How do I change the aspect ratio in an MPEG file without........

[Canon GL-2 Guy]

it being encoded or re-encoded?

What tool or tools is best suited?

a) I have multiple NTSC SD MPEG-2 files which are currently progressive 4:3.

b) I need SD 16:9 widescreen for broadcast.

Thanks so much

[aedipuss]

depends. are they 4:3 or 16/9 with incorrect headers? if you open them with vlc do they play correctly?

[Canon GL-2 Guy]

I will let you know shortly.

Not known yet.

[mike20021969]

Try SD Copy:
http://paulmcgrath.net/download.php?view.8

[Canon GL-2 Guy]

I sincerely apologize that I dropped the ball and this thread ran off the radar screen so to speak. So many things going on.

Aedipuss, the file (s) in question play just fine on VLC player.

Longer term, I will have access to 4:3 progressive files which I will have broadcast.

Without getting into the specifics of why, they will/should look "better" and become more suitable if I can submit them to the local station in SD 16:9.

Actually they prefer/reccommend SD NTSC 16:9 over 4:3 to their producers/contributors.

My goal is to have the audience see less black space onscreen when the programs air!

[Canon GL-2 Guy]

Mike,

Very interesting.

Is this as simple as checking off the widescreen 16:9 flag and renaming the file in the target directory?

It doesn't recode?

If so, and it works fantastic!

Thanks so much.

[poisondeathray]

If it's actual 4:3 content, the professional way to do it would be to pillarbox it

If you don't want black borders, you cannot convert it to 16:9 without losing active image area . This won't look better IMO, and requires re-encoding

If it's 16:9 content but flagged 4:3 incorrectly, then you can just reflag it with restream without re-encoding, but it sounds like you have 4:3 content

[Canon GL-2 Guy]

PDR:

Thanks for pointing out restream for spelling out the options.

Yes, I have 4:3 material to the best of my current knowledge. Co-incidently, my wife called me from her workplace and told me the hard drive with the content under discussion had just arrived.

Definitely do not want to lose any active image area!
Yes, professionalism is important, so is it easily pillarboxed? I see it on tv all of the time.

Never done that before.

Please advise.

Thanks

[poisondeathray]

Yes it's quite easy to do

In Premiere, You can use a NTSC DV 16:9 sequence setting, and if you import 4:3 NTSC content into that timeline, it should automatically be pillarboxed.

This only works if Premiere interprets the aspect ratio correctly (for example it will do this correctly for files directly from a camera, like a DV-AVI file). But for other types of files, you might have to interpret the aspect ratio manually (right click the clip in the clip bin and interpet the AR as DV NTSC 0.9091 for the source file if it isn't already). Note those numbers displayed by premiere are the pixel aspect ratio , not the display aspect ratio.


Other options: You can use avisynth and calculate the numbers with fitcd. You have to be careful when working with "non square" pixels; either work in square pixel equivalents or use the numbers given by fitcd. It says to resize to 528x480, then add 96px borders to the left and right (assuming NTSC content 720x480). Because the resizing is only in the horizontal dimension, there are no special considerations for interlaced resizing

e.g.
MPEG2Source()
Spline36Resize(528,480)
AddBorders(96,0,96,0)

[Canon GL-2 Guy]

PDR:

Prem Pro solves the first part, however then one would have to re-encode because I'm getting finished MPEG- 2 dvd spec files on that HD which already compressed at least once. more compression. Less quality.

I wish PP could save from the timeline as is without re-exporting. A big omission in my opinion.

Thanks for the fitcd example.

[poisondeathray]

You have to re-encode it either way when pillarboxing

Re-flagging without re-encoding only works if the original content was flagged incorrectly in the first place (it doesn't sound like you have this). If you just reflag 4:3 content as 16:9 , it will look distorted and displayed incorrectly

[Canon GL-2 Guy]

Your are right 100% again.

There is always a problem somewhere!

Could I re-interpet the footage or adjust the pixels/aspect ratio in PP?

[poisondeathray]

Your are right 100% again.

There is always a problem somewhere!

Could I re-interpet the footage or adjust the pixels/aspect ratio in PP?

Nope. Any transformation that involves resizing, adding borders , or cropping, things like that - require re-encoding.

Premiere cannot smart render mpeg2 (without 3rd party plugins) anyways. Even if you used vegas, which CAN smart render mpeg2, it still would require re-encoding because you are essentially resizing and adding borders.

If you flag 4:3 content as 16:9 it will be stretched and distorted (=very bad)


There are other options , but most local cable stations use the pillarboxing method when displaying 4:3 content. This way you don't throw away active image area.

[mike20021969]

Is this as simple as checking off the widescreen 16:9 flag and renaming the file in the target directory?

Yes.
A new file will be created (identical to the original) which should now display in widescreen.
(i.e. if your video is 16:9, but displaying as 4:3, this is what it SDCopy is for).

AFAIK, it was designed to work with .MOD files from certain camcorders - when video shot as 16:9, after being copied to the computer, played back as 4:3 (everything squashed). It works happily with MPG.