Aspect Ratio Issues..

[calhoun]

I download some widescreen TV programs that have been been encoded with DivX or XviD, they have been cropped so the resolution is usually 624x352. I like to convert these videos to Mpeg2 and make DVDs out of them.
I use PowerDirector to convert these videos and during the setup for this I elect to stretch the image, this gives me perfect aspect ratio when I view my DVDs on my widescreen TV however when I watch on a normal TV the images are stretched, I have no black bars top and bottom. The other option I have tried during the setup for conversion is to change the image to "letterbox".. This option gives me black bars on my widescreen TV which shouldnt be there.. and when I watch on normal TV the black bars are TOO big(image squashed slightly)..

Is there an easy way to maintain correct aspect ratio on these videos encoded originally at 624x352 when converting to DVD??

Hope this all makes sense..

[manono]

Hi-

What are you doing? Using the same DVD player for both TVs, and moving it from one to the other? The reason I ask is that if it plays with proper Aspect Ratio on one TV, it should also play properly on the other. When outputting for a 4:3 TV set, the player will add the black bars to maintain AR if you have it setup correctly. My suggestion is to go into the setup menu of the DVD player when displaying to the 4:3 TV set and make sure it's outputting for 4:3 (standard), and not for 16:9 (widescreen).

[midnightsun]

Yes.

Since 624/352=16/9 all you have to do is resize to 720x576/480 and encode as 16:9.

Alternatively you could letterbox the 16:9 movie to a 4:3 frame. To do that you need to resize to 720x432/360, add black bars top and bottom to fill a 720x576/480 frame and encode as 4:3.

This latter way is not the best if you're also watching the movie on a widescreen tv as you'll end up with double letterboxing (i.e. on all four sides).

[calhoun]

Thanks for the replies,

What is the best way to go about resizing these videos? Bear in mind that if I load these videos into virtualdub I have problems with the audio (improper VBR audio encoding error) I have never successfully processed these videos with virtualdub because of the VBR audio..(I get big sync problems). However when I convert these videos with Powerdirector the audio always turns out fine I just have issues with aspect ratio.

Convoluted I know.. such is my life

[midnightsun]

Talking about virtualdubmod here:

load the file, go to video, filters, lanczosresize, enter 720x576 or 720x480 depending whether the source is Pal or NTSC. Then frameserve to your favorite encoder. Once you've done that encode at 16:9.

If you don't know how to frameserve from virtualdub, look <<<<, there are quite a few guides/articles explaning this.

[midnightsun]

BTW you can process the video alone in virtualdub(mod) if the audio is giving you hell. If all you're going to do is resize, the audio is ok the way it is now

[calhoun]

Thanks Midnightsun,

I had a play with VirtualDubMod and I believe what you suggest is basically the same as what Powerdirector does(in respect to resizing anyway). When I select "stretch" in the setup for PowerDirector my 624x352 video gets resized to 720x576 which is fine when I watch on my 16:9 TV but I want to be able to loan to friends who only have a normal TV and the videos play stretched on normal TV. I want to be able to display these videos in proper aspect ratio on both TV formats(full screen 16x9 and black bars top and bottom on 4x3)

Make sense?

[midnightsun]

sure it does.

I take it you're making a dvd out of this material. If that's the case, when you author your files set the project at 16:9 letterboxed; that way if you're viewing it on a regular (4:3) tv, the movie will be displayed with letterbox bars at the top and bottom, preserving the source aspect ratio.

I believe every decent authoring software lets you define the display settings.

[calhoun]

Yes I am converting to DVDs.

We are getting the the crux of it now..

I agree letterboxing should solve all my problems.. but as I said in my original post when I letterbox these widescreen TV programs I get black bars top and bottom on my widescreen TV(which shouldnt be there) and I get really really BIG black bars on normal TV (improper aspect ratio(image squashed))

This is getting frustrating... there is probably a simple explanation out there somewhere.

624x352 seems a strange resolution to end up with after cropping a 16x9 video. How do you suppose they arrived at that res? I am assuming they started at 720x576/480 ??

[guns1inger]

I doubt they cropped, simple resized down to get the best size/quality ratio when compressing. Does the original video fill the entire frame ? Remember that many film aspect ratios still leave black bars, even on a 16:9 TV (unless you go to the local TV retai stores, where they leave the image stretched to fill the screen, even if it looks like crap).

Also, you can fix the audio in virtualdubmod by setting audio to full processing mode and saving the audio out as an uncompressed wav file. Load this into your encoder instead of the original audio and everything should be OK.

[Skynet107]

624x352 is exactly 16:9 aspect ratio. It does NOT come out this way mathematically though. This is because the pixels of a TV are not square.

To encode use a script like this:

DirectShowSource("C:\Xvid\video.avi")
LanczosResize(720,480,0,0,624,352)

Set the encode to 16:9 and it will come out perfect. Just make sure your authoring software is set to do letterbox on a 4:3 TV. You're source is obviously an HDTV rip so you are set.

Remember, there is NEVER any reason NOT to use 16:9 encoding unless the vertical resolution is less than needed to fill up the entire frame after the video is resized. If the rez is less than full frame, then you have to decide if it is worth doing 16:9. But not true in your case.

[calhoun]

Heya Skynet107,

You have shown me there is light at the end of the tunnel but i'm not quite there yet.

How can you tell the source is obviously a HDTV rip?

Can you please elaborate on:

To encode use a script like this:

DirectShowSource("C:\Xvid\video.avi")
LanczosResize(720,480,0,0,624,352)

and dumb it down as much as possible for me i've not encoded using scripts before and dont have a clue where to start.

Thanks