (above): it's important to know that although PDF allows you to embed multimedia content in a number of different formats, not all of these formats are natively supported by Acrobat Reader (or Acrobat Professional, for that matter). This means that, depending on the specific format that is used in your PDF, you may have a dependency on an external viewer. See this thread on the Adobe forum for more info (the thread dates back to 2011, but from what I understand the situation hasn't changed):

https://forums.adobe.com/message/3754143

Also see the PDF format spec (1.7 ISO version, link: http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf), which says (section 13.2.1):

PDF 1.5 introduces a comprehensive set of language constructs to enable the following capabilities:

• Arbitrary media types may be embedded in PDF files.
• Embedded media, as well as referenced media outside a PDF file, may be played with a variety of player software. (In some situations, the player software may be the conforming reader itself.)

So this basically means you could encounter any audio/video format in a PDF, and from a practical point of view this rather complicates maintaining access to the interaction software, mainly because you may be needing several different players (depending on the formats of the embedded files).

There's some further info on this that may be useful on Adobe's help page:

https://helpx.adobe.com/acrobat/using/playing-video-audio-multimedia-formats.html

Finally here's just one example:

http://www.opf-labs.org/format-corpus/pdfCabinetOfHorrors/embedded_video_quicktime.pdf

This PDF has an embedded Quicktime video. If I open it in Acrobat XI Pro and then click on the image, a dialog window pops up that tells me an external media player is needed to play the file.

Funnily enough, clicking on the Get Media Player button takes me to http://cgi.adobe.com/special/acrobat/mediaplayerfinder/mediaplayerfinder.cgi?, which tells me "Sorry, browsing is not allowed in this directory"! Also, in Edit/Preferences are some settings related to the rendering of multimedia content. You can select a preferred player from a drop-down list, but the number of items on that list is limited, and it doesn't include all media players on my PC. I can't really figure out how to tell Acrobat of any players that aren't in the pre-populated list, which in this particular case means I can't even get a simple Quicktime movie working! I think this is a bit worrying...

Answer 2

One option is to commit to maintaining access to a relevant version of an interaction software tool for as long as you need access to the content. In the case of the PDFs that might be Acrobat Reader. Taking that approach would mean that the formatting of the files shouldn't be a problem provided you can confirm that the files are intended to be interacted with using the software you are maintaining for that purpose. Any apparent interaction/rendering issues could then be assumed to be authentic to the original file.

Comments

As Johan points out. You may need to preserve an entire environment including other software dependencies. The basic approach should still work however.

Answer 3

This is in reponse to Sheila's suggestion to use PDF/A-3: keep in mind that the "embedding" in PDF/A-3 only allows you to store the file as a file attachment. It doesn't support any of the actions and annotations that you need for e.g. placing a multimedia object at any particular position in the document!

See also this blog I once wrote on "embedded" files in PDF:

http://openpreservation.org/blog/2013/01/09/what-do-we-mean-embedded-files-pdf/

That aside, I really don't know what existing migration tools do with files that contain multimedia content. They may be clever enough to migrate the embedded file streams to file attachments, but I wouldn't count on it without trying first.

Out of curiosity I opened the following PDF (which contains a Quicktime movie) with Acrobat XI:

http://www.opf-labs.org/format-corpus/pdfCabinetOfHorrors/embedded_video_quicktime.pdf

I then tried to save it as a PDF/A-3. This resulted in a PDF in which the Quicktime movie was simply removed! The output PDF had several other issues as well, and the conversion also resulted in a number of error messages.

Answer 4

Just following on to Euan and Johann - you could migrate to PDF/A-3, which does allow embedding of files in arbitrarily any format -- but this does not resolve the long-term preservation problems Johann mentions below -- for more details, see the NDSA Standards and Practices Working Group report on PDF/A-3 at http://www.digitalpreservation.gov/ndsa/working_groups/documents/NDSA_PDF_A3_report_final022014.pdf?loclr=blogsig

Comments

BTW -- I should have been more clear -- this is not a recommendation -- it is "doable," and meets the letter of the law in using an "A" version of PDF - but it does not solve the long-term preservation issue of ensuring the availability and usability of those embedded files -- again -- please see Euan's and Johann's comments