Samsung UN46ES7500F E-Manual page 464

resolution to 1080i or 720p.
The picture is distorted: macro block error, small
block, dots, pixelization
The compression of video contents may
cause picture distortion especially in fast
moving pictures such as sports and action
movies.
A weak or bad quality signal can cause picture
distortion. This is not a TV issue.
Mobile phones used close to the TV (within
3.3 ft) may cause noise in the picture on
analog and digital channels.