Convert 4:3 to widescreen letterbox without stretching the video

[MR Nice]

I dont know what section to put my query in so here go's, I have a small avi clip I did with my cam its 4:3, does anyone know of a program that can convert it to widescreen letterbox without the video looking stretched?

[netmask]

You can crop and resize in VirtualDub

[Ghitulescu]

I don't get it. WS LB is the way to watch 16:9 videos on 4:3 TVs.

The reverse situation is called pillar box, ie 4:3 image with black/grey blocks left and right. Some satellite providers broadcast this way.

So you have 2 options to fit 4:3 in 16:9 (1. and 2. are one option, 3. is the second one):

1. crop the bottom and top by about 72 pixels each - do then a vertical resize if you want this to match a standard DVD resolution
2. alternatively you can replace the cut out parts with black bars - it's called mating - that's a real LB. I think there is a filter in VDub, if not use crop and addborders.
3. add left and right borders, about 120 pixels each - then you might rescale it to 720 horizontal pixels (DVD compliant).

So, in option 1 (points 1. or 2. above) you'll lose parts of the image, in option 2 (point 3.) you'll have the side bars.

If you rescale from 432 to 576 you'll have an anamorph 16:9 video but the scaling will look bad on average to bad quality videos. It will be displayed as WS LB on 4:3 TVs if Letterbox is activated on your player, and 16:9 on 16:9 TVs ("zoom" activated).

For option 2, if shrunk to 720x576, it will be displayed as 4:3 on 4:3 TVs and as pillarbox on 16:9 if your player has pan&scan.

[MR Nice]

Ghitulescu I did try some of the things you said but, it looks stretched when I play it back on full screen tv. I don't know if there is a program tha can convert 4:3 to a true 16:9 ratio. I googled, tried some other ideas but to no avail. Anyway thanks to you both for your help I am greatful.

[Keiyakusha]

If you have 4x3 video (like this), then there is no way to make 16x9 from it, exept cropping some parts (like here).

Oops, you want letterbox? Then add black bars using avisynth Addborders() command. It will be something like this.

[MR Nice]

Originally Posted by Keiyakusha

If you have 4x3 video (like this), then there is no way to make 16x9 from it, exept cropping some parts (like here).

Oops, you want letterbox? Then add black bars using avisynth Addborders() command. It will be something like this.

Is there a tutorial on how to did with avisynth? I did crop the 4:3 in virtualdub but it looks stretched on my widescreen tv.

[Ghitulescu]

There is no known way of fixing a 4:3 image into a 16:9 bit-per-bit.

You have to stretch it, to cut off parts of it or to add "dummy" parts.

Of course, your TV should also be prepared to this material (zoom, wide, full, cinema etc.). For instance, a pure 16:9 clip will look stretched if seen in wide modus.

Zoom or similar enlarge the image vertically so the very upper and the very lower parts are not seen (same as cutting them out, then stretching the image to full screen - because you need the video to be conform to standards).

Wide does a sort of "Wide angle" transformation: the closer to margins the higher the distorsion (people at screen edges look fatter ).

Full stretches the image (people look squeezed) in vertical.

Cinema is a combination of zoom with full (cut+squeeze).

4:3 is shown with L/R vertical mates (black or grey).

It's your decision what method you want to use.

[MR Nice]

I found another way around the problem I used photoshop, using a black background I cut out the shape I wanted, and then I reized the video to fit into the layered cut out section. Now it looks great no stretching on wide full screen tv.

[mäger]

how could i add the ambient borders like they do on tv these days now? (to make the poor iphone footage look like 16:9)

[huhn]

this thread is pretty old but you simply need simple math.

first you need the DAR resolution and scale the PAR to it with 1:1. this can be skipped in most cases.

the rest is simple math.
example:
640x480 = 4:3

((480/9)*16-640)/2 = 106.7

source(4:3 640x480.mkv).Addborders(106,0,106,0)

result= 852x480

[raffriff42]

Originally Posted by mäger

how could i add the ambient borders like they do on tv these days now? (to make the poor iphone footage look like 16:9)

This has been discussed before, but I don't remember where. You do something like, stretch the video to full 16:9 width, but blur it and reduce contrast; then overlay the original video in the center.

## Last=...
ConvertToYV12
new_wid = Round(Float(Height)*16.0/9.0)
new_wid = new_wid - (new_wid % 4)
Last.BilinearResize(Width/4, Height/4)
\   .Blur(1.0).Blur(1.0).Blur(1.0)
\   .BilinearResize(new_wid, Height)
\   .Tweak(bright=-24, cont=0.7, sat=0.5) [* adjust to taste *]
\   .ColorYUV(off_u=10, off_v=-10)        [* adjust to taste *]
\   .Overlay(Last, x=new_wid/2-Width/2, y=0)

https://www.dropbox.com/s/6l2mmlzq02...t-01.jpg?raw=1