A Few Questions

[TheSeeker]

I have a few questions before I try out this program that really has piqued my curiosity because everyone seems to love it so much.


1. Can you crop the black bars off the top and bottom of the video as I know this will allow for higher quality video and still fit onto dvd-r. Also i believe that most players will auto add in the black bars anyways so they arent really needed as i understand it.

2. Can you do a movie only encode as Im a big fan of very high quality and for me all the little extras and the menus and all that stuff is really pointless to me and only serves to take space away from the movie itself thereby decreasing quality.

[DDogg]

1> If jdobbs decided to use AutoCrop in the future this could be done, but frankly it does not save near as much bitrate as the "common knowledge" says it does. There is also a cost in that another external DLL is needed. Hell, many people could not even make sure mpeg2dec3dg was installed properly, the support aggravation of adding another may not justify the small gain.

2> The new version of D2S/D is coming out tonight if all goes well. Pretty hard to beat that for movie only, but then I have a very biased opinion :)

[RB]

Originally posted by TheSeeker
1. Can you crop the black bars off the top and bottom of the video as I know this will allow for higher quality video and still fit onto dvd-r. Also i believe that most players will auto add in the black bars anyways so they arent really needed as i understand it.No you can't just crop away the black bars. Video must be a DVD compatible resolution such as 720x576/480. You can crop and add them back in a (macro)block optimized way to get the last bit of quality, but this can hardly be automated. I think such tweak are just out of the scope of DVD-RB.

[TheSeeker]

I have to disagree with you in the fact that it would be really hard to do some autocrop feature. Many encoding programs have an autocrop feature so we know its possible to detect the edges of the veiwable movie. How hard would it be to then examine the resulting resolution and conform it to the correct dvd standards?

[Joergen]

TheSeeker, you obviously have misunderstood how DVD video functions.

Do you want to ZOOM into the video (ie essentially creating a 4:3 full screen monster) or what?

The only cropping that can be done is 4:3 letterbox -> 16:9 anamorphic but that only applies to badly mastered non-anamorphic DVDs that thankfully are a fraction of commercial hollywood DVDs. And this feature BTW is already in DVD-RB.

[TheSeeker]

Actually I am probably mistaken. It wouldnt be the first time. I just assumed (probably incorrectly) that cropping could be done on dvd video the same as it can be done when encoding to divx from dvd video. I just figured the dvd player would automatically add in the black bars when playing the video back.

[Joergen]

Only in the case of aspect-ratio can a DVD player add the bars.

As in, an anamorphic 16:9 full frame video is squashed vertically by the player on a 4:3 TV. But this is as far as you can "crop", and cannot be used for 2.35:1 video to crop out its black bars, but instead the halved black bars are there to fill the 16:9 aspect which is then squashed again by the player so half of the black area is infact video and the other half added by the player.

[TheSeeker]

I see. thats too bad. some bitrate could be gained if you could crop out the black bars like you can when encoding to divx. i figured every little bit of bitrate that can be gained towards a higher quality dvd is always good. oh well.

[Joergen]

The full black areas are mostly digitally re-added to the master so they dont contain any grain which makes them compress really well, and the edge between the black bar and the image might use some extra bitrate but since the outer edge of the image (black and end of area) doesnt, I suppose the difference is highly theoretical.

[DDogg]

Well generically you certainly can save a ton of bitrate, like 10% [Anecdotal - not tested by me] if you crop overscan and use a 704x480 resolution. I do this all the time. In fact this is what FitCD [typo] and FACAR can both do. That actually might be a darn good option for dvd-rb down the road when the other things on the list are done. Who knows, maybe it could be part of the Smart Bitrate Allocation features if jdobbs decides to go forward with those. 10% bitrate saving are nothing to sneeze at.

[Joergen]

But scaling the image up after cropping brings more artifacts and eats up more bitrate, doesnt it?

Sounds counter-productive to me :(

Couldnt the edges inside the overscan area be precisely blurred instead?

edit: Oh yes, and you can prolly get 10% by removing unneeded subtitles.

[TheSeeker]

just a question.. i know the dvd standard for resolution is 720x480 but is this iron clad. meaning if the video is anything but 720x480 then it wont play in any standalone players?

[Joergen]

There are several more resolutions, like 704x480 and half-d1, but those are the most supported. Some DVD players can handle special DVB and SVCD resolutions while others cant.

[Matthew]

Originally posted by Joergen
But scaling the image up after cropping brings more artifacts and eats up more bitrate, doesnt it?

The image doesn't need to be resized after cropping, overscan area is replaced with black borders.

Originally posted by Joergen
edit: Oh yes, and you can prolly get 10% by removing unneeded subtitles. [/B]

No way hose...not even on a 2500 bitrate rip.