ALEMBIK Media Transcoding Server

Alembik Media Transcoding Server is a Java application providing transcoding services for variety of clients. Sharing the name with a device for carrying out alchemical transmutations it reshapes and reformats media files according to needs and capabilities of any environment. Any Alembik client needs only to pass to the server the URL of a media file with a set of transcoding parameters (like desired dimensions, size, mime-type, etc.). The latters may even remain unspecified - Alembik will evaluate them automatically according to the User-Agent string passed by a client.

Alembik is developed as an open-source project, whose goal is to provide an OMA-STI fully-compliant media transcoding server based on J2EE technology. OMA-STI stands for Open Mobile Alliance's Standard Transcoding Interface, which precisely defines a contract between a client (requesting some media files to be transcoded) and a server (which carries out the transformation process according to the passed parameters set). Alembik is the first open-source attempt to meet that standard.

There are four communication channels at present that Alembik server exposes:

• SOAP service for all types of clients,
• JSP tag library for development in Java-based web containers,
• EJB facade for J2EE clients,
• HTTP service for web pages development in any environment.

The application architecture is composed in a modular fashion, where five main modules are: Java transcoding API, SOAP service implementation, EJB-based facade (including JMS-based asynchronous processing support), JSP tag library and core libraries. Further on the core part may be logically divided into several blocks:

• Pluggable media processors, each one serving a particular media type (image, audio or video),
• Storage providing media loading features and quick access cache for original and transcoded media files,
• WURFL library-based User-Agent resolver,
• Mime-type detector using media's file extension and actual content analysis (Mime-Util library),
• Pre-defined transcoding profiles repository,
• Synchronizer component securing concurrent access to resources.

Alembik may be deployed into any Java-based web/application server, although it has been so far tested and released for three platforms only: Glassfish, JBoss and Apache-Tomcat. Each release bundle contains a relevant archive file (EAR or WAR) as well as client JAR files (both SOAP- and EJB-based) and an example web application (WAR) showing the JSP transcoding tag library in action. Although still in the beta stage, Alembik has been already deployed in production for Spanish telecom operators (e.g. Telefonica and Vodafone).

The upcoming beta 2 release will introduce support for JBoss servers in cluster. Recently there has been also started an extensive development of the text transcoding module, which will result in a fully-featured HTML rendering engine. The first release featuring that module is scheduled to be out in May 2008.

Alembik server requires one of the following Java containers: Glassfish v2, JBoss 4.2.x.GA and Apache-Tomcat 5.5.2x. Additionally its functionality depends on the following third-party software:

• binary build of FFmpeg utility (for video and audio transcoding),
• binary build of ImageMagick utility (otherwise GAIA image transcoding module is used),
• distribution of Darwin Streaming Server (only if streaming support is required),
• MP4Box library (only if streaming support is required).

The application is distributed under the LGPL license.

Alembik can be downloaded from here.

Unpack the release bundle and copy the alembik archive (EAR or WAR) into your application server's deployment directory. Then enter Alembik administration console and adjust application settings.

For detailed information refer to the on-line documentation, whose content is periodically updated according to the development progress. You may also check Alembik mailing list archive and the project's main page for latest news.

Alembik is currently an open-joint-venture of two companies: Kimia from Spain and Open Reply from Italy. Nevertheless we are striving to build a strong development community around Alembik project. Hence we warmly welcome all developers (or companies), which are willing to lend a hand in its construction. Every contribution in any form will be highly appreciated.

Download it, try it and join us!