Abstract
Traditionally, the media consumption model
has been a passive and isolated activity. However, the
advent of media streaming technologies, interactive social
applications, and synchronous communications, as well as
the convergence between these three developments, point
to an evolution towards dynamic shared media experiences.
In this new model, geographically distributed groups of
consumers, independently of their location and the nature
of their end-devices, can be immersed in a common virtual
networked environment in which they can share multimedia
services, interact and collaborate in real-time within
the context of simultaneous media content consumption. In
most of these multimedia services and applications, apart
from the well-known intra and inter-stream synchronization
techniques that are important inside the consumers
playout devices, also the synchronization of the playout
processes between several distributed receivers, known as
multipoint, group or Inter-destination multimedia synchronization
(IDMS), becomes essential. Due to the
increasing popularity of social networking, this type of
multimedia synchronization has gained in popularity in
recent years. Although Social TV is perhaps the most
prominent use case in which IDMS is useful, in this paper
we present up to 19 use cases for IDMS, each one having
its own synchronization requirements. Different approaches
used in the (recent) past by researchers to achieve
IDMS are described and compared. As further proof of the
significance of IDMS nowadays, relevant organizations
(such as ETSI TISPAN and IETF AVTCORE Group)
efforts on IDMS standardization (in which authors have
been and are participating actively), defining architectures
and protocols, are summarized.
