Consideration of scalable transcoding method in video content delivery methods for quality selection

Now, we often use video contents stream over the networks, however, we select the quality of video data according to their environments of access terminals, such as, network speed, CPU, graphic accelerator, size of local memory and hard disk and so on. Then, in video sites, multi-quality video contents are prepared for any user requirement, but from the point of view of data size, it makes not only the hardware cost of memory high, but also amount of video data over the network huge, so it is not efficiency. Moreover, from the video data structure, data compression is not enough in database. Then, we pay attention to scalability transcoding structure comparing with simulcast coding for multi-quality video. At this time, it is important that data transmission time and transcoding time are trade-off. In this paper, we use video access model with guaranteed bandwidth considering by data transmission and browsing. Moreover, we propose the video contents delivery methods with scalable transcoding, when users use multi-quality video, and evaluate transcoding time in video access model. By evaluation experiments, these situations of users' access are made clear. At this time, we indicated the case when proposed methods are more useful than simulcast type for multi-quality video. From the view point of transcoding time, influence of users' access time is clear in this model, comparing proposed methods with simulcast type by simulation experiments.