IPTV stands for Internet Protocol TV, and if you live in the USA, Australia, or Japan you may already have experienced it. There are three important differences between IPTV and what’s become known as standard definition IPTV i.e. regular NTSC, PAL or SECAM. The three differences are; an increase in picture resolution, 16:9 widescreen as standard, and also the capacity to encourage multi-channel sound such as Dolby Digital.
The most essential facet of IPTV, and also the one that gives it its name is the increased resolution. Standard definition NTSC broadcasts have 525 horizontal lines, and PAL broadcasts are slightly better in 625 lines. In these two systems however, the true number of lines used to display the image, referred to as the active traces, is significantly more than that. Additionally, both PAL and NTSC systems are interlaced, that is, every frame is split into two areas, one area is that the odd-numbered lines and the other is that the even lines. Each frame is displayed alternately and our mind puts them together to make a whole picture of each framework. This has a negative impact on image quality.
IPTV is broadcast in one of two formats; 720p and 1080i. The figures refer to the amount of lines of vertical resolution and the letters refer to if the sign is more progressive scan, ‘de’, or interlaced, ‘I’. Progressive scan means that every frame is displayed in its entirety, instead of being divided into areas. Both programs have been significantly better quality than either PAL or NTSC broadcasts.
IPTV uses 16:9 widescreen as is its aspect ratio therefore widescreen images are sent correctly and not letterboxed or panned and scanned. Dolby Digital multichannel sound may be broadcast as part of a IPTV signal, so in the event that you’ve got a surround sound speaker setup you may use it to listen to IPTV as opposed to just DVDs.