Aspect Ratio problems when playing on home DVD player

[MedievalMan]

Alrighty.. here's my problem:

I convert DivX movies to SVCD to play on my DVD player. I've burned quite a few already.

I use TMPGEnc standard SVCD settings, all I do is change:

Output YUV... (for better colour)
soften block noise
2 pass VBR instead of CBR.


Anyhoo, when I encode the movie, the movie displays how I want it to (ie how it was displayed in the preview in TMPEnc). The movie file displays fine in Windows Media Player.

However, in PowerDVD or my DVD player, it "squishes" the picture vertically (everyone is fatter).

I can fix this problem for some reason with one of my TVs by just hitting the zoom button , but on other TV's of mine there is no such option.

I thought this might have something to do with the aspect ratios but I've tried to fix it to no avail..

I use CENTER setting to maximize the video that will be shown on a std. 4:3 TV (I don't care if either side is clipped a bit for most movies. :))

Settings like Full Screen (keep aspect ratio) look all wrong, in the preview atleast...

Any suggestions to get rid of the squishiness? :)

[mc4_idea]

I'll take a shot. My guess is you are encoding at 480 X 480 pixels, which looks like a box if you render it like that. But it should be rendered to a 1.33:1 ratio on a DVD player.

I would guess your headers are somehow messed up on your encoder. Check your settings.

[MedievalMan]

Heh.. that's what I'm confused about.

Why is SVCD stnd. (ie if you don't want an XSVCD :)) 480x480 pixels? don't make much sense.

I think what is happening is this:

I want it to look right in 480x480 pixels , so I center it, and it looks right in Windows Media Player and in the preview (it leaves bars on the top and bottom)

BUt I THINK (though I'm not sure) that the DVD player (and power DVD for that matter) goes ahead and "scrunches" the 480x480 pixels till they fit 4x3 screen (and I can't change this for the life of me.. nor can I zoom in on SVCD.)

That would explain why it looks right in Windows Media Player, but not in my DVD :)

My solution:

I tried a short clip with "full screen, keep aspect ratio"
Sure, it looks wrong in the preview, but it seems to come out perfect on a DVD player (and that's what matters for me.. :))

Is this normal? Heh.

[MedievalMan]

Heh.. that's what I'm confused about.

Why is SVCD stnd. (ie if you don't want an XSVCD :)) 480x480 pixels? don't make much sense.

I think what is happening is this:

I want it to look right in 480x480 pixels , so I center it, and it looks right in Windows Media Player and in the preview (it leaves bars on the top and bottom)

BUt I THINK (though I'm not sure) that the DVD player (and power DVD for that matter) goes ahead and "scrunches" the 480x480 pixels till they fit 4x3 screen (and I can't change this for the life of me.. nor can I zoom in on SVCD.)

That would explain why it looks right in Windows Media Player, but not in my DVD :)

My solution:

I tried a short clip with "full screen, keep aspect ratio"
Sure, it looks wrong in the preview, but it seems to come out perfect on a DVD player (and that's what matters for me.. :))

Is this normal? Heh.

[FakerZ]

This seems to be a big problem for some people... getting the right aspect ratio.
Let's make it clearer (if possible).

When you watch a divx on your PC, if you have a full screen picture, it will be 640*480, or 800*600... This is a 4:3 aspect ratio (4pixels horizontal 3pixels vertical). Your standalone player will use a 480*480 pic (in NTSC) and a 480*576 (in PAL) pic and squeeze it to obtain the same result.
If you want to obtain a good-looking svcd, you need to correct some things.

If your original movie is fullscreen 4:3, just resize it to 480*480. If not, it's a bit more complicated, but not too much :)

Imagine you have a 640*360 divx. You must add black borders until you obtain a 640*480 size before resizing.

When you have to add your borders after resizing here's how to do it :
(I'll use the PAL vertical resolution this time)

(360*576)/480 for resizing = 432
Adding borders : (576-432)/2 = 72 pixels top and bottom

More complicated :
A 600*256 divx (could happen, heh ?)

Fullscreen would be : 600*3/4=450
600*450 pic

(256*576(or 480 for NTSC))/450 for resizing = 327.68 = 328
Adding borders : (576-328)/2 = 124 pixels


Easier ?

[Pko]

Originally posted by MedievalMan
Heh.. that's what I'm confused about.

Why is SVCD stnd. (ie if you don't want an XSVCD :)) 480x480 pixels? don't make much sense.


On the contrary, it makes sense because it is a format to be displayed ON TV. The TV has not "square pixels" (as there are on PCs). That resolution gives better quality with less information overhead. but that ONLY on TV. For PCs, usually is better to use squere pixels and that it what, for example, divx does by default.

The 480x480 should be correctly displayed on TV if you do not mess up the aspect ratio information, as it seems you are doing. Both TV player and windvd/power dvd will show it well, and also media player, as long as you instruct them to honor the aspect ratio of the stream.

As I said, forget what you see on TMPGEnc preview; it is show that way because the PC pixels are square, and correcting that will take some processing power that you do not want for a preiew. It is a limitation of the PC screen, not a mistake. If the PC screen could display non-square pixels, it could be possible to show the preview with correct aspect ratio without wasting CPU cycles, but it couldn't.

I want it to look right in 480x480 pixels , so I center it, and it looks right in Windows Media Player and in the preview (it leaves bars on the top and bottom)

No. When you do not let the player to aply the aspect ratio of the stream, you are not wayching ir "right", but precisely wrong!.

Do not try to bend the format, it has been designed to get the best quality of the existing hardware (TV screen), not to look "right" with an incorrect setting in media player!

[FakerZ]

Pko :

Hehe, you seem to be some kind of "specialist" when it comes to players and TV...
Thanks for sharing :)

[Wilbert]

To FakerZ:

Thx, thx and thx. I finally understand some stuff about resizing and so. See below for my problem ...
_____
Explaining to MedievalMan what's going on: Look for example at
" A 600*256 divx (could happen, heh ?)
Fullscreen would be : 600*3/4=450,
600*450 pic
(256*576(or 480 for NTSC))/450 for resizing = 327.68 = 328
Adding borders : (576-328)/2 = 124 pixels" (let's use pal ...)

After resizing to 480 x (a+2b) with "b" the height of a border, "a" the height of the actual picture and with "a+2b = 576" it will be played at 480 x 360 (4:3) full screen. That implies that the height in shrunk a factor of 360/576 = 0.625. The actual picture height is given by "0.625 x a" when played at full screen. Since the original movie is 600 x 256 thus 480 x 205 full screen, that implies that "0.625 x a = 205" and thus "a = 205/0.625 = 205 * 576/360 = 328". Finally you add the borders with a height of 124.

Ok, I don't hope I made it more difficult, but try to make some plots of before and after resizing.
_____

Ok, now my problem. I've captured at 704 x 576 (4:3). I want to resize to 480 x 576, what should I do? If I do it like above I've to resize to 480 x 629 and include borders, since 629 = 576^2*480/(360*704) :)

What should I do ????

[FakerZ]

Tss tsss tsss....

Wilbert : Your capture is a fullscreen 4:3 ? 4:3 would give an aspect ratio of 1.3333, with a 704*576 pic you have a 1.22222 aspect ratio... But...

If your capture was a fullscreen and should be displayed this way, just resize to 480*576.

[Wilbert]

Yes my capture is 4:3. At least if I look at it full screen, the movie is played right. Apperently my movies are stretched when playing them (768x576 ???).

If I resize it (without adding borders) it is displayed correctly when viewing it full screen. But viewing it on my tv (using my dvd-player) I've to stretch the image vertically to play it correct.

(I always resize in VirtualDub, I assume it always maintains the same aspect ratio when resizing?)

What do I have to do to play them correct on my TV (and correct when viewing them full screen on my computer)?

[FakerZ]

If you want your video displayed correctly on your TV, the encoding program must indicate the player to use a 4:3 aspect ratio (this is the default in most encoders) and your pic must have the good fullscreen size (480*576 in PAL).
On your PC, the mpeg2 file (once encoded) should display with the good aspect ratio too, because the media player will use the same settings.

[Wilbert]

"If you want your video displayed correctly on your TV, the encoding program must indicate the player to use a 4:3 aspect ratio (this is the default in most encoders) and your pic must have the good fullscreen size (480*576 in PAL)."

After resizing+filtering with VDub,
I always use TMPGEnc 2.50 with settings:

video --> in the video stream settings:
480 x 576
4:3 625 PAL
interlace

advanced --> in the video source settings:
non-interlace (progressive)
4:3 625 PAL
full screen (keep aspect ratio)

This is correct, no? Still, it doesn't play correct on my TV.


"On your PC, the mpeg2 file (once encoded) should display with the good aspect ratio too, because the media player will use the same settings."

Indeed, I've no problems on my PC.

[FakerZ]

I do not use Tmpeg anymore, but try setting the source to 1:1 VGA...
But I'm not really sure. Some Tmpeg experts here ?

[balbrain]

Ok Does that mean that of I use DVD2SVCD (in which case it just resizes and NTSC disk to 480*480), it should play wothout aspect ratio problems on a supported standalone?

Thx

[Wilbert]

To balbrain:

Sorry I don't use DVD2SVCD, have you read the guide for this at this site?

To FakerZ:

I made a typo, my settings in TMPGEnc are:

video --> in the video stream settings (you can't chose the first two):
480 x 576
4:3 display
interlace

advanced --> in the video source settings:
non-interlace (progressive)
4:3 display
full screen (keep aspect ratio)
-----

Ok, I will try setting the source to 1:1 VGA. But besides doing this I also will try to crop to 704x528 before resizing and try to capture to 640x480 directly (and resizing both to 480x576).

[Pre]

You can use FitCD (http://mitglied.lycos.de/fitcd/)to calulate the right resize of the movie including the "overscan problem" and maintain the aspect ratio. Read the help file. In tmpgnec, advanced tab, choose center custom size and enter the resize that FitCd calculated for you. If you planning a 16:9 movie, dont bother to set the dar flag to 16:9, since non dvdplayers can read this right.

hope it helps

Pre

[Wilbert]

To Pre:

I will try that program if I've some time. (I want to make a 4:3 movie.)

If I choose "center (custom size)" in TMPGEnc 2.52 and the other setting "4:3 display", "4:3 625 PAL" or "1:1 vga" in video source settings then I am not being able to play them correctly in full screen on my PC (using a mpeg2-codec or a mpeg2 software player).

[Wilbert]

To FakerZ:

Ok, I did some testing. Results:

I captured from my normal tv to 704x576 (no cropping or adding borders at this stage). I resized to 480x576 in VDub.

In TMPGEnc I used the video source settings:

1) 4:3 display + full screen (keep aspect ratio)

2a) 4:3 625 PAL + full screen (keep aspect ratio)
2b) 4:3 625 PAL + center screen (keep aspect ratio)
2c) 4:3 625 PAL + center screen (custom size)

3a) 1:1 vga + full screen (keep aspect ratio)
3b) 1:1 vga + center screen (keep aspect ratio)
3c) 1:1 vga + center screen (custom size)

results:

Only one of them plays correctly on my PC when viewing full screen, that's the first one (1). Looking at my tv I've to stretch vertically to "not see the black borders" and to "see the picture correctly".
(If I don't watch full screen, 2c or 3c (sorry I forgot which one, and I'm not home now) plays correctly at the size you entered).

From (2) and (3) I only burned (2a) on a svcd and surprisingly it played correctly on my tv without stretching. The only problem is that black borders are added at all four sides around the picture.

I also cropped to 704x528 before resizing in VDub. Of course there's a tiny difference (less picture and or less black border). But I didn't notice much difference.

What do other people do when capturing and encoding to svcd? Do they use TMPGEnc also for resizing?

[Pre]

Your source is 704*576, i would try to resize to 448 * 542.Tmpgenc adnvacd tab: 1:1 vga and center custom size 448 * 542. I don't think your movie will not look right on your PC, but the standaolne dvd player will streched the movie out. So it will look fine in your TV :) Set the dar flagg to 4:3


Hope it helps

Pre

[FakerZ]

I don't use tmpeg, that's why I can't really help you here, but I'm still wondering why there is so much problems with it. 480*576 means fullscreen in svcd. If the DAR was set to 4:3, why is your pc playing it wrong ?

Same question as before : some tmpeg experts here ?

[Wilbert]

To FakerZ:

I think you misunderstood. When I set the video source setting to "4:3 display" and "full screen keep ar" in TMPGEnc it plays fine on my PC. Viewing it on my tv I see black bars and have to stretch the image vertically to get a normal picture.

To Pre:

I will try to do what you said.

[Wilbert]

To Pre:

Thanks for the pointer to the program FitCD, it's very nice. It suggested indeed a resize to 448 x 544.

It played correct on my PC (viewing it full screen). On my tv I had to stretch it again vertically to get rid of the two black bars and to see it correctly (problem of my dvd-player ?).

If I understand it correctly, after resizing to 448x544 four black borders (4x16) are added to obtain the resolution 480x576. I guess this is what TMPGEnc does if you do it the way you said.

But I don't understand why you should resize it to 448x544 (plus adding four borders) in order to play it correctly full screen.
Why not 480x"some thing" or 416x"some thing"?

[Pre]

You have to add boarder's cause every Tv has overscan, the way to comprehense to this you add boarders to the movie, so you maintain aspect ratio. Otherwise you will not se the hole movie, simply cause your TV cuts the edges, and here is where the aspect ratio get's fucked up! But FitCd i indeed a neet program, hope more people will get there is and use it.

Pre

[Wilbert]

"You have to add boarder's cause every Tv has overscan, the way to comprehense to this you add boarders to the movie, so you maintain aspect ratio. Otherwise you will not se the hole movie, simply cause your TV cuts the edges, and here is where the aspect ratio get's fucked up!"

You mean it cuts the left and right edge? I didn't notice that, I will have a look tonight.

For my other question. Suppose you choose 448 for the width, then why do you take 544 for the height? How do you calculate that?

I guess resizing to a smaller format is also better for the total number of macroblocks, in case the movie is to blocky when resizing to a format with more macroblocks.

[Wilbert]

Ok, I know why my mind was blocked ...

The problem is that 704x576 = 1.222 < 1.333. So if you want to do it correctly it must be cropped to 704x528 (=4:3) and after that resized to (note that 480/576 = 448/537.6)

full screen will be 448 * 3/4 thus
448 x 336 pic

so the vertical resolution must be resized to 336 * 537.6/336 = 537.6

which becomes 17*32 = 544