Distorted Video From Conversion(Pal to NTSC)

NFLD Pipes wrote on 5/2/2011, 6:02 PM
Hi, I have an old video that was converted from Pal to NTSC and thus suffers from distortion or so I am informed.

" the standard PAL format has the same spatial resolution horizontally, but vertically it has a higher spatial resolution (720 x 576 for PAL – 720 x 480 for NTSC) than doe NTSC. Many PAL and NTSC converters simply eliminate the extra horizontal lines from the PAL format in order to conform to the NTSC format. This results in an image that appears to be ‘squashed’ along the vertical axis…making people and objects look fatter after the conversion. "

As I do not have access to the original video, how can I try to unsquash this video and make it look like the original by using Vegas.

Thanks!

Comments

Chienworks wrote on 5/2/2011, 6:21 PM
Sounds backwards to me. If some of the vertical resolution was removed then everything should look tall & skinny, not short & squashed.

In Pan/Crop, turn off Maintain aspect ratio, then change the vertical size as necessary. Make it smaller to stretch the image larger vertically.
musicvid10 wrote on 5/2/2011, 7:23 PM
Sounds right to me, Kelly.
576->480 = short and squashed
Chienworks wrote on 5/3/2011, 4:15 AM
If the conversion was done by trimming 96 lines, that's removing 1/6 of the height of the frame. The remaining 5/6 of the lines would end up stretched vertically to fill the frame, since NTSC scan lines are taller in relation to the frame than PAL scan lines. Vertical stretch = tall & thin.

If the conversion is done by resampling all 576 lines into 480 then the vertical relationship is unchanged and the image will still look normal.

Neither way results in short & squashed. Therefore it would seem that some other transform has come into play which may not even be related to the PAL to NTSC conversion.
John_Cline wrote on 5/3/2011, 12:45 PM
When you say that the video was "converted from PAL to NTSC" are you capturing a converted videotape or did they convert it to a file? If it's a file, what is Vegas reporting for image dimensions? 720x480 (NTSC) or 720x576 (PAL) and what is the frame rate? There is the image size difference between PAL and NTSC and there is also a frame rate difference, which can be more of a problem than image size. If it's just image size, then that is a fairly easy problem to solve.