Cropping

[joy]

I'm not sure where to post this but I feel like this is the most appropriate place to do this.

Should I use an encoder like Procoder Express or a video editor like Premiere to crop a 16x9(aspect ratio) video to 4x3. Which method will give the least loss of quality if there will be such.

[guns1inger]

It is a 16:9 widscreen movie, or a letterboxed 4:3 ?
What is the aspect ratio of the movie ?
Do you want to remove all black bars ?

If you are targetting going back to DVD at the end of it, I would use avisynth. You will have to crop and resize the image (how depends on the answer to the initial questions). This will result in a softer image, so you may then want to sharpen the image slightly to add details back into it. Avisynth can do all this quickly, and frameserve the results directly into ProCoder for encoding.

[joy]

Thanks for the reply!

Actually this is a home video shot in widescreen mode,16x9 using a sony mini dv.

I shot this video in this mode because I now have a widescreen tv. The problem is most of my relatives have only 4x3 tv's and they don't like to watch those black bars at the top and bottom. That is why I plan to produce 2 versions of this video,1 in 16x9 and 1 in 4x3 to make dvd's later on.

By the way I'm not familiar with avisynth so hopefully you can help me a bit with this proggy.

[guns1inger]

I wouldn't give them the option, but that's just me

Does the sony shoot 1.78:1 letterbox, or 16:9 anamorphic ? i.e. is the video stretched vertically when watched on a 4:3 TV ?

The other problem you may face in doing this (and which may mean that Premiere is the better option) is pan and scan. If you shot in widescreen, and have subjects at the edge of the frame (say, two aunts sitting side by side), simply doing a crop may mean you less that half of each face. Commercial films address this by panning across the frame, so both subjects get to be seen in full. While it is feasible to do this in avisynth, it is much easier to do in a visual environment with keyframes.

Watch the movie again, this time concentrating on the just the centre 4:3 section. Anything outside this area will be gone after the cropping. If that is OK, then life is pretty simple. If not, you have a lot more work ahead of you.

[joy]

Does the sony shoot 1.78:1 letterbox, or 16:9 anamorphic ? i.e. is the video stretched vertically when watched on a 4:3 TV ?

That's supposed to be another question I was about to ask in this forum because I am really confused with these terms 1.78:1 letterbox or 16:9 anamorphic and etc.... I just noticed if I play this video on my 4:3 tv the picture is stretched vertically but plays fine on the widescreen tv(no black bars top and bottom).

The mini dv manual doesn't explain about these terms but just shows some illustrations of what's going to appear on the tv if shooting in this wide mode.

Watch the movie again, this time concentrating on the just the centre 4:3 section. Anything outside this area will be gone after the cropping. If that is OK, then life is pretty simple. If not, you have a lot more work ahead of you.

I know that cropping will remove some portion of the video that's why when I shot this I provided some allowance on the side so the job that's gonna be done later will not be too much a problem.

Hope I have made myself clear so you can advice me on which route to take, the premiere or the procoder way. If what you mentioned earlier about using avisynth to improve the quality after the cropping process I might take it.

Thanks again for the very informative response. I wonder what will happen to us guys like me without you guys around to give something like this for free.

[guns1inger]

The following script will

1. Resize the 16:9 frame to adjust for the stretch
2. Crop the ends off to get a 4:3 aspect ratio
3. Resize back to full frame

It does not do any filtering or clean up, but it will get you started.

Note : I am in PAL land, so the script has been tested for PAL footage. I have converted the numbers for NTSC, but you should check them, just in case.

#Load avi file
AviSource("path to your file here")

#Resize down from 16:9 to 4:3 letterbox (without bars)
BicubicResize(720,360)

#Crop off left and right sides to get 4:3 AR
Crop(88,0,528,360)

#Resize back up to full frame
Lanczos4Resize(720,480)

Put this in a text file with the extension .avs, and load it into virtualdub to see the results (make sure you have avisynth installed first, of course)

[joy]

Thanks a lot Gunslinger. Your help was much appreciated and glad to have u around!

[joy]

The following script will

1. Resize the 16:9 frame to adjust for the stretch
2. Crop the ends off to get a 4:3 aspect ratio
3. Resize back to full frame

It does not do any filtering or clean up, but it will get you started.

Note : I am in PAL land, so the script has been tested for PAL footage. I have converted the numbers for NTSC, but you should check them, just in case.

#Load avi file
AviSource("path to your file here")

#Resize down from 16:9 to 4:3 letterbox (without bars)
BicubicResize(720,360)

#Crop off left and right sides to get 4:3 AR
Crop(88,0,528,360)

#Resize back up to full frame
Lanczos4Resize(720,480)

Put this in a text file with the extension .avs, and load it into virtualdub to see the results (make sure you have avisynth installed first, of course)

Although I have finished my project with success using the script that you have provided (thanks!), I just cannot help myself from wondering how you got the numbers 88 and 528 on the 6th line of the script.

Can you please explain. Thanks again.