PDF Thumbnails Gone

Thank you for your question, and for the time you took to include the shortcode text and link to the example page.

I regret that Google has discontinued support of the thumbnail generator. You can find more information in these recent topics:

Thumbnails not displaying

mla_galery thumbnails are too small

I am marking this topic resolved, but I am working on a better replacement for the Google thumbnail generator. I will post an update here when I have progress to report.

Thanks for your interest in the plugin.

Ah. Thanks Google. ??

I appreciate the speedy response!
Thanks- Marc

I have run some experiments with an mla_viewer replacement that uses Imagemagick and Ghostscript to produce PDF thumbnails on the local server. It works, but performance is uneven. Small PDF documents are processed in a few seconds, but larger documents are impractical (as they were with the earlier Google implementation). One of my test documents is 32MB and requires 107 seconds (1.78 minutes) to process. It appears that the entire document is generated even though the thumbnail comes from page 1.

If you want to play with this experimental version, let me know. I will work on a version that generates the thumbnails ahead of time and supports some sort of “cover art” feature along the lines BuddyPress uses for audio and video files.

Hi David – That would be great. I’d love to try this method out.

I’ve been combing through the links you provided by got a bit lost on how to specifically implement my particular solution (mostly because I haven’t had a ton of time to work on this). All our files are under 5MB so hopefully it’s not too much of a performance issue. Do the thumbnails get cached at all, or are they generated on the fly each page load?

Thanks for your quick response. Since this is an experiment I do not want to upload it as a Development Version but I can send you a copy by e-mail. Give me your contact information at the Contact Us page at our web site:

Fair Trade Judaica/Contact Us

Important note: For this code to work you must install both Imagemagick and Ghostscript on your server. My first attempt did not have the proper Ghostscript, and Imagemagick crashed the server trying to find it!

In this version the images are generated on the fly, with no caching. I haven’t been able to think of an effective caching scheme, so I am pursuing a more flexible “cover art” approach that will work for all non-image types. The Imagemagick/Ghostscript combination only works for PDF files, and I want to include something for Microsoft Office files, etc.

I have an improved experimental version of the “Google File Viewer replacement” feature:

• The “Imagemagick thumbnail” implementation is faster and more reliable.
• You can now assign a “Featured Image” to any Media Library item, such as a PDF document. If you do, the image is used a thumbnail for the item instead of generating an “Imagemagick thumbnail” on the fly.

I am still working on some other aspects of this project:

• Detect missing Ghostscript support without crashing the server.
• Use Imagemagick to generate an PDF single-page image manually, saving it as a Media Library item that can become the “Featured Image” of the document without on-the-fly delays.
• Add some hooks to give more control over the various options.

The new “mla_viewer” feature has several parameters:

• mla_viewer – set this to “true” to activate the viewer.
• mla_viewer_extensions – set this to txt to prevent PDF processing when Ghostscript is not installed but Imagick is installed.
• mla_viewer_limit – set this to a value in MB to limit PDF processing to files smaller than the parameter value.
• mla_viewer_width – set this to a positive value to limit the width of the generated thumbnails.
• mla_viewer_height – set this to a positive value to limit the height of the generated thumbnails.
• mla_viewer_page – set this to 2 or higher to select that document page as the thumbnail. Default is the first/only document page.
• mla_viewer_resolution – set this something higher than the default (72) to increase the quality of the thumbnail image; try 200 or 300.
• mla_viewer_type – set this to “image/png” to return thumbnails in that format; default is “image/jpeg”.

If you set neither mla_viewer_width nor mla_viewer_height, the default process will return thumbnails with a width of 150px and a proportional height. If you set both, the image will be exactly the height and width you set, which may distort some images.

If you set mla_viewer_resolution to a high value the images will look great but take longer to process.

If you set mla_viewer_type to “image/png” the background will be transparent and image generation may be slightly faster. The default jpeg images will have a white background.

I have just uploaded a new MLA Development Version that includes a new “thumbnail substitution” replacement for the Google File Viewer. The “Thumbnail Substitution Support” section of the Settings/Media Library Assistant Documentation tab has all the details.

You can find step-by-step instructions for using the Development Version in this earlier topic:

MLA errors when using plugin

I will leave this topic unresolved until the new feature is released in the next MLA version. If you get a chance to try the Development Version, let me know if it meets your needs. Thanks for your interest in the plugin.

I have uploaded a new MLA Development Version dated 20150625 that includes a new “Thumbnail Generation” capability. The Media/Assistant “Thumbnail” Bulk Action lets you select one or more non-image items and generate new thumbnail image items you can use as the Featured Image for those items. That lets mla_viewer display the thumbnails without re-generating them each time the gallery is composed. You can find step-by-step instructions for using the Development Version in this earlier topic:

MLA errors when using plugin

I am very interested in feedback on this new feature. If you get a chance to try the Development Version please let me know how it works for you. Thanks for your interest in the plugin.