4:3LB-->16:9 question(s)

[mpennel]

I've always wanted to try to convert a 4:3 letterboxed DVD to 16x9 using DVD-RB to see how well it worked, but I've never taken the time to do it until yesterday. I decided to take my copy of THE BLACK HOLE, and convert from 4:3lb to 16x9. Unfortunately (fortunately?), the DVD is already a single layer 4.7 gig disc, so it really didn't require shrinking, and DVD-RB told me that when I hit the TRANSCODE button.

When DVD-RB was finished, I appear to have a nice 16x9 DVD, but the size is well under 4.7 gig (3.57gig to be exact).

So, my question is, what did I do wrong? Am I going about this all wrong, or are there more settings to tinker with in DVD-RB to get the size closer to the target 4.7 gig? Or should I use something like ifoedit to change the 4:3 flag to 16x9?

I've got lots of original MGM discs and others that are 4:3LB, and I'm hoping to someday convert them to 16:9 instead buying the reissues!

Thanks,
Mark

[Sir Didymus]

Hi mpennel. :)

Be careful: it's NEVER a good idea to re-encode a title that fits already in a single layer DVD-R (a part than for doing some uncommon testings :p ). The encoding process changes totally the MPEG2 (the video) structure. Also the re-authoring involved is a complex and heavy process. Why doing these steps if they are not necessary for producing your backup ?

The option of converting 4:3 LB ---> 16:9 is meaningful for original movies (bad authored in its original contents I would say, but this happend, especially on some old DVD's...) that doesn't fit on a single layer DVD-R. In such cases, since the re-encoding is necessary, you can take the opportunity to "repair" this little fault in the authoring of the original title.

But it's not a matter of changing some flags in the ifo's: this option really changes the picture frame before it is fed to the encoder, by cutting out the horizontal bars, and resizing the rest of the picture back to the original dimension, through the inclusion of an avisynth resizing script...

Edit: and some purists may have arguments saying it's NEVER a good idea at all, saying that the original black bars are part of the pictures placed in the DVD's, so their position is to keep them untouched anyway...

[TheSeeker]

Well since 4:3 movies are LESS compressable then 16:9 that is why you came out with undersized output. You may be able to use RB-Opt and oversize the target size in global settings. That could possibly work. Try it out and let me know.

[jdobbs]

Did you remove any audio? If so -- don't. DVD-RB will never go more than 100% of the original video's size. So if you remove audio it will reduce the total size.

[mpennel]

Nope, I didn't remove any audio. Do you think oversizing the target size in global settings would have any effect then? And if so, how/where would I change the size in global settings. I can't find anywhere to change it.:confused:

[jdobbs]

No. 100% is the maximum encoding rate.

[mpennel]

Just an update. I redid a trial of The Black Hole, and this time told DVD-RB to convert all the VOB's to 16:9 (instead of just the movie as my first try), but alas, I got the same 3.7gig disc size when done.

On another note, I tried doing a 4:3LB-->16:9 conversion of The Truman Show, which is also single layer, and the results were much closer to 4.7gig. Very Strange.

A question about this whole process. How much image quality am I losing when doing these conversions? Since right now, I don't have a widescreen TV, I can't really test my final results. I'd love to hear from others who have done this, and find out if they believe it is really worth the effort.

Also, I read somewhere while searching this forum that I should turn off dynamically assign cell bitrates. Is this true?

Thanks,
Mark

[jdobbs]

IMHO you should never turn off dynamic bitrates. I will probably remove the option to do so at some point...

The only way changing the target size will affect the resulting output is if you are currently reencoding with less than 100%. If so, setting the "TargetSectors=" INI entry to a higher value can force a larger output size.