Abstract : New activities have been recently launched in order to challenge the H.264/AVC standard. Several improvements of this standard are already known, however the targeted 50% bitrate saving for equivalent quality is not yet achieved. Abstract In this context, a previous work proposes to use data hiding techniques to reduce the signaling information resulting from an improvement of Inter-coding. The main idea is to hide the indices into appropriately selected chroma and luma transform coefficients. To minimize the prediction errors, the modification is performed via a rate-distortion optimization. Abstract In this paper, the scheme is extended for Intra-coding and 4:4:4 sequences in order to explore the limits highlighted by the previous study and tackle some remaining issues. A different rate-distortion optimization built on the Pareto theory is also proposed. Resulting improvements (1.5% in average) for several sequences are reported and analyzed.