AVS Forum banner
Status
Not open for further replies.
1 - 4 of 4 Posts

·
Registered
Joined
·
235 Posts
Discussion Starter · #1 ·
After reading about the mixed reviews concerning ABC's HD presentations, I believe that there are several factors that come in to play.


1. Most people do not have HD sets that can display native 720p.

instead there sets upconvert to 1080i which is bound to introduce some digital artifacts.


2. Possibly that your local ABS affiliate is broadcasting a sub channel while still sending a HD signal.

Because of this, you will have a degraded signal, do to over compression.

WBAL here in Baltimore,Md. Actually simulcasts a HD, standard as well as the weather radar. That's 3 channels, 52.2,52.3 and 52.4.

Many broadcaster feel that people can't tell the difference.


3.It just may be that ABC is not doing a good job with some of their HD broadcasts.


4. Or may be, just may be. 1080i is truly better than 720p, especially when it come to movies.
 

·
AVS Forum Special Member
Joined
·
11,139 Posts
Good points about all the variables involved at the broadcast end of HDTV, especially the 2-subchannel ABC station. I found all the variation in comments about the quality of CBS's weekend HDTV football game and ABC's 720p "Saving Private Ryan" intriguing.


Suspect a lot of the variation involves individual stations. But until everyone starts posting how many subchannels their station(s) broadcast, how other programs usually appear, etc., and what equipment they're using, it looks like the confusion can only increase as HDTV programming and viewers expands.


Perhaps a computer can sort things out. Suggested earlier that a more-advanced version of the forum's new polling feature (my 10/27 post) might analyze and store evaluations based on zip codes. Projecting such data on U.S. or state maps isn't that complex. I have a vintage DOS-based Systat statistics program with this feature. -- John
 

·
Registered
Joined
·
443 Posts
Quote:
Most people do not have HD sets that can display native 720p. Instead there sets upconvert to 1080i which is bound to introduce some digital artifacts.
Years ago, when ABC announced their preference for 720p, (we) affiliate engineers raised quite a ruckus at our annual meeting with the network during the NAB Convention. One of our major points was the fact that this format would be converted within the viewers set as most manufacturers display at 1080i and upconvert any other HDTV format. They wouldn't listen. As we feared, not all of the sets/receivers do a good job with the conversion.

Quote:
Possibly that your local ABS affiliate is broadcasting a sub channel while still sending a HD signal. Because of this, you will have a degraded signal, do to over compression. WBAL here in Baltimore,Md. Actually simulcasts a HD, standard as well as the weather radar. That's 3 channels, 52.2,52.3 and 52.4. Many broadcaster feel that people can't tell the difference.
Not all of the bandwidth is necessary for the HD program stream. Last night, WVEC ran our first successful test of our plant during ABC's airing of SPR. We also ran a SD channel for the radar. Even during the periods of SPR that demanded the most bandwidth, there were still some null packets. That is, part of the 19.38 Mb/s that was not used for either the HD stream, SD stream, PSIP or audio. Of course, when you start trying to shoe-horn another SD stream, that will probably start squeezing things a bit.
 

·
Registered
Joined
·
3,325 Posts
The picture quality of Saving Private Ryan was not as good as other movies on ABC.


But don't fault 720p. Most of ABC's presentations are very good - better than what HBO does.


If you can't tell the difference between 720p and a DVD on your TV, then you have a lousy TV or your box is doing a bad job of scaling. And there's no excuse for bad scaling because 720p is very easy to scale.

Stills from Saving Private Ryan, Mission Impossible, and Toy Story 2:


http://www-personal.engin.umich.edu/...iles/spr-1.jpg
http://www-personal.engin.umich.edu/...iles/spr-2.jpg
http://www-personal.engin.umich.edu/...files/mi-1.jpg
http://www-personal.engin.umich.edu/...files/mi-2.jpg
http://www-personal.engin.umich.edu/...iles/ts2-1.jpg
http://www-personal.engin.umich.edu/...iles/ts2-2.jpg
 
1 - 4 of 4 Posts
Status
Not open for further replies.
Top