1. A method of preprocessing video with a smoothing filter, the method comprising: identifying a first region of interest in a first frame of video using a source encoder; determining an importance value for the identified first region of interest using the source encoder; when the importance value for the identified first region of interest satisfies a predetermined criterion, applying an intra frame smoothing filter to pixels within the region of interest using the source encoder; wherein applying an intra frame smoothing filter to pixels within a specified region of interest, comprises: dividing the specified region of interest into pairs of pixel groupings, where the pixel groupings in each pair are the same size and are adjacent to each other; calculating the difference between the average luminance component value of the pixels within each pixel grouping in a pair of pixel groupings; when the calculated difference is less than a predetermined amount: calculating the average luminance component value for all pixels in the pair of pixel groupings; and assigning the calculated average luminance component value to all pixels within the pixel groupings that form the pair of pixel groupings.