mpeg4 hd cropped

C

clauderains

Thread Starter
Member
Apr 30, 2005
12
0
When I put my display(1080p native) into 1:1 pixel mode every mpeg4 hd channel is slightly cropped
(black) at the sides all of the time. Its only about an inch or less on each side. All of the black/cropped
out parts are what you usually wouldn't see due to overscan/having the tv set to 16:9 mode. All of the
mpeg2 hd channels fill the whole screen. Is there any reason for this? Saving space or some technical
reason?
 
Max Wright

Max Wright

SatelliteGuys Pro
Jan 10, 2006
282
2
Missouri
What actual channels are doing this? I know TLC has been doing this for a while now. There is at least one thread on them and this issue.
 
C

clauderains

Thread Starter
Member
Apr 30, 2005
12
0
Every mpeg4 hd channel is doing this when my tv is set to 1:1 pixel mode. Mpeg2 hd channels don't have this problem. I believe that this is a different problem than the one you are talking about. The few channels that do what TLC does actually shows up when my tv is set to 16:9 mode. I think those channels are actually zooming in and up-converting SD material. The problem I'm talking about is that every mpeg4 hd channel even while showing HD material is slightly cropped when my tv is set to 1:1 pixel mode.
 
R

royrose

SatelliteGuys Family
Apr 29, 2005
50
18
Do you mean cropped or shrunk? To me, cropped means that some of the picture is being cut off. On one of my TVs,I get the same thing you do but I think I get the entire picture. That TV, a cheap Westinghouse 720p, has Zero overscan. On my SXRD, there is no black border (and no option of setting it for zero overscan).

Anyway, it may be how the "HD Lite" is displayed when you have no overscan,

Roy
 
ncted

ncted

SatelliteGuys Master
Pub Member / Supporter
Jul 4, 2004
5,381
3,672
Durham, NC
When I use the JustScan (1:1) mode on my Samsung LCD (with 722), I get noise along the right side of the screen, but no black border.

Ted
 
C

clauderains

Thread Starter
Member
Apr 30, 2005
12
0
Do you mean cropped or shrunk? To me, cropped means that some of the picture is being cut off. On one of my TVs,I get the same thing you do but I think I get the entire picture. That TV, a cheap Westinghouse 720p, has Zero overscan. On my SXRD, there is no black border (and no option of setting it for zero overscan).

Anyway, it may be how the "HD Lite" is displayed when you have no overscan,

Roy

It doesn't look like any of the picture is cut off so shrunk would be more accurate.

If it is the HD Lite that is causing this to happen wouldn't the same thing happen with the mpeg2 HD channels as well.? I thought those were HD lite too.
 
K

kvnfl

SatelliteGuys Pro
Feb 19, 2008
531
0
SWFL
The gray bar 4:3 overscans, too. And that is a shame, because daytime SD sporting events look much better with gray bar.

The HD overscan drove me nuts. Did some research on it and found professional TV Calibrators consider overscan of 5% or less to be acceptable. 5% is about the height of scrolling text at the bottom of newscast and sporting events. The reason that percentage is acceptable is because not all sources will overscan and adjusting for one source that overscans will result in underscan from other sources.
 
N

noremac

SatelliteGuys Pro
Oct 28, 2004
251
0
Wash, DC
... Did some research on it and found professional TV Calibrators consider overscan of 5% or less to be acceptable.
Yes, but that sounds like an old standard made during the days of NTSC and cathode ray tubes, the combination of which could not reliably maintain good geometry at the extreme scan edges. I would guess that 95+ % of TVs being made today are digital pixel forming types. Therefore, even the concept of overscan is obselete in the ATSC era. I suspect the only reason that technicians and camera operators still abide by rules-of-thumb for title safe cropping etc is because of backward compatibility with all the tube sets still out there.
 
H

hendrix04

SatelliteGuys Pro
Jan 16, 2008
601
0
when mine is on Just scan i do not see any black or noise...
 

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