H.264 video coding for low bit rate error prone channels: an application to Tetra systems

This work investigates a H.264 coding scheme for video transmission over links characterized by heavy packet losses and low available bitrate. The H.264 resilient coding tools such Flexible Macroblock Ordering, Redundant Slices and Arbitrary Slice Ordering are here tuned in order to adapt the application layer coding parameters to the physical layers characteristics. Due to the limited bandwidth, the tools are differentiated on a Region Of Interest. Moreover, the Redundant Slices tool is integrated by suitable application level interleaving to counteract the bursty nature of the errors. The performances of the coding scheme choices are assessed on a TETRA communication channel, that is quite challenging due to both limited bandwidth and severe error conditions. However, the illustrated codec design criteria can be adopted in different low bit-rate, error prone channels.