Digital subchannel


Digital television in the United States supports multiple digital subchannels if the 19.4 Megabits-per-second (Mbit/s) bitstream is divided. Full quality 1080i HDTV requires 18 Mbit/s; however, many stations compress this down to 11 Mbit/s. A 720p HDTV signal can be compressed to 8 Mbit/s, and a SD signal compressed to 6 Mbit/s without perceivable loss of quality. 4 Mbit/s or less yields acceptable results if the subject in the video moves very little (such as a slideshow automated weather channel).