16:9 1080i to 4:3 720x480

[fishywishy]

hi i want to convert 16:9 1080i to 4:3 720x480 with virtualdub

ive screwed around with resizing and null transform cropping and the video is always squished. 1st i tried resizing the video from 1080 to 720x480, then changing the aspect, but that didnt work. then i tried changing the aspect, then resizing, which didnt work either. any help would be great, thx

[txporter]

1920x1080 is 1.777777.... aspect ratio. 720x480 is 1.5. Try resizing to 848x480 or 854x480 (if you don't mind non-mod16) to see if looks more to your liking. I don't do any conversions with vdub, so I don't know how to set the aspect ratio flag in the header.

[guns1inger]

I don't believe the AR flag can be set in virtualdub, but depending on what happens next there may be other solutions.

As for the resize - do you want to letterbox the original wide-screen source within a 4:3 frame (i.e. letterbox bars top and bottom of the screen), or do you want to crop off the left and right edges so the image fills the 4:3 frame ?

[manono]

I think he thinks 720x480 is 4:3 when it's not. It's 1.5:1 or 3:2. Assuming you make this thing progressive one way or another (IVTC, deinterlace, whatever), you do a straight resize to 704x480 (or 720x480 if you don't mind a slight aspect error), add 8 columns of pixels to both the left and right sides, and then encode as 16:9 in your MPEG-2 encoder. At 720x480 things will look too tall and slender, but after being reencoded things will look 'normal' again during playback.

And if the goal really is MPEG-2 for DVD, VDub is the wrong encoder to be using. An Avisynth script frameserved to a proper MPEG-2 encoder (CCE, HCEnc, whatever) is a much better method. And if you're making an AVI, for which VDub is ideally suited, then txporter's suggestion is the one to follow - resize to some 1.78:1 ratio. And, again, 1080i is interlaced, and you either make it progressive one way or another before the resize, or you resize in an interlace aware manner.

[fishywishy]

well turns out the video size needed is 640x480, and i didnt need to change the AR

i just use the avchd_convert_v9 "__856x480_Deinterlaced_NTSC.bat" and trim the fat on the sides