Can i get anamorphic movies with DivX?

[woxiz]

Can i make anamorphic movies with DivX or Xvid? I don't like the fact that i have to zoom the picture on my widescreen to get the right picure. Could i get anamorphic movies just like dvd has?
Read something about anamorphic divx. But i don't know if it really the same as anamorphic dvd's, when the dvd movies get "zoomed" without quallity loss.

[jggimi]

Hello, welcome to Doom9's forum, woxiz!

DivX is an MPEG-4 codec. As far as I know, the MPEG-4 codec standard does not describe pixel shape. The most commonly MPEG-4 container is AVI, which also does not describe pixel shape, and expects square pixels, which is usually fine for PC playback.

There are other container formats for MPEG-4 that allow for a display aspect ratio, such as Matroska or MP4. I recommend perusing the New A/V Formats - Containers (http://forum.doom9.org/forumdisplay.php?s=&forumid=74) forum, where you will find plenty of information. Note that if you are using a standalone DivX player, you should check the supported container formats with your manufacturer. You may be restricted to using AVI and square pixels.

If you are using a PC for playback, there are many software players that can adjust aspect ratio with AVI or other containers ... one such is BSPLayer.

[woxiz]

Okey... I am using my xbox with XBMP 2.3 to play my movies.
Are there any anamorphic mpeg-4 trailers around??

[SeeMoreDigital]

Originally posted by woxiz
Okey... I am using my xbox with XBMP 2.3 to play my movies.
Are there any anamorphic mpeg-4 trailers around??

Hi woxiz,

I have a whole load of short PAL and NTSC 'Video Only' - Aspect Ratio Test Files, on my WebSite you can download!

Once you are there, visit 'Area 51'

Don't forget to let us know how you get on?

Cheers

[woxiz]

I tryed them now. But it does'nt seem to be "real" anamorphic like mpeg-2 uses!? Like in some movies when the black bars totaly disapears.

[SeeMoreDigital]

Originally posted by woxiz
I tryed them now. But it does'nt seem to be "real" anamorphic like mpeg-2 uses!? Like in some movies when the black bars totaly disapears. Encodes with no black bars have a PAR (Picture Aspect Ratio) of either 1.33:1 (4:3 TV size) 1.77:1 (16:9 TV size) or 1.85:1

The source file that I used to generate all the 'Aspect Ratio Test Files' on my web site has a PAR of 2.35:1. So on playback there should always be black bars at the top and bottom of the picture. Some will be visible because I put them in there. Other will only be visible if the user puts them in by adjusting his/her player. That's why there are several versions of the encode on the web site

Admittedly, some of the encodes have image pixel frame sizes that might never be used (in the real world) but that's why they are labelled as tests!

Encode #01 is a proper anamorphic encode. However, the reason why it does not automatically stretch (ping) out like an Mpeg2/DVD/vob file does, is because both DivX and the AVI container don't support anamorphic flagging!

Shame really..... Cheers

[woxiz]

So there are'nt any real sullotions to get "real" anamorphic mpeg-4? Is that what you are saying? :( Your "anamorphic" trailers is just the same as zooming in an ordinary letherbox right? Just made it in wide sreen resolution and cropped a bit of the black bars of?

[jggimi]

No, he repeated what I already wrote. AVI does not include a Display Aspect Ratio.

If you'll follow the link to the New A/V Containers Forum that I provided above, you'll find discussions of how to create anamporphic MPEG-4 files in the Matroska or MP4 container Q&As threads, which are sticky, and found at the top of the forum thread list.

I'll clarify what I wrote earlier. With AVI containers, you must know the aspect ratio and adjust your player accordingly, assuming your AVI player can have aspect ratio adjustments.

With containers that support DAR fields, the player will shift aspect ratio automatically.I don't know anything about your Xbox player. For information on your player's capability (container support, aspect ratio, and the like) review either the documentation or the developer's website.

[jggimi]

Perhaps something else may be confusing you. There are only two "standard" sizes for televisions and computer monitors. 4:3. Also described as 1.33:1. The standard shape of televisions and computer monitors for many decades.

16:9. Also described as 1.85:1. The much more modern and less common shape of widescreen televisions, and a few computer monitors. But movies are made with all sorts of aspect ratios. SeeMore's example, 2.35:1, is a common widescreen film format, there are many others ... far more than the two formats for television screens. When viewing a 2.35:1 widescreen production (e.g.: Cinemascope) on a 16:9 screen, you will still have letterboxing above and below the image, but less then on a 4:3 screen, obviously. And when viewing 4:3 images on a 16:9 TV, you should have letterboxing on the left and right.

It's just a guess, but perhaps you have your standalone player set to "squeeze" or "squish" images. They may fill your screen more, but they are not at the correct aspect ratio.

[Stux]

Originally posted by jggimi
As far as I know, the MPEG-4 codec standard does not describe pixel shape

Actually its the opposite. The MPEG-4 Visual Specification allows the bitstream to specify the pixel shape of the encoded pixels, ie the Pixel Aspect Ratio or PAR.

This is how the 3ivx MP4 AR stuff works.

[SeeMoreDigital]

Originally posted by jggimi
...16:9. Also described as 1.85:1. The much more modern and less common shape of widescreen televisions, and a few computer monitors. Just a slight correction my friend 16:9 = 1.7777777:1.

One of the reasons why 1.85:1 is used with DVD instead of 1.77:1 is because most TV's are not setup to display 'all' the visible image..... unless you adjust it yourself that is!

EDIT:
Originally posted by Stux
...Actually its the opposite. The MPEG-4 Visual Specification allows the bitstream to specify the pixel shape of the encoded pixels, ie the Pixel Aspect Ratio or PAR.

This is how the 3ivx MP4 AR stuff works. Hey, don't forget about the new version of XviD that can offer aspect ratio switching while still being in an avi container. As long as you have a suitable software player!

Cheers

[jggimi]

Thanks for the corrections, Stux and SeeMore. Woxiz will still have to determine if anamorphic encoding is what he's really looking for in the first place, and, if so, can his player/platform/television combination take advantage of it.

[SeeMoreDigital]

Hi woxiz,

I've just added some XviD encodes to my website, that support 16:9 'anamorphic signalling'!

Please give them a try and report back?

Cheers

[DevilsChild]

Originally posted by SeeMoreDigital

I've just added some XviD encodes to my website, that support 16:9 'anamorphic signalling'!

Please give them a try and report back?


Hi,

I was looking at the "Audio Only (AAC Encodes)" section of your website and noticed that some of the links are invalid. You might want to fix that...

[SeeMoreDigital]

Originally posted by DevilsChild
Hi,

I was looking at the "Audio Only (AAC Encodes)" section of your website and noticed that some of the links are invalid. You might want to fix that... Yeah, sorry about that.

While shuffling some files and folders around and lost the links!

Should be ok now though,

Cheers

[calinb]

Originally posted by woxiz
So there are'nt any real sullotions to get "real" anamorphic mpeg-4? Even if your container/codec lacks support for AR flags, it doesn't mean you can't make and play anamorphic encodings. If your player supports scaling presets, like the pan & scan feature of MPC, you can easily make a preset for every screen resolution that you use for playback. In MPC, for example, you select video frame >> normal and also, pan&scan >> <your custom preset> for that display. To store a preset, use the Pan&Scan >> Edit... feature.

The best way to calculate the scaling factors for the MPC "Zoom" entries is to calculate how much you'd need to stretch a 1.85 anamorphic DVD (720x480 for NTSC) screen from right to left (or shrink it if you're using a diplay < 720 pixels wide). Then figure out how much you need to scale the height such that the "active" pixel area of the image will have a final AR of 1.85. The horizontal scaling factor goes in the lower left box and the vertical scaling factor goes in the lower right box. Leave the upper position boxes alone, unless you don't want the image centered on your screen.

If you always crop any black bars from your encodings, this same preset should be about right for ARs other than 1.85 too.

For NTSC 4:3, I often don't resize to correct for pixel AR because MPC has another handy feature, "Video Frame >> Stretch To Window." This will give you the correct scaling for a 4:3, as long as you're using a 4:3 display obviously. So even if my image is encoded from an NTSC 704x480, for example, without resizing, I simply stretch the image to fill my 4:3 square pixel computer screen and the scale will be correct.

Here are the numbers I entered into MPC and saved to an mplayerc.ini file, which I can pass around between my compters with different displays/display settings. These numbers could be wrong--I'm bad at arithmetic :) If the circle around the MGM Lion at the beginning of movies looks fairly round, I'm happy enough :)

Screen Width
(pixels)........Zoom-X....Zoom-Y
----------......------....------
1400............1.944.....1.576
1280............1.778.....1.441
1024............1.422.....1.153
800..............1.111.....0.901
640..............0.889.....0.722

Notice that the Zoom-X:Zoom-Y factors are 1.85:1.5 (~1.23) to scale the anamorphic 720x480 (1.5) out to 1.85.

Some of us have been petitioning Gabest to read matroska AR flags within MPC and make this unecessary :) -- for mkv files at least. Although ffdshow overlay mode also able to handle this, some adapters don't seem to work with overlay correctly.

Anyone ever notice that 16:9 is exactly (4:3)^2? i.e., 4/3 x 4/3 = 16/9. Is there any physical reason the television industry chose the 16:9 AR?

[chilledoutuk]

if you playback a .avi created with xvid and has a par of say 16:11 pixel aspect ratio (16:9 picture aspect) in video lan media player it will display it in the corect aspect even though it is an .avi file.

p.s Nero showtime also can do this

[SeeMoreDigital]

Originally posted by chilledoutuk
if you playback a .avi created with xvid and has a par of say 16:11 pixel aspect ratio (16:9 picture aspect) in video lan media player it will display it in the corect aspect even though it is an .avi file.

p.s Nero showtime also can do this 'Tiss true!

I posted some XviD encodes that support this feature on my website, for woxiz to try.

Don't forget woxiz is using an xbox with XBMP 2.3 to play his movies.

Cheers

[calinb]

Originally posted by SeeMoreDigital
Don't forget woxiz is using an xbox with XBMP 2.3 to play his movies. Oops--well Gabest will probably add xbox support soon too :) Joking, of course!