Preface

This document is part of the Campcaster project, Copyright © 2004 Media Development Loan Fund, under the GNU GPL.

Scope

This document describes the architecture of Campcaster.

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Architecture



UML diagrams in Poseidon 2 format are available in a Poseidon project file.

The Software architecture is discribed on a different page.

Scheduler

The scheduler is responsible to execute playlists.

Local storage

The local storage holds locally available audio clips

Media archive

The media archive is a centralized media archive holding audio clips and storing metadata.

Authentication

The authentication component provides basic authentication functionality.

Playlist editor

The Playlist editor component is the user interface tool to create playlists.

Feature – component mapping

This section contains a mapping from the features listed in section 3.3 the original Campcaster proposal to the components that fulfill these features.

Campcaster Feature List

For convenience the features listed in section 3.3 of the Campcaster proposal are quoted below, with their original section numbers.

3.3.1 Intuitive User Interface

Campcaster will feature an easily-localizable and intuitive user interface that draws on the applicants’ extensive previous project experience.

3.3.2 Storing Metadata

Most audio formats allow the storage of some information inside the media file itself. However, this feature was developed primarily to handle music tracks, storing information on artist, title, record, genre, track number and so on. It is impossible to store essential information like the language of an audio file – essential for spoken word productions, such as educational or news material.

Campcaster will use existing open standards, such as RSS feed standards in XML format, to store all information needed to describe a file sufficiently. Additionally, this metadata information will fully support the Unicode format, making the database of metadata available to all character sets and fully searchable.

3.3.3 Automation and Scheduling

Campcaster will provide a scheduler, allowing stations to fill parts of the radio schedule with automated broadcasts. Throughout automated broadcasting times, the station will still be able to deliver advertisement, generating income while minimizing the running costs. Longer times of daily broadcasts via automation also help the station to make its frequency known in the community.

3.3.4 Playlist Management

Small radio stations in the developing world mainly use playlists generated by audio player software such as MusicMatch, Windows MediaPlayer or WinAMP. Such simple playlists provide no more information than a list of file names, and are inaccessible for full text search. As mentioned above, Campcaster will use the potential of XML metadata in Unicode to manage and archive playlists.

3.3.5 Proof of Broadcast

Proof of broadcast is essential to establish serious business relationships with advertisers. Campcaster will provide accurate and detailed log files stating the precise time each item was broadcast over the system. In a radio-network context, the proof of broadcast tool developed by MDLF in conjunction with Radio 68H in Indonesia will be used to aggregate and analyze logs created by individual Campcaster installations.

3.3.6 Mixing Local Audio Sources

A producer running Campcaster in a studio will be able to mix audio files (e.g. reports, music, jingles), phone calls and the microphone into a live broadcast.

3.3.7 Mixing Local and Remote Sources

If connected to the Internet, and given enough available bandwidth, Campcaster will be able to play local files (stored on the system’s hard disk), remote files (stored anywhere on the Internet) or include audio streams from the Internet as part of the local transmission – all of which could also become part of a playlist.

3.3.8 Remote Control of Transmitter Locations

A radio reporter/producer will be able to remotely access all of Campcaster’s scheduling features over the Internet using a standard web browser. She will be able to upload audio programs as well as create playlists and schedule transmission.

Feature – component mapping

The following table associates features with components.
feature
component
3.3.1
Intuitive User Interface
Playlist editor
3.3.2
Storing Metadata
Media archive
3.3.3
Automation and Scheduling
Scheduler
3.3.4
Playlist Management
Scheduler, Playlist editor
3.3.5
Proof of Broadcast
Scheduler
3.3.6
Mixing Local Audio Sources

3.3.7
Mixing Local and Remote Sources
Local storage, Media archive, Scheduler, Playlist editor
3.3.8
Remote Control of Transmitter Locations
Scheduler, Playlist editor