**6. Conclusions**

In this chapter it is analyzed the transcoding framework for video communications between mobile devices. In addition, it is proposed a WZ to H.264/AVC transcoder designed to support mobile-to-mobile video communications. Since the transcoder device accumulates the highest complexity from both video coders, reducing the time spent in this process is an important goal. With this aim, in this chapter two approaches are proposed to speed-up WZ decoding and H.264/AVC encoding. The first stage is improved by using parallelization techniques as long as the second stage is accelerated by reusing information generated during the first stage. As a result, with both approaches a time reduction of up to 73% is achieved for the complete transcoding process with negligible RD losses. In addition, the presented transcoder performs a mapping for different GOP patterns and lengths between the two paradigms by using an adaptive algorithm, which takes into account the MVs gathered in the side information generation process.
