Originally Posted by
DEmberton:
“This is my problem with NowTV. It's all juddery. My "less powerful" device is an LG TV that handles 4K Netflix absolutely fine.
TVs smooth it out anyway, which means most are not going to notice. Unfortunately LG in their infinite wisdom have disabled TruMotion in 720p.
The normal broadcast is 1080i50*; if Sky would give us that on NowTV then it'd be fine, but they might have to spend some money increasing the bandwidth. Clearly they have a vested interest in not making NowTV too good...
*i50 is in 50 fields. Nobody seems to be able to make up their minds about whether it's i50 or i25. But there are 50 time points in a second.”
It's Juddery because the Now TV stream is removing half the (interlaced) frames!
As far as your TV is concerned, it's outputting it as 25p because NowTV is saying "OK TV i'm giving you a 25p stream".
And it depends on the TV and your set top box. They wouldn't smooth it out (unless you as the user have specifically told it to - I don't know what options your TV has or where you're getting your stream from), beacuse as far as they're concerned, they're getting a 25p stream and they should play it as such.
You can refer to interlaced content with the number of fields per second (50) or the number of frames per second (25). Obviously as interlaced is 2 fields per frame, i25 infers i50.
The reason why the stream is in progressive and never interlaced, is because unless you have a CRT Television (which naturally de-interlaces all content correctly) or monitor, whatever is outputting that footage to your screen, (be that web browser, Set top box, whatever) has to de-interlace that footage itself, and to do that acceptably, that's a difficult task to do, especially with users who's PCs will probably be crap.
That's why the stream is given to users in progressive format. Plus your OS would always (nowadays and even in the 90s when we had CRT monitors) be outputting a progressive image anyway in general. So the only way to restore motion correctly is for Sky (or whoever serves NowTV to create a 50p stream from that i25 source - which for them takes time & resources - and then give us that 50p stream - and because its progressive, we don't need to do any de-interlacing our end.