DVD Resolution / cropping settings

tonydav

Hi,

I've been struggling to get my mind around this and despite heaps of reading it's not "clicking" yet.

I'm trialling DVDFab 6 with the intention of converting my large library of DVD's to h.264 to be used with a DVico 6600. (Well those that the kids haven't totally destroyed :().

I'm in Australia and as I understand it our standard resolution is 720x576.

However, if I attempt to convert a DVD to h.264 the frame resolution suggested by DVDFab is 720x300. This is despite any changes to bitrate (e.g. I have it at a ludicrous 5000kbps and that's the suggested resolution albiet at .926 bits/pixel).

In case it matters, the DVD I'm backing up at present is Race to Witch Mountain, I've converted it to ISO via the full DVD to DVD funtion first to save further wearing out the disk whilst playing with it.

The profile I'm using is "generic.mkv.h264.audiocopy".

Back to the resolution.

If I click on Advanced resolution settings, and crop settings, it appears that it's removing black bars from the top and bottom of the movie, (74 lines top and 74 lines bottom).

If I disable the cropping the resolution reverts to 720x400.

Yet DVDFab still displays "original frame resolution 720x576 at the top of the screen.

So I'm having trouble reconciling this.

My thinking is that if I've started with 576 lines, remove 74 lines from the top and 74 from the bottom I should be left with 720x428 rather than 720x300.

And in fact 720x428 at aspect 1.68 would fit a 16:9 TV much better than 720x300 at aspect 2.40.

I realise I'm no doubt showing my ignorance here on some pretty basic matters but if I don't ask I'll never understand.

Thanks,
tony

GregiBoy

I'm in Ausralia too so I'll try to assist you but I'll try to keep it simple and not in technical terms.

Firstly here in Oz (or any PAL area) the native resolutions of standard definition televisions are 720 x 576 (4:3 older style TVs) or 720 x 400 (Newer widscreen TV's) and the DVD's are composed for these resolutions and generally are "anamorphic", in other words, the DVD shows up as 720 x 576 but the DVD player will resize it to the correct aspect ratio.

Now let's take the case of movies on DVD (TV series are a different ball game and I will not go into that here !!!)

Movies are originally shot fo playing in cinemas and are shot at different aspect ratios to normal TV. I have just pulled my original "Gladiator" out of the library and on the back of the case, it says that it is shot in 1:2.35 aspect ratio and also says "This film is presented in the widescreen or "Letterbox" format. Black bars appear at the top and bottom of your screen"

This is correct and this equates to a resolution of 720 x 306.

Most movies are like this and I have seen the aspect ration range from 1:1.85 (720 x 390) to 1:2.45 (720 x 294)

If these movies are stretched to fit a 16:9 TV, they will be displayed incorrectly. Everything will appear too tall/skinny.

In fact, I always have crop turned off and the resolution set to 720 x 400 and actually encode the black bars at the top and bottom into the file,

I do this because some hardware and software players will stretch a 720 x 300 movie to fit the screen and again cause the too tall/skinny effect.

Hope this helps. I have tried to keep it simple.

GregiBoy

tonydav

Thanks Gregiboy, I think that's cleared up much of the confusion.

Does leaving the black bars top and bottom use up much additional space in a ripped file?

thanks,
tony

GregiBoy

Nope. It's only black and not changing so the encode is not much larger.

iffer

But if the original material is anamorphically encoded? we want to keep the full 576 rows of picture data - and to retain the extra picture information in the avi (eg, encode the original 720x576 dvd content to 720x576 avi and let the display device do the anamorphic scaling)

I'd just like a "output resolution and frame rate matches input" button/profile.
Jen
For example breaking dvds of tv series into avi's for each episode - I dont want to lose quality, just want to encode them into seperate chunks. And yes, every player and every display has an aspect ratio button so I can adjust for anamorphically encoded material as required.

bernard500

Hey Gregiboy,

720x400 is the highest resolutin thats most compatible with car dvd players, codec divx players, etc.... right?
Anything higher most likely the player wont recoginize because its considered high def, right?
So thats why you always leave it to that setting? Is that kinda like software upscaling or is it just stretching some times. you would only want to do 720 x 400 on 16:9 movies right? 4x3 the max is 640 by 480 or something right?

Thanks for your time

GregiBoy

Let's start at the start.

All players are different so we cannot generalise here. Some will play higher def stuff, some will not.

I'll try to be simplistic here so don't jump on me about "anamorphic" resolutions, "Upscaling", etc please.

I'll use PAL figures here but if in NTSC Land use 704 instead of 720 and adjust the other figures accordingly.

DVD's are usually composed with an X resolution of 720. The Y dimension depends on the aspect ratio of the title. 16:9 = 720 x 400, 4:3 = 720 x 576..

So if you are selecting any size LARGER than that, you are asking Fab, or any other encoder to fill in or guess the expanded pixels.

When playing a DVD on a hi-def TV, the TV will upscale the 720 x XXX to 1920 x 1080 using the decoder within the TV.

I generally find that the results from the upscaling by the TV are better than the results of any software upscaling.

iffer

Hi Greg - not jumping on you... nor geeking (well maybe a little geeking :) )
But the point of the anamorphic encoding is the (PAL) dvd is _always_ encoded with 576 rows of picture data regardless of the aspect ratio (so on a widescreen movie, the encoded image is the tall skinny version. A flag in the video (or the user with the remote) has the display device scale the vertical to the correct ratio. This gives the best picture quality (more picture information for the display device to work with - which is why the discs are encoded like that in the first place).
Dvdfab needs to give people the option to encode the content at "free" aspect (original or user specified) as well as the "I've read the flag that says this is a 1:2.35 movie and I will only generate videos coded at/near that ratio" that it does now.
I understand some devices -especally mobile/pmp players can't do a scale + playback so dvdfab needs to pre-scale (as its doing now) but some of us are making jukebox libraries feeding lcd/plasma/projectors that are happy scaling (my projector has 5 predefined aspect ratio scaling settings as an example and while I don't have one, many people with projectors are fitting an external anamorphic lens to their projector - scaling in the analog domain so they get maximum quality from the projector panels). We know we are going to eventually get the black bars - but need to do it as late in the process as possible so every step has the most picture information to work with.

This forum seems to be the place to let the developers know how we are/want to use the software - and being able to retain all the source picture data would seem to be a good thing (to me! ). (At the moment it seems the only way to keep all 576 rows of picture is to stretch the horz 720 out to over 1k.)
Jen (the geek - lol - btw I do know we don't actually have 576 rows of picture data - lose a bunch of rows to signaling, data carry, etc but thats another posting :) )

GregiBoy

Hi Jen,

I did say that I was trying to be simplistic !!!!....

I think you will kill the poor buggers with information overload.

And to be quite honest, in all the years that I have been associated with Fab/Zensonics/Ziova and now importing my own players, you are the ONLY one that seems to keep bringing up this topic.

Maybe the marketplace hasn't caught up to you yet?

iffer

lol maybe - but I suspect the real reason is the other guys are all using Anydvd and splitting with any of a whole bunch of other tools.
I purchased dvdfab (and yeah keep pushing for features) because I need a package that I can suggest and support to friends - many of whom are non-geeks so it needs to be easy to use and an all-in-one tool. (As you can tell, there is a strong element of self-interest here - nothing spells fun like spending an hour on a phone trying to hand-hold someone through a computer problem - *sigh* took 20 mins to talk one friend through getting their tv/dvd/hifi to all be on the right settings to watch a movie - and that was on her own system!)
The aspect ratio thing is really such a small change (just an option to unset the aspect ratio flag read off the disk - call it "output resolution same as original" and a tickbox). But it is the feature that keeps me just using fab to make isos (and not using the inbuilt file encoder).
Jen

alexcel

Hi:

I fully endorse the feature request to allow anamorphic encoding at 720 * 576, the original DVD frame size.

Not only because I also own a projector, but also because I transcode my DVD to mkv with the maximum possible quality.

Frankly, reducing frame size from 576 to 400 is a huge quality loss.

That is the only thing that prevents me to use DVDFab to transcode to mkv

So, right now, I use DVDFab DVD to DVD Main movie, to a hard disk folder. From my folder, I trnscode using other sw like megui, handbrake, staxrip, etc. All of them allow for anamorphic transcoding

Hope to see this feature in the near future ;)

Plase let me know if you wont consider anamorphic transcoding

spqrbc753

Need more tips from Gregiboy!

Maximum Quality....

So Gregiboy after reading up on your best practices and reading through this resolution thread i tried to do some comparisons.

I am converting a widescreen dvd to an mp4 file or ps3 playable default file(mp4)

it seem setting the bit rate and not just the resolution has a major impact on the quality produced...i maxed out the bit rate for a 2h30m dvd and ended up with a 9gb file....i compared that on my PC to the DVD playing in WMP versus the file playing quicktime. The quality dropoff still exists....obviously the default ps3 settings produce a smaller file 1.2gb in size with the lowest quality of the 3....

As some of the other posters are looking to do...I simply want the best quality if not equal quality from my rip. You give some good tips about saving off the vob first then encoding, I will look into that. I am in the USA so I am looking for what to set the best Frames per second, resolution and bitrate at.... I am not worried about file size really as I want to archive my DVD collection just as you outline in your 'best practice' page...

Look forward to the feedback...

tommyboy76

[QUOTE=spqrbc753;29802]Maximum Quality....

So Gregiboy after reading up on your best practices and reading through this resolution thread i tried to do some comparisons.

I am converting a widescreen dvd to an mp4 file or ps3 playable default file(mp4)

it seem setting the bit rate and not just the resolution has a major impact on the quality produced...i maxed out the bit rate for a 2h30m dvd and ended up with a 9gb file....i compared that on my PC to the DVD playing in WMP versus the file playing quicktime. The quality dropoff still exists....obviously the default ps3 settings produce a smaller file 1.2gb in size with the lowest quality of the 3....

As some of the other posters are looking to do...I simply want the best quality if not equal quality from my rip. You give some good tips about saving off the vob first then encoding, I will look into that. I am in the USA so I am looking for what to set the best Frames per second, resolution and bitrate at.... I am not worried about file size really as I want to archive my DVD collection just as you outline in your 'best practice' page...

Look forward to the feedback...[/QUOTE]

Agreed on the desire for native anamorphic support. It makes a huge difference in preserving the faithfulness to the source material. If you want maximal quality it is a must!

Another feature I would love to see, is the ability to encode at a "constant quality" level. It uses variable bit rate to keep that constant quality level (via a "--crf" flag in other apps), which I assume is determined by the application in the first pass of the encoding process.

Without this feature I'm unclear on how to guarantee a certain quality level simply via a fixed file size, or fixed bitrate?