No, for the most part that covers the p vs i discussion. If you read
avsforums most people say that it's hardly noticeable, except in fast action
sequences where the p will look better since there's more frames so it
reduces "tearing", i.e. the feeling the image is choppy; it basically looks
a bit smoother, but some folks don't even notice it at all.
But the 3/2 pulldown (really 2/3) only matters when you have movies involved
at that's the telecine process; it's b/c movies are filmed at 24fps and tv
(NTSC) is displayed at 30fps, and to get the two to sync, they have to
add/duplicate extra frames to the movie to match up.
I read about this recently b/c the new Blu-Ray player that I got, the
Samsung BD-P2550 actually has a mode where it can output the movie in the
normal 24fps as long as your tv accepts that, which all the av nuts say is
the best way to do it (eliminating all the 2:3 issues).
HTH!
BINO
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Brian Weeden
Sent: Wednesday, April 08, 2009 9:27 AM
To: [email protected]
Subject: Re: [H] HDTV Math
Digital OTA broadcasts will be the best signal in terms of compression, no
doubts about it. The only thing better is BluRay.
Part of this goes back to past discussions we've had on here about whether
1080i is better than 720p. The biggest reason for the difference you are
seeing is in the framerate. 720p is progressive scanned, which means that
they are scanning every line of video from top to bottom. 1080i is
interlaced, meaning they only scan every other line and alternate between
frames. This way you get appearance of a full image for only half the
bandwidth, and that shows up in your measurements. So 1080i does have more
lines of resolution, but 720p is sending more frames.
And for you videophiles, yes I know I greatly oversimplified the
progressive/interlaced, 3/2 pulldown and fps definitions for the sake of
argument.
---------------------------
Brian Weeden
Technical Consultant
Secure World Foundation <http://www.secureworldfoundation.org>
+1 (514) 466-2756 Canada
+1 (202) 683-8534 US
On Wed, Apr 8, 2009 at 12:16 PM, James Maki <[email protected]>wrote:
> Brian,
>
> I pay for HD and would like to think I get HD, but if comcast is only
> giving
> 2/3 of the bandwidth that is considered HD, I may look elsewhere. I have
> read that digital over the air broadcasts better than analog. I am about
> 30-40 miles from Seattle and Tacoma, where all the networks have broadcast
> towers, so am thinking of investigating an antenna. It is a shame that we
> have investing in a switch-over to HD only to not really be getting HD.
>
> I would rather have 100 quality stations than 600 crappy stations. But
that
> is just me. I am sure there are people who get cable just for the soap
> network or game network, but not me.
>
> Anyway, I was just looking for confirmation or correction on my math.
>
> Thanks,
>
> Jim
>
> > -----Original Message-----
> > From: Brian Weeden
>
> > If you looked at satellite HD broadcasts I would suspect you
> > would find even
> > worse bitrates among several of the HD stations.
> >
>
> > Brian Weeden
> > Technical Consultant
>
> > On Wed, Apr 8, 2009 at 1:35 AM, James Maki
>
> > > I discovered something this week and am trying to understand its
> > > ramifications. I noticed lots of pixelation and motion blur
> > > the last two weeks of Heroes.
>
> > > NBC is averaging about 4.8 GB per hour for a 1080i show. I
> > > thought is a bit low
>
> > > I am wondering
> > > if my math is correct). I am not sure how to factor in the
> > > fps figures, if at all.
> > >
> > > If you can add some insight, it would be appreciated.
> > >
> > > Thanks,
> > >
> > > Jim Maki
>
>
>
