AVS Forum banner
Status
Not open for further replies.
1 - 12 of 12 Posts

·
Premium Member
Joined
·
258 Posts
Discussion Starter · #1 ·
I live in New York and get FOX DTV on channel 44-1.


Sometimes, the picture quality is just amazing, and sometimes it looks worse than FOX over RCN cable (channel 5).


Sometimes, the picture seems wider than regular 4x3, but not as wide as 16x9.


I am trying to understand how and why FOX picture quality varies so much. I am aware that FOX does not broadcast DTV in 1080i or 720p, hence it is not TRUE HD, but 480p done right looks awesome. I remember stumbling across Jerry Maguie a few weeks ago on FOX (same night that Max Bickford premiered on CBS) and thought it was great, I've come across baseball games that look AWESOME too, so 480p can be a huge improvement (at least to my eyes).


Is there a rhyme or reason for this variation? Why would some baseball games be crisp and clear and others be murky and soft?


Can anyone make sense of these questions? CBS makes perfect sense to me--when it's in HD it's in HD 'nuff said...but FOX totally confuses me.
 

·
Registered
Joined
·
907 Posts
You could probably get a lot of info by searching this forum, but the general reason is this:

The local FOX affiliate is using a terrible convertor locally to take its NTSC programming and convert it to a 480p 14x9 stretched image. So the image is both soft and distorted. Sometimes the local affiliate gets an actual 480p (usually 16x9) image from the network. When that happens (like Titus, Dark Angel, some movies, etc.) the image quality is much better as they are bypassing the local converter. Although people on this forum will argue about whether 480p is worthwhile or not, I think it is obvious that the true 480p picture that FOX sends to its affiliates is often very good.


-Gergg
 

·
Registered
Joined
·
553 Posts
I believe that a few shows like Dark Angel, Malcom in the Middle, Ally MacBeal etc. are 16X9 480p. These look pretty good, but definitely not HD. Most of Fox's 4X3 programming however is slightly blown up or zoomed in so that it fills more of the 16X9 screen. Unfortunatly this makes a lot of their programming look like crap. I wouldn't say its worse than analog cable, but not much better. (And remember if you have TW digital cable you are still getting basic cable stations via analog.)


Other than the fact that they are blowing up the image there is also different equipment involved. CBS does a pretty good job of converting 480i NTSC programming. There news for example looks pretty good. Somewhere inbetween true 480p and cable.


Someone correct me if I'm wrong--I think FOX's 16X9 480p shows are telecined for that format the same way that DVD is. But their 4X3 programming goes through a line doubler so that 480i material is sent out 480p. Correct? Add that with the blow up effect and you get a less than optimal picture.


And a station like UPN is simply transmitting 480i via digital so your HD box does the line doubling. Am I right?
 

·
Registered
Joined
·
1,144 Posts
Quote:
Originally posted by shadowbox


Someone correct me if I'm wrong--I think FOX's 16X9 480p shows are telecined for that format the same way that DVD is. But their 4X3 programming goes through a line doubler so that 480i material is sent out 480p. Correct? Add that with the blow up effect and you get a less than optimal picture.

Well, sort of, but not quite. 480p is a broadcast format only. There is no video recorder that operates in that format. Film is by nature a progressive format (it's shot one frame at a time, no scanning because it's not electronic), and most commonly shot at 24 fps. In telecine, these 24 frames are converted to 60 fields by means of introducing a 3:2 pulldown, in which each film frame is transferred to either 3 or 2 video fields, alternating on each film frame. This gives (12*2) + (12*3), or 60 fields of video. For broadcast, Fox's shows are processed (prior to delivery) so that this pattern is continuous on the master tape. The MPEG2 encoder can detect this pattern, and recreate the original 24 frames. It then processes these frames again to create 60 true progressive frames (some of which contain information from more than one film frame, of course) and sends this stream out.

Video originated programming, however, is different in that there are never any true progressive frames in the original material, because NTSC is an interlaced format to begin with. Any progressive presentation of NTSC originated material is a "cheat", in which each field (only half the original interlaced image) is doubled. This has the advantage of minimizing interlace issues, but each frame has only half the resolution.
 

·
Registered
Joined
·
497 Posts
I've read here that the recent baseball playoffs were sent to the stations in 4:3,480p. Mmost, is this the "cheat" mode you mentioned?


The Phoenix FOX affiliate used to show a 14:9 faded upconvert. Once the playoffs started they changed to the 4:3 format for both baseball and local stuff. I have two different brand of receivers and neither will stretch the 4:3 to full screen. Both will stretch other 4:3 digital programming to full screen. Is the FOX 4:3, 480p a 16:9, 480p with the black bars sent as part of the picture? I haven't been able to look at any of the programming that FOX network provides as 16:9, 480p (widescreen).


Thanks for any clarification,


Al Keown
 

·
Registered
Joined
·
3,325 Posts
Quote:
Originally posted by mmost



Fox's shows are processed (prior to delivery) so that this pattern is continuous on the master tape.
Not true,


FOX's shows are edited in 480i without regard to the progressive 24 fps. The 3/2 pulldown cadence is not preserved across edits.


However the 480i -> 480p converter is smart enough that it usually finds the progressive frames even across cuts.



Additionally, FOX's deinterlacer is adaptive. It doesn't always do a bob, but sometimes a weave. So the resolution is not always half - only when there's motion.
 

·
Registered
Joined
·
1,144 Posts
Quote:
Originally posted by balazer



Not true,


FOX's shows are edited in 480i without regard to the progressive 24 fps. The 3/2 pulldown cadence is not preserved across edits.


However the 480i -> 480p converter is smart enough that it usually finds the progressive frames even across cuts.



Additionally, FOX's deinterlacer is adaptive. It doesn't always do a bob, but sometimes a weave. So the resolution is not always half - only when there's motion.
I'm not going to get into a pissing match here, but you're wrong. It is true that Fox film programs are on-line edited without regard to continuous cadence. But the 16:9 version is processed (primarily by a company called International Image in Santa Monica, CA.) for continuous cadence prior to delivery. This is the responsibility of the program supplier, in order to adhere to Fox's delivery requirement of a continuous cadence 16:9 master, as well as a 4:3 master for analog air that does not have to be processed. The only shows that do not require such processing at the moment are Titus and Pasadena, which are both shot on 24p HD video and posted in that format, then downconverted for delivery. The downconversion automatically creates continuous cadence 3:2 pulldown. Prior to its switch to HD production, Titus was actually posted in PAL for one season to achieve continuous cadence in the NTSC version. This was a "mad scheme" that the Fox folks tried to get other program suppliers to follow, which fortunately for many of us was resisted. When International Image's system came along, it was a moot point.


In case you're wondering about my knowledge of this particular area, I've worked in production and post production on a Fox film program for the last 5 years, and on many other shows for the last 20 years. I know what we do and I know what others do.
 

·
Registered
Joined
·
2,067 Posts
A few months ago, there were a bunch of reports that 90% of Fox's prime time shows were going to be in 16:9 480P. What ever happened to all of those shows? All of the new shows I have seen on Fox, like "Undeclared" are in 4:3.


I like the 16:9 480P shows.. The image quality is quite good. It blows away any DVD I have seen. I was excited to hear that most of the Fox shows would be in this format.... What happened?
 

·
Registered
Joined
·
4,304 Posts
Quote:
Originally posted by tji
I like the 16:9 480P shows.. The image quality is quite good. It blows away any DVD I have seen.
You got a problem with your DVD's then. The FOX 16:9 480p shows don't come close to a progressive DVD.
 

·
Registered
Joined
·
2,067 Posts
Quote:
Originally posted by vruiz



You got a problem with your DVD's then. The FOX 16:9 480p shows don't come close to a progressive DVD.
Perhaps your local Fox affiliate is using different equipment than mine. From the reports on this forum, it seems like there is a lot of variability in the picture quality of different Fox stations.


My Fox affiliate, KTVU - San Francisco, broadcasts in 720P and it looks clearly better than a DVD. This is in comparison to my HTPC ( upconverting to 720P), My progressive DVD player (Panasonic DVD-RP56), and many more expensive progressive DVD players I have viewed in stores.
 

·
Registered
Joined
·
553 Posts
I noticed something tonight that brings up a point from the original post. As has been mentioned before in this forum , sometimes when watching Fox primetime you can see the FOX logo in the bottom left corner partially cut off. This is true if its widescreen or sometimes 4:3 (And the 4:3 is not blown out). The picture looks pretty good when this is the case. Other times the 4:3 material is blown out and looks terrible as described above. I remember during the MLB playoffs that some games had the FOX logo in the bottom right and cut off while other times it was the inferior blown out picture. This describes the difference that the original post was talking about.


I assume this a difference between network equipment/feeds and local broadcasts equipment. But why would some primetime programming be affected by this, especially MLB?
 
1 - 12 of 12 Posts
Status
Not open for further replies.
Top