1. A method, implemented by a video coder including a processor, for motion analysis of a video signal, the method comprising steps of: receiving, by the video coder, the video signal, wherein the video signal comprises at a selected time at least one of the following input pictures: a current picture, one or more past pictures, and one or more future pictures; temporal down sampling, by the video coder, the video signal to generate one or more sampled input pictures at a temporal resolution; spatial down sampling, by the video coder, the input pictures at a selected spatial resolution, selecting, by the video coder, a number of reference pictures to generate one or more reference pictures for a sampled input picture, calculating, by the processor, motion parameters based on a number of the reference pictures or a combination of the one or more reference pictures and a selection of input pictures; determining, by the processor, if the calculated motion parameters have a desired motion accuracy; if the calculated motion parameters do not have the desired motion accuracy based on a prediction error threshold, repeating the temporal down sampling, the spatial down sampling, and the selecting steps by using a binary search algorithm to reselect the one or more reference pictures, reselecting the one or more reference pictures, calculating motion parameters, and determining if the calculated motion parameters have the desired motion accuracy, wherein the steps are repeated until a desired motion accuracy is reached; designating, by the processor, the calculated motion parameters with the desired motion accuracy as the final calculated motion parameters; predicting, by the processor, one or more selected sampled input pictures based on the final calculated motion parameters, wherein motion analysis comprises the predictions of the one or more selected sampled input pictures; and outputting, from the video coder, an output video signal of output pictures based on the predicting.