SCALABLE VIDEO CODING ACROSS HETEROGENEOUS NETWORKS

Scalable Video Coding (SVC) is a standardized extension to the widely accepted H.264/MPEG-4 Advanced Video Coding (AVC) standard. SVC provides scalability at a bit stream level and allows multiple formats of a single video source to be encoded in a single video stream. This facilitate the delivery of video content to a diverse set of end users with a variety of receive device capabilities, over transmission paths of varying bandwidth. Scalability serves different needs of a variety of users with dissimilar receive devices connected through diverse network links. DoD video services currently broadcast across a variety of network types to a diverse group of Warfighters. Without SVC, each end user with different receive capabilities will require additional encoded and disseminated source video streams. Decoding the original encoded video stream and re-encoding for disadvantaged end users is possible, but video quality will degrade during each decode/encode instance. Also, since source broadcast facilities must tailor each transmitted stream for specific transport networks or end user groups, networks that cannot afford to transmit multiple versions of the same video may simply continue to not reach disadvantaged end users. The SVC stream includes an A VC back-wards-compatible base layer and one or more enhancement layer(s). The base layer, which can also be decoded by an AVC decoder, corresponds to a minimum quality, frame rate, and resolution while the enhancement layer represents the same video at gradually increased quality, resolution and/or frame rate. With SVC encoding, a single disseminated stream can provide high quality/resolution video to end users with the capability to receive it, and lower quality/resolution video to disadvantaged end users. Encoding multiple video configurations into a single stream also minimizes resources needed at the video archival sites, and storage of a SVC encoded video ensures that within a single stream, multiple formats of the source video are available for future redissemination. DISA is currently working with industry partners to develop SVC capable network resources (i.e. encoder, decoder, network extractor). As DISA expands its video content service offerings, SVC should be implemented to maximize the limited transport layer bandwidth and optimally disseminate content from all sources to various end users across multiple domain platforms. This paper will discuss the operational potential of implementing SVC within the DISN network architecture, the benefits as seen by the Warfighters, and current industry development of SVC resources.