VOB From DVD Analyzed @ 16:9 and 720x580 . . . This Doesn't Add Up! :-)

[caseydiamond]

Can someone explain in layman's terms how a VOB file from a DVD is shown by both Mediacoder and Super as having an aspect ratio of 16:9 (which is 1.78) and a width/height of 720x480 (1.5).

Help! How can a video be both?????

I'd like to know because I want to reincode the video to play on my Zune. But it's NOT the Zune that matters!! It's learning how a video can have an aspect ratio of 16:9 and a height/width of 720x480.

TIA for any help in understanding this!!!!!!!!!!!!!

~casey

[poisondeathray]

Non square pixels

Look up DAR, SAR, PAR if you want a deeper understanding

Start here
http://www.doom9.org/index.html?/capture/par.html

[manono]

Yep, and a DVD player doesn't play the 720x480 video at that resolution. It gets resized at playback time to roughly 854x480 (480 x 16/9 = 853.33). For a better understanding of what's going on read these:

http://www.doom9.org/aspectratios.htm
http://www.thedigitalbits.com/articles/anamorphic/anamorphic185demo.html

720x480 is the DVD-Video resolution as stored in the VOB files. 16:9 is the Display Aspect ratio (DAR) which tells the player how it's to be resized for playback.

[caseydiamond]

Thanks!!!

If I want the converted VOB to play on my Zune with the same aspect ratio (not stretchy or fatty), do I have to choose a resolution that has the same ratio as 720x480 . . . such as 540x360 or 360x240?

In other words, how do I navigate through two sets of choices (aspect ratio choices and video resolution) when using Mediacoder or Super?

TIA!

~casey

[guns1inger]

Normally you would convert to a square pixel based resolution, unless you know for sure that the Zune respects AR flags. this would mean converting 16:9 material to 640 x 360 and 4:3 material to 640 x 480 (assumes NTSC DVD source). Even 640 x 360 may end up encoding some black bars depending on the original film aspect ratio.

[caseydiamond]

Yes, guns1inger, it is an NTSC HD-DVD source (16:9 at 720 x 480) .

Buuuut, ironically, it says on the Zune specifications page that it plays 320x240 (so, that's 1.33 aspect ratio).

This is getting confusing:

--Zune says convert eveything to 320 x 240 (1.33).

--guns1linger says convert NTSC DVD source (16:9) to 640 x 360 (1.78)

I'm still wondering what to pick on Mediacoder: would it be, as Zune says, 320 x 240 and leave the aspecta ration at 16:9 . . . and then predict that there with be fairly huge black bars, as the 16:9 (1.78) plays on a screen with a physical aspect ratio of 1.3 (I measured the screen and it's about 6.3mm x 4.65 (about 1.35).

Assuming I'm right, that I would have BIG black bars if I converted 16:9 HD-DVD source (720 x 480) to 320 x 240, then which program can crop the sides off the original source, so it'll end up filling my sceen without black bars?

I'm assuming this process is complex.

TIA!!!

~casey

And guns1inger says above that I should go with 540x480 16:9

[guns1inger]

If you need to crop as well, I would try virtualdub, then frameserve to Windows Media Encoder