Prioritized packetization for video with intra-refresh macroblock line

When transmitting video over low bandwidth networks a cyclic intra-refresh (IR) line is preferable to periodic intra frames as an error mitigation technique. This paper shows that IR lines introduce non-uniform error sensitivity among regions within a picture that are identifiable by the position of the IR line. To exploit this characteristic, a packet prioritization scheme is proposed in which priorities are assigned on a packet-level basis. Thus, higher priority packets can be given better protection. The proposed scheme is demonstrated for prioritized access to a congested IEEE 802.11e network. Experimental results indicate that, when compared with the classic non-prioritized packet access scheme, the proposed scheme can achieve quality gains of up to 3.6 dB for a 10% data loss rate.