Kook-yeol Yoo

Local statistics adaptive entropy coding method for the improvement of H.26L VLC coding

In this paper, we propose an adaptive entropy coding method to improve the VLC coding efficiency of H.26L TML-1 codec. First of all, we will show that the VLC coding presented in TML-1 does not satisfy the sibling property of entropy coding. Then, we will modify the coding method into the local statistics adaptive one to satisfy the property. The proposed method based on the local symbol statistics dynamically changes the mapping relationship between symbol and bit pattern in the VLC table according to sibling property. Note that the codewords in the VLC table of TML-1 codec is not changed. Since this changed mapping relationship also derived in the decoder side by using the decoded symbols, the proposed VLC coding method does not require any overhead information. The simulation results show that the proposed method gives about 30% and 37% reduction in average bit rate for MB type and CBP information, respectively.

Region and time based unequal error protection for video transmission over mobile links

A new standard-compatible combined source channel coding approach to unequal error protection method based on regional and temporal sensitivity to error propagation is presented utilizing RCPC coding. This scheme can be adapted to time-varying mobile channel characteristics. The same RCPC coding scheme as that in MUX layer of H.32/spl times/ is used so as not to add additional complexity in system level and some error concealment techniques are used to further mitigate the image degradation. It is shown that the proposed scheme achieved 0.3/spl sim/1 dB improvement in PSNR with the same bit rate compared with fixed rate convolutional coding scheme.