DVD TO DivX (PAL 720x576 16:9 Letterboxed)

[SamFisher]

I am trying to convert a number of DVD movies in my collection to DivX so I can burn multiple movies to DVD and watch it on my Samsung DVD and DivX player. I use Gordian Knot to rip the DVD (DVD Decrypter) and create the d2v file with DGIndex. The stream information from DVD Decrypter says it is "PAL 720x576 16:9 Letterboxed" and DGIndex's preview gives 16:9, 25.00fps, 720x576 as well.

I open the d2v file in GK, set audio 1 to vbr mp3. then i move on to resolution. I select PAL, and PAL Anamorphic 16:9. Then, I first select Auto crop, check the frames in the preview window, and then click Smart Crop All.

The output resolution is left at default: 640x352. Then I click save&encode, leave the default options, and click save&encode again. I add the audio file, GK works out the interleave, etc. and I let it encode.

After about 3 hours (extreme quality), it is done and I burn it to CD-RW and try to play it on my stand-alone DivX player. The picture looks good, but with one problem. Almost 50% of the top half of the screen is taken up by a black bar, and 50% of the bottom is taken up by the bottom black bar. On computer, it looks great, but that’s because DivX player resizes to fit the video.

Any ideas on how I can encode a DivX rip of the DVD that looks exactly as it did when I played the DVD? I am playing it on a 4:3 CRT TV and I am in Australia (PAL region).

If you need more info, please tell me. Thanks.

Here is my avs:

# Created with Gordian Knot
#
# http://gknot.doom9.org

#  PLUGINS
LoadPlugin("C:\Program Files\GordianKnot\DGMPGDec\DGDecode.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\decomb.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\KernelDeInt.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\UnDot.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\dgbob.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\Convolution3d.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\FluxSmooth.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\TomsMoComp.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\VSFilter.dll")
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\SimpleResize.dll")

#  SOURCE
mpeg2source("E:\Images\MOVIES\BENCHWARMERS\BENCHWARMERS.d2v")

#  TRIM
#trim(startframe,endframe)

#  IVTC
#Telecide(order=1,guide=1).Decimate()
#  or use
#IVTC(44,11,95)
#GreedyHMA(1,0,4,0,0,0,0,0)

#  DEINTERLACING (1)
#FieldDeinterlace()
#FieldDeinterlace(blend=false)
#TomsMoComp(1,5,1)

#  DEINTERLACING (2)
#KernelDeInt(order=1,sharp=true)
#  or maybe
#DGBob(order=1,mode=0)

#  DEINTERLACING (3) - special requests
#GreedyHMA(1,0,0,0,0,0,0,0)
#Telecide()
#SeparateFields()

#  CROPPING
crop(14,22,696,532)

#  SUBTITLES
#VobSub("FileName")

#  RESIZING
LanczosResize(640,336)

#  DENOISING: choose one combination (or none)
Undot()

#  1) little noise
#Temporalsoften(2,3,3,mode=2,scenechange=6)
#mergechroma(blur(1.3))
#FluxSmoothST(5,7)

#  2) medium noise
#Temporalsoften(3,5,5,mode=2,scenechange=10)
#Convolution3d("moviehq") 
#FluxSmoothST(7,7)

#  3) heavy noise
#Temporalsoften(4,8,8,mode=2,scenechange=10)
#Convolution3d("movielq") 
#FluxSmoothST(10,15)

#  BORDERS
#AddBorders(left,top,right,bottom)

#  COMPRESSIBILITY CHECK
#  !!!!Snip Size now has to be 14 for use in GKnot!
#SelectRangeEvery(280,14)

#  FOOL CCEnc
#empty = BlankClip()
#AudioDub(last,empty)

[guns1inger]

Your source is widescreen, and you are encoding it to Divx (1:1 PAR) with a fixed width of 640 and a fixed height of 352. This is approx 1.81 : 1, or slightly wider than 16:9. This means that anything that is actually 16:9 (1.778 : 1) will have slight pillarboxing, and anything wider than 1.81 : 1 will have embedded black bars.

I don't know what else you expected. If you want to fill the screen when encoding widescreen material then you have to crop the ends off the image to get a 4:3 frame. Why anyone would want to do this is beyond my understanding.

If you play these widescreen DVDs on your TV now, do they

a) have black bars above and below
b) fill the screen top to bottom, but appear vertically stretched
c) fill the screen, but cuts the left and right sides off

It must be one of the above.

[manono]

Almost 50% of the top half of the screen is taken up by a black bar, and 50% of the bottom is taken up by the bottom black bar. On computer, it looks great, but that’s because DivX player resizes to fit the video.

The AVI is (from your script) 640x336 (not 640x352, as you said). 640/336=1.90476. You have a 4:3 TV set=1.33:1. 1.33/1.90476=.698. About 70% of the screen is taken up with active video, and about 30% is black bars above and below. I'll ignore the effect of the overscan on the calculations. This isn't quite "Almost 50% of the top half of the screen is taken up by a black bar, and 50% of the bottom is taken up by the bottom black bar". It's more like "Over 30% of the top half..."

It's a widescreen movie. You said yourself, "The picture looks good". What's your complaint? You don't seem to be saying it plays with bad aspect ratio. You aren't really complaining that there's black above and below the video, are you? The movie is wider than your TV set. What do you expect? Get a widescreen TV set and then there won't be any black bars for that particular ratio, or very little. Then you can whine about black bars on the sides of 1.33:1 movies, or black bars above and below 2.35:1 movies.

[SamFisher]

Yes, I realise that widescreen DVDs are going to have black bars on my humble 4:3 TV. However, the difference in thickness between the black bars when playing the original DVD and the black bars when playing the DivX rip is quite large. The black bars in the DivX movie are around double the size of those when playing the DVD on the same TV + DVD player. BTW, Under codec settings for DivX 6 in my case, on the video tab, what should my output resolution be? Should it match the input resolution (16:9)?

Oh, and my cousin tried the DivX movie that I burnt on his 1080p Bravia LCD TV but he reported that it looked "tall" ie. stretched vertically. Like I said on my TV, the picture is too small vertically and the rest is covered by black bars. On his, the picture appears stretched, whilst the original DVD plays without any black bars whatsoever on his TV, being 16:9 and all that.

Still confused.

[guns1inger]

That you are both getting different results to me says more about setup of the equipment. Without knowing what the original aspect ratio of the image was on the DVD, I cannot tell you what resolution you should have after encoding, and what it should look like.

Look on the back of the DVD case and find out what the actual aspect ratio is.

[SamFisher]

It was 2.40:1. Thanks for replying so quickly and helpfully, btw.

[manono]

There's a review of the Aussie version here:

http://www.michaeldvd.com.au/Reviews/Reviews.asp?ID=7239

It's anamorphic 16:9 1.85:1, so the black bars above and below the DVD (and to the sides) would be pretty much hidden by the widescreen TV set's overscan. The overscan of the DVD will make the DVD picture a bit larger than the DivX version, which doesn't usually have any overscan. So, the AVI might have a little bit more black, but not nearly the amount you're describing for your 4:3 TV set.

Some DVD/MPEG-2 DVD players do stretch AVIs to fill widescreen TV sets, especially the ones with ESS chipsets. But without being stretched, there should be only a little bit of black above and below that 640x336 AVI, and stretching it shouldn't make it very obviously stretched, as it'll be strrectched only a very little bit. Can you find anything round in the movie, like a sun, moon, or a ball? You seem to be saying that the AVI is playing with wrong aspect ratio. If so, round things should appear to be ovals. I can't see that you did anything wrong with the cropping and resizing (except that I do mine manually, and don't trust the AutoCrop and SmartCrop). If you do find ovals, then go find the same thing by opening the AVI in VDubMod on the computer. They are probably round there, instead of being ovals. And if so, either your player is set up wrong, or both you and your friend have funky players. I lean towards the funky player theory. I think you're saying on yours that people look short and fat. But on his people are tall and skinny.

It was 2.40:1.

What was 2.40:1? Not the DVD (if I found the right one), and not your AVI of it, if you followed that script. Open the AVI in VDubMod and go File->File Information to confirm the resolution.

[guns1inger]

2.40 : 1 is very widescreen, so the black bars will be very evident, even on a widescreen TV. However the disc you are referring to is 1.85 : 1 (and the review you have linked too says this as well), so yes, the bars should be very small.

So the next question is, what exactly does your converted file look like ?

Can you open it in g-spot and post a screenshot ?

You might also open it in mpeg4modifier and check what it thinks the various aspect ratios are set to.

[SamFisher]

LOL. I think I may have deleted it already... whoops. However, I am currently converting a new copy, so I will get back to you on that. I am now using AutoGK to see if the automatic aspect ratio settings will fix it. Will post soon. Thanks.

[SamFisher]

BTW, what setting in AutoGK in limiting the size of the avi generally provides excellent quality with good compression?

[manono]

No way to tell. It depends at least partly on the length of the movie and how well it compresses. Since, at 80 minutes long, it's fairly short, you can probably do it for 1 CD with decent quality. Leave the rest of the settings at default and let AutoGK find the best resolution and other settings to use. If you don't like the results, you can always do it over again.

[SamFisher]

Right, thanks. But you know when you download 'legal' movies from the Internet that are 700mb using XviD, how do they manage to get such good quality for ~90 minute movies? Should I be using XviD instead of DivX? Or is it some other factor?

Thanks once again for all of your help.

[manono]

Well, I don't know that I'd call them all "good quality", since most of the "sceners" are after credits rather than releasing quality encodes. But let's assume for the sake of argument that you've seen some encodes put out by people that know what they're doing. They're not using AutoGK. Not that there's anything wrong with AutoGK; quite the contrary. But it was developed to allow newcomers and rookies to produce good quality encodes without really knowing anything about the process.

By encoding manually, you have access to the vast number of AviSynth filters that can aid in compressibility and sometimes in quality. You can easily give the end credits less quality, to increase the bits available to improve the main movie. This is available in the AutoGK Hidden Options. You can choose the optimum resolution for the size and compressibility. Yes, AutoGK does this as well, but maybe you don't agree with the criteria it uses. You can tweak each part of the encode, however you like.

Should you be using XviD rather than DivX? Although I used to use XviD myself, the 2 are pretty much equal these days, and if yours don't look like theirs (same movie, same size, same audio, for an apples to apples comparison), it's not because you're using DivX and they're using XviD.

[SamFisher]

Cool. Thanks. I think the other question that was on my mind was, in AutoGK, there are three methods to set quality: target size, custom size and target quality. I usually focus on either target size, but now I'm experimenting with target quality. 100% target quality gives me a 2.2GB file, which means I can squeeze two movies onto one DVD.

If I limit the target size to 1/4 of a DVD (which is an option of about 1100MB in AutoGK so I can fit 4 movies to a DVD), the approximate quality is about 72%.

So, my question is, what quality as a percentage of the original quality of a DVD generally provides excellent viewing on, say, a 46-inch 16:9 TV?

[guns1inger]

On a TV that size I would stick with two movies per disc. Even at 4 movies per disc I see artifacts on Divx/Xvid material on my 72 cm CRT TV. If quality is your main concern, then don't convert to Divx/Xvid at all.

[jagabo]

So, my question is, what quality as a percentage of the original quality of a DVD generally provides excellent viewing on, say, a 46-inch 16:9 TV?

You should try it yourself and find out what's acceptable to you. Encode short representative samples at various quality settings and see where you start noticing macroblocks and DCT ringing. I don't know AutoGK but 100 is almost certainly overkill. I suspect you won't see any difference (at normal playback speeds) between 100 and 90, maybe even lower. The file size may go down significantly though.

The Divx and Xvid codecs call this mode "1-pass quality based" and "Target Quantizer mode". They allow you to select a quantizer value -- essentially, how much detail to throw away. A quantizer of 2 will produce output frames almost indistinguishable from the source (probably about what you're getting from AutoGK at 100 percent). A value of 3 will produce a little macroblocking if you look at enlarged still frames but they won't be noticeable at normal playback speed. Higher values will give smaller files with more macroblocking and ringing. Most Divx/Xvid files you might download from the web have average quantizers around 5 or 6.

In target size mode you are specifying the size of the result but you don't know exactly what the quality will be. In target quality mode you are specifying the quality you want but don't know what the size will be.

[SamFisher]

Thank you. That explains a lot. Will try!