Resizing a PAL to NTSC conversion

[buddycat]

Here are my stats from Fit CD on the vid I dowloaded supposedly already converted to NTSC:

The aspect is 1.3674

LanczosResize(672,448,0,0,720,480)
AddBorders(24,16,24,16)
#Trim(0,77617).FadeOut(150)
ConvertToRGB24() # For TMPGEnc or VFAPI

The source window says 720 by 480. but there appear to be small borders top and bottom in aspect window. Now, I do notice that the IT URBT 601.4 is checked. When I uncheck it, I notice the aspects change to 1:3333 and 1:3348. Does this make a difference?

When I look at this in Nero, it appears the picture is a little squashed from the sides. Has this been formatted to 4:3 and I'm trying to encode it for 16:9? When I see the show broadcast over here, I think it's more letterboxed. Any ideas on how and whether I should re-size and with what borders?

[guns1inger]

Use g-spot to tell you what you have. Use the 2.52b beta version if the source is mpeg encoded.

[buddycat]

G=spot says the original is a divx file. The x:y file info says - 720x480 (1.50:1) [=3:2]. Is there something else I should be looking at?

[guns1inger]

If it is already DVD res (which it is) then you don't need to resize in avusynth unless you want to add broders. In your case, you have added borders, which is why you see them in the FitCD pane.

If the file is already anamorphic - i.e. it appears stretched vertically (or squashed horizontally - semantics), then you should be able to simply load it into tmpgenc and encode it as 16:9. When played back the player will adjust accordingly.

If it is letterboxed - i.e. it already has black bars top and bottom - and you want to create a 16:9 file then you need to first crop 60 pixels from the top, and 60 from the bottom, then resize it back to 480 pixels, then encode as 16:9.

At the moment it appears that your fitcd settings are adding the border when you don't actually need to use fitcd at all.

[buddycat]

Hmm. Well, when looking at Fit CD on the left hand side, it seems to show very small amounts of border all the way around. Maybe I just need to do a test burn and see if the player makes it look right. It's just that all my other letterboxed downloads come out okay, and this is the first one that doesn't look right when I'm working to author it in Nero.

Here's what it looks like. But you think I don't even need to bother with it?

[guns1inger]

I am confused by the subject title - where is the PAL part ?

You have NTSC resolution source, which you want to encode as NTSC mpeg2 output - yes ?

What are you actually resizing ?

The script you are producing is going to add borders to your video. Is this what you want ?

[buddycat]

Ah, it was convereted to PAL and then uploaded as an NTSC file. I was presuming it kept the same screen format, but I guess not.

[guns1inger]

That doesn't make any sense. Converted from what to PAL ? And then to NTSC ? Assuming there was PAL somewhere in it's dim dark past, there is no indication of PAL in anything you have presented to date.

I still don't understand your problem. You want NTSC output, you have NTSC source (correct resolution, correct framerate). So where is the issue ?

Can you post a screen shot to illustrate what you are trying to change ?

[buddycat]

Hello.

I'm back, still trying to get this right. I'll post pics shortly. I was re-reading this and noticed that you said that the player will adjust accordingly. I'll have to check this. I've run a couple of experiments. I've encoded for 16:9, but things still look a bit squashed when I play it on the TV. Now, the file says 720 x 480. I think the first time I did it I don't remember what aspect I used as the source. Since the show was shot over in England as 16:9, should I show the source as such? I did a test as 16:9 as the source and encoded as 16:9, but the the picture looked a little squashed from the top and bottom this time. Do I need to custom re-size it somehow, keeping the width but widening it a little top and bottom?

[buddycat]

Perhaps I need to re-script so there is no re-sizing and then encode as 16:9 in TMPGenc?

[manono]

The FitCD pic from earlier shows you set it up as a 4:3 source, intending to encode it for 4:3. Maybe that's why you get bad aspect ratio when encoding for 16:9, if the source really is 4:3.

If the source is already 720x480, I have no idea why you're adding the blocks overscan. You're lowering the resolution and forcing a resize. If resizing isn't absolutely necessary, I wouldn't do it, if I were you.

G=spot says the original is a divx file. The x:y file info says - 720x480 (1.50:1) [=3:2]. Is there something else I should be looking at?

So either the original encoder didn't know what he was doing, or he expected the player to resize. You'll have to use a player that can switch between 4:3 and 16:9 resizing. I might suggest Media Player Classic. Tell us which looks more normal, and then the script will be easier to generate.

[buddycat]

Okay, explain what "blocks overscan" means. I just plugged in the avi and that's what I got. I didnt' change anything. This may be left over from anime I've been converting(?)


Also, I see I wasn't paying attention to what I posted before: I should have said this file was converted from PAL to NTSC, which I downloaded.

[buddycat]

Maybe I've been misunderstanding some of the fundamentals of display. If the file is 720 x 480, should I encode to the aspect as 4:3 or 16:9?

[buddycat]

I just ran one test where I removed any overscan and the source was 4:3 and the asect display was 4:3. I wound up with huge borders all the way around and the same slightly squished from the sides look.

[guns1inger]

Your file is already DVD resolution. Unless you need to add borders, you don't need to use fitCD. You may not even need to use an avisynth script, but if you do, you don't need much more than

AviSource("path to file")
ConvertToRGB24() #assumes Tmpgenc is your encoder

As for 16:9 versus 4:3 - that depends on how the image looks. If it looks pretty much normal, go 4:3. If everyone looks tall and thin, encode as 16:9. This is something you do in your encoder, not the script.

[manono]

This is something you do in your encoder, not the script.

Yes, unless the source is 4:3 (widescreen, I guess), and he decides he wants to encode for 16:9, as I think he has already tried. If that's the case, then FitCD will generate a good script.

Okay, explain what "blocks overscan" means.

Did you get that one figured out? I can't tell. In FitCD you had Blocks Overscan set for 2. Maybe it's a default setting, I don't know. This added an AddBorders line to the script that added black on all 4 sides of the video. The idea behind this is to account for the TV set's overscan, so you see the complete picture, something I don't agree with, unless you might lose some burned in subs because of the TV verscan. In my opinion, the Blocks Overscan in FitCD should be set for 0. Different people have different opinions on that. But the fact remains that by adding Blocks Overscan and forcing a resize you lose both resolution and quality.

If the file is 720 x 480, should I encode to the aspect as 4:3 or 16:9?

Kind of depends on what it was originally, 4:3 or 16:9. I'd recommend keeping it what it was. If, as seems to be the case, it was 4:3 originally, I'd recommend encoding for 4:3. Then you'd feed guns1inger's basic script into TMPGEnc.

[buddycat]

I tried removing all the borders, and encoded for 16:9 and it looks "okay". So I'm not sure if it's just me or what. When I play it, there's still a small border on the sides and larger ones on the top and bottom. Somehow, though, the people look a little "wide". When I have some time, I'll post some pics and you guys can decide if I'm just overly picky or what.

[manono]

I expect you removed way too much black bars. You don't remove them all (especially if it's a 2.35:1 movie being encoded for 16:9). My guess is that the reason TMPGEnc does it wrong is because it expects AVIs to be 1:1 and yours isn't. It was never resized properly, so it's a 4:3 source.

And it could also be some setting in TMPGEnc you screwed up, that had it add the wrong amount of black bars. I can't help there, as I don't use TMPGEnc, but you had better list your encoder settings if you want help on that one.

Look, this isn't rocket science. If your source is NTSC 720x480 4:3 (as seems to be the case) and you want to encode for 4:3, then you drop guns1inger's basic script into TMPGEnc. If the source is 4:3 and you want to make it 16:9, then:

AviSource("C:\Path\To\Movie.avi")
Crop(0,60,0,-60)
LanczosResize(720,480)
ConvertToRGB24() #assumes Tmpgenc is your encoder

If it turns out wrong, then you set something up wrong in TMPGEnc.

[buddycat]

I'll post images shortly. You might be right, but I still think it's wide-screen.

[manono]

...but I still think it's wide-screen.

I do, too. I think it's 4:3 widescreen. You seem to think that widescreen is by definition 16:9, and that's not true.

[buddycat]

Aha. You're correct. Myabe that's part of my confusion.

[buddycat]

So here is a capture from my monitor and the way it looks on my TV when I play it. AS you can see, it looks a bit squished.



test%20pic1.jpg

[buddycat]

Double checking, it doesn't look quite so bad on the TV: the borders on top are not visible. But it's still slightly elongeated. Now, watching the show on the network, there appears to be about a 1 3/4" border on the tops and bottom and none on the sides. As you can see by the pic I posted, that border is a lot narrower. So what do I need to do to get that same approximate border as the broadcast?

[guns1inger]

I think part of the problem is the original file. It's not correct in it's own right. The following script crops the existing borders off, then resizes and adds new borders top and bottom. You can use this as a basis to get everything else correct. This assumes, of course, that the still you posted is identical to video

AviSource("C:\Path\To\Movie.avi")
Crop(8,22,-12,-24) #Crop all borders from video
LanczosResize(720,372) #Resize video to correct res
AddBorders(0,54,0,54)
ConvertToRGB24() #assumes Tmpgenc is your encoder

[buddycat]

Okay. Let me give that a shot and I'll report back. Thanks!

[buddycat]

Okay, so here's what it looks like with the new script. That looks pretty darn close! I think at this point, the actors are just a bit skinny - especially the Doctor.

I think the initial problem you surmised is correct - they did a straight conversion from PAL to NTSC without the proper re-adjustments. But, hey, beggars can't be choosers. Some generous soul it going to the trouble of converting them and posting them in NTSC every weekend, and I'm glad to have them, especially if I can fix the problem with great help like yours!

Thanks!

Here's the adjusted pic.



test%20pic%202.jpg

[buddycat]

So before I go, could you explain the resizing to 720 x 372, rather than 480? Or at least point me to a discussion? I obviously am not quite clear on the widescreen vs. 16:9 thing yet. Could I do this on the fly in TmpGenc? (BTW, this time I encoded the source as 4:3 and the output 4:3).

[Pinstripes23]

So before I go, could you explain the resizing to 720 x 372, rather than 480? Or at least point me to a discussion? I obviously am not quite clear on the widescreen vs. 16:9 thing yet.

It's cuz the addborders command counts in the final resolution - 372+54+54 = 480 for a 4:3 conversion. Looking at your screenshot you can encode it as 16:9 WS as opposed to 4:3 letterbox WS. It might make the AR better since you said the Doctor looks skinny. You will just have to adjust your script like this:

using guns1nger's sample:

AviSource("C:\Path\To\Movie.avi")
Crop(8,22,-12,-24) #Crop all borders from video
LanczosResize(720,480) #Resize video to correct res
ConvertToRGB24() #assumes Tmpgenc is your encoder

Just get rid of the addborders command and change the vertical res to 480

Then just feed this script into your encoder and encode as 16:9. Encoding to 16:9 automatically squeezes the vertical resolution, so you don't have to add borders to the top and bottom.

[guns1inger]

There are three basic display formats; 4:3 (fullscreen), 16:9 letterboxed (16:9 image in a 4:3 frame) and true 16:9 (or anamorphic). For NTSC, all fit within a 720 x 480 pixel resolution. A 4:3 image a nd a true 16:9 image will fill the full frame with image. The 16:9 image will necessarily be distorted. A 16:9 letterboxed image will fill a 720 x 360 image area, and fill the rest out with black bars top and bottom.

In your case, you have letterboxed image, however it has been incorrectly resized during a previous conversion. Because of this, it actually seems to occupy an image area close to 720 x 372 (not exactly, but close - you need to keep playing to get it exact), rather than 720 x 360, which you would normally expect.

In an ideal world, the script manono supplied would do the job - crop the bars, resize for true 16:9 and encode. Because of the distortion in your source, you can't use that method. My script removes the existing borders, attempts to resize for a letterboxed display (again, the 372 is close, but not quite exact), then adds borders back to fill out the image. If you can work out exactly what the final resolution of the visible image should be, you could crop it correctly and resize for 16:9 display, but this would require cropping some of the image itself, not just the borders, or adding vertical borders to the edges.

You might be able to do this in tmpgenc alone, but I haven't used it in so long I could not tell you how. Personally I would stick with avisynth, and even consider adding something like asharp into the mix to improve the quality along the way.

[buddycat]

You might be able to do this in tmpgenc alone, but I haven't used it in so long I could not tell you how. Personally I would stick with avisynth, and even consider adding something like asharp into the mix to improve the quality along the way.

When you say "stick with avisynth", I'm not sure how to do that, but using the asharp sounds lilke a plan. You advised me on the settings for anime - would I use the same ones?

I am using using the script you provided above, by the way. So I could easily add asharp to the mix.

I think I will try using 16:9 as the output source, just for grins, before I encode it for real.