Release status: stable
|Description||Allows to handle PDF files like multipage DJVU|
|Author(s)||Martin Seidel (xarax)
<jodeldi at gmx dot de>
|License||GNU General Public License 2.0 or later|
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The PdfHandler extension shows uploaded pdf files in a multipage preview layout. With the Proofread Page extension enabled, pdfs can be displayed side-by-side with text for transcribing books and other documents, as is commonly done with DjVu files (particularly in Wikisource).
Pre-requisites[edit | edit source]
This extension requires the following packages to be installed first:
|ghostscript for gs||Renders the page images||http://www.ghostscript.com|
|imagemagick||dynamic resizing and thumbnailing of images||http://www.imagemagick.org/script/install-source.php for instructions on how to install|
|xpdf-utils for pdfinfo||Extract metadata from pdf. If you see "0 × 0 pixel" on the file description of a PDF, you lack this package.||http://www.foolabs.com/xpdf/download.html
On Ubuntu and Debian, the poppler-utils package can be used instead of xpdf-utils.
Type into a shell "which gs convert pdfinfo pdftotext" to see if you have the below installed first.
Installation[edit | edit source]
Note: The required software must be installed first.
- Download and place the file(s) in a directory called
- Add the following code at the bottom of your LocalSettings.php:
wfLoadExtension( 'PdfHandler' );
- Configure as required (see also the examples provided)
- Done - Navigate to Special:Version on your wiki to verify that the extension is successfully installed.
To users running MediaWiki 1.24 or earlier:
The instructions above describe the new way of installing extensions using
wfLoadExtension(), since MediaWiki 1.25. If you need to install this extension in earlier versions, instead of
wfLoadExtension( 'PdfHandler' );, you need to use:
Configuration[edit | edit source]
You can or depending on the operating system of the server will have to set some variables in the "LocalSettings.php" file:
$wgPdfProcessor(default = "gs")
- path to your ghostscript implementation
$wgPdfPostProcessor(default = "convert")
- path to your imagemagick convert
$wgPdfInfo(default = "pdfinfo")
- path to your pdfinfo
$wgPdfOutputExtension(default = "jpg")
- extension of the files to be rendered
$wgPdfHandlerDpi(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.
$wgPdfHandlerJpegQuality(default = "95" / since MW 1.24+ )
- Quality level, which the post processor should use.
$wgPdfCreateThumbnailsInJobQueue(default = "false")
- Puts creating pages' thumbnails into a job queue, so they do not have to be created while browsing a file page, but during normal wikibrowsing. Be advised that setting this to "true" may significantly increase CPU load of your webserver on a high-traffic website. Job queue was designed to perform quick tasks on page views, and creating thumbnails can be included into that queue, according to this definition. Nevertheless, as quick as it is, it also requires certain CPU load to convert PDF pages to another format. The solution to that would be either setting $wgJobRunRate to rather small value (ie. 0.05) or disabling job queue on the high-traffic wiki and setting up another server to do just job queue (like Wikimedia did).
- Variables below are not specific to this extension
- Enable PDF uploads, if you haven't already: $wgFileExtensions = 'pdf';
- Enable ImageMagick, if you haven't already: $wgUseImageMagick = true;
- $wgMaxShellMemory - memory limit for gs, convert and pdfinfo. The default value might be too low.
Ubuntu[edit | edit source]
Note: This is identical to the default settings for this extension.
$wgPdfProcessor = 'gs'; $wgPdfPostProcessor = $wgImageMagickConvertCommand; // if defined via ImageMagick // $wgPdfPostProcessor = 'convert'; // if not defined via ImageMagick $wgPdfInfo = 'pdfinfo'; $wgPdftoText = 'pdftotext';
Debian[edit | edit source]
$wgPdfProcessor = '/usr/bin/gs'; $wgPdfPostProcessor = $wgImageMagickConvertCommand; // if defined via ImageMagick // $wgPdfPostProcessor = '/usr/bin/convert'; // if not defined via ImageMagick $wgPdfInfo = '/usr/bin/pdfinfo'; $wgPdftoText = '/usr/bin/pdftotext';
Windows[edit | edit source]
$wgPdfProcessor = 'C:\Programme\gs\gs8.60\bin\gswin32.exe'; $wgPdfPostProcessor = $wgImageMagickConvertCommand; // if defined via ImageMagick // $wgPdfPostProcessor = 'C:\Programme\ImageMagick-6.6.2-Q16\convert.exe'; // if not defined via ImageMagick $wgPdfInfo = 'C:\Programme\xpdf-3.02pl1-win32\pdfinfo.exe'; $wgPdftoText = 'C:\Programme\xpdf-3.02pl1-win32\pdftotext.exe';
Usage[edit | edit source]
- 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
- Another option, introduced quite long ago (r25575), is to use it to display PDF files as an image, showing a single page at a time, like so: [[File:myPdfFile.pdf|page=1|600px]]. 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: [[File:myPdfFile.pdf|page=1|thumb|My PDF]].
- 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: [[File:myPdfFile.pdf|page=1]] [[File:myPdfFile.pdf|page=2]]
Debugging[edit | edit source]
- If PDFs don't display after upload, make sure that MediaWiki can execute the pdfinfo command and that
$wgPdfInfois set properly. Also check your error log, and make sure that your host hasn't disabled running external commands.
- If PDFs don't show properly after installation you may need to use the maintenance scripts
- If PDFs are rendered randomly check if a UTF-8 locale is available on your server by running
locale -aand make sure that
$wgShellLocaleis set to this locale.
See also[edit | edit source]
- http://wiki.4intra.net/PdfHandler - a fork with much faster thumbnail generation by using pdftocairo instead of ghostscript+imagemagick
- Extension:Proofread Page (may be used with PdfHandler)
- Manual:How to use DjVu with MediaWiki
|This extension is being used on one or more Wikimedia projects. This probably means that the extension is stable and works well enough to be used by such high-traffic websites. Look for this extension's name in Wikimedia's CommonSettings.php and InitialiseSettings.php configuration files to see where it's installed. A full list of the extensions installed on a particular wiki can be seen on the wiki's Special:Version page.|