[geeks] 1080p TV broadcasts?

[nate at portents.com]

On Mon, 14 Jun 2010 14:47:44 -0400, Andrew Jones <andrew at jones.ec> wrote:
> With today's consumer televisions, 24 fps anything is a waste of time.

Most movies are still made at 24 fps.

> 1. We can all agree 3:2 pulldown kinda sucks.  It makes scenes with
panning
> jerky.  It's just best to avoid it.

Well sure, but you can't avoid it if you don't have a display that can do
3:3, 4:4, or 5:5 pulldown and you're watching a movie.

> 2. 3:2 reversal won't help you: only a few TVs support 5:5 pulldown.
Most 
> "120 Hz" units just do interpolation on 60 Hz inputs, not any real 120
Hz
> display modes.  No 5:5 pulldown means no decent 24 fps viewing.

Plasma screens typically do 3:3 (72Hz) and/or 4:4 (96Hz) pulldown, which
is one of the reasons movies look better on your average plasma screen vs.
average LCD.

And I agree, a 120Hz screen without 5:5 pulldown is quite the waste if you
watch films on it.

> Very little TV is shot on film anymore, so there's no intrinsic
advantage
> to 24p over 60i.  I'd much rather have 60 interlaced fields than jerky
> progressive-scan, particularly if the source material was 60 Hz.  (And
it
> usually is.)

I'm not sure anyone talked about intrinsic advantages to 24p or 60i/p...
all I was saying was that the only time anyone in the US will see a 1080p
broadcast over any network right now will be when they show a 1080p24
movie, and that 1080p24 movie will be transmitted inside a 1080i60 MPEG-2
bitstream with flags to reconstruct a 1080p24 signal when played back on
decoders that are designed well.

> ATSC supports all kinds of progressive-scan framerates other than 24. 
How 
> many of them actually get used ?

The kinds that ATSC supports depends on whether you're talking about the
pre-2008 or post-2008 ATSC ratified standard, like I said. Pre 2008:
1080p24, 1080p25, 1080p30 MPEG-2.  Post 2008: 1080p50, 1080p60 H.264/AVC
High Profile Level 4.2.  And since the installed base of H.264/AVC ATSC
decoders is close to zero, no networks in the US are currently broadcasting
anything above 1080p24 (which as far as I know is limited to when they
broadcast movies).

- Nate