collective.transcode.* or transcode.star for short, is a suite of modules that provide transcoding services to Plone sites.
Both the naming scheme and the basic design priciples were inspired by collective.blog.star. Namely:
- Be modular. Not everyone wants everything your software has to offer.
- Be flexible. Don't assume that people want to use your software in one way.
- Be simplistic. If there is a simple way of doing it, do it that way.
- Be Ploneish. Plone already has 90% of what we need built in. Use it.
It works out of the box with standard Plone Files, providing transcoding services to web friendly formats (mp4, ogv) when uploading video content. Additionally, a jpeg thumbnail is being extracted from the 5th second of the videos and a flowplayer viewlet pointing to the produced mp4 file will be displayed inside the IAboveContentBody viewlet manager when transcoding is complete.
Transcode.star can be easily configured through the Plone Control Panel to work with any custom AT content type, as long as there is a File field in the schema. In the Transcode Settings panel you can enter a new line in the supported portal types, following the format customPortalType:fileFieldName where customPortalType the name of your portal_type and fileFieldName the name of the file field that you need transcoding for.
Support for Dexterity content types is planned for the coming versions.
For the transcoding to work you need to start the transcodedaemon instance provided in the buildout.
If your transcoding needs are high, you can configure several transcode daemons in a load balanced setup. Transcode.star will select the daemon with the minimum transcoding queue length.
All communication between transcode.star and transcode.daemon is encrypted using symmetric encryption by the pycrypto module so that the transcode server(s) transcode videos sent by the Plone site only, preventing abuse by third parties. Also extra care has been taken to transcode videos in private state (typical senario for a Plone site, when users upload a file) by using the same secure channel.
Apart from what is assembled by the buildout, the following dependencies must be installed manually for the transcoding scripts to work:
- ffmpeg with x264 support
In Ubuntu 10.04 you can install the above using the following commands:
sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list \ http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list sudo apt-get --quiet update && sudo apt-get --yes --quiet \ --allow-unauthenticated install medibuntu-keyring sudo apt-get --quiet update sudo aptitude install build-essential libavcodec-unstripped-52 ffmpeg \ ffmpeg2theora
python2.6 bootstrap.py ./bin/buildout
Start the transcode daemon:
./bin/transcodedaemon start # or fg to start it in the foreground
Start the worker instance:
Add a new Plone site, go to the Install Products Form and install transcode.star A new control panel screen called "Transcode Settings" will be available. You can use it to configure the supported profiles, the supported mime_types and the portal_types and respective fields that you need transcoding for. If you have changed the secret key in your buildout make sure you enter the new key here as well.
Then simply add a new object (File by default) and upload a file with a mimetype in the supported mimetypes. If you are running transcodedaemon and zope in the foreground you will be able to see the transcoding process taking place. When the transcoding is complete, refresh your content type's view page and you should see a flowplayer instance above your content loaded with the mp4 version of your video.
For production deployments make sure you change the secret key in buildout.cfg and in the Transcode Settings Panel.
Also, when using in production make sure that the transcoded files are served directly by Apache instead of Twisted.