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.

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

To enable a media type, add the the media type under the [plugins] section in you mediagoblin.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. If you have deployed MediaGoblin as an unprivileged user as described in “Further Considerations for Production Deployments”, you’ll first need to switch to this account:

sudo su mediagoblin --shell=/bin/bash
$ cd /srv/mediagoblin.example.org/mediagoblin

Now run dbupdate:

$ ./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.

Audio

To enable audio, install the GStreamer and python-gstreamer bindings (as well as whatever GStreamer plugins you want, good/bad/ugly):

# Debian
sudo apt install python3-gst-1.0 gstreamer1.0-plugins-{base,bad,good,ugly} \
gstreamer1.0-libav python3-numpy

# Fedora
sudo dnf install gstreamer1-plugins-{base,bad-free,good,ugly-free} \
python3-numpy

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

$ ./bin/gmg dbupdate

Restart MediaGoblin (and Celery if applicable). You should now be able to upload and listen to audio files!

On production deployments, you will need to increase Nginx’s client_max_body_size to allow larger files to be uploaded, or you’ll get a “413 Request Entity Too Large” error. See “Nginx as a reverse-proxy”.

Production deployments will also need a separate process to transcode media in the background. See “Run MediaGoblin as a system service” and “Background Media Processing” sections of this manual.

Video

To enable video, first install GStreamer and the python-gstreamer bindings (as well as whatever GStreamer extensions you want, good/bad/ugly):

# Debian
sudo apt install python3-gi gstreamer1.0-tools gir1.2-gstreamer-1.0 \
gir1.2-gst-plugins-base-1.0 gstreamer1.0-plugins-{base,bad,good,ugly} \
gstreamer1.0-libav python3-gst-1.0

# Fedora
sudo dnf install gstreamer1-plugins-{base,bad-free,good,ugly-free,openh264} \
python3-gobject python3-gstreamer1

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

Run:

$ ./bin/gmg dbupdate

Restart MediaGoblin (and Celery if applicable). Now you should be able to submit videos, and MediaGoblin should transcode them.

On production deployments, you will need to increase Nginx’s client_max_body_size to allow larger files to be uploaded, or you’ll get a “413 Request Entity Too Large” error. See “Nginx as a reverse-proxy”.

Production deployments will also need a separate process to transcode media in the background. To set that up, check out the “Deploying MediaGoblin” and “Further Considerations for Production Deployments” sections of this manual.

Configuring video

available_resolutions

The list of resolutions that the video should be transcoded to, in the order of transcoding. Choose among 144p, 240p, 360p, 480p, 720p and 1080p. The default is 480p,360p,720p.

default_resolution

This is the initial resolution used by the video player. The default is 480p. For example:

[[mediagoblin.media_types.video]]
available_resolutions = 144p,240p
default_resolution = 144p

Raw image

MediaGoblin can extract and display the JPEG preview from RAW images.

To enable raw image you need to install the Python library py3exiv2. This library is not currently available for Debian 11 but can be installed from the Python Package Index after installing the build dependencies:

# Debian 11
sudo apt install libexiv2-dev libboost-python-devn
./bin/pip install py3pyexiv2

# Debian 12
sudo apt install python3-pyexiv2

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

Run:

./bin/gmg dbupdate

Restart MediaGoblin (and Celery if applicable). You should now be able to submit raw images.

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 your mediagoblin.ini. In the [plugins] section, add [[mediagoblin.media_types.ascii]].

Run:

$ ./bin/gmg dbupdate

Restart MediaGoblin (and Celery if applicable). 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 recent 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.ini and restart MediaGoblin.

Run:

$ ./bin/gmg dbupdate

Restart MediaGoblin (and Celery if applicable). 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 dnf install 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 update --init
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.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 blog posts are themselves media types!).

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