1. A method of juxtaposing still and dynamic imagery to generate a cliplet, the method executed by a processor of a computing device, the method comprising: setting a first subset of a spatiotemporal volume of pixels in an input video as a static input segment; mapping the static input segment to a background of the cliplet, wherein the background is repeated across output frames of the cliplet; setting a second subset of the spatiotemporal volume of pixels in the input video as a dynamic input segment based on a selection of a spatial region within the input video, a start time within the input video, and an end time within the input video; refining the dynamic input segment, the refining further comprises at least one of: spatially refining the dynamic input segment based upon: a first region within the spatial region over a time interval from the start time to the end time, the first region being along a spatial boundary of the spatial region; and a second region within the static in input segment that abuts the spatial region; or temporally refining the dynamic input segment based upon: the spatial region in frames within a first temporal region of the dynamic input segment that includes the start time; and the spatial region in frames within a second temporal region of the dynamic input segment that includes the end time; mapping, based on a predefined temporal mapping function, the dynamic input segment as refined to an output segment of the cliplet defined within at least a portion of the output frames of the cliplet, wherein the predefined temporal mapping function is one of a play temporal mapping function, a loop temporal mapping function, or a mirror temporal mapping function; and compositing the output segment over the background for the output frames of the cliplet.