Please need ultimate answer about aspect ratio setting

[Ubiq]

Hi all.
I see a lot of threads dealing with the 16:9 encoding topic.
I am experimenting with svcd since i got a svcd capable player.
Did a few disk to experiment with best process for encoding and different authoring methods, compared VBR vs CBR solutions and more.

I finally chose a process that I think is the best for me and guess it's a common one: Smartripper-->DVD2AVI-->TMPEG-->TSCV

I experimented and read a lot (all the FAQs, guides and forums) but still hven't found the ultimate answer to my great doubt.
HOW TO CORRECTLY HANDLE THE ASPECT RATIO

At present I get the best result in TMPG with the following settings

4:3 as target encoding (Video Tab)
16:9 as source aspect ratio (Advanced Tab)
Full screen keep aspect ratio.

This way I get a correct proportion in figures and I see the whole original frame top2down left2right.
But...

The image I get is indeed too ... thin! I mean the black bars of letterboxing are in may opinion too big.
When I look at a dvd i get a letterboxing half of what i get in my svcd.
Indeed the black area added while encoding is half of the one I see when I play the svcd. My player adds the other half (you can distingue by a little bit different shade of black).

Well so maybe I am doing something wrong but... If the black bars (coding+player) were tninner then the image will lose its correct proportion! Or I have to lose sometingh on left and right!
Not what I want!

Looking for the final answer I build an experimental svcd with all the elegible combinations. That's 27 (!) video tracks!

SOURCE 4:3 KEEP ASPECT RATIO
SOURCE 4:3 KEEP ASPECT RATIO 2
SOURCE 4:3 NO MARGIN
SOURCE 16:9 KEEP ASPECT RATIO
SOURCE 16:9 KEEP ASPECT RATIO 2
SOURCE 16:9 NO MARGIN
SOURCE 1:1 KEEP ASPECT RATIO
SOURCE 1:1 KEEP ASPECT RATIO 2
SOURCE 1:1 NO MARGIN

These 9 were repeted for 4:3, 16:9 and 1:1 target. That is 27.
Build all the 27 segments, burn and test .
More: my player allows to set the dispplay to: Normal Pan and Scan, Normal Letter box, Wide, so i repeated the test with all of these.
(BTW changing this setting on the player doesn't affect the SVCD while it works perfectly with DVD)
After the 81 (!) combination of test the answer seems to be the same:
THE ONLY WAY I HAVE TO SEE THE WHOLE PICTURE WITH CORRECT RATIO IS TO USE 4:3 TARGET, 16:3 SOURCE AND FULL SCREEN KEEP ASPECT RATIO (or full screen keep aspect ratio 2, they look the same)
But this means also I have to accept the big black area.
Am I wrong am i right?
Please help me: tired to burn test disks. Wanna code and look some movie to look with my wife. She's still waiting to see one of my promised SVCD...

Thank you bye

[mb1]

Did you read the guides ?
http://www.doom9.org/aspectratios.htm

16:9-dvds store the movie vertically stretched (4/3; anamorph). so you have to deanamorph for svcd and therefore add black bars.

16:9-svcds are within the specs but almost no player can´t handle it correctly, so you have to make 4:3-svcds for highest compatibility.

you wrote a lot but not some important facts. player model ? tv set 4:3 or 16:9 ?

regards
mb1

[jsm]

I have the same problem. I'm trying to create a full screen (4:3) SVCD from video that I've captured from my Hi8 video camera. I've captured it in 480x480, tried a wide variety of encoding options with TMPGenc, and then burned the SVCD with Nero. But when I play it on my standard 27" 4:3 TV, my DVD player scrunches the image as if it was a 16:9 anamorphic DVD, i.e. I get letter boxing.

My DVD player is a pioneer DV-440. From what I've read, most DVD players do not honor the DAR encoded in the MPEG stream for SVCD's. I wonder if it is possible that this player does honor it, and TMPGenc is hardcoding the DAR as 16:9.

What kind of DVD player are you using?

Does anyone here know of a utility that will tell me the value of the encoded DAR in a MPEG2 file?

[mb1]

All Pioneer DV 4xx have a scaling bug for svcd.

http://planetpink.bei.t-online.de/dvdplayer/pioneer444/pix/svcd43.jpg

http://planetpink.bei.t-online.de/dvdplayer/pioneer444/pix/svcdletter.jpg

The second picture is in 4:3 LB which should have no influence on picture.

Change to 4:3 Full in your player settings and you have correct aspect ratio.

But if you then wan´t to watch dvd you have to change back again.
And so on.

Here is the link to the excellent german testing site
http://www.dv-rec.de/test/dvdplayer/pioneer444/main.html
But its in german.

A freeware prog which shows the coded aspect ratio in mpg-headers is tecoltds bitrateviewer 1.5:
http://www.tecoltd.com/bitratev.htm

There are also possibilities to change that value without reencoding or saving as a new file.

regards
mb1

[zambelli]

People, why do we keep recycling this topic over and over again? The exact same thing is being discussed in a topic only few rows down...

It's simple. The most important thing is what kind of TV you have. Do you have a standard (4:3) TV, or a nice widescreen (16:9) TV? The second most important thing is to figure out whether your DVD is a letterboxed widescreen movie or an anamorphic widescreen movie. The first already has black bars on top and bottom, whereas the latter is squeezed horizontally (anamorphically) to fit into the DVD resolution.

If you have a widescreen TV, you have two options. First is to preserve the anamorphic widescreen. In TMPGEnc select 4:3 as your target ratio (that's the one on the first tab), then select "Full Screen" for scaling. For source aspect ratio select the same ratio as the one you select in DVD2AVI or Flask or XMPeg as your output pixel ratio. Make sure it's the same thign! It doesn't matter if it's 1:1 or 4:3 or 16:9, but it has to be the same! It's the same concept as passing variables to functions in a programming language - you always have to make sure it's the same variable type in both the call and the declaration. :)
Your second option with widescreen TVs is to force letterboxing. That's not a wise choice, since you're not taking advantage of your nice expensive widescreen TV then. :) Letterboxed movies can be viewed nicely on widescreen TVs by forcing Full mode, which zooms into the movie and blows it up full screen.

On 4:3 TVs, you only got one option and that is letterboxing. Why do we letterbox on 4:3 TVs? We do it because most DVD players are unable to letterbox SVCDs automatically for us. And the ones that do even have bugs, hehe... :) Anyway, letterboxing is accomplished by setting a 4:3 target aspect ratio and choosing "Full Screen (keep aspect ratio)" as your scaling option. That will automatically add black bars to top and bottom of your movie. That's it!

For good information about anamorphic widesceen check out
this page. (http://gregl.net/videophile/anamorphic.htm)

[zambelli]

My bad... "Full mode" on widescreen TVs is usually what you need to use in order to watch anamorphic widescreen SVCDs correctly. In order to watch letterboxed movies correctly you need to choose something like "Auto mode" which automatically detects black bars and zooms in on the movie.

[Ubiq]

OK I feel I had been missunderstood.

Now I read all the guides I found: here on Doom9 and elsewhere (my subdirectory for SVCD related link has 27 entries...)
And yes I know the topic is few rows down: stated on the first line of my msg.

What i was looking for is a confirmation that I am using the only correct way to handle aspect ratio after both reading guides and testing (I belive the two always come side by side).

Now my player is a keymat (same as Mustek 560) and I own both 16/9 and 4/3 TV set. But I am coding for the 4/3 since in my understending this will we be viewable on the 16/9 too. The reverse seems to not be always true.

My doubt comes from these simple statements:

1. with target ratio 4:3 (video tab) source 16:9 and full screen keep aspect ratio (Advanced tab) I've correct proportion in images and can see the whole picture, no cuts. But...

2. I see a bar twice of the one i got when looking at dvd. Half from TMPG coding half added from the player

[mb1]

I understood your question but you didn´t for my answer ...

Ok the long way.

You encoded correctly.

I assume now your Player has not the above mentioned scaling bug. Ok.
To play a 16:9 dvd correct on your 16:9 TV-set you have to set your player to 16:9. With this setting you can´t play correct on a 4:3 TV-set (long faces, eggheads). So for 4:3 Tv-set you have to change to 4:3 LB in players setup.

Now to svcd:

16:9 TV-set
To play your 4:3 svcd (correctly encoded from 16:9 source with letterboxing) you can normally leave your 16:9 player setting untouched, as it will be ignored for svcd (maybe 2-3 players don´t ignore that). If thats right you will see thick black bars on your TV set. Then you have to zoom your 16:9 TV set. "Zoom" is the term used for Sony, others maybe named that "cinema" or similar.
Then playback is correct.

4:3 TV-set
Player setting is 4:3 LB for DVD and SVCD.
Correct playback without need for changings. Thick black bars are correct !
With the above setting 16:9 dvd shows the same thick black bars which is correct.
If you have 16:9 dvd with 16:9 player setting you will have thinner black bars (or none). But thats wrong aspect ratio. You have long faces and eggheads.

More I´m not going to write. If you didn´t understand that you even don´t know anything about aspect ratios ...

[Ubiq]

mb1 I am sorry you feel hurted by me.
The rude (?) part of my second msg was not stright to u.

Btw it's true: I know nothing about aspect ratios... :)

I understend your explenation and is much the same I experimented.
My doubt (on the 4:3 set) was why I am getting half letterboxing bars while watching dvds than svcd, while kepping correct proportion in images. If thick bars in svcd are correct then I've to suppose I lose part (left & right) of the screen while watching dvds. Elsewhere the correct proportion would be lost. That is my player doesn't handle correctly dvds while watching 'em with its "Letter box" option.

I'll keep coding my svcds with the option I'am already using.
And leave with black bars. Thick.

Last but not least thanks for the time wasted in writing.
Writing on a forum is always the last resort I use and thus any help is really appreciated.

Bye

[Gazsi]

UBIQ,

Are you sure you don't loss litle amount of data from the edges?
I ask because i red your message and i gave it a try.
I used Snatch movie form 4000 to 7000 frames. That is when the jews seen on the tv sets, and you easily remember what were on the edges.
My opinion is neither of setting are wrong, i mean always loss a wery little pieces on the left and the right also.

I don't try the custom size....

any suggestion from experted encoders?

[Ubiq]

Gazsi,

I am pretty sure I don't lose anything on the edges. At least with the setting that seems to be the correct one (4:3 target, 16:9 source, full screen keep aspect ratio).
Some other of my tests had (even big) area cropped on the left and right sides.
Me too I am testing with 7/8000 frames.

Ubiq

[Gazsi]

Hi UBIQ,

I used same settings like you and the result was cropping. My DVD player was in 4:3 letterboxing, Source: 16:9, Output: 4:3, Fullscreen (keep aspect ratio). Anyway the Snatch movie is 1.85:1 aspect ratio The lost area is very, very small, i mean very small but there it is.
Please try that movie and see the monitor on the left edge there is a cabinet or locker on the end of the small corridor. If you encode it with the mentioned settings i'm sure you won't see the locker only the little piece of corridor's wall.

[mb1]

TV-Sets have a so-called TV-Overscan-Area.

This area cuts viewable picture for ~8%.

For example, a PAL-SVCD with 480x576 pure picture (no black) will show maximum 448x536.

This can only be verified on PC-Monitors or with special test discs which show the resolution in lines and numbers.

I personally always encode the way that only viewable area is used, so f.e. I have to resize horizontally to 448 and add one black macroblock-row on the left side and another one on the right side (to get 480 again).
Of course you have to calculate proper aspect ratio first.

And sometimes players have some bugs. Not every player handles "Full screen (keep aspect ratio)" the same way. Some do a little to strong zoom up ...

@Ubiq
Your posting wasn´t rude and I don´t feel hurted :)
I think the answers are given ... so let us rest in peace ;)

[Gazsi]

mb1,

I used your recomendations and i set the horizontal size to ~448 and then picture h-size is correct everything was visible on the left and right side also but i didn't follow your recomendations about aspect ratio because i always got a wrong vertical size.
My source is 720x400 DivX movie, settings: (video arrange: center custom size) 448 for horizontal size and 400!!! for vertical and this gives the perfect result on a 4:3 TV like original letterboxed DVD movie. If i downsize the vertical size for keeping the mathematical aspect ratio i will get a smaller vertical size than original. I used TMPGEnc and put a yellow mask around the movie for checking. The output stream was always 4:3 aspect ratio and 480x576 PAL settings.

have any idea...

[mb1]

720x400 DivX has to be resized to 448x400 for SVCD. That´s absolutely correct.

You forgot to consider that DivX has pixel aspect ratio 1:1 whereas PAL-TV-Sets have 1.061 (or correct 1.092 following ITU-R BT.601-4).

Use FitCD and you can play around with the correct values
http://members.tripod.de/fitcd/

Set the resize round to slider to 2 (MMX-optimized).