2 research outputs found
Efficient mobile video transmission based on a joint coding scheme
In this paper, we propose a joint coding design which uses the Symbol Forward Error Correction (S-FEC) at the application layer. The purpose of this work is on one hand to minimize the Packet Loss Rate (PLR) and, on the other hand to maximize the visual quality of video transmitted over a wireless network (WN).The scheme proposed is founded on a FEC adaptable with the semantics of the H.264/AVC video encoding.This mechanism relies upon a rate distortion algorithm, controlling the channel code rates under the global rate constraints given by the WN.Based on a data partitioning (DP) tool, both packet type and packet length are taken into account by the proposed optimization mechanism which leads to unequal error protection (UEP). The performance of the proposed JSCC unequal error control is illustrated over wireless network by performing simulations under different channel conditions. The simulation results are then compared with an equal error protection (EEP) scheme
Application-Layer FEC Scheme Configuration Optimization via Hybrid Simulated Annealing
An optimization technique based on an adapted combination of simulated
annealing (SA) and tabu search (TS) is presented. This method aims at finding
near-optimal unequal error protection (UEP) application-layer FEC code
configurations. This approach is intended to smartly protect audio and video
transmission over IP networks when hard time restrictions apply. The considered
code is a UEP version of the widely-used Pro-MPEG COP3 codes enabling the use
of several matrices of dissimilar size and thus of unequal recovery capability.
Finding the optimal configuration frequently requires the evaluation of a large
solution space. So, to fulfill the imposed constraints, SA is adapted to the
specifics of the scenario. In particular, the annealing schedule is conditioned
by the real-time restrictions. Furthermore, solution neighborhood structures
are determined by a proposed definition of distance between protection
configurations, which, jointly with TS, conditions the selection of candidate
solutions. Experimental results show a significantly improved performance of
the optimization process, which invariably fulfills imposed timing constraints,
at the expense of a very low distortion increase, when compared to using
exhaustive search. These results allow the use of UEP Pro-MPEG COP3 codes for
protecting video and audio transmission, which distinctly outperforms the
standard code in a wide range of scenarios