Best way to make PSUEDO LETTERBOX vids from old VHS tapes?

[ahhaa]

Compression is the name of the game when up/downloading; I've noticed that trimming some area from still images greatly reduces their file size...

So, I transferred some 20 year old VHS tape (always meant to do something with it) to AVI at the best quality I could manage on my gear. At the bottom, there is a little folding, a little fuzzy along the top, and on the left, an odd line running down just inside the edge of the frame... VHS- I'm lucky the oxide stayed on the tape for the transfer. Image is quite stable otherwise.

SO I was thinking- why not go all the way?

If I could 'batch-crop' the scenes to a 16:9 shape - not conversion, but use a black matte mask (something like a non-moving rectangular wipe)... I wouldn't lose much visually interesting picture, and all the busily wobbling edge pixels would become sharply framed unchanging video black, which should really help compression. Again- not changing the format itself, just overlaying black.

This may sound dumb, but there may be others out there who could use the idea on their funkier tapes.

Then I went looking at the tools here, found Wax2 & AVIsynth; thought I should ask what some of you who are already users of these tools which would be the simplest way to go?
I'm thinking this conversion would just be done in the most compatible way possible, as I don't have specific shots in mind for use...

also might be useful for keyhole, binoc, periscope, etc afterEFX?

[FulciLives]

You would want to use AviSynth AVS scripting.

Assuming you captured your VHS tapes at Full D1 resolution (720x480 for NTSC or 720x576 for PAL) here is how you convert from 4:3 to 16x9 WS ...

PAL capture at 720x576:
crop(0,72,-0,-72)
LanczosResize(720,576)

NTSC capture at 720x480:
crop(0,60,-0,-60)
LanczosResize(720,480)

The crop command is like this:
crop(left,top,-right,-bottom)

In the PAL example we cut 72 from the top and bottom then resize what is left to 720x576 which makes it 16x9 WS

In the NTSC example we cut 60 from the top and bottom then resize what is left to 720x480 which makes it 16x9 WS

You can also add "fresh clean" black back to the image with the AddBorders() command.

It works like this:
AddBorders(left,top,right,bottom)

So let us say that you have a NTSC capture at 720x480 and you have determined (using VirtualDubMod is the best thing to use here) that you need to cut 12 off of the left but only 8 off of the right to remove the black. As for the top and bottom you want to convert to 16x9 WS so here would be your script:

crop(12,60,-8,-60)
AddBorders(12,0,8,0)
LanczosResize(720,480)

I hope that makes sense

I should point out though that this is how you would resize IF the original video is PROGRESSIVE video. However since this is from a captured VHS the video will be INTERLACED instead of PROGRESSIVE.

So to properly do the above with INTERLACED video we have to change to this:

crop(12,60,-8,-60)
AddBorders(12,0,8,0)
SeparateFields()
LanczosResize(720,240)
Weave()

Here we crop and then add borders which leaves us a video frame of 720x360 but a frame has two fields so one frame of 720x480 has two fields of 720x240 yet by doing the cropping etc. we have made each field 720x180 (or a single frame of 720x360) so we need to resize each field from 720x180 to 720x240 ... this is how you have to do it with INTERLACED VIDEO.

So we start with 720x480 and we crop then addborders which gives us a frame of 720x360 ... the SeparateFields() part then gives us two fields of 720x180 ... we resize each field to 720x240 ... then the Weave() part combines the two fields back into a frame and we end up with 720x480

If this was a PAL VHS then the script would look like this:

crop(12,72,-8,-72)
AddBorders(12,0,8,0)
SeparateFields()
LanczosResize(720,288)
Weave()

The difference here is that a frame of PAL is 720x576 and a field is 720x288.

Of course a "finished" script needs a source so let us assume you captured NTSC at Full D1 resolution (720x480) and you called the captured file "MOVIE.AVI" and put it in a DIR/FOLDER called CAPTURES which is on the D: drive. You want to convert it to 16x9 WS and cut 12 from the left and 12 from the right to remove the wavy black lines.

Here would be a complete finished script for that:

AviSource("D:\CAPTURES\MOVIE.AVI")
crop(12,60,-12,-60)
AddBorders(12,0,12,0)
SeparateFields()
LanczosResize(720,240)
Weave()

You would type this into a text editor ... such as the Windows NOTEPAD ... and save it with AVS at the end ... so for example you would have "MYMOVIE.AVS"

The AVS file now becomes the input file (instead of the AVI file) for your MPEG-2 DVD encoder.

- John "FulciLives" Coleman

P.S.
One thing to be clear on when it comes to cropping ... with PROGRESSIVE VIDEO you would want to crop MOD 2 such as 2, 4, 6, 8, 10, 12 etc. and this goes for width and height. For INTERLACED VIDEO you can crop MOD 2 for width but for the height you must crop MOD 4 which would be 4, 8, 12, 16, 20, 24 etc.

[ahhaa]

Whoa! right over me head! Thanks John, gonna take a bit to absorb this... will getback later. I was thinking in terms of not changing the resolution from straight DV so that it could be intercut with my camcorder output (that old 'home movies in the movie' gimmick; only different). My output is archive DVD & out to Google Video.

thanks much for a very clea procedure, now I have to give it a try!:]

[guns1inger]

If you want to maintain a 4:3 aspect ratio for the project, you can use a variation on John's script that skips the resize and just adds borders :

AviSource("D:\CAPTURES\MOVIE.AVI")
crop(12,60,-12,-60)
AddBorders(12,60,12,60)

This will give you a letterboxed 1.78:1 image (16:9) inside a 4:3 aspect ratio. This would fit nicely into a 4:3 project, however you will have the balck bars as part of the image.

FWIW, if I am doing this type of cropping (full screen images to widescreen) I prefer to do it in an editor, rather than avisynth. Avisynth is brilliant, and tool of choice if I am just removing borders and resizing. However if you have old fullscreen VHS tapes, chances are that the framing will not be exactly what you need for a widescreen. If you just use a simple script across the whole tape, there is a very high probablility that you will be cutting out important parts of the image - heads, children etc. If you use an editor such as Vegas or Premiere, then you can still crop and resize (or add borders) as required, however you can also reframe the image as you go to ensure that the important parts of the image remain inside the frame that you will be keeping.

If you are just removing the garbage around the edges and adding masking, avisynth is the way to go. If you can gaurantee that the original video was framed and shot with later conversion to 16:9 in mind, avisynth is the way to go. But if you are going to remove 25% of the visible image area from a fullscreen shoot, I would be doing it visually in an editor. Just my 2 cents.

[ahhaa]

If you use an editor such as Vegas or Premiere, then you can still crop and resize (or add borders) as required, however you can also reframe the image as you go to ensure that the important parts of the image remain inside the frame

hmmm...

well, this idea is still evolving, thanks to you guys. I only have AvidFreeDV and Nero to work with, plus whatever is in the tools here. Maybe I'm misunderstanding the Wax2 composting, er, compositing features, but that sounds like what I thought it might do. With all my recent downloads, I gotta steep learning curve to plow, too.

Am getting a fuzzy notion of adding foreground elements- its great to people to talk to about this stuff!

[FulciLives]

What guns1inger was saying is that when you convert 4:3 to 16x9 WS you have to cut some of the picture. The standard way is to cut "X" amount from the top and "X" amount from the bottom. For instance with NTSC you cut 60 from the top and 60 from the bottom. That means you go from 720x480 to 720x360 (cutting a total of 120 from the image). You then resize the 720x360 to 720x480 to make it 16x9 WS.

However guns1inger is saying that with some shots you might have more going on in the top of the image than the bottom of the image.

So for instance to keep the stuff you need at the top you might want to only cut 20 from the top and 100 from the bottom.

Or maybe cut nothing from the top and cut 120 from the bottom.

Maybe you have another scene were all the action is near the bottom of the image. With that you might want to cut only 20 from the bottom and 100 from the top.

With a program like he suggested each scene can be done however it is best for that scene.

With the AviSynth AVS script it will always cut equal amounts (60 for NTSC) from the top and bottom.

Maybe that makes more sense now

- John "FulciLives" Coleman

[guns1inger]

However in order to make the letterboxing consistent, you then need to move the image back to the centre so it is still 60 pixels from the top and bottom. With Vegas you would use track motion to keep the part of the image you want to see centred within the letterboxing.

[FulciLives]

However in order to make the letterboxing consistent, you then need to move the image back to the centre so it is still 60 pixels from the top and bottom. With Vegas you would use track motion to keep the part of the image you want to see centred within the letterboxing.

Yes ... I forgot to mention that didn't I

- John "FulciLives" Coleman

[olyteddy]

I captured some streaming video using my capture card (Laptop S-Video out -> Hauppauge PVR in -> record to laptop HD). The video was about 400 x 700 on a 600 x 800 screen. I used the resize filter in VirtualDub Mod to resize and letterbox in one step. It worked pretty well.

[Pinstripes23]

Not to say that it isn't impossible to create a WS from a FS using avisynth, and correctly framing the image in certain scenes. It may be a bit more messy and dirty but it is possible. I was able to create a very good WS from a FS movie (no WS version was ever released) using the avisynth-virtualdubmod combo. You use vdubmod as your timeline for avisynth, plus as a guide for the cropping. Then generate a script for each scene using the trim(x,x) command for the frames. Then after you are done for each scene you would create one last avisynth script and import all the scripts you generated and append them in scene order

import("d:\movie-scene1.avs")+import("d:\movie-scene2.avs") ........etc

so they become one seamless file. You use this last file to import into your encoder. All this is dependent on your knowledge of avisynth and vdubmod but if anything they are freeware, so it is an alternative option.

[guns1inger]

As a picture is apparently worth a thousand words, give or take, I have quickly knocked up this image. It uses PAL stills (and has been scaled down by 50%), but the theory stands for NTSC



1. Top left corner shows the original frame from a VHS tape
2. Top right shows the cropping as done by a simple avisynth script, as decribed in the posts above. Note the top of the head has been cropped off. As the scene progresses, the head constantly moves in and out of the cropped area because of the original framing
3. Bottom left shows the area we really want in frame (bounded by red)
4. Bottom right shows the letterboxed version, correctly framed.

It is not difficult to move the crop area up or down in a script, and to then re-centre it when the borders are added. The problem is that the area you really want in shot will constantly shift throughout, especially if a tripod wasn't used. Using something like track motion and key framing allows you the freedom to subtly shift the framing up or down as required.

[The_Doman]

I see often TV-channels here doing this kind of stuff....
Butchering up good 4:3 material to make it 16:9 widescreen....
I really hate it...

Better just keep the original picture format and put small black bars over the sides of your VHS material to hide the disturbances..

[guns1inger]

If you are working with mixed source it can be less annoying than either jumping to full frame, or going to full pillarbox. But it certainly doesn't suit all material.

[ahhaa]

thanks guys- OK, I'm getting it sorta, and it is the effect I want visually...
(btw, my Sony Digital8 camera has a widescreen mode, (but I've seen many posts about probs transferring/showing it) I should prob'ly match that just in case?).

G'day gunslinger! - thanks much for the effort; you've got the start of an EFX tutorial here I'm sure.

I'm still 'absorbing'; right now its like somebody telling you how they sailed to Borneo, vs doing it yourself.

What I'm not getting is what is happening on the digital level; it is one thing to paint unwanted pixels black and another to 'crop' them off into a different format, right?
And would there be any real compression savings in file size?

Doman- I'm looking for an Effect here, a matter of style, otherwise I agree. Perhaps add subtitles of what they are really thinking, or I dunno yet... Something Completely Different.
I remember one flick where the Panavision>FS had just a nose & arm handling a major plot point- it was so annoying it was hilarious. This could be the reverse of that...

[guns1inger]

masking can reduce bitrate requirements in two key areas. The first is removing the excess noise in the overscan area. This area isn't seen, the noise isn't part of the image, so it's no loss to kill it. The second is by replacing almost 25% of the image with still black. Again, it reduces the amount of bitrate required to store the data.

However, if the output is DVD, you don't have the option of simply cropping the unneeded area, as the final resolution still has to be compliant.

In the instance above, the area that is cropped is then replaced with black. The end result is the same as just painting over the area with black. The bitrate requirement however is lower than either fullscreen 4:3 or 16:9 anamorphic.

[ahhaa]

OT- Gunslinger- looked at your reviews, not shabby. Didn't see one for Undead, which I quite enjoyed! Love ingenious no-budget productions, and that was BOB.
Starting with Gallipoli & Snowy River I've noticed an integrity to Aussie storytelling that quite unique even in genre.
Problem is hollywood steals all your talent, and puts up an iron curtain against serious distribution over here. I've often wished somebody would do 'trailer compilations' on DVD so we could at least see what we are missing from around the world!

[guns1inger]

Cheers. Undead was pretty good. If you want to look at some other worthwhile Australian cinema (and not all of it is - we all produce crap from time to time), I would also recommend

Mad Max and Mad Max 2 (Road Warrior in the 'States) - two of the best exploitation action films ever made, anywhere.

Picnic at Hanging rock - a little slow and polite nowadays, but shows early Peter Weir (Witness).

I would also recommend Peter Weir's The Cars that Ate Paris (get the Australian version, as the original US released was badly dubbed) and The Last Wave.

Breaker Morant with Edward Woodward
Sunday Too Far Away with Jack Thompson
The Year of Living Dangerously with Mel Gibson
The Man Who Liked Flowers, by Paul Cox
Bad Boy Bubby by Rolf Der Heer

Many of these took a long time to be released on disc, and some still don't have decent releases, even over here.

You are right about talent moving off shore, but then we don't have a huge television or cinema industry, so they have to go elsewhere. Thankfully many of them come back to make local films or appear on the stage. I believe our greatest talents have been behind the camera. For such a small industry we are very well represented in the ranks of great cinematographers, for instance.

[ahhaa]

Fooled around with my storyboard a bit to see what'd be lost/gained...
Kinda like the early Polanski look!