We present an end-to-end optimized video streaming system comprising of synergistic interaction between a robust source coding and packetization strategy and an efficient as well as responsive, TCP-friendly congestion control protocol (Linear Increase Multiplicative Decrease with History (LIMD/H)) to achieve this goal. The proposed source packetization scheme transforms a scalable/layered video bitstream so as to provide graceful resilience to network packet drops. The proposed congestion control mechanism provides low variation in transmission rate in steady state and at the same time is reactive and provably TCP friendly.
While the two constituent algorithms identified above are novel in their own right, a key aspect of this work is the integration of these algorithms in a simple yet effective framework for exchange of connection state that is used by the interface to maximize the expected delivered video quality at the receiver. This integrated framework allows our system to gracefully tolerate and quickly react to sudden changes in the available connection capacity due to the onset of congestion.
Contact: Rohit Puri
We present an application of Generalized Multiple Description Coding based on for video multicasting to
heterogeneous receivers over the Internet. Contemporary receiver driven video multicasting approaches suffer because of the lack of coordination between
receivers, which can potentially lead to destructive interference
in delivered quality at the receivers. In this work, observing the fundamental properties of a multicast session tree,
we propose an elegant application layer architecture that can be exploited to do extremely efficient video multicasting, the key
observation being that the existence of a receiver-capacity hierarchy is fundamental to any multicast tree. The technique used for
generalized MD coding facilitates fast transcoding and enables
``optimal'' matching of the transmitted bitstream to each level in the hierarchy as the stream descends through
the multicast tree. The proposed scheme upperbounds the performance of any receiver based or source based multicasting schemes with increasing
gains for increased degree of heterogeneity in the receivers.
Contact: Rohit Puri