Description

Video streams, either in form of on-demand streaming or live streaming, usually have to be converted ( i.e., transcoded) based on the characteristics of clients’ devices ( e.g., spatial resolution, network bandwidth, and supported formats). Video stream clients have unique QoS demands. In particular, they need to receive video streams without any delay. Such delay may occur either during streaming, due to an incomplete transcoding task by its presentation time, or it may occur at the beginning of a video stream. Transcoding is a computationally expensive and time-consuming operation, therefore, streaming service providers currently store numerous transcoded versions of the same video to serve different types of client devices. However, the challenge in utilizing cloud services for video transcoding is how to deploy cloud resources in a cost-efficient manner without any major impact on the quality of video streams. The proposed system present the Cloud-based Video Streaming Service (CVSS) architecture to transcode video streams in an on-demand manner. The architecture provides a platform for streaming service providers to utilize cloud resources in a cost-efficient manner and with respect to the Quality of Service (QoS) demands of video streams. Thus, to minimize the cost of utilizing cloud resources, our system should adapt its service rate (i.e., transcoding rate) based on the clients’ demand rate and with respect to the video streams QoS requirements. Results demonstrate that the CVSS architecture can satisfy video streaming QoS demands and reduces the incurred cost of stream providers.