Is 1080p really 1080? - High-Def Digest Forums
Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-01-2008, 01:46 PM
Member
Thread Starter
 
Join Date: Mar 2008
Posts: 31
Default Is 1080p really 1080?

As far as I understand it, 1920 x 1080 is the overall resolution for the entire screen. Since most movies are anamorphic at 2.35:1 instead of say, 16:9, wouldn't that make 1080p technically, untrue? Unless they always encode the picture based on 1080p vertical resolution and scale horizontal respectively? This certainly doesn't seem to be the case for DVDs...

Why do they use the scan line resolution as name anyway? Why not the horizontal resolution? I mean, with the exception of NTSC (0.9 pixel ratio), those are the numbers that stay constant...

I mean, 480i isn't even relevant... It's actually 240 lines being scanned at any given frame anyway... I mean, going by that principle, a TV can scan one line a second and still be 480... You just have to wait eight minutes for the picture to update one frame LOL.
Reply With Quote
  #2  
Old 04-01-2008, 01:57 PM
Josh Z's Avatar
Senior Member
 
Join Date: Mar 2007
Posts: 11,925
Default

Quote:
Originally Posted by Zamboni View Post
As far as I understand it, 1920 x 1080 is the overall resolution for the entire screen. Since most movies are anamorphic at 2.35:1 instead of say, 16:9, wouldn't that make 1080p technically, untrue? Unless they always encode the picture based on 1080p vertical resolution and scale horizontal respectively? This certainly doesn't seem to be the case for DVDs...
The High Definition frame is 1920x1080 pixels. On a 2.35:1 movie, some of those pixels are used to create the black letterbox bars. In that case, the resolution of the active movie picture area is around 1920x800 pixels.
__________________
Josh Z
Writer/Editor, High-Def Digest (Blog updated daily!)
Curator, Laserdisc Forever
My opinions are strictly my own, and do not necessarily reflect those of this site, its owners or employees.
Reply With Quote
  #3  
Old 04-01-2008, 02:04 PM
Member
Thread Starter
 
Join Date: Mar 2008
Posts: 31
Default

Quote:
Originally Posted by Josh Z View Post
The High Definition frame is 1920x1080 pixels. On a 2.35:1 movie, some of those pixels are used to create the black letterbox bars. In that case, the resolution of the active movie picture area is around 1920x800 pixels.
I thought the letterbox are just inactive pixels...?

Inactive pixels are naturally black, no? So I'm right? That most BR movies aren't true 1080p? Afterall, it's not like they encoded two giant black bars into the video itself...

I knew it! HD is nothing but a hoax!!! It's a lie people!!! Run for the hills!!!
Reply With Quote
  #4  
Old 04-01-2008, 02:09 PM
Banned
 
Join Date: Oct 2006
Posts: 2,580
Default

Quote:
Originally Posted by Zamboni View Post
I knew it! HD is nothing but a hoax!!! It's a lie people!!! Run for the hills!!!
Yes my eyes deceive me on a daily basis!


PAY NO ATTENTION TO THE MAN BEHIND THE CURTAIN!!!1!!one1one!!
Reply With Quote
  #5  
Old 04-01-2008, 02:32 PM
Junior Member
 
Join Date: Apr 2008
Posts: 7
Default

Quote:
Originally Posted by Zamboni View Post
I thought the letterbox are just inactive pixels...?

Inactive pixels are naturally black, no? So I'm right? That most BR movies aren't true 1080p? Afterall, it's not like they encoded two giant black bars into the video itself...

I knew it! HD is nothing but a hoax!!! It's a lie people!!! Run for the hills!!!
This has already been discussed at length over at AVS. The black bars are active pixels and part of the encoded image, much to the chagrin of Constant Height anamorphic afficiandos.

Either way, it's all relative. The same was true of DVD, VHS and Laserdisc before it.

So, you're wrong, sorry about that.
Reply With Quote
  #6  
Old 04-01-2008, 02:55 PM
Member
Thread Starter
 
Join Date: Mar 2008
Posts: 31
Default

Quote:
Originally Posted by muterobert View Post
This has already been discussed at length over at AVS. The black bars are active pixels and part of the encoded image, much to the chagrin of Constant Height anamorphic afficiandos.

Either way, it's all relative. The same was true of DVD, VHS and Laserdisc before it.

So, you're wrong, sorry about that.
Wait, WHAT!? The black bars are part of the encoded image!?!?!?

So a good deal of coding bandwidth is used to define the edge between actual picture and black bars!? Oh say it isn't so!!!

Unless there's a special function in Mpeg2 that specifies black bars and somehow uses zero video bandwidth for them?

This is an April Fool's joke right? RIGHT!?!?
Reply With Quote
  #7  
Old 04-01-2008, 02:59 PM
Banned
 
Join Date: Oct 2006
Posts: 2,580
Default

Quote:
Originally Posted by Zamboni View Post
Wait, WHAT!? The black bars are part of the encoded image!?!?!?

So a good deal of coding bandwidth is used to define the edge between actual picture and black bars!? Oh say it isn't so!!!

Unless there's a special function in Mpeg2 that specifies black bars and somehow uses zero video bandwidth for them?

This is an April Fool's joke right? RIGHT!?!?
Like muterobert said, its been like this for all movie formats ever created. Suprised you are just now learning about this.
Reply With Quote
  #8  
Old 04-01-2008, 03:01 PM
Member
Thread Starter
 
Join Date: Mar 2008
Posts: 31
Default

Quote:
Originally Posted by GamerGuyX View Post
Like muterobert said, its been like this for all movie formats ever created. Suprised you are just now learning about this.
VHS aside (which isn't even a digital format), when I watch DVDs, the encoded picture does not include the black bars... I don't know what you guys are talking about.
Reply With Quote
  #9  
Old 04-01-2008, 03:39 PM
Squozen's Avatar
Senior Member
 
Join Date: Jan 2008
Posts: 1,142
Default

Quote:
Originally Posted by Zamboni View Post
VHS aside (which isn't even a digital format), when I watch DVDs, the encoded picture does not include the black bars... I don't know what you guys are talking about.
Sure it does. You may be watching an anamorphic 1.78:1 film which wouldn't (as the DVD image fills the entire frame vertically and is then squashed down), but a 1.85:1 or 2.35:1 film will still encode some black.
Reply With Quote
  #10  
Old 04-01-2008, 03:54 PM
Aurora's Avatar
Senior Member
 
Join Date: Aug 2007
Posts: 1,818
Default

Quote:
Originally Posted by Zamboni View Post
Unless there's a special function in Mpeg2 that specifies black bars and somehow uses zero video bandwidth for them?
MPEG uses motion vectors as part of its compression/encode--basically, if something doesn't move from one frame to the next, it gets afforded little attention. Because the black bars remain fixed the entire file, they take up almost no real space in the overall encode.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Teminator: Salvation sucks really, really, really, really, really, really bad!!! ATLFalconsFAN Film Forum 2 05-21-2009 03:24 AM
Will Satellite's 1080p HD Really Be 1080p? Lee Stewart High Definition Smackdown 18 08-05-2008 06:03 PM
would you rather watch in 1080p or 1080/24p? 007 Blu-ray Software General Discussion 8 01-10-2008 11:07 PM
PS3 - FW 2.10 Fixes POTC:3 1080/24 freeze Z_T Blu-ray Software General Discussion 4 12-18-2007 05:36 PM
Horizon Semiconductors Unveils Industry's First True 1080/60p Universal System-On-A-C diabolo HD DVD Hardware General Discussion 0 10-01-2007 03:09 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off