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VOB file displaying wrong aspect ratio

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Jamie Carsten
VOB file displaying wrong aspect ratio
on Dec 7, 2014 at 10:56:29 am

Hi there,

I’m having problems with aspect ratio on some very old video. It’s from an old camcorder and when I drag the VOB file in Mediainfo, it tells me the footage is “720x576 (16:9)”. See image below. 720x576 is not a 16:9 aspect ratio though, but rather 5:4. To be 16:9 at 720 wide it would have to be 405 height. The resolution is definitely 720x576 as Vegas tells me this when it matches the project properties to the first clip dropped in the timeline. The individual clips also tell me they are 720x576 when I click on each event’s pan/crop.

My first question then is, why would Mediainfo be telling me this is 16:9 when it's not?

Also on Mediainfo - why is it telling me the bit rate is 535Mbps (see image again) when it is low-quality footage on a 2007 amateur camcorder? Is there any way to tell the real bit rate so I can assess what bitrate I should render my final video at? Am I right in thinking that there is no point in making the bit rate any higher than the bit rate of the original video because the quality isn’t there to begin with?

Lastly, in Vegas, I rendered out a WMV 1280x720 version and it filled my standard TV screen nicely. It chopped a bit of the sides off but I assume this is to accommodate for the change in size from a 5:4 aspect ratio to a 16:9 aspect ratio. Is that correct? I believe this is further proof the actual footage is 5:4, not 16:9.

Thanks a lot and, errr... hope that makes sense.
Jamie



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john bolton
Re: VOB file displaying wrong aspect ratio
on Dec 7, 2014 at 12:08:58 pm

I guess the 720x576 is Anamorphic as it was recorded on a 4x3 chip situation so the 720x576 should look a bit squashed in 4x3 mode. When stretched out it will be 16:9 and looking correct.

Had a lots of problem when using FCP with video from a Sony Camera which had 4x3 sensor but was actually 16:9 anamorphic.

I will leave some of the Pro's to answer the other questions as maybe my answer may not be exact///


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John Rofrano
Re: VOB file displaying wrong aspect ratio
on Dec 8, 2014 at 12:27:42 pm

[Jamie Carsten] "My first question then is, why would Mediainfo be telling me this is 16:9 when it's not?"
Because it is! SD DV video and SD MPEG video often does not use square pixels. That video is PAL 16:9 Widescreen with a pixel aspect ratio of 1.4568. That means that each pixels is really 1.4568 pixels wide when compared to square pixels. When you multiple 720 x 1.4568 you get 1049 x 576 in square pixels which is actually 25 pixels wider than 16:9 but close enough.
[Jamie Carsten] "Also on Mediainfo - why is it telling me the bit rate is 535Mbps (see image again) when it is low-quality footage on a 2007 amateur camcorder?"
Again, because it is. This is NOT the footage from the camera. This is an MPEG2 rendering of the footage from the camera. Apparently at 535Mbps.
[Jamie Carsten] "Is there any way to tell the real bit rate so I can assess what bitrate I should render my final video at?"
There is no way to know what the original bit ate of the footage was. It is now 535Mbps.
[Jamie Carsten] "Am I right in thinking that there is no point in making the bit rate any higher than the bit rate of the original video because the quality isn’t there to begin with?"
That's right. This is all you have to work with and while rendering to a slight higher bit rate may avoid some further quality loss, render a lot higher will not make it a lot better.
[Jamie Carsten] "Lastly, in Vegas, I rendered out a WMV 1280x720 version and it filled my standard TV screen nicely. It chopped a bit of the sides off but I assume this is to accommodate for the change in size from a 5:4 aspect ratio to a 16:9 aspect ratio. Is that correct? I believe this is further proof the actual footage is 5:4, not 16:9."
Something for messed up somewhere along the line.

First, if you are dropping VOB files into Vegas Pro stop doing that. You should be using File | Import | DVD Camcorder Disc... and let Vegas Pro covert the footage from a DVD Video OBject file back into regular MPEG2 stream. Then set you project for PAL DV Widescreen (720x576, 25.000 fps) and work in the correct aspect for the footage. If you want to create a 1280x720p file you can do that at render time.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Jamie Carsten
Re: VOB file displaying wrong aspect ratio
on Dec 9, 2014 at 10:46:40 am

OK thanks, I think I get that. I haven't come from any technical background whatsoever and am completely self-teaching myself Vegas Pro so that stuff goes over my head a lot of the time.


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John Rofrano
Re: VOB file displaying wrong aspect ratio
on Dec 9, 2014 at 12:19:10 pm

Yea, well it's not anything that would be intuitively obvious. Unless you work on analog video back in the day, you'd have no clue that pixels don't have to be square. Sometimes it pays to be old. lol (but not very often) ;-)

~jr

http://www.johnrofrano.com
http://www.vasst.com



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