Noisy Video
Because a large portion of MPEG’s compression power depends on its ability to locate
areas of the image that do not change between successive frames, “noisy” video can
reduce the efficiency of MPEG encoding. While the actual video may be identical between
two frames, if there are noise artifact differences between the two frames, they are
detected as a change in video and require more bits to encode. A lot of noise causes poor
encodes, because the encoding resources are tied up trying to faithfully reproduce the
noise.