Multiple description coding (MDC) is an approach to retrieve the loss of bursty packets in wireless networks and on the internet as well. It enables traffic dispersion when combined with multiple path transports (MPT) to reduce the network congestion. MDC provides suitable quality without any retransmission of loss packet (in case the rate of lost packets is not so high), which is the main reason that MDC is the most used technique. In all standards of video coding, MDC is the basic element. This method is particularly for the retransmission of the video applications where it was not possible or unaccepted to transmit again. In MDC the many independent descriptions are created so that it can contribute to the characteristics of the video e.g. frequency content or spatial resolution etc. The quality of the decoded video is directly proportional to the number of descriptions received.
Advantages over traditional single description coding (SDC):
a. The advantages of multiple description coding over traditional Single description coding is that at least one of paths is received.
b. The congestion factor, quality and bit rate is less as compared to SDC because of transformation into various parallel data streams of source symbols.
c. Also, the delay of packet and dropping from the stream of the packet also occur in SDC but not in MDC
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