23   Platforms for video transmission and production

Streaming platform built by CESNET in previous years reached a production status at the end of 2002. Consequently, in the year 2003 we focused on making its use more effective and widespread.

23.1   International cooperation

In 2003 we joined the Netcast Taskforce (TF-Netcast) activity within the TERENA Technical Programme framework. TF-Netcast, being the successor of TF-STREAM, focuses on gathering information about the status of media-streaming applications in the national research networks, coordinating activities in this area and developing tools for an effective use of streaming media in the high-speed networking environment.

23.1.1   Development

We concentrated our development effort primarily on extending the functionality of the Announcement portal at http://live.academic.tv/ by implementing support for multiple languages and automated access.

The multilingual support enables access for the pan-European academic community. While the portal is now configured to announce events in all supported languages, a multilingual documentation and an active interface still to be added. To this end, we modified portal to allow for adding a new language just by sending a text file with translated sentences. At the same time we asked representatives of the NRENs participating in TF-Netcast to provide these translations. Thanks to their active cooperation we now have our portal in nine different languages.

An automated access was mandated by the requirement of interoperability with announcements issued by other networks, irrespective of whether they are public or not. As we want our portal to play an integrating role functionality, we must be able to accept data from others. Internal data structures of announcement portal are based on the XML language and so it was quite natural to use XML for automated access as well. The access module is realised as an application gateway based on the SOAP protocol - data format is identical to the data format for user access. Each remote system is authenticated in local user database and authorised for operating only upon own data (i.e., those submitted earlier by itself).

23.1.2   Live transmissions

One of the goals of TF-Netcast is to provide an infrastructure for live transmissions from significant conferences with a pan-European impact. During the year 2003, TF-Netcast set up two ad-hoc Content Delivery Networks. These networks distributed live transmissions from RIPE 45 and RIPE 46 meetings. We participated in both networks and have been the only node distributing that contents over IPv6.

23.2   Metadata Indexing

With continuously growing volumes and quality of digital multimedia (not only in the research and development area) the need for an effective organisation of the material and flexible search capabilities becomes more pressing. Instead of a direct similarity-based search in the stored material (sound sample or picture), one can search the metadata that describe the stored material. We were not able to find any public Internet search engine capable of metadata searching.

Because metadata are typically represented as text, we adopted a common full-text search engine (Jyxo) for this purpose. While aiming primarily at searching the Czech part of the Internet, we tried to make the system architecture scalable and portable. Input data (URLs pointing to multimedia data) are obtained from the crawler, which is a part of the full-text search engine. Our distiller component then extracts metadata from files pointed to by those URLs and sends them back to the search engine (the format of metadata is XML). Finally, the search engine processes these XML files and stores them into its full-text database. The presentation part relies on standard WWW interfaces.

[Figure]

Figure 23.1: Structure of the multimedia indexing

All communication between components is asynchronous and independent of particular user requests. The system is ready for parallelisation, which can be useful for indexing large amount of data. Because of the open data format and open interfaces, it is possible to integrate our component into any other search engine.

The system we developed is able to search the majority of multimedia files that are publicly available in Czech Internet (about 23 thousand files by now). As a side-effect of this activity, we also solved the issue of full-text search in the CESNET video archive, volume of which is also steadily growing.

23.3   Streaming Platform

The base for all our activities is the streaming platform we built in the previous years. The system supports the following formats: Real Video, Windows Media, QuickTime (up to version 4) and MPEG-4 (3GPP profiles only).

An important part of our activities is the support we provide to the scientific and research community in the area of media streaming.

23.3.1   IPv6

The only new component is the streaming system for IPv6. This server shares data files with the other components so that we are able to send the same data using various transports and, if necessary, add new storage and networking capacities without endangering data integrity.

On the basis of our previous evaluations we selected Windows Media 9 (based on Windows 2003 Server) as the only usable platform for IPv6 streaming. This server has been connected over both IPv4 and IPv6 to the CESNET2 network. It is thus possible to redistribute the streams between both environments (we used this feature during live streaming from the RIPE 46 meeting and Megaconference V).

23.3.2   Live transmissions

During 2003 we continued the methodological and technical support of live transmissions from professional conferences. We supported more than 20 events, the most important being:

[Figure]

Figure 23.2: Recording from the workshop New Ways in Development of High-speed Networks and their Applications

From the viewpoint of networking technologies, the most important event was the live transmission of Megaconference V, a worldwide videoconference organised by Ohio State University with support from Internet2. Our streaming server has been the only server outside Internet2 infrastructure and the only one streaming video over the IPv6 protocol.

We continued our support for lecture recording at the Masaryk University and Czech Technical University. In addition, we started a new cooperation with the audiovisual centre of the Student union of Czech Technical University, which produces a lot of high-quality content (mainly in the area of natural sciences and IT).

23.3.3   Video archive

The CESNET video archive contains around 200 hours of video material and 800 individual contributions.

So far, a considerable manual effort has been necessary for maintaining the presentation side of the video archive. We thus migrated the archive system to a database platform with the aim of eliminating most of the manual work. The migration happened successfully at the end of 2003.

23.4   Announcement portal

Along with the development of the announcement portal we have been taking care about its routine operation throughout the year. In 2003 we registered more than 200 announcements through this portal.

In addition to announcing events organised by CESNET, the portal was also used for announcing live transmissions from a number of lectures on diverse topics or academic events.

Approximately half of the active users are from the international research community (mostly from the TF-Netcast group). These users have been announcing 20-30 % of live transmissions.

23.5   Portal streaming.cesnet.cz

Due to the active dissemination of project results, we had to cope with an increasing demand for methodical support of multimedia services. In order to make such a cooperation more effective and also to present our know-how in a summarised form, we decided to start a new portal streaming.cesnet.cz.

[Figure]

Figure 23.3: Server streaming.cesnet.cz

The portal integrates our experience and recommendations in the area of multimedia streaming with our publications and a video archive. The portal contents are supposed to evolve in the future in order to reflect the state of the art.

23.6   Conclusions

During 2003 we successfully continued the development of the CESNET media streaming platform and actually delivered more than was planned. An important decision was to concentrate our capacities on the cooperation within TF-Netcast, instead of developing a distributed transcoding system.

Our contacts with other national research networks in Europe and in USA also became more intensive in 2003.

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