Media Types

In the future, there will be all sorts of media types you can enable, but in the meanwhile there are six additional media types: video, audio, raw image, ascii art, STL/3d models, PDF and Document.

First, you should probably read “Configuring MediaGoblin” to make sure you know how to modify the mediagoblin config file.

Enabling Media Types

Note

Media types are now plugins

Media types are enabled in your mediagoblin configuration file, typically it is created by copying mediagoblin.ini to mediagoblin_local.ini and then applying your changes to mediagoblin_local.ini. If you don’t already have a mediagoblin_local.ini, create one in the way described.

Most media types have additional dependencies that you will have to install. You will find descriptions on how to satisfy the requirements of each media type on this page.

To enable a media type, add the the media type under the [plugins] section in you mediagoblin_local.ini. For example, if your system supported image and video media types, then it would look like this:

[plugins]
[[mediagoblin.media_types.image]]
[[mediagoblin.media_types.video]]

Note that after enabling new media types, you must run dbupdate like so:

./bin/gmg dbupdate

If you are running an active site, depending on your server configuration, you may need to stop it first (and it’s certainly a good idea to restart it after the update).

How does MediaGoblin decide which media type to use for a file?

MediaGoblin has two methods for finding the right media type for an uploaded file. One is based on the file extension of the uploaded file; every media type maintains a list of supported file extensions. The second is based on a sniffing handler, where every media type may inspect the uploaded file and tell if it will accept it.

The file-extension-based approach is used before the sniffing-based approach, if the file-extension-based approach finds a match, the sniffing-based approach will be skipped as it uses far more processing power.

Configuring Media Types

Each media type has a config_spec.ini file with configurable options and comments explaining their intended side effect. For instance the video media type configuration can be found in mediagoblin/media_types/video/config_spec.ini.

Video

To enable video, first install gstreamer and the python-gstreamer bindings (as well as whatever gstremaer extensions you want, good/bad/ugly). On Debianoid systems

sudo apt-get install python-gi python3-gi \
    gstreamer1.0-tools \
    gir1.2-gstreamer-1.0 \
    gir1.2-gst-plugins-base-1.0 \
    gstreamer1.0-plugins-good \
    gstreamer1.0-plugins-ugly \
    gstreamer1.0-plugins-bad \
    gstreamer1.0-libav \
    python-gst-1.0

Add [[mediagoblin.media_types.video]] under the [plugins] section in your mediagoblin_local.ini and restart MediaGoblin.

Run

./bin/gmg dbupdate

Now you should be able to submit videos, and mediagoblin should transcode them.

Note

You almost certainly want to separate Celery from the normal paste process or your users will probably find that their connections time out as the video transcodes. To set that up, check out the “Considerations for Production Deployments” section of this manual.

Audio

To enable audio, install the gstreamer and python-gstreamer bindings (as well as whatever gstreamer plugins you want, good/bad/ugly), scipy and numpy are also needed for the audio spectrograms. To install these on Debianoid systems, run:

sudo apt-get install python-gst-1.0 gstreamer1.0-plugins-{base,bad,good,ugly} \
gstreamer1.0-libav python-numpy python-scipy libsndfile1-dev libasound2-dev

Note

scikits.audiolab will display a warning every time it’s imported if you do not compile it with alsa support. Alsa support is not necessary for the GNU MediaGoblin application.

Then install scikits.audiolab for the spectrograms:

./bin/pip install scikits.audiolab

Add [[mediagoblin.media_types.audio]] under the [plugins] section in your mediagoblin_local.ini and restart MediaGoblin.

Run

./bin/gmg dbupdate

You should now be able to upload and listen to audio files!

Raw image

To enable raw image you need to install pyexiv2. On Debianoid systems

sudo apt-get install python-pyexiv2

Add [[mediagoblin.media_types.raw_image]] under the [plugins] section in your mediagoblin_local.ini and restart MediaGoblin.

Run

./bin/gmg dbupdate

Now you should be able to submit raw images, and mediagoblin should extract the JPEG preview from them.

Ascii art

To enable ascii art support, first install the chardet library, which is necessary for creating thumbnails of ascii art

./bin/easy_install chardet

Next, modify (and possibly copy over from mediagoblin.ini) your mediagoblin_local.ini. In the [plugins] section, add [[mediagoblin.media_types.ascii]].

Run

./bin/gmg dbupdate

Now any .txt file you uploaded will be processed as ascii art!

STL / 3d model support

To enable the “STL” 3d model support plugin, first make sure you have a recentish Blender installed and available on your execution path. This feature has been tested with Blender 2.63. It may work on some earlier versions, but that is not guaranteed (and is surely not to work prior to Blender 2.5X).

Add [[mediagoblin.media_types.stl]] under the [plugins] section in your mediagoblin_local.ini and restart MediaGoblin.

Run

./bin/gmg dbupdate

You should now be able to upload .obj and .stl files and MediaGoblin will be able to present them to your wide audience of admirers!

PDF and Document

To enable the “PDF and Document” support plugin, you need:

1. pdftocairo and pdfinfo for pdf only support.

2. unoconv with headless support to support converting libreoffice supported documents as well, such as doc/ppt/xls/odf/odg/odp and more. For the full list see mediagoblin/media_types/pdf/processing.py, unoconv_supported.

All executables must be on your execution path.

To install this on Fedora:

sudo yum install -y poppler-utils unoconv libreoffice-headless

Note: You can leave out unoconv and libreoffice-headless if you want only pdf support. This will result in a much smaller list of dependencies.

pdf.js relies on git submodules, so be sure you have fetched them:

git submodule init
git submodule update

This feature has been tested on Fedora with:

poppler-utils-0.20.2-9.fc18.x86_64 unoconv-0.5-2.fc18.noarch libreoffice-headless-3.6.5.2-8.fc18.x86_64

It may work on some earlier versions, but that is not guaranteed.

Add [[mediagoblin.media_types.pdf]] under the [plugins] section in your mediagoblin_local.ini and restart MediaGoblin.

Run

./bin/gmg dbupdate

Blog (HIGHLY EXPERIMENTAL)

MediaGoblin has a blog media type, which you might notice by looking through the docs! However, it is highly experimental. We have not security reviewed this, and it acts in a way that is not like normal blogs (the blogposts are themselves media types!).

So you can play with this, but it is not necessarily recommended yet for production use! :)