Macroblocking
This is a non-technical term, used when macroblocks are either missing and show up as video errors, or when bandwidth is not enough to encode fine detail. Square areas of the picture do not show the correct portion of the image. Instead they either show a single color block, or a low-resolution block with noticeable edges. This effect is also referred to as tiling, mosaicing, pixelating, quilting or checkerboarding. Advanced decoders hide these types of errors with a technique called error concealment. Consumer equipment often calls this technique 'MPEG Noise Reduction'.
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