Forward error protection of H.263-DG bit streams

The purpose of our work is to report a solution for the problem of the joint source-channel coding (JSCC) of the H.263-DG bit stream to be transmitted through error prone channels. Our investigations show that the H.263 syntactical elements have different error sensitivities. This result led us to classify them into several classes of different significance. A more robust scheme, named H.263-DG, was obtained by optimally grouping the H.263 classes. This resulted in a maximum PSNR gain of 5.5 dB at a 10^-3 bit error rate (BER). The solution presented in this paper further increases the error robustness by unequal protection of the classes of the H.263-DG coding scheme. A good reconstructed video quality is achieved at 64 kbps transmission rate using rate compatible punctured convolutional (RCPC) codes. By exploiting the different class sensitivities, we present an unequal error protection (UEP) scheme that outperforms the optimal equal error protection (EEP). The forward error correction adopted has resulted in PSNR improvements over 20 dB for bit error rates higher than 4×10^-3.