Hi there,
on my docker-based 4.0.1 setup, I have two very large PDF files that Mayan won't create a preview for. There is no bug in the events log. How can I debug the reason for this? These are private documents, but I'd share these files with the developers if it helps.
Broken preview of a PDF document
Re: Broken preview of a PDF document
Hello,
It could mean that the PDF is not correct or deviates from the standard PDF file format. PDFs are a family of formats and not all of them are open. Implementations vary and sometimes some software produce PDFs that are not valid or readable by other software => What does “Couldn't read xref table” mean? => https://tex.stackexchange.com/questions ... table-mean
It could also mean you've encountered an issue with the PDF previewer we use, pdftoppm => https://gitlab.com/mayan-edms/mayan-edms/-/issues/991
The version of pdftoppfm shipped with Mayan 4.0, seems to have a bug. This library is packaged by Debian, so there is not much we can do at the moment but wait to see if a new version is released and packaged. We are actively trying to find a way to ship our own package of pdftoppm, however attempts end up getting us into a dependency hell of conflicting librarires => https://en.wikipedia.org/wiki/Dependency_hell
This in an ongoing issue but sadly falls outside of our control.
It could mean that the PDF is not correct or deviates from the standard PDF file format. PDFs are a family of formats and not all of them are open. Implementations vary and sometimes some software produce PDFs that are not valid or readable by other software => What does “Couldn't read xref table” mean? => https://tex.stackexchange.com/questions ... table-mean
It could also mean you've encountered an issue with the PDF previewer we use, pdftoppm => https://gitlab.com/mayan-edms/mayan-edms/-/issues/991
The version of pdftoppfm shipped with Mayan 4.0, seems to have a bug. This library is packaged by Debian, so there is not much we can do at the moment but wait to see if a new version is released and packaged. We are actively trying to find a way to ship our own package of pdftoppm, however attempts end up getting us into a dependency hell of conflicting librarires => https://en.wikipedia.org/wiki/Dependency_hell
This in an ongoing issue but sadly falls outside of our control.
Re: Broken preview of a PDF document
I might implement a bash shell wrapper to work around the bug in pdftoppm. I created a script /usr/local/bin/pdftoppm.sh...
It uses the "convert" command from the Imagemagick package so that needs to be installed. Also, the path to the pdftoppm binary must be changed to "/usr/local/bin/pdftoppm.sh" as above.
Certainly not perfect and could be improved, but it does catch the odd PDF that triggers the XREF bug.
Code: Select all
#!/bin/bash
# shell wrapper script to process a pdf with Imagemagick's "convert" command
# if poppler-utils "pdftoppm" command cannot handle the PDF
/usr/bin/pdftoppm $*
if [ $? -eq 99 ]; then
fp="$(($6-1))"
lp="$(($8-1))"
/usr/bin/convert -quality 100 -density 150 -flatten $4[$fp-$lp] jpg:-
fi
Certainly not perfect and could be improved, but it does catch the odd PDF that triggers the XREF bug.
---
LeVon Smoker
LeVon Smoker
Re: Broken preview of a PDF document
You should recheck the PDF standard in this regard.hhz wrote: ↑Mon May 31, 2021 7:43 pm Hi there,
on my docker-based 4.0.1 setup, I have two very large PDF files that Mayan won't create a preview for. There is no bug in the events log. How can I debug the reason for this? These are private documents, but I'd share these files with the developers if it helps.