Non-anamorphic to anamorphic...

[fewtch]

I'm sure this has been covered a million times, but I wanted to ask specifics...

I have a DVD I want to back up (NTSC, 4:3, 100% FILM, visible picture is 2.35:1) and want to reencode/store it anamorphically to make best use of the bits. Tools I have available are AVISynth, TMPGEnc Plus and (eventually) TMPGEnc DVD Author.

Here's what I *think* I need to do:

(1) Crop off black bars (easy with Autocrop plugin).

(2) Resize/crop video from 2.35:1 to 16:9 while preserving aspect ratio. Here I don't have a clue -- can somebody give me one? . Sample AVISynth commands and/or link to a software calculator to figure this stuff out would be very helpful.

(3) Do I need to resize the final result to 720x480, or will TMPGEnc do this automatically when I select NTSC DVD, 16:9, 720x480 in its parameters? If the latter, can AVISynth do the resize with better quality?

TIA for any help, suggestions or corrections (I probably missed something).

[The Geek]

(1) Crop off black bars (easy with Autocrop plugin).

(2) Resize/crop video from 2.35:1 to 16:9 while preserving aspect ratio. Here I don't have a clue -- can somebody give me one?

Well, you don't have to crop off all the black bars. 2.35:1 is wider than 16:9, so it still has black bars. So, only crop as much black bars as it's necessary to get a 16:9 image, and then stretch it vertically to 480 pixels, so that the image has a resolution of 720x480, and the image looks disorted.

Now encode that as 16:9 (so that the players and/or TVs know how to display it properly), and that's it, your anamorphic DVD Stream is complete, you only need to author and burn it.

However, you should know that you are not gaining any quality by doing that, as you are only resizing what you already have. The quality will even be a bit lower due to the necessary second encoding.
The only thing you'll gain is that 16:9 TVs will display it properly, and you don't need to zoom anymore.

The Geek

[fewtch]

Wouldn't I be wasting less bits on black bars, and spending more of them on the main picture? As for re-encoding, I need to anyway because the main movie w/no extras and just one audio stream comes to over 7.3GB (something like 54.1% in DVDShrink, quality is pretty bad even using AEC).

[The Geek]

Wouldn't I be wasting less bits on black bars, and spending more of them on the main picture?

You do, but also, the area of the main picture is bigger on the anamorphic picture, so you also need more bitrate.
On the letterbox picture, half of it is just black bars, and black bars don't use up much bitrate.

The Geek

[fewtch]

OK, sounds good... could you help me a bit with this portion?

Originally posted by The Geek
So, only crop as much black bars as it's necessary to get a 16:9 image, and then stretch it vertically to 480 pixels, so that the image has a resolution of 720x480, and the image looks disorted.

How do I determine how much of the black bars to crop (I'm bad with this kind of math, especially since most filters use pixels and not aspect ratios). The vertical stretch to a fixed resolution has to be easy (still need to look it up tho, it's been awhile since I've used AVISynth manually -- maybe just Lanczosresize(720,480)?).

Thanks much...

[HockeyStick]

One of the best guide i've found so far:
http://www.videohelp.com/forum/userguides/171216.php

Follow carefully the sections: "Finding Letterbox and Aspect Ratio" &
"Figuring Resize Values for your Aspect Ratio"

Even if the main goal of this guide is SVCD to DVD conversion and PAL to NTSC, you will find your answers for 4:3 letterboxed to 16:9 DVD to DVD conversion.

[iradic]

look for videosizecalc.exe ...

[fewtch]

Originally posted by HockeyStick
One of the best guide i've found so far:
http://www.videohelp.com/forum/userguides/171216.php

Follow carefully the sections: "Finding Letterbox and Aspect Ratio" &
"Figuring Resize Values for your Aspect Ratio"

Even if the main goal of this guide is SVCD to DVD conversion and PAL to NTSC, you will find your answers for 4:3 letterboxed to 16:9 DVD to DVD conversion.

Thanks, that was extremely helpful. Even the Pulldown.exe prog looks like it will come in handy (if in case I use HC instead of TMPGEnc, for example).

[mpucoder]

There is a bit in the video attributes that can be set by IfoEdit to avoid all of this. It's called "letterboxed (top&bottom cropped)" (true name "source letterboxed). If set compliant players will signal a widescreen display to zoom. To set it open the titleset ifo in IfoEdit, click on VTSI_MAT, scroll down to location 200, double click on it and a dialog will open up with all the video attributes. The one you want is in the lower right.
As for the cost of encoding black bars, it is very low provided they are absolutely black, and not noisy, ie digitally matted.