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Discussion Starter · #1 ·
I rented Vin Diesel's Triple X last weekend to be played on my Sony 755V progressive player feeding my Sony 34XBR800. The player knows my TV is 16:9 format.


At several points during the film, subtitles in bold yellow letters appear in the lower black bar to provide the audience with the foreign language translation.


I was under the impression that since this DVD is in a widescreen anamorphic format, all 480 progressive lines are concentrated in the visible space between the upper and lower black bars.


So how could the player make the subtitles appear in the lower bar without stretching the 480 lines to fill more of the vertical screen space than usual?


Or are the subtitles encoded separately on the DVD and when necessary, the player temporarily add extra lines to display the text message in the bottom black bar?


Does anyone have a clue?


Thanks
 

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Is it a 2.35:1 aspect ratio film? If so the black bars (for a 16:9 image) are included in the video area. There should be no black bars on a 16:9 display with a 1.85:1 aspect ratio film for an anamophic DVD.
 

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Discussion Starter · #3 ·
Thanks ThumperBoy,


This film has an aspect ratio of 2.40:1 according to the technical details listed by Amazon.com.


So your answer makes sense. This means that some of the 480p lines are used up generating the black bars when the ratio is over 1.85:1.


I was mistakenly under the impression that no matter what the ratio, if the format is anamorphic, then the visible space consumes 480 lines and the TV set generates the black bars separately.
 

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Discussion Starter · #4 ·
As a footnote:


If ever an anamorphic format were to have the visible space always consume 480 lines and the TV set generate the black bars separately, it would require that the TV set squeeze the height of the visible area differently depending on the aspect ratio.


Squeezing the same 480 lines into a shorter image might be difficult if the shadow mask's vertical dot pitch did not match up with the vertical distance between scan lines.


However CRTs which use aperture grills would have no such problems and the result would be impressive.
 

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There are only two general types of DVDS, non-anamorphic (480 lines for a 4:3 image) and anamorphic (480lines for a 16:9 image) - so any other film aspect ratios are formatted with extra black area to fill one of the two types. If a new type (anamorphic 2.35:1 for example) were created it wouldn't be compatible with the current DVD players.
 

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Montreal,


To add to what has been said………


All DVDs are encoded in 4:3 format (480X720) rectangular pixel.


The anamorphic process involves squeezing (through a lens or scaler) an original film horizontally by 25% and then encoding it onto DVD. 25% horizontal is the exact difference between 16:9 and 4:3 or in other words 1.78:1 and 1.333:1.


Therefore if the original film is 2.40:1 then it must first be resized to 1.78:1 (this will reduce the vertical and horizontal definition) and black bars will have to be added on top an bottom. Then the subtitles are added.


Finally, the newly resized film goes through the anamorphic process to achieve a 1.33:1 ratio and both the black bars and the subtitles are encoded.


But if the original film is 1.78:1 then no initial resizing is needed and therefore no black bars are present. The film goes through the anamorphic process without the presence of black bars and with the full vertical resolution in tact.


On a 16:9 tv the anamorphic 4:3 frames are expanded by 33% to to get full screen.
 

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Jeff Lam -

The problem isn't so much with subtitling per se, as the way they're implemented in this film.


It seems likely that were they using subtitles throughout the entire film, they would be handled in the manner you're suggesting. This situation is somewhat different though, as from my understanding the original poster isn't viewing subtitles throughout the entire film, but short sections have been subtitled when certain characters speak another language. To have these displayed as subtitles instead of image would be nice, but from a practical standpoint it would require the disc to have a subtitle track which only includes subtitles for non-english speaking portions of the film. It seems pretty obvious that this would cause a great deal more confusion among the general public, and would probably result in most people having no idea what characters might be saying when they speak in another language.
 

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Discussion Starter · #9 ·
XROX,


So if an original film is 1.78:1 or 1.85:1, then little or no resizing will be necessary and no black bars will be encoded into the video space. In this case, subtitles would have to be superimposed on top of the regular image, unlike the case of the Triple X DVD where they are in the bottom black bar.


I never saw the original film in the theater, but I assume the occasional subtitle must have appeared within the frame, since there are no black bars printed on movie film in anticipation of the need for adding text below the image. In other words if the aspect ratio of the DVD is 2.40:1, then the aspect ratio of the camera film is also 2.40:1.
 

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montreal,


You are right, (well almost).......


If the original film is 1.85:1 then there will be very small black bars unless they have decided to just crop the film edges off (masking)


Only if the original was 1.78:1 (16:9) will you not have encoded black bars.


But remember, even in that case you will still end up with black bars on a 4:3 set unless you want everything to look tall and skinny. It is just that in this case the black bars are not encoded. And there is still plenty of room for subtitles.


Anamorphic DVDs only benefit 16:9 tv owners.


DVDs are sold in two forms:


Letterbox: 4:3 frames with black bars are encoded.


Anamorphic: 4:3 full screen (albiet horizontally squished) frames


But if you have a 4:3 set you will see the identical picture with black bars either encoded (letterbox) or not (anamorphic)
 

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Discussion Starter · #11 ·
XROX,


What a shame that for film over 1.85:1, the encoded black bars end up consuming some of the 480 lines that could otherwise be used to make a higher resolution image.


This better image would end up appearing horizontally squished on a 4:3 set, but perfect on a 16:9 set.


Instead of adding ZOOM modes to stretch horizontally on 16:9 sets, maybe they should be adding SHRINK modes to squeeze vertically on 4:3 sets.


Thanks to you all for your comments.
 

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montreal,

While this is true, you do not lose any rezolution on wider material, you just don't use the entire viewing area.

Quote:
Instead of adding ZOOM modes to stretch horizontally on 16:9 sets, maybe they should be adding SHRINK modes to squeeze vertically on 4:3 sets.
Actually, they do. Most 4x3 sets nowdays have the 16x9 enhanced mode or "anamorphic squeeze" to allow you to take full advantage of all 480 lines of rezolution. Instead of stretching the picture horizontally to get the correct aspect ratio and geometry like 16x9 sets, they simply squish the picture virtically to get the correct aspect ratio and geometry.


If you need more explination on anamorphic DVD, this may help:

http://www.dvdweb.co.uk/information/anamorphic.htm


jjarmoc,

This is what I'm talking about. If an english speaking movie is filmed and there is a different language spoken on screen, subtitles should be shown, burnt into the picture (like in lord of the rings when the elves speak). It seems that many movies subs are player generated and often cause problems, such in this case and in other films like Star Wars. Not to mention that the orange or yellow box-like player generated subtitles are ugly as hell.
 

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jeff,


I agree that if you're 4:3 set has the 'anamorphic squeeze' function you will not lose scan lines (vertical resolution)


But if you don't have this function you will lose vertical resolution detail.



BTW Montreal,


It is a rather confusing topic with many redundant terms. Don't get confused (as I did) when a display has an "anamorphic squeeze" function. It refers to the display reducing the the space between scan lines in order to show anamorphic DVDs with the full 480 lines per frame. In this case the black bars you see are dead pixels (not active - or part of the 480 lines)


A 4:3 tv without this function would either show a full screen (horizontally squished) picture - when the DVD player is set for 16:9, or letterbox (black bars not encoded) when the DVD player is set for 4:3.


It is all very confusing and the best way to remember it is that aspect ratio is everything.


1 - The original film will have a widescreen aspect ratio (2.4:1 or 1.78:1 or whatever)


2 - It must be converted to DVD format which is 4:3 by either letterboxing (scaling both vertical and horizontal and adding black bars to signal) or by anamorphic transfer ( horizontally compressing into 4:3 and maintaining the 480 lines)


2 - Then the DVD player must output to the proper display aspect ratio of (4:3 or 16:9) with or without an 'anamorphic squeeze' function.
 

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Discussion Starter · #14 ·
XROX,


You say "in this case the black bars you see are dead pixels (not active - or part of the 480 lines)".


Is that true for a 16:9 TV or only 4:3?


When I viewed the Triple X DVD with the yellow subtitles in the lower black bar, those were not dead pixels in the black bar, but some of the 480 lines.


My complaint is that when the 2.40:1 film must be resized down to 1.78:1 by adding black bars, we should not waste valuable lines on pixels that are black most, if not all of the time.


If more and more films are shot with aspect ratios well above 16:9, then whether the film is viewed from DVD or a HD-DVD or a HD feed, some percentage of the data involved in the storage and or transmission which is devoted to black bars from resized films is a total waste.


Which leads me to this question. Is today's 16:9 wide screen TV already too narrow for future viewing of films?
 

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montreal,


Yes, when an original widescreen film is resized for a 4:3 tv the black bars are part of the 480 lines.


Letterbox - the bars are encoded onto the dvd


Anamorphic - the bars are not encoded (the player resizes the frame)


But what I was talking about was displays that have the 'anamorphic squeeze function' - as I said this can be confusing. Don't get confused between resizing, compressing, and 'squeeze'. The squeeze maintains the 480 lines but just pushes them closer together. Resizing and compressing involves loss of resolution and replacing some of the 480 lines with black bars.



Now, if you were to watch an anamorphic DVD on a 4:3 set with the DVD player set to 16:9 you will see a full screen squished (tall and thin) picture. TV's with the 'anamorphic squeeze' function recognize this feed and reduce the space between the 480 scan lines to eliminate the squished look. So you still have 480 scan lines per frame but since they are closer together you see inactive parts of the screen on the top and bottom.


Now, if a tv does not have this feature it has a fixed position for the scan lines. In this case the dvd player must be set for 4:3 and will compress/resize the signal vertically and add black bars. In this case the bars are part of the 480 lines and therefore can show subtitles.


Regarding your complaint. I suggest that the industry do anamorphic transfers of all films (all aspect ratios). And that all tv's including 16:9 tv's have a variable squeeze function. This way every film we watch regardless of the aspect ratio will show full vertical resolution. But in order for this to work the dvd player must recognize the original film aspect ratio and flag the display to properly squeeze the signal vertically.


The problem though is that displays are quickly moving to fixed pixel displays such as plasma and LCD. These displays have fixed definitions and therefore require a scaler (resize, compress) to adjust the picture to fit the screen.
 

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Discussion Starter · #16 ·
XROX,


I understand - anamorphic squeezing does not lead to a loss of vertical resolution, but resizing does if the original film is wider than 1.78:1.


If the industry were to follow your suggestion of an intelligent variable squeeze, then sub-titles would have to be burnt in as JEFF LAM noted above.


Or the industry would have to develop a way to encode the sub-titles separately (like close captioning) and let the player add additional lines for the text which hopefully the TV sets would be able to recognize.
 

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I'm not sure on this but I think that subtitles are encoded seperatly on DVDs


You can turn them off and on in the setup menu.


The way it must work is that they are placed into the signal at say lines (400 - 420) so they will appear in the lower black bar (when the bars are part of the signal)


If the picture is full screen you would still see the subtitles in the picture but at the same position (400-420).


And if you had 'anamorphic squeeze' the subtitles would still be in the picture at (400-420)


just my guess though.......
 

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Discussion Starter · #18 ·
XROX,


I'll see tonight if my player lets me disable subtitles, and if so, I'll replay Triple X to see if the yellow text disappears.


I'll report my findings tomorrow.


Thanks for all your input.
 

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Discussion Starter · #19 ·
XROX,


Yes the subtitles are encoded separately on the DVD since I can turn them on and off in real time and change the language of the subtitles as well, independent of the language selected for the viewing of the film.


In the case of Triple X, the subtitles appear in the black bar generated during the resizing of the film. Had the original film required no resizing, then there would have been no black bars encoded and the player would have been forced to overlay the subtitles in the lower part of the visual image giving a burnt in look.


Thanks to all posters for their comments.
 

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That's what I said. These are player generated subtitles and are completely independent of the language being played. This is why player generated subs cause problems sometimes. IMO, all subs should be burnt into the picture.
 
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