Video Size.

[biferi]

I would like some help with Understanding How Video Size works?

I know when you make a video the standard RES. is 720x480 for both 4:3 None Widescreen and 16:9 Widescreen.

But I want to know if I make a JPEG Image and export it and I want it to fill the whole screen I thought I export it as 720x480 pix.

But it does not fill the screen.

So if my project is a standard 4:3 720x480 and I want my JPEG to fill up the whole screen what do I export it as?

I know years ago 4:3 was 640x480 but now the sctreen is 720x480 RES.

Can sombody help me?
I am in the USA.
Thanks.

[jagabo]

AR = width : height
AR = width / height
height * AR = width

480 * 4 / 3 = 640
480 * 16 / 9 = 853.333. Or 854x480.

[JVRaines]

I think you're talking about DV resolution, which uses rectangular (10:11) pixels. It also has 8 extra pixels on the left and right sides to accommodate timing irregularities in converted analog video, so it's a tad wider than 4:3. Depending on your software, you probably have to create your still image in the equivalent square-pixel resolution, which is 655 × 480.

[johnmeyer]

FWIW, I always use 656x480, rather than 655x480, when I capture an image from an SD video and then re-import it for a still or overlay. I find that most programs are "happier" dealing with images stored with an even number of pixels in each direction, especially those which are divisible by 4.

[jagabo]

It depends on whether the editor uses ITU resizing (where the 4:3 or 16:9 image is in a 704x480 sub-portion of the 720x480 frame) or MPEG resizing (where the 4:3 or 16:9 image is in the full 720x480 frame).

[biferi]

Well let me start over.

I have a JVC Digital Video Camara.

And I can take Videos at 4:3 witch is 640x480 or I can take Videos at 16x9 witch is 720x480.

So I take my Videos at 720x480 and all is good even when I play back.

Now at some point in my Video I am going to put a JPEG image on screen that I want to cover the whole 720x480 video.

So when I export my JPEG image what Pix. size do I export it as?

This is what I should have asked.

[jagabo]

As was pointed out, it depends on the software you're using. Just try all the possibilities mentioned and see which works for you.

[biferi]

OK I found some information.

In my Video Editor I have my project setup as 720x480.

But I can pick all these diferant Pix Aspec Ratios
1.0000 Square.
0.9091 NTSC DV.
1.2121 NTSC Widescreen.

Now I would gather if I am going to be showing this on a Widescreen 16:9 TV I keep it as 720x480 but I pick a Pix of 1.2121 NTSC Widescreen.
So what is
1.0000 Square.
0.9091 NTSC DV.
for?

I read and read but can not understand what is going on.
Can anybody tell me?
Thanks for the time.

[jagabo]

Square pixel (1:1, 1.0) is for when DAR = FAR (frame width / frame height). 0.9091 is the aforementioned ITU pixel aspect ratio where the 4:3 image is in a 704x480 frame, or portion thereof.

DAR = FAR * PAR

DAR = display aspect ratio, the shape of the displayed picture
FAR = frame aspect ratio, the width:height of the stored frame
PAR = pixel aspect ratio, the width:height of individual pixels

DAR = FAR * PAR
DAR = 640:480 * 1:1
DAR = 640 / 480 * 1 / 1
DAR = 640 / 480
DAR = 1.333 = 4:3

DAR = FAR * PAR
DAR = 704:480 * 10:11
DAR = 704 / 480 * 10/11
DAR = 704 / 480 * 0.9091
DAR = 1.4667 * 0.9091
DAR = 1.333 = 4:3

DAR = FAR * PAR
DAR = 704:480 * 40:33
DAR = 704 / 480 * 40 / 33
DAR = 704 / 480 * 1.2121
DAR = 1.4667 * 1.2121
DAR = 1.778 = 16:9

[biferi]

Thanks for getting back to me.

Let me see if I have this right.

I am in the USA so NTSC 4:3 Display Ratio uses Rectangular Pixels.
And the Pixel Size is 0.9091 do I have this right?

And NTSC Widescreen 16:9 Display Ratio uses Rectangular Pixels.
But the Pixels are 1.2121 in size?

[hello_hello]

To make its confusing there's no way to know the exact pixel aspect ratio used (as a rule). There's two standards (kind of). You either resize the 720x480 video to exactly 4:3 or 16:9, or you resize it using an ITU/mpeg4 pixel aspect ratio (they're almost identical), which results in something a tad wider than 4:3 or 16:9. Hopefully your camera uses the mpeg4 PARs.

There's a list of PARs here. The generic PARs give you exact 4:3 and 16:9 dimensions, while the mpeg4 PARs give you something a little wider. They're the PARs jagabo suggested.
https://forum.doom9.org/showthread.php?p=1058927#post1058927

If in doubt, use the mpeg4 PARs (it's a long story in itself) although be aware most software players will generally resize to exactly 16:9 or 4:3 when displaying NTSC.

To calculate the display aspect ratio you can multiply the video width by the PAR and then divide the result by the height. So if you used the MPEG4 PARs.

720 * (10/11) / 480 = 1.363637 which would give you a DAR of 654x480 (rounded). 480 * 1.363637 = 654.545 (it actually makes sense to round up to 656x480)

Again for 16:9 (mpeg4 PAR):

720 * (40/33) / 480 = 1.818182 which would give you a DAR of 872x480 (rounded). 480 * 1.818182 = 872.723

The above assumes you're resizing the video to the correct display aspect ratio yourself when editing (resizing to square pixel dimensions) but you can leave it at 720x480 when editing and set the appropriate PAR (10/11 or 40/33) and the player will resize the edited video on playback accordingly, as it did previously.

[_Al_]

Better not to resize at all if loading image into project 720x480 or any anamorphic project, so image is not resized more than twice, it is SD resolution.

if having square pixel picture 640x480 get it into Photoshop (maybe also xnview but I'm not not sure) and put it into NTSC DV file or NTSC widescreen new project, whatever, it gets proportionally fixed. That you can load it into videoeditor, that project , not image, if you seem to have problems setting aspect ratio within your videoeditor. In Photoshop you can also set your custom aspect ratio.

This workflow is used while creating DVD menus and subpictures but you can give it a shot as well.

This topic gets complicated and I think one of those videoeditors that does it correctly is Sony Vegas. Square pixel image loaded into NTSC DV project gets interpreted proportionally with NTSC DV or widescreen in regard and it creates 8 black pixels left and right. But folks actually hate it and mostly ged rid of it. Because working with their own DV avi, not VHS capture and such. So no winner what ITU is set as a default.

[biferi]

Is this Video Right?
I seem to understand it.
https://www.youtube.com/watch?v=bae5DIqa6tk

[jagabo]

Let me see if I have this right.

I am in the USA so NTSC 4:3 Display Ratio uses Rectangular Pixels.

No. Not because you are in the USA but because your software supports that particular standard. Several other countries also use 720x480 with non-square pixels. And countries that use PAL also use non-square pixels with 720x576 frames. And there are other non-square pixel standards like VCD (352x240, 352x288) and SVCD (480x480, 480x576), and SD satellite broadcasts (many different frame widths with non-square pixels).

And the Pixel Size is 0.9091 do I have this right?

The software you are using is assuming BT.601 (AKA rec.610, ITU) standards where the pixel aspect ratio is 10:11 (0.9091). Some other software might assume MPEG standard (8:9) or square pixel (1:1). Or the software may let you specify exactly what you want.

And NTSC Widescreen 16:9 Display Ratio uses Rectangular Pixels.
But the Pixels are 1.2121 in size?

Only when following the BT.601 (rec.601, ITU) standard.

[poisondeathray]

what video editor / software are you using ?

In addition to the different types or interpretation, different editing software might handle image imports differently . e.g. some might resize to the timeline dimensions automatically (you might have to adjust or disable it), in others you might have to "interpret" or override what the software "thinks" that image AR is .

[jagabo]

you might have to "interpret" or override what the software "thinks" that image AR is .

And you may have to do this for imported videos too.

[poisondeathray]

Also, what is your final format goal ? How are you intending to watch this ?

For example, if you were uploading to youtube or web, you would resize using square pixel equivalents for the export ; But DVD-video (as in physical DVD playable in a DVD player) would not .

[biferi]

I have been doing a little more reading so let me ask this?

Just about Pixals just Pixals do I have this right?

If an NTSC Pixal has a PAR of 1. this means the Pixal will be 1 Unit wide and 1 Unit High.
If a NTSC Pixal has a PAR of 2. this means the Pixal will be 2 Units wider for every 1 Unit High.
If a NTSC has a Pixal PAR of 1.21 this means the Pixal will be 1.21 Units wider for every 1. Unit High.

Just tell me if I have this?

[mike20021969]

Pixals...Pixals...do I have this right?...NTSC Pixal...the Pixal...NTSC Pixal...the Pixal...a Pixal...the Pixal...Just tell me if I have this?

I think there's no hope

Also, what's with "pixal"? After being mentioned 29 times already, you've renamed it pixal not once but 8 times.

[jagabo]

I have been doing a little more reading so let me ask this?

Just about Pixals just Pixals do I have this right?

If an NTSC Pixal has a PAR of 1. this means the Pixal will be 1 Unit wide and 1 Unit High.
If a NTSC Pixal has a PAR of 2. this means the Pixal will be 2 Units wider for every 1 Unit High.
If a NTSC has a Pixal PAR of 1.21 this means the Pixal will be 1.21 Units wider for every 1. Unit High.

Just tell me if I have this?

You have the general idea. But it's not because the pixels are NTSC. And the word is pixel, short for picture element, not pixal. And theoretically, pixels are dimensionless points. What one is really referring to is the horizontal and vertical spacing between those points. This is why the term has changed to Sampling Aspect Ratio, or SAR, in newer terminology. In practice, when displayed or printed, you fill the spaces between those points, one way or another.

[JimmytheCool]

It depends on whether the editor uses ITU resizing