MultiChoice announced at the start of August that its SuperSport channels would be available on DStv in high definition (HD).
This caused some confusion, but SuperSport later clarified that it was referring to 1080i — resolutions of 1,920×1,080 using interlaced scan.
When companies refer to HD without qualifying it, they may be talking about several different standards of screens, picture resolutions, or broadcasting technologies: 720p, 1080i, or 1080p.
The numbers refer to the horizontal rows of pixels in an image — its pixel height.
For 720p, each frame of video then has 1,280 columns of pixels. In the 1080i and 1080p standards, there are 1,920 columns of pixels.
Resolution specifications such as 1,280×720 and 1,920×1080 therefore refer to the width and height—in pixels—of an image, video, or screen.
The “i” in 1080i refers to interlaced scan, which first draws the odd horizontal lines of an image on screen, followed by the even lines. This means that each frame has a resolution of 1,920×540, and two frames are required to make up a full 1,920×1,080 image.
In South African broadcasting, 50 frames are displayed every second — coinciding with the 50Hz frequency that our 220V alternating current (AC) power runs at. You can therefore get 25 full frames per second from a 1080i50 broadcast.
When streaming services such as Netflix and YouTube offer high definition, however, they are referring to the 1080p standard.
The “p” in 1080p refers to progressive scan.
Netflix’s HD is 1080p – which means each frame contains 1,920×1,080 pixels. This can give viewers a better experience, as 1080i may appear to flicker or blur during action scenes or sports.
Channel5 states that “many people do not notice the difference between 1080p and 1080i”, though.
“If you have a large HD TV, you may prefer 1080p, but the difference is often negligible,” it said.
No 1080p on DStv decoders
DStv is working on ultra high definition streaming for its DStv Now app, and conducted a successful streaming test of the last four matches of the FIFA World Cup, but it is unlikely to upgrade its 1080i broadcasts to 1080p.
This is because offering a channel in 1080p would take up roughly double the satellite capacity of a 1080i channel.
MultiChoice could therefore launch two 1080i channels for every one 1080p channel it might bring on air.
Connected Video will be headed up Niclas Ekdahl, and will run the Showmax and DStv Now services in South Africa. It will also be responsible for developing new over-the-top services for the MultiChoice group.