Efficient video transcoding technique for QoS-based home gateway service

The home gateway integrates heterogeneous home network environments and interconnects the home network and the public access networks. It is natural that users want to see the visual contents on the home network from outside the home. However, there exist significant differences in network capability and computing power of users. Video transcoding technique is an efficient mechanism to deliver visual contents to a variety of users who have different network conditions or terminal devices with different display capabilities. In this paper, we propose an efficient video transcoding technique as the key component of the home gateway architecture. It consists of two types of transcoding methods for adapting the bitrate of streaming video to the bandwidth of the transmission channel; spatial resolution reduction transcoding and temporal resolution reduction transcoding. The two transcoding methods are alternatively or simultaneously operated according to the requirements of users. Experimental results show that the proposed transcoding methods can preserve image quality while transcoding to the low bitrate.