Extension:PdfHandler/en

The PdfHandler extension shows uploaded PDF files in a multipage preview layout.

Together with the Proofread Page extension, PDF files can be displayed side-by-side with text. This allows users to transcribe books and other documents.

Usage

 * A user can display PDF files as an image, showing a single page at a time, like so: . The page and size parameters are optional; the default page is page #1. Instead of a size-parameter, you can also use the thumb-parameter, with or without captions:.
 * Because PdfHandler extends ImageHandler, you can use all the arguments that you would for an Image -- for example: thumb, right/left, caption, border, link, etc.
 * If you would like to present a 2-page pdf, for example, do the following:


 * The main usage of the PdfHandler extension is without user interaction. If you upload a new pdf file, the metadata will be stored in the database, and then this file can be shown in a multipage preview layout like the djvu handler does. Without this extension, pdfs will not display properly when uploaded.
 * Additionally, this extension allows Extension:ProofreadPage to handle pdfs in side-by-side view for transcribing/proofreading, as is done on Wikisource

Pre-requisites
This extension requires the following packages to be installed first:

Type the following in your shell to see if you have the above installed first (it should list 4 rows):

If something is missing, install the related packages. Example in Debian and Ubuntu:

sudo apt install ghostscript imagemagick xpdf-utils

If you are unable to install these packages, kindly contact your server administrator for assistance in your environment.

Configuration
You can (or, depending on the operating system of the server, will have to) set some variables in the "LocalSettings.php" file:
 * (default = "gs")
 * path to your ghostscript implementation


 * (default = "convert")
 * path to your imagemagick convert


 * (default = "pdfinfo")
 * path to your pdfinfo


 * (default = "pdftotext")
 * path to your pdftotext


 * (default = "jpg")
 * preferred output format


 * (default = "150" )
 * resolution in dpi
 * The extension extracts a bitmap image for each page of the PDF, using this resolution (dpi = dots per inch). For example, a PDF page with the European size A4 is 210 mm wide, corresponding to 595 points (at 72 dpi). This yields an image 1240 pixels wide (at 150 dpi). If instead this parameter is set to 300 dpi, the width will be 2480 pixels.


 * (default = "95" / since MW 1.24+ )
 * Quality level, which the post processor should use.


 * Variables below are not specific to this extension
 * Enable PDF uploads, if you haven't already:
 * Enable ImageMagick, if you haven't already:
 *   - memory limit for gs, convert and pdfinfo. The default value might be too low.

Ubuntu
This is identical to the default settings for this extension.

Troubleshooting

 * General issues
 * If PDF files do not display after upload, make sure that MediaWiki can execute the pdfinfo command and that configuration parameter  is set properly. Also check your error log, and make sure that your host hasn't disabled running external commands.
 * If PDF files do not show properly after installation (for example saying 0 height and width) you may need to use the maintenance scripts "refreshImageMetadata.php -f" and "rebuildImages.php"
 * Example:
 * php refreshImageMetadata.php --mime application/pdf --force
 * Also try to purge the page of the file. See Manual:Purge.
 * If PDF files are rendered randomly check if the "C.UTF-8" locale is available on your server by running  and make sure that configuration parameter  is set to this locale.
 * If the main preview image of PDF files is broken (image not found by browser), but all other images are working, also check your configuration parameter . If it is set to a locale that does not use the point as a decimal separator (e.g. "de-de", which use a comma), the   for the   tags will be broken. MediaWiki strongly recommends to use the "C.UTF-8" locale.

If you are running this extension on a windows machine with PHP 7, please see Tommeyheyser's workaround description.
 * Special solutions for Windows Server running MW 1.31.x

If you are having pdfoinfo and/or pdftotext hanging issue that prevents a big PDF upload, please check the modified extension by SeongMoon