I need help with cropping!

[UnD3R0aTh]

..i'm new to ripping DVD's, i still don't understand how to crop correctly to achieve highest resolution with least aspect ratio error, is there a program that can calculate the cropping values for me to achieve that?

[Baldrick]

Use AutoGK or Staxrip and let they autocrop. Or else can you try fitcd to calculate cropping and aspect ratio.

[UnD3R0aTh]

i rather do it manually in Fairuse, but i don't understand how to use fitcd to calculate the cropping values!

also, shouldn't there be some standard values for that kind of stuff? i'm sure a lot of ppl ripped so many 16:9 1.78 NTSC DVDs before me, the same settings should work for me too right?

[creamyhorror]

Handbrake is exactly suited for the task of handling both interlaced (30i) and telecined (24p in 30i) DVDs. Its Decomb+Detelecine functions will handle either correctly, or even combinations of them.

DVDs can be telecined, interlaced, or progressive. I generally use AvsP+Avisynth to inspect the DVD source frame-by-frame. I can then apply the appropriate filtering to obtain progressive output, and inspect the result directly. (This is the manual method.)

For cropping and determining aspect ratio, all you do is crop off the black borders and use the same PAR (pixel aspect ratio) to encode. PAR is the amount that each pixel should be stretched horizontally during display, which means that it isn't affected by cropping. The two possible PARs for NTSC widescreen DVDs are 32:27 and 40:33. It's not really possible to tell which is correct; you just have to compare preview images with your eyes.

(If you really want more information, google "par 32:27 40:33" and read any results from Doom9.)

If your program doesn't allow entry of a PAR but only accepts DAR (display aspect ratio), then do your cropping, then multiply the final width by either 32/27 or 40/33, depending on which ratio you think it is. Let's say you crop from 720x480 to 712x474. Multiply the final width by a ratio: 712*(32/27) = 844. This is the width that the cropped video should be displayed at. So the display resolution should be 844x474, i.e. the DAR should be 844:474.

[UnD3R0aTh]

Gspot can easily tell you if it's 32:27 or 40:33 by analyzing the VOB file! as for Handbrake, it's just awful, big file sizes, wrong cropping values, wrong AR, wrong display size, all the automatic functions in Handbrake is downright awful!

p.s. Fairuse will analyze the DVD to see if it's telecined or not, and it will react accordingly! there's also an option to deinterlace "Bob deinterlace", but it requires the user interference, so plz, i need an answer for the questions i asked above!

..as for cropping, Fairuse allows me to do some manual cropping, then pick a display resolution (i can't specify a certain DAR or PAR), but the resolution i desire will not give the correct AR, that's the dilemma! i can pick 512x288 (very small, but will give the same AR of the DVD), 656x368 (close) or 720x400 (big aspect error) but these picks are based on my personal calculations! is there a program that can calculate all that for me?

also, can i pick resolutions with width that exceeds 720, or with height that exceeds 480? also, is it ok to pick "unpopular" or shall i say "non-standard" resolutions? for example like "700x400"?

bottom line is, i want the biggest resolution i can get out of this, with a correct AR!

[creamyhorror]

Gspot can easily tell you if it's 32:27 or 40:33 by analyzing the VOB file!

All Gspot does is take DAR (16/9) and divide it by SAR (720/480 = 1.5), which always gives 32:27. But 40:33 sources also use 16/9 and 1.5, so it won't be correct for them. (Info from this post.)

as for Handbrake, it's just awful, big file sizes, wrong cropping values, wrong AR, wrong display size, all the automatic functions in Handbrake is downright awful!

No it's not - don't go making assertions like that without proof. What "wrong AR"? What "wrong display size"? It's more likely that your own values are wrong and not Handbrake's. And what wrong cropping values?

p.s. Fairuse will analyze the DVD to see if it's telecined or not, and it will react accordingly! there's also an option to deinterlace "Bob deinterlace", but it requires the user interference, so plz, i need an answer for the questions i asked above!

Go read the Fairuse guide/manual then - they should have their own advice on how to do it. I can only tell you to use another program like Handbrake or AvsP+Avisynth. I will say that, for NTSC, movies need to be inverse telecined, and videos need to be deinterlaced. You never do both at the same time.

..as for cropping, Fairuse allows me to do some manual cropping, then pick a display resolution (i can't specify a certain DAR or PAR), but the resolution i desire will not give the correct AR, that's the dilemma! i can pick 512x288 (very small, but will give the same AR of the DVD), 656x368 (close) or 720x400 (big aspect error) but these picks are based on my personal calculations! is there a program that can calculate all that for me?

Why are those the only options?

also, can i pick resolutions with width that exceeds 720, or with height that exceeds 480? also, is it ok to pick "unpopular" or shall i say "non-standard" resolutions? for example like "700x400"?

bottom line is, i want the biggest resolution i can get out of this, with a correct AR!

I think you don't understand resolutions and AR at all.

1. You should avoid resizing, for quality purposes. If you crop to 712x474, for example, you should encode at that exact resolution.

2. You should only set a PAR or DAR. This is a flag in the encode that during playback tells the player how much to stretch the 712x474 video. For example, setting a DAR of 844:474 will cause the video to display at 844x474 during playback. This is called anamorphic encoding.

[UnD3R0aTh]

ok, Handbrake is not as bad as i said, and i do understand what you're saying, if i set the anamorphic options to loose in Handbrake, it will encode at the same display resolution of the DVD, and put a AR flag inside the video file to tell the player to play it correctly! look the problem with me is, i wanna use all the advanced options to produce high quality rips through one-click solutions like Handbrake or Fairuse, i guess i'm expecting too much! i'm gonna have to learn how to useAvisynth and stuff like that!

but also, what i said about handbrake has some truth to it! check this out:

http://i49.tinypic.com/243rq7t.png

o.0

though, i can reduce the file size greatly if i set the advanced options like bframes=16 and the other stuff!

can you at least explain this to me? why ppl crop if they're not gonna resize? afaik, it's either you crop and resize or you don't crop, nor resize and use the "AR FLAG" method! and most of the videos i download from the internet, if not all, are resized!

[creamyhorror]

look the problem with me is, i wanna use all the advanced options to produce high quality rips through one-click solutions like Handbrake or Fairuse, i guess i'm expecting too much! i'm gonna have to learn how to useAvisynth and stuff like that!

Handbrake already allows you to specify all the advanced x264 settings in a commandline box. It's what I recommend to people who just want something that works simply and well. If you want to learn Avisynth properly, you should be prepared for at least weeks of reading and searching for threads as well as testing. You should use AvsP, a live previewer, along with Avisynth. And you'll do the actual encoding with either x264 CLI or a GUI like MeGUI.

but also, what i said about handbrake has some truth to it! check this out:

http://i49.tinypic.com/243rq7t.png
o.0

That does look like a bug, unless your source is quite unusual. Probably worth posting on the Handbrake forum.

though, i can reduce the file size greatly if i set the advanced options like bframes=16 and the other stuff!

bframes > 6 is largely pointless for live-action material. Only on very static anime is bframes 16 useful. Anyway, you can set it anyway if you want.

can you at least explain this to me? why ppl crop if they're not gonna resize? afaik, it's either you crop and resize or you don't crop, nor resize and use the "AR FLAG" method! and most of the videos i download from the internet, if not all, are resized!

?? No, you should always crop any black bars away. Assuming we're talking about anamorphic DVDs, you have 2 choices from there:

1) resize to the correct DAR, generally between 1.78 and 1.82; or
2) encode as it is and set the AR flag in the container

Option 2 is appropriate for MKV and probably MP4, while option 1 is used for AVI since standalone players may ignore AR flags in AVI containers, resulting in a squished picture.

[UnD3R0aTh]

it's not anamorphic, its AR is 1.78, anamorphic is 2.35 right? anyway, i decided i'm gonna stick with Handbrake now :P and use the AR flag method, it's easier and it's gonna save a lot of time, but i need your help with two things:

1- recommend a program for me that i could determine the crop values with, then use it in handbrake (since as you know, handbrake doesn't have a preview for cropping)

2- help me tweak the advanced settings in Handbrake to get the maximum quality with the maximum compression possible(slowness is not an issue)

3- which is better in your opinion, AAC or Mp3 (i'm gonna use the MKV container)? and is it possible to use VBR mp3 in handbrake?

thx a lot

[manono]

it's not anamorphic, its AR is 1.78, anamorphic is 2.35 right?

Not exactly. The aspect ratio (1.78:1 or 2.35:1) has nothing to do with whether or not the DVD is anamorphic (encoded as 16:9) or not (encoded as 4:3). Both can be 16:9, both can also be 4:3. To find out the true DAR (Display Aspect Ratio, 16:9 or 4:3), open a VOB in such programs as GSpot or MediaInfo. By the way, I think you don't understand what 16:9/Anamorphic mean since earlier you said:

p.s. i'm dealing with a 16:9 1.78 NTSC DVD 720x480

If it's 16:9 it's anamorphic, as that term is usually used when talking about DVDs.

1. I use Gordian Knot to get crop values. Make the D2V, open it in GKnot, go to the Resolution Tab, and then you can crop using the video as a guide. Maybe others do it differently.

2. Someone else (creamyhorror) will have to help as I don't use that program.

3. I don't answer 'which is better' questions, although I suspect AAC is.

[UnD3R0aTh]

lol yeah, from the readings i did, i understood that anamorphic DVDs squeeze the width of the frames to fit on a DVD (720) then set a DAR flag in the VOBs to play correctly!

so anamorphic DVD's are DVD's with DAR 16:9 huh? such tiny details that clear a lot of confusion, but could not be found anywhere!

thx for your reply!

Edit: i meant DAR, sorry for the typo

[manono]

I'm no expert on all those confusing acronyms, but anamorphic DVDs are those where the DAR is 16:9. I thought SAR stood for Storage Aspect Ratio which, if true, is 3:2 or 1.5:1 for NTSC. 720/480=1.5. If I'm wrong I'm sure someone will come along and set you (and me) straight.

[creamyhorror]

it's not anamorphic, its AR is 1.78, anamorphic is 2.35 right?

As manono said, widescreen (16:9) DVDs are generally called anamorphic.

1- recommend a program for me that i could determine the crop values with, then use it in handbrake (since as you know, handbrake doesn't have a preview for cropping)

I use MeGUI's live preview for cropping:

Tools > DG Creator > select the first VOB of your movie, usually 1GB > Queue button > Queue Tab > Start button > wait for job completion. A live preview window will pop up, along with the Avisynth Script Creator window (which contains the cropping controls). You can then crop and see the live preview.

AvsP also has this function, but it's sort of pointless unless your workflow already uses Avisynth. Avidemux and VirtualDub also have their own cropping functions.

2- help me tweak the advanced settings in Handbrake to get the maximum quality with the maximum compression possible(slowness is not an issue)

Firstly, make sure you use the current snapshot of Handbrake, which is the latest development version.

For Handbrake:

me=umh:subq=9:ref=8:b-adapt=2:b-pyramid=1:bframes=8:direct=auto:deblock=-2,-2:analyse=all:8x8dct=1:trellis=2:merange=24:no-fast-pskip=1:rc-lookahead=60:aq-strength=1.2

will give you very high quality for live-action content, although it will be very slow. Use an RF (CRF) value of 17-18.

For something a bit faster and not very different quality-wise:

ref=6:b-adapt=2:bframes=6:direct=auto:me=umh:subq=8:8x8dct=1:deblock=-2,-2:rc-lookahead=50:aq-strength=1.2:b-pyramid=1

3- which is better in your opinion, AAC or Mp3 (i'm gonna use the MKV container)? and is it possible to use VBR mp3 in handbrake?

You should use AC3 Passthrough, which retains the original audio track and thus preserves full quality.

[creamyhorror]

I thought SAR stood for Storage Aspect Ratio which, if true, is 3:2 or 1.5:1 for NTSC. 720/480=1.5. If I'm wrong I'm sure someone will come along and set you (and me) straight.

You aren't wrong, of course. It's just that x264 (and possibly other software) uses SAR to stand for "sample aspect ratio", which is the same thing as PAR. So there's some potential for confusion there.

[UnD3R0aTh]

alright, will try that and get back to you!

btw, what if there isn't any black bars? i can't see any, but when i press the auto crop, it suggests to crop 2 from bottom, do i set it to 2 or to 0?

[creamyhorror]

btw, what if there isn't any black bars? i can't see any, but when i press the auto crop, it suggests to crop 2 from bottom, do i set it to 2 or to 0?

I don't know, maybe there is a row of black pixels after all. Those can be quite hard to see. Handbrake's auto-crop checks a few segments of the video to determine the crop value, so it should be pretty trustworthy.

edit: just a thought, but are you using Strict Anamorphic? Or Loose? There's a small chance Loose might change the cropping criteria, but I doubt it. Strict is better anyway.

[UnD3R0aTh]

Handbrake is exactly suited for the task of handling both interlaced (30i) and telecined (24p in 30i) DVDs. Its Decomb+Detelecine functions will handle either correctly, or even combinations of them.

DVDs can be telecined, interlaced, or progressive. I generally use AvsP+Avisynth to inspect the DVD source frame-by-frame. I can then apply the appropriate filtering to obtain progressive output, and inspect the result directly. (This is the manual method.)

For cropping and determining aspect ratio, all you do is crop off the black borders and use the same PAR (pixel aspect ratio) to encode. PAR is the amount that each pixel should be stretched horizontally during display, which means that it isn't affected by cropping. The two possible PARs for NTSC widescreen DVDs are 32:27 and 40:33. It's not really possible to tell which is correct; you just have to compare preview images with your eyes.

(If you really want more information, google "par 32:27 40:33" and read any results from Doom9.)

If your program doesn't allow entry of a PAR but only accepts DAR (display aspect ratio), then do your cropping, then multiply the final width by either 32/27 or 40/33, depending on which ratio you think it is. Let's say you crop from 720x480 to 712x474. Multiply the final width by a ratio: 712*(32/27) = 844. This is the width that the cropped video should be displayed at. So the display resolution should be 844x474, i.e. the DAR should be 844:474.

sorry to revive the thread, but i need to know three things!

1. what about PAR for a NTSC 4:3 DVD? one value that gspot comes up with is 8:9! (also, tell me PAR for PAL 16:9 and 4:3)

2. what if i cropped so the width is 708 (6 pixels from right and left), then multiplied the original width, which is 720, by 8:9 which gives 640 (that will result in a 720x480 video displayed at 640x480 and a perfect aspect ratio 1.33), but do i lose quality or footage if i did that?

3. isn't this flag method basically the same as resizing? because the video will always display at a lower display resolution to maintain the AR, and the excess pixels will go to waste, and also make the file bigger!

so i think resizing (to smaller resolution) is better because this FLAG method also does not solve the problem of having some aspect error, because if i multiplied the cropped width 708*(8/9)=629 which gives AR 1.31


also, just to make sure i got this right, scaling is altering the width without the height, correct? while resizing is scaling both dimensions and if it's downscaling, it will cause no loss of quality right?


thanks in advance

[creamyhorror]

1. what about PAR for a NTSC 4:3 DVD? one value that gspot comes up with is 8:9! (also, tell me PAR for PAL 16:9 and 4:3)

Okay, first, the two possible PARs are based on the ITU standard and the non-ITU standard.

NTSC fullscreen (4:3): ITU PAR: 10/11, non-ITU PAR: 8/9 (approximate values)

To derive widescreen PAR from fullscreen PAR, multiply by 4/3:
Fullscreen: 720/480 = 1.5 --> 1.5 x 10/11 = 1.36 (approx 4:3)
Widescreen: 720/480 = 1.5 --> 1.5 x 10/11 x 4/3 = 1.82 (approx 16:9)
Therefore, (10/11 x 4/3) = 1.212 = 40:33 (which is the ITU widescreen PAR)
(You can do a similar calculation for non-ITU, which gives a final PAR of 32:27)

PAL fullscreen (4:3): ITU PAR: 12/11, non-ITU PAR: 16/15 (approximate values)

(Do the calculations for PAL widescreen PARs yourself.)

A handy table of values is in this post on Doom9.

2. what if i cropped so the width is 708 (6 pixels from right and left), then multiplied the original width, which is 720, by 8:9 which gives 640 (that will result in a 720x480 video displayed at 640x480 and a perfect aspect ratio 1.33), but do i lose quality or footage if i did that?

Huh? If you crop it, why are you multiplying the original width by 8:9? And why do you care about a "perfect aspect ratio"?

If you really want to know, the "perfect aspect ratio" is obtained (in the case of the ITU standard) when you crop to 710.85x486 (the true active picture frame) and use a PAR of 4320/4739. This gives (710.85x486) x (4320/4739) = 1.333333333333 = 4:3 exactly. But this is pointlessly complicated and you'd be better served simply using 8:9 and not aiming for a perfect 4:3 ratio. (My numbers come from this page, but I'm not going to try to answer any questions about it.)

3. isn't this flag method basically the same as resizing? because the video will always display at a lower display resolution to maintain the AR, and the excess pixels will go to waste, and also make the file bigger!

It won't be a waste since mostly any screen is wider than 873 pixels (the widest possible NTSC display width). Downsizing reduces the resolution and therefore the detail level!

so i think resizing (to smaller resolution) is better because this FLAG method also does not solve the problem of having some aspect error, because if i multiplied the cropped width 708*(8/9)=629 which gives AR 1.31

That's not an error - that's just the final display aspect ratio, which you expect to be different from the film's original since you cropped it. If you simply resized to a 4:3 resolution, you'd end up with a stretched picture!

also, just to make sure i got this right, scaling is altering the width without the height, correct? while resizing is scaling both dimensions and if it's downscaling, it will cause no loss of quality right?

Scaling = resizing. Downscaling = loss of detail = loss of quality. It's all the same thing in my book.


edit: corrected typo for non-ITU PAR: 16/5 --> 16/15

[UnD3R0aTh]

thank you

[UnD3R0aTh]

sorry, new DVD, new problem, more questions xD

..i have a letterboxed widescreen ntsc DVD WITH AR of 4:3. the video already has black bars! do i crop it? after i crop i get dimensions 716x362, now how to handle this one? 716*8/9=636 so display size will be 636x362 with AR= 1.76 (this is what handbrake did)

Question 1: do i crop here? if so, how to fix the AR?

Question 2: is it necessary to crop? sometimes the black bars are so tiny they're not even noticeable! does it affect quality/size?

Question 3: can i pick any display resolution i want, as long as i'm keeping the full source display resolution?

p.s. question 3 is exactly what i meant when i said:

"2. what if i cropped so the width is 708 (6 pixels from right and left), then multiplied the original width, which is 720, by 8:9 which gives 640 (that will result in a 720x480 video displayed at 640x480 and a perfect aspect ratio 1.33), but do i lose quality or footage if i did that?"

hope you get my point!

thank you for your patience

[creamyhorror]

..i have a letterboxed widescreen ntsc DVD WITH AR of 4:3. the video already has black bars! do i crop it? after i crop i get dimensions 716x362, now how to handle this one? 716*8/9=636 so display size will be 636x362 with AR= 1.76 (this is what handbrake did)

Question 1: do i crop here? if so, how to fix the AR?

Question 2: is it necessary to crop? sometimes the black bars are so tiny they're not even noticeable! does it affect quality/size?

You should always crop black bars away, unless they're really tiny, but it doesn't hurt to crop them anyway. Leaving big bars uncropped means bits will be wasted on encoding the black areas.

In Handbrake, make sure you're using "strict anamorphic", which will result in an actual resolution of 716x362 - no resizing involved. The display aspect ratio will be 636/362 =1.758 as you said, which Handbrake should handle automatically. Do a video preview to make sure it looks correct.

Question 3: can i pick any display resolution i want, as long as i'm keeping the full source display resolution?

p.s. question 3 is exactly what i meant when i said:

"2. what if i cropped so the width is 708 (6 pixels from right and left), then multiplied the original width, which is 720, by 8:9 which gives 640 (that will result in a 720x480 video displayed at 640x480 and a perfect aspect ratio 1.33), but do i lose quality or footage if i did that?"

With the flag (anamorphic) method, using Handbrake, you don't do any resizing or calculations. You simply select "strict anamorphic", crop away black borders, and encode. Handbrake will set the appropriate flag (either a pixel aspect ratio (PAR) or a display aspect ratio (DAR)) in the encode. You don't pick any display resolution.

The final video file will simply contain a 708x480 video and a PAR of 8/9 (OR a DAR of [708*(8/9)]/480 = 629.33/480 = 1.311).

If you cropped to 708x480, did not resize, and somehow set a DAR of 640/480 = 4:3, your video would display at exactly 4:3 but would appear stretched horizontally. Is that what you were thinking of doing?

[UnD3R0aTh]

yeah exactly, but why is it gonna be stretched? also, will the same thing happen if i resize (not planning to though!)?

but so far, i get the idea, HB pretty much handles everything, i just ask all these questions becoz i wanna understand what's going on! i thought 636/362 will give a wrong AR (1.758) and not 4:3 like the DVD, but i forgot that it's a letterboxed DVD with the actual AR, of the frame without the black bars, will be like i and handbrake calculated!

btw, is it possible to measure DAR of the actual frame without the bars?

thx for your help

[creamyhorror]

The "4:3" ratio that the DVD claims to have is actually the display aspect ratio (DAR), the AR it will display at during playback.

The original storage resolution is 720x480. Thus, the storage aspect ratio (SAR) is 720/480 = 1.5.

The PAR for this DVD is 8/9. You can think of this as meaning that each pixel is horizontally shrunk to 8/9th of its original width during playback.

Now, the relationship is DAR = SAR x PAR. You can think of this formula as "display dimensions = storage dimensions x pixel stretch factor".

Therefore the display aspect ratio (DAR) is 1.5 x 8/9 = 4/3. This is why the DVD is labeled 4:3.

Whether it's letterboxed-widescreen doesn't really matter, because when you crop the black borders off, the PAR does not change, since the PAR is a stretch/shrink factor applied to each pixel. Applying the same PAR of 8/9 will make sure the cropped picture is displayed at the correct AR.

However, when you crop, the DAR changes, since there is less of the original image remaining. Therefore if you crop you will no longer have a 4:3 image, but something different (it could be wider or narrower than 4:3, depending on how much you cropped on each side). The video is no longer a DAR 4:3 video.

I can explain it better with images, but I don't have the time or interest to draw them.

[cairuitao123]

..i'm new to ripping DVD's, i still don't understand how to crop correctly to achieve highest resolution with least aspect ratio error, is there a program that can calculate the cropping values for me to achieve that?

I think you can use Gordian Knot to crop the video image, it crops much accurately.A very useful tool.
For most of DVD source video , you can crop it into 640X272(2.35:1) or 640X360(16:9),GK will help you do it automaticly ,if you wanna define your own ,you can change the configuration in the avs script.