Determining Aspect Ratios and Resolutions

[danvx6]

Hi. I'm encoding an AVI file that has no letterboxing with CCE SP to MPEG2 format. The source AVI has the dimensions 720 x 384 and an aspect ratio of 16:9 according to MediaInfo. My problem is that the MPEG2 is always either stretched or squished vertically and has letterboxing that wasn't there before. When I divide the width by the height as you say, I get a ratio of 1.875:1. CCE only doesn't allow me to use a ratio like this (only 4:3 and 16:9). Should I resize the video or will I be able to proportion the video properly with a different encoder? Thanks!

EDIT: I've figured out what to resize my video to in VirtualdubMod (720 x 540), but I can only resize in full processing mode, which will end up generating a 100 GB+ file! I only have an 80 GB hard drive (which is 90% full), so an alternative is NECESSARY. Is there any way to cut down the file size?

EDIT 2: If I am able to get a large hard drive from a friend and I successfully resize the video, will the file still be enormous when i convert it to MPEG2?

[manono]

Hi-

Learn AviSynth, and use FitCD to do the calculations. This is for PAL DVD, right? With ITU resizing on, I get:

AVISource("C:\Path\To\Movie.avi")
LanczosResize(720,546)
AddBorders(0,15,0,15)
ConvertToYUY2() #Probably a good idea

And encode for 16:9. Or you can frameserve using VDub, but it's slower, produces inferior results, and is obsolete. There's no need to make an uncompressed AVI, and if you did, don't use the uncompressed VDub default, but Lagarith or HuffYUV.

Should I resize the video

Yes, of course. CCE won't do it for you automatically, although TMPGEnc and other encoders can do it.

[DJRumpy]

Remember an mpeg's physical dimensions cannot be used to determine it's aspect ratio directly. The display aspect ratio embedded in the mpeg is the key. If your video (avi) has a 16:9 ratio, and you want to place it into an mpeg, your mpeg will look stretched. That is normal. On playback in a player that understands mpeg display ratios (like a dvd player), it will be properly proportioned assuming you have encoded it properly. For a dvd mpeg (720x480 or 704x480), it should not have letterboxing at all. For an SVCD, it would have letterboxing in order to fit properly into the SVCD's 4:3 aspect requirement. For SVCD the image area would be 480x360 with letterboxing filling in the 360 to 480.

What format are you encoding to?

[Steve Walsh]

I've looked at all the guides I can find, tried online calculators etc... but I'm still going wrong somewhere ?
I've got an avi - 624 x 352 - that I want to encode for PAL 16:9 DVD.
Using HCenc I've tried many different avisynth scripts along the lines of :

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(720,400)
AddBorders(0, 88, 0, 88)

but the picture is always cropped at each edge.
Using :

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(624,352)
AddBorders(48, 112, 48, 112)

fills the widescreen tv (always set to 16:9) at the right size/aspect with only small visible bars at either side (as well as top/bottom) but obviously this is not the most efficient.
Please can you help me understand what's going wrong ?
Thanks.

[DJRumpy]

Your avi is a 1.77 video. For dvd, it would be resized to the edge with no letterboxing.

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(720,576)

I'm assuming you're putting commands in to change the speed from 23.976 to 25 fps.

[Steve Walsh]

Thanks for quick reply.
I changed fps using virtualdub for video, besweet for audio (+ac3 conv).
finger crossed - everything ready now... Thanks again.

[Steve Walsh]

I'm afraid that using :

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(720,576)

doesn't solve my problem !

It looks fine on PC (played with videolan) but when seen on the TV the left and right edges are missing (the picture fills the screen though - no black lines at top/bottom)!

I've checked and the TV is set to "widescreen" (not 4:3, superlive etc...) and the DVD player is also set to 16:9 widescreen.

Any ideas why I'm not seeing the full picture ?
Thanks

[DJRumpy]

You do realize that your TV always cuts off the edges of your video? The amount is very small in the larger view of things. It's called overscan. Remember your TV is not a computer monitor. It does not display 'edge to edge'.

Normally the amount of overscan is usually somewhere around 20 or so odd pixels per side, which would amount to less than an inch on most medium sized sets. You can compensate for overscan by adding letterboxing to your video's outer edges, but it's a bit extreme for such a small number of pixels. To do so, you would simply resize your image downward by a small number of pixes on all sides, and then add letterboxing to those area's. I would try a small test clip, as the amount of overscan varies for each tv. Try starting with a small number like 8 pixels per side. If we shrink your total images width by 8 pixels on the left and and 8 pixels on the right side of your TV you end up making room for an additional 16 total pixels in your overall width (720 - 16 = 704). In order to fill out that newly available space so that our width is still 720 we add letterboxing (black edges) to fill out the 704 width back to 704:

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(704,576)

Note that you resized to 704 instead of 720 (720-16=704). We've shrunk the width by 16 total pixels.

Now we just add letterboxing to fill up the newly available space on the edges. Again we add back 16 total pixels in letterboxing (8 + 8):

AviSource("C:\MPEG2\test1.avi")
Lanczos4Resize(704,576)
AddBorders( 8,0,8,0)

If you want to do both the top and the sides, then it might look like this:

AviSource("C:\MPEG2\test1.avi")
LanczosResize(704,560)
AddBorders(8,8,8,8)

That's the basic concept for letterboxing via the AddBorders and resizing your image. If you want to be exact with respects to the aspect ratio of your television, you can multiply the width and height of your tv screen in pixels by aroud 6% to get a good number. You would do this because your televisio is not perfectly square. Since it's a bit wider than it is tall, you would end up taking a bit more off the sides than the top to keep the aspect correct. If you have a 4:3 television, you would use 640 for the width (640*.06 = 38), and 480 for the height (480*.06=28). Round both of those values to the nearest 4 (40 and 28 respectively).

Using the above values, we would shrink the left and right side by 20 pixels each (40 pixels total) and then add 20 pixels of letterboxing on each side to compensate (again adding back 40 pixels total in letterboxing).

We would shrink the top and bottom by 14 pixels (14*2=28 total pixels) and add 28 total pixels of letterboxing back in to compensate:

AviSource("C:\MPEG2\test1.avi")
LanczosResize(680,548)
AddBorders(20,14,20,14)

Approximately how much is being cropped from the sides? Are we talking a huge amount or just a piece of the edge?

[G28]

Very informative guide. If I am creatiing a after effects animation from scratch not importing any video. The after effects file will be authored by DVDit! Pro 6 and then the DVD will be played off a standard DVD player onto Christie LX-45 ZProjectors onto a DaLite Cosmopolitan Electrol Screen, actual screen size of screen 78"x139" HDTV format (16:9).

Those are the details, I am struggling with what I should set my composition settings in after effects to, for widescreen to play off the dvd?

Any help?

[DJRumpy]

If your content is widescreen, then encode it as widescreen. It will automatically be adjusted to the proper aspect on playback. Otherwise treat it as fullscreen 4:3 video.

[G28]

Thanks, so the actual setting in after effects would be NTSC DV Widescreen, with a frame pixel ratio of 1.2. Does that sound correct? I wouldn't want it to be letterboxed and I would want it to cover the entire screen once projected? or is that just something you have to test? And by the way, this is off topic but would you know if DVDit Pro 6, is built for the mac platform and if not are there any other DVD autoring programs for the mac other than DVD Studio Pro?

Thanks so much, -G

[DJRumpy]

Again it just depends on the aspect ratio of your source material.

If your aspect ratio it 1.78 and you are displaying it on a widescreen display then it will completely fill up the screen with no letterboxing. If you can make your project fit a 1.78 aspect then that's what I would choose for a widescreen option.

If you do not want a 4:3 television to letterbox your material, then don't choose widescreen, go with a 4:3 (1.33) aspect ratio.

What aspect ratio is your source material?

[G28]

ok, so my source material I am creating in after effects, so I can set it to any aspect ratio that I want. I am bringing in imagery from Photoshop and using type in after effects. But this needs to go on a DVD so, well here's a pic of the setting. the Frame aspect ratio is at 9:5 which is the same 1.78. But is the resolution to right because that says 720x480 3:2 aspect ratio? I am adding a pic to show you my settings.



picture%201.pdf

[DJRumpy]

Aah. I understand. Select a Widescreen 1.78 aspect ratio at 720x480, but only if your projector is capable is displaying a widescreen aspect. Otherwise the playback software is likely to add letterboxing if your projector presents only 4:3 aspect ratio's. If it only supports 4:3, then go with a 4:3 aspect ratio (720x480)

[G28]

ok, got it. thank you so much, this has been VERY helpful!

[G28]

one more thing, you mentioned the projector being able to support the widescreen format, here is a link to the projector, I don't see were it supports 16:9 widescreen? It must though because it's a high end HDTV projector that will be attached to the DVD player.

http://www.christiedigital.com/products/lx45/lx45Specifications.asp

[G28]

when I look at the widescreen setting "NTSC DV Widescreen" it doesn't look right. Your saying when it is projected it would look widescreen. I;ve attached two setting pics with the composition. The setting of 864x486, would be wrong? correct?

picture%203.pdf

[DJRumpy]

It is 16:9 compatible. It has the standard set of 16:9 hdtv modes (720p/1080i). I wouldn't use the Lock Aspect Ratio to 3:2 though. That would give you a 1.5 aspect ratio. The rest looks fine. Your video should look a bit 'tall' if your viewing the raw images in 720x480. When they are stretched out to a widescreen display they will look normal. If in doubt, just encode a small sample on RW media.

[G28]

great, thanks. So, my settings are all figured out at NTSC DV Widescreen, 720x480 aspect ratio 3:2 and pixel aspect ratio at D1/DV NTSC Widescreen (1.2), Frame aspect ratio: 9:5, fps 29.97, color is at 8bpc.

Now, when I output my movie, for the settings I leave it at full quality, Quicktime, Animation 100%, no compression. So when I view it in Quicktime it looks distorted and that's fine, but when I try to bring it into iDVD (Apple) the movie still looks distorted in iDVD and when I try to burn a disc it says, "please check project, validation error"?

Would you have any suggestions?

[DJRumpy]

At a guess I'd say your framerate is wrong. You should be able to duplicate frames to get the framerate to 23.976 frames per second, and the dvd software should be able to do the rest with pulldown.

[G28]

well, I changed the frame rate to 23.976, and now it burned, it works! But, when I play it on my computer through apple's DVD player it is not in it's widescreen format, it still looks like it's 4:3. Shouldn't it play correctly through your DVD player on your computer or not?

[DJRumpy]

It should play correctly on your computer using DVD software. You can use AVICodec (check the tools section) to examine a few of the VOB's to make sure they are listed as 16:9 and not 4:3. You can also use IFOEdit to examine the IFO to make sure it's correctly set to 16:9 as well.

[TheClaus]

First off this has been a real eye opening experience and great guide but I do have some issues that I hope you can shed some light on.

I am trying to convert The Incredibles DVD which is 2.35:1 to XviD. Now when I play the DVD on my Widescreen TV I get no black bars. However when I use AutoGK or AVI.NET or Fairuse Wizard I get a resolution of 640x272 and when I play it on my TV regardless of what pic size I choose I get the black bars.

The DVD Player I am using is Phillips 642DVP. The DVD plays without black bars and the XviD encode on the same player gives the black bars.

How would I go about making the XviD the proper resolution so that I don't see the black bars like the DVD.

[j1d10t]

Well, you should see black bars on your widescreen TV - your TV is 16x9 ( 1.78 ) and the movie is 2.35:1.... So there there should be small black bars on the DVD to maintain the correct aspect ratio....

But if you want the movie to fill the screen you can resize the image to 640x360 - that will of course make evething look tall/thin because it will be stretching the image vertically.

[FulciLives]

First off this has been a real eye opening experience and great guide but I do have some issues that I hope you can shed some light on.

I am trying to convert The Incredibles DVD which is 2.35:1 to XviD. Now when I play the DVD on my Widescreen TV I get no black bars. However when I use AutoGK or AVI.NET or Fairuse Wizard I get a resolution of 640x272 and when I play it on my TV regardless of what pic size I choose I get the black bars.

The DVD Player I am using is Phillips 642DVP. The DVD plays without black bars and the XviD encode on the same player gives the black bars.

How would I go about making the XviD the proper resolution so that I don't see the black bars like the DVD.

A widescreen TV is 16x9 or roughly 1.77:1 so a movie that is 2.35:1 and anamorphic enhanced will still have SOME black bars below and above it.

What is happening in your case is that your DVD source is 2.35:1 but 16x9 WS enhanced ... the MPEG-4 you are making is also 2.35:1 but is not 16x9 WS enhance ... it is 4:3 Letterboxed.

To make a 16x9 WS MPEG-4 from a 16x9 WS movie at 2.35:1 you would have to crop from 720x480 to 720x272 and then resize that to approximately 640x352 for the MPEG-4.

The problem is ... very few (if no) stand alone DVD/MPEG-4 players can properly handle a 16x9 WS MPEG-4 file. I am almost positive that this includes your model.

The alternative method?

Do as I said above but when you resize to 640x352 ... add 64 of black on the top and bottom so you have 640x480 total.

Now it should play back OK but only on a 16x9 WS TV and even then it depends on your TV being able to "force itself" into 16x9 mode even though the Philips will be telling it the source is 4:3 instead of 16x9.

Of course maybe the Philips can handle a 16x9 WS MPEG-4 correctly as long as it is "flagged" as 16x9 WS but I thought it lacked that ability.

- John "FulciLives" Coleman

[TheClaus]

Thanks for the quick replies.

I am still trying to retrain myself on using the old methods of vdub. Though from a guide I found here I have seen the results of the resize and I am liking what I am seeing so far.

Thanks again. You guys are very helpful and was a welcome change from doom9.

[TheClaus]

Thought I would give you a little update. I finished my encode and it looks very nice. I cropped the black bars and then resized and it turned out very nice.

Cropped 720x480 -> 720x356

Resized 640x360

It looks great and I am happy. The only thing that I couldn't get quite right was the size of the file. I was going for 896mb and it came out to be 901.

Thanks again for your help

[DJRumpy]

If you wanted to get rid of the vertical bars, you should have simply converted your video to 1.77 aspect, and left it as widescreen so it displayed properly on a 4:3 display as well as a 16:9 display. You would simply crop off some of the horizontal, and all of the letterboxing (crop the video to 640x360) and then resize it to 720x480, and burn it as widescreen. You would have a true 16:9 widescreen video, which would play properly (with letterboxing) on a 4:3 display. On a widescreen display, it would be fullscreen

Just make sure you encode it as 16:9, and not as 4:3.

[FulciLives]

If you wanted to get rid of the vertical bars, you should have simply converted your video to 1.77 aspect, and left it as widescreen so it displayed properly on a 4:3 display as well as a 16:9 display. You would simply crop off some of the horizontal, and all of the letterboxing (crop the video to 640x360) and then resize it to 720x480, and burn it as widescreen. You would have a true 16:9 widescreen video, which would play properly (with letterboxing) on a 4:3 display. On a widescreen display, it would be fullscreen

Just make sure you encode it as 16:9, and not as 4:3.

Hey you!

Where have you been hiding?

So many "old timers" not posting these days.

Makes me sad

Stick around some

- John "FulciLives" Coleman

[DJRumpy]

lol..I was thinking the same thing about you. I'm still around and about. I don't do much converting these days since I put the media pc together. I just leave it 'as is'. About the only thing I burn to DVD anymore are backups, and the occasional HDTV .TS to XVID. I'm exploring backing up my entire DVD collection to .X264 or possibly XviD. I'm doing the dry runs now to find a good bitrate/resolution balance considering I've only got 350 GB or so to work with.

I still get the occasional e-mail on my guides, and every so often I try to check on these to see if anyone has posted any questions. For some reason it no longer notifies me when somone posts, but my e-mail notices still work

I always get a grin when I see someone referencing one a guide form the old crowd in here. Kind of funny when you do them, you would never expect they would propogate they way they do. I still get hits to methods you've done in the past. I should probably try to be a little more pro-active. Don't want Baldrick to wack my account for inactivity!