How do I crop 4:3 content from 16:9 frame?

[tluxon]

I have some video that was recorded with a ReplayTV from the s-video 480i output of my Hughes HIRD-E86. The source was digital TV in 4:3 format but the E86 was setup for my 16:9 screen, so the video has black bars on each side as shown below.

http://mysite.verizon.net/tb.luxon/pics/RoseBowl04_E86_480i-small.jpg

Can anybody give me a step-by-step (or point me to the right resource) describing how to crop out the black bars before using on a DVD?

Thanks,

Tim

[edit]
BTW, the video is MPEG-2 with the following characteristics:

Resolution: 720 x 480
Framerate: 29.97
Bitrate: approx. 4000 Kbps VBR
Audio: 48KHz @ 192kbps, MPEG-1 layer II

[Wilbert]

Two possibilities:

1) Just leave it at that and encode it as widescreen (16:9).
2) Crop the black bars, resize it back to 720x480 and encode it as letterboxed widescreen (4:3).

If you want to view in on your 16:9 TV I would choose for option (1).

[tluxon]

It will played on 4:3 TVs for the most part, so I'm not in favor of leaving black bars on it or letterboxing it.

A short segment of this video will be joined to other video that is 4:3 DAR and I hoped to make it all the same. I've just never done it before and hoped for some direction. I'm figuring I could use some kind of cropping filter in Avisynth and re-encode in CCE, but I've not written any more than the most basic of scripts, mostly to convert higher bitrate MPEG-2 to SVCD.

Thanks,

Tim

[Wilbert]

2) Crop the black bars, resize it back to 720x480 and encode it as letterboxed widescreen (4:3).


Script:

mpeg2source("c:\file.d2v")
Crop(?,0,-?,0)
BicubicResize(720,480)

Documentation on AviSynth filters like Crop:
http://www.avisynth.org/index.php?page=Crop

When generating the d2v file in dvd2avi you can find the crop values. Make sure that they are even.

[Kedirekin]

It's surprisingly easy to do. AviSynth has a crop command.

Your current footage is 720x480 with a 16:9 display aspect ratio. The image within the 16:9 display is 4:3. The height in both cases is the same.

Taking the various scalings into account, the 4:3 image within the 16:9 display should be 540 pixels wide (I think). I wish I could show my math for this, but I've never found a good mathematical way to represent all this aspect ratio stuff. Basically I normalize everything to a square aspect (16:9=>853x480), get the area of interest (4:3==640x480), then denormalize (853=>720, so 640=>540).

Your crop command should be something like:

Crop(90,0,540,480)


You then want to resize to 720x480 using your favorite resize filter. Your are making the image bigger (wider), so don't expect too much; the quality simply won't be as good as if you had a 720x480 4:3 capture to begin with.


Oops! Wilbert beat me to it. Guess I took too long to type my post.