An efficient key-frame-free prediction method for MGS of H.264/SVC

This paper proposes a Key-Frame-Free (KFF) prediction method for the medium-grain scalable (MGS) coding of H.264/SVC, in which the key pictures can be completely avoided to reduce the memory complexity and improve the coding efficiency. In our proposed method, the encoder employs a joint rate-distortion model to decide which quality layer is reconstructed and used for prediction of base quality macroblocks in the coarsest temporal layer, while the remaining macroblocks always predict and reconstruct from the highest quality layer. The proposed method requires no change to the H.264/SVC standard and experimental results show that compared with the MGS key-picture control method the proposed scheme significantly improves the scalable coding efficiency from 0.8 to 1.5dB at higher bit rates while maintains similar drift error as MGS with key pictures at lower bit rates. Our proposed method can also coexist with SVC-to-AVC rewrite function which is conflict with the key picture of MGS.