Audio Visual Content
The Audio Visual Content Component (AVCC) supports the experimenter in the audiovisual content lifecycle, ranging from content acquisition, edition, adaption for different terminals, to distribution to consumer applications (players). The consumer applications or players are expected to be provided by the experimenter. However, there is a generic player available at the project software repository in Flex technology as a reference, which should not limit the experimenters to Adobe technologies as the service supports all major industry technologies.
The AVCC comprises the following modules:
Input ManagerManages the reception of all live content including audio, video and metadata from the live metadata acquisition management. Can receive as input video and audio in multiple formats, providing as output a decapsulated stream.
Device Adaptation ManagerAdapts the media content to different platforms without changing the audio or video codecs. The content is fragmented and encapsulated for different devices and platforms.
Multiquality ManagerPerforms transcoding for multiquality support, providing the same feed at different bitrates, but aligning the GoPs (groups of pictures) in such a way that the player is able to continuously adapt to network capabilities. Coordinates multiquality content generation.
Media DistributionIn charge of the actual content delivery, which includes the continuous generation of the manifest, final packaging of the content and transport protocols. Produces all multiplexes media output of the main distribution.
Timeshift ManagerContinuously records live streams for immediate playback on deferred. Allows the user to have DVR experiences such as rewind, pause or fast forward. The content is received from Device Adaptation Manager and it flows both to the AV repository and the Media Distribution Module.
VoD ManagerDelivers prerecorded video and audio streams to the Input Manager from a single set of source files. Can record a live stream to a file available for playing on-demand later, allowing segmentation into multiple files for chapter replay, or start and stop recording at predetermined points for partial archiving. The content is temporally stored in MP4 containers including video, audio and metadata.
Live Metadata Acquisition managementManages the reception of metadata and the timestamps from the Video analysis module or from the user. These metadata are sent to the Input Manager module to be synchronised with the video stream. This module’s input is an XML file defined by the user in a way that the file’s content influences the behaviour of the module.
MoreVideoAllows for multiple mobile users to simultaneously stream real-time audio and video from mobile phones over 3G/4G mobile networks or WLAN. The live streams are sent to a mixer running on a laptop, allowing a director to select and combine live streams with prerecorded content into a composite output stream, mimicking how a TV director produces a live TV show. The system is modelled after professional TV production, but is aimed at advanced amateur users, with high emphasis on simplicity and ease of use. The output stream from MoreVideo can be fed into the Input Manager, and MoreVideo can also receive streams from the Media Distribution component.
Combining these modules, a large number of different services can be supported. The nature of the selected service depends on the particular requirements of each experiment. Here are some examples: