Error concealment in the network abstraction layer for medium grain scalability of SVC

This paper presents an error concealment method for medium grain scalability (MGS) of the scalable extension of H.264/AVC. Instead of reconstructing a lost frame using a typically compute-intensive error concealment method, in this method, a light-weight decoder preprocessor generates a valid bit stream from the available network abstraction layer (NAL) units in case that MGS layers are used. NAL unit header and slice header are parsed to detect the loss of a NAL unit from MGS layers. Modifications are applied to NAL unit header or slice header if some NAL units of MGS layers are lost. Hence, the number of additional packets that a decoder has to discard as a result of a packet loss is minimized. The proposed method requires low computational cost which is suitable for real-time video streaming. The experimental results demonstrate that the proposed method achieves an improvement of 2.16 dB compared to the NAL unit removal method at 5% packet loss rate. The proposed method can work complementary with other error concealment schemes for a whole-frame loss or serve as a preprocessor to a standard decoder.