This paper presents two types of techniques suitable for rate reduction transcoding for wireless video streaming applications. We begin this paper by reviewing existing approaches and addressing several issues related to transcoding. Next, we describe the first type of transcoding based on intra refresh architecture for spatial resolution reduction. Then, we present the second type of transcoding scheme based on rate-distortion (R-D) characteristics of the pre-encoded video. This R-D based approach can be applied to architecture simplification, rate control, frame dropping control, and channel adaptive transcoding. We conclude this paper by pointing out that transcoding is an integral part of wireless video streaming because it provide a flexible interface between the wired network and the wireless network.