Merge Frame Design for Video Stream Switching Using Piecewise Constant Functions
Abstract of Merge Frame Design for Video Stream
Merge Frame Design for Video Stream Switching Using Piecewise Constant Functions.
The ability to efficiently switch from one pre-encoded video stream to another (e.g., for bitrate adaptation or view switching) is important for many interactive streaming applications. Recently, stream-switching mechanisms based on distributed source coding (DSC) have been proposed.
However, the use of bit-plane coding and channel coding in many DSC approaches leads to complex coding and decoding. In this paper, we propose an alternative approach for merging multiple SI frames, using a piecewise constant (PWC) function as the merge operator.
In conventional non-interactive video streaming, a client plays back successive frames in a pre-encoded stream in a fixed order.In contrast, in interactive video streaming, a client can switch freely in real-time among a number of pre-encoded streams.
Examples include switching among multiple streams representing the same video encoded at different bit-rates for real-time bandwidth adaptation, or switching among views in a multi-view video.
See for more examples of interactive streaming. A major challenge in interactive video streaming is to achieve efficient real-time switching among pre-encoded video streams.
Conclusion
In this Merge Frame Design for Video Stream Switching Using Piecewise Constant Functions paper, we propose a new merging operator—piecewise constant (PWC) function—for merging different reconstructed versions of a target frame to a unique one—to enable stream switching while preserving coding efficiency. Specifically, in order to merge k -th transform coefficients of different side information (SI) frames to the same value, we encode appropriate step sizes and shift parameters of a floor function, so that all the SI coefficients fall on the same constant interval. We propose two methods to select floor function parameters for signal merging. In the first method, we selected parameters so that coefficients are merged identically to a pre-determined target value.
