Cropping Question

[darkdream787]

I am encoding a DVD of mine into a 640x480 MKV file. I have the script mostly all ready to go but I need some help on a decision that goes along with the cropping.

I already know all about cropping on the sides and when I should and shouldnt and or how much but I don't have alot of experience with cropping from the top or bottom. I do not wish to ruin the aspect ratio and make it look stretched when its done being cropped but I also do not wish to have a fuzzy black line going across the bottom of the video.

Should I just leave that black line on the bottom and get used to it like it or not, or should I crop it off the bottom and stretch the video a bit? Some episodes only need cropped on the bottom about 6 pixels and its hardly noticeable being stretched up and down but some of the episodes require more like 10-14 to get rid of the black line on the bottom and its a bit more noticeable when you compare it with the source.

Is that little bit of stretching alright or should I just leave it alone? If my MKV files aren't in Mod 16 resolution and I try to resize to a height that isn't mod 16 it appears as a blank black block in windows media player and you don't see any video. Yeah I know people can say don't use Windows Media Player but I like to keep my video files playable in a standard player like Windows Media Player so I don't have to go get VLC or something else.

My point is I don't want to ruin the aspect ratio too much and I want the black line gone if possible so what do you suggest?

Crop off the bottom and stretch it to 640? crop off the bottom and shrink the height a bit to 624? just leave it alone all together and get used to the black line? or something else?


I have a video sample you can look at of 1 episode uncropped and the same episode cropped and stretched to 640. maybe you will be able to help out a bit more if you see the video in both aspects.


CROPPED

http://www.megaupload.com/?d=LA7SG4DN

UNCROPPED

http://www.megaupload.com/?d=31KJ8I86

ORIGINAL SOURCE

http://www.megaupload.com/?d=JAGQZ300

[aedipuss]

if the original is ntsc dvd 4:3 720x480, then i'd encode to 640x480 and leave it alone. that's how the studio intended it. if it's for playback on a tv you may not notice it at all as it may be in the overscan area.

[darkdream787]

if the original is ntsc dvd 4:3 720x480, then i'd encode to 640x480 and leave it alone. that's how the studio intended it. if it's for playback on a tv you may not notice it at all as it may be in the overscan area.

Yes its the original ntcs DVD at 720x 480, and its for playback on my PC only, I dont care about burning to DVD for watching on my TV. Does that change anything? That sample had a small one, other episodes have one 3x as thick at the bottom and its annoying. Disc 1 had small, Disc 2 had large, Disc 3 had small, Disc 4 had large, and so on up till disc 6.

[manono]

Cropping away the bottom two pixels is of minor concern as the aspect ratio will change so little that neither you nor anyone else will even notice anything. It's usually said that the aspect ratio has to be off by about 2% before people can notice (circles can be seen as slight ovals, for example). You're talking about a 0.5% difference. Me, I'd crop it away as I don't like any leftover black. I'll even crop into the active video if necessary, if it means a lower aspect error.

A good way to do the cropping and resizing with as little of an aspect error as possible is to open the D2V in Gordian Knot and then crop and resize in the Resolution Tab with the video to guide you.

[darkdream787]

Cropping away the bottom two pixels is of minor concern as the aspect ratio will change so little that neither you nor anyone else will even notice anything. It's usually said that the aspect ratio has to be off by about 2% before people can notice (circles can be seen as slight ovals, for example). You're talking about a 0.5% difference. Me, I'd crop it away as I don't like any leftover black. I'll even crop into the active video if necessary, if it means a lower aspect error.

A good way to do the cropping and resizing with as little of an aspect error as possible is to open the D2V in Gordian Knot and then crop and resize in the Resolution Tab with the video to guide you.

Actually it would be the bottom 6 pixels for smaller ones and bottom 10 for larger ones.

Well I have tried with and without the cropping for an episode with the 2x as large black bar at the bottom and you cant really even notice the stretch at all unless your staring at both the source and the encode both at the same time right next to each other. even then its a very minor stretch so I will go with crop the black bar off of the bottom this time, but only because the black bar at the bottom isnt dark enough to not be noticed and its annoying because of that.

Thanks for the opinions everyone.

[manono]

Oh yeah, you're right. I didn't read carefully enough. I apologize. 6 pixels is significant. I had no interest in your reencodes (why didn't you upload a sample from the source DVD?), but I did explain how I do it myself and it's very accurate.

Of course, you have to assume that the DVD production company knows what they're doing and sometimes that's a really big assumption. Quite a few times I've seen retail DVDs where the aspect ratio was already off.

[darkdream787]

Oh yeah, you're right. I didn't read carefully enough. I apologize. 6 pixels is significant. I had no interest in your reencodes (why didn't you upload a sample from the source DVD?), but I did explain how I do it myself and it's very accurate.

Of course, you have to assume that the DVD production company knows what they're doing and sometimes that's a really big assumption. Quite a few times I've seen retail DVDs where the aspect ratio was already off.

By significant do you mean too much or alright? as for the sample from the source DVD, I forgot how I used to take out just 30 seconds from a DVD and make it into a VOB file. I havent made a sample or requested help on here in a few months so I forgot what I did to get my VOB samples.

[jagabo]

If you're concerned about keeping the aspect ratio, crop a little of the sides as well as the top. While still at DVD resolution crop 1.5 times as much off the sides. So if you crop 8 lines off the bottom crop 12 (6+6) lines off the sides.

[manono]

By significant do you mean too much or alright?

I mean too much, for me anyway. I always aim for 0.5% or less. The ones with 10 pixels of black on the bottom would be even more off without compensating by cropping more from the sides.

I havent made a sample or requested help on here in a few months so I forgot what I did to get my VOB samples.

We don't need a VOB as we don't need the included audio. Open a VOB in DGIndex, use the [ and ] buttons to isolate a small section, and then File->Save Project and Demux Video. Upload the resulting M2V here if less than 30 MB, or else to MediaFire or SendSpace.

[darkdream787]

By significant do you mean too much or alright?

I mean too much, for me anyway. I always aim for 0.5% or less. The ones with 10 pixels of black on the bottom would be even more off without compensating by cropping more from the sides.

I havent made a sample or requested help on here in a few months so I forgot what I did to get my VOB samples.

We don't need a VOB as we don't need the included audio. Open a VOB in DGIndex, use the [ and ] buttons to isolate a small section, and then File->Save Project and Demux Video. Upload the resulting M2V here if less than 30 MB, or else to MediaFire or SendSpace.

Well the black lines on the sides take 14 pixels on each side to get rid of, is that enough to compensate for the 10 on the bottom? Should I just take 2 more off of each side perhaps?

Oh yeah!! thats how I used to do my sample getting, thanks for the reminder. I forgot about DGIndex since I havent used it in a long while.

[jagabo]

Why don't you just leave the frame at whatever size is left and use PAR (pixel aspect ratio) (SAR, sample aspect ratio, in x264) signaling to set the aspect ratio? PAR remains the same no matter how you crop.

[darkdream787]

Why don't you just leave the frame at whatever size is left and use PAR (pixel aspect ratio) (SAR, sample aspect ratio, in x264) signaling to set the aspect ratio? PAR remains the same no matter how you crop.

I might just say this is a pain in the @$$ and make it AVI at 640x 470 resolution.

Does anyone know how to crop off the 6 from the bottom and then re add 6 more to the bottom afterwards that are pure dark black so they cant be seen? Then I wont have to see the lighter black ones at the bottom and the ratio is unharmed.

[manono]

Does anyone know how to crop off the 6 from the bottom and then re add 6 more to the bottom afterwards that are pure dark black so they cant be seen? Then I wont have to see the lighter black ones at the bottom and the ratio is unharmed.

Letterbox(0,6)

http://avisynth.org/mediawiki/Letterbox

[darkdream787]

Does anyone know how to crop off the 6 from the bottom and then re add 6 more to the bottom afterwards that are pure dark black so they cant be seen? Then I wont have to see the lighter black ones at the bottom and the ratio is unharmed.

Letterbox(0,6)

http://avisynth.org/mediawiki/Letterbox

Thanks alot manono that just solved a big problem for me, I didnt know about that filter.

Should I put it right after crop and resize or before resize but after crop? where should I stick it at?

[manono]

Since, if I understand what you're doing correctly, you plan on only cropping and resizing the sides, then it doesn't make any difference where you put the filter since it's the only time the bottom is being touched. Remember, the Letterbox filter as used here does the same as cropping from the bottom and then adding back a true black - it, in effect, covers the original black with new fresh black. I usually stick it at the end of the script, though.

But I, personally, wouldn't use it in this case, although I sometimes use it for DVDs. In your case I'd either crop away all the black and then resize the whole thing, or do as jagabo suggested and crop away all the black, not resize at all, and then set a PAR/SAR.

[darkdream787]

Since, if I understand what you're doing correctly, you plan on only cropping and resizing the sides, then it doesn't make any difference where you put the filter since it's the only time the bottom is being touched. Remember, the Letterbox filter as used here does the same as cropping from the bottom and then adding back a true black - it, in effect, covers the original black with new fresh black. I usually stick it at the end of the script, though.

But I, personally, wouldn't use it in this case, although I sometimes use it for DVDs. In your case I'd either crop away all the black and then resize the whole thing, or do as jagabo suggested and crop away all the black, not resize at all, and then set a PAR/SAR.

Thanks, Ill remember that.

Here I should give this since the example in my first post is quite a bad one to show what I wanna fix. This is what Im trying get rid of, this time I'm giving a direct source sample and its the one with the 2x as large black bottom. After you see that tell me what you would do.

Crop it all and resize it, Crop the sides and letterbox the bottom, or something else?

Demuxed video and D2V file.

http://www.megaupload.com/?d=JAGQZ300


I cropped 16 from the left side, 12 from the right side, and 10 from the bottom then resized to 640x480, but I feel its a little off ratio. Thats why I was gonna go with letterboxing after you brought it up.


Here is what mine looks like after being cropped my way I mentioned above.


Before Cropping = TOP
After Cropping = BOTTOM







Is my aspect ratio really off by that much? I only really notice the slightest bit of stretching in the image when compared to the source.


Also, here is with the smaller black bottom. I cropped 14 off the left, 14 off the right, and 8 off the bottom instead of 6 because it looked better to me then resized to 640x480. I also fixed it up with a script to make it look better.

[manono]

If you're asking me, I'd do it:

Crop(18,0,-14,-10)
LanczosResize(640,480)

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player. Others might do it differently yet, like only crop the black, resize to 640x480, and let the aspect error be damned. Pay your money and take your choice.

I apologize, jagabo, if I've stated your position incorrectly.

[darkdream787]

If you're asking me, I'd do it:

Crop(18,0,-14,-10)
LanczosResize(640,480)

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player. Others might do it differently yet, like only crop the black, resize to 640x480, and let the aspect error be damned. Pay your money and take your choice.

I apologize, jagabo, if I've stated your position incorrectly.

well then we did it pretty close to the same choice, only 2 pixels width apart from each other.

Someone else told me to use this calculator called yoda's Resize calculator. I filled it out and its got me confused as hell lol.
this is what it said.




Someone else said this about the top 2

"Well according to the aspect ratio calculator, it's off by -1.88%. Whether that's off by much is your call. Probably not."

and this about the bottom 2

"Yeah, 8 off the bottom only gives you -2.31% aspect ratio distortion. 6 gives you -2.53%. Of course cropping 18 off the bottom would have given you 0.14% aspect ratio distortion. An extra 2 off one side and 20 from the bottom would have given you zero."


I did that calculator and I didnt see either of those 2 percentages they mentioned show up anywhere on that calculator. Then again it was my first time using it and Im not 100% sure how to read it or fill it out yet. I think I filled it out right but I dont get how to tell what its saying Im doing right and wrong. From my guess its saying my height of 640 is ok but the width aspect is off. I guess that because the width is in orange color. But if thats the case how is this calculator telling me how much Im off by? I dont get this thing fully yet.

[manono]

It has the 'Resize Aspect Error' to tell you how much you're off. However, I'm not sure why, if your aim is to remove all the black, you'd remove only 6 from the bottom. The most recent sample you provided needed 10 rows of pixels removed from the bottom to get rid of all the black. Maybe you were using a different sample.

[jagabo]

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player.

Yes, that's more or less what I'd do. After IVTC:

Crop(14,0,-10,-8)

That crops mod2 (so the chroma channels aren't split) and leaves mod8 frame dimensions. Then encode with 4:3 pixel aspect ratio. In x264: "--sar 10:11" if you go by the ITU spec, "--sar 8:9" if you follow the DVD spec.

[darkdream787]

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player.

Yes, that's more or less what I'd do. After IVTC:

Crop(14,0,-10,-8)

That crops mod2 (so the chroma channels aren't split) and leaves mod8 frame dimensions. Then encode with 4:3 pixel aspect ratio. In x264: "--sar 10:11" if you go by the ITU spec, "--sar 8:9" if you follow the DVD spec.

This would be soooooo much easier if windows media player would play MKV in mod 8,4 or 2. Too bad it only plays in mod 16 properly.

I learned plenty from this except how to use that calculator. The other person says Im getting it wrong because I have the ITU option checked.

Im not even sure what ITU is. Can someone define it for me? its the only thing on that calculator that I dont know what the selection means.

Other than that I got everything how I wanted it, its good enough for my liking even if it is stretched a tiny unnoticeable bit. 16, 0, -14, -10 640x480

[darkdream787]

It has the 'Resize Aspect Error' to tell you how much you're off. However, I'm not sure why, if your aim is to remove all the black, you'd remove only 6 from the bottom. The most recent sample you provided needed 10 rows of pixels removed from the bottom to get rid of all the black. Maybe you were using a different sample.

What I typed in the calculator was my second example of pictures or first link at the top. Half of the discs are like that and the other half are like the first 2 pics where you need to take 10 off the bottom.

[jagabo]

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player.

Yes, that's more or less what I'd do. After IVTC:

Crop(14,0,-10,-8)

That crops mod2 (so the chroma channels aren't split) and leaves mod8 frame dimensions. Then encode with 4:3 pixel aspect ratio. In x264: "--sar 10:11" if you go by the ITU spec, "--sar 8:9" if you follow the DVD spec.

This would be soooooo much easier if windows media player would play MKV in mod 8,4 or 2. Too bad it only plays in mod 16 properly.

WMP has no problems with non-mod16 videos. Something's wrong with your system. Try this file...

[darkdream787]

jagabo would do it differently. He doesn't believe in ITU resizing (which I use), and (I think) he'd go with only cropping away the black, not resizing at all, and then setting a PAR value to let it be resized by the player.

Yes, that's more or less what I'd do. After IVTC:

Crop(14,0,-10,-8)

That crops mod2 (so the chroma channels aren't split) and leaves mod8 frame dimensions. Then encode with 4:3 pixel aspect ratio. In x264: "--sar 10:11" if you go by the ITU spec, "--sar 8:9" if you follow the DVD spec.

This would be soooooo much easier if windows media player would play MKV in mod 8,4 or 2. Too bad it only plays in mod 16 properly.

WMP has no problems with non-mod16 videos. Something's wrong with your system. Try this file...

Well anytime I ever made the resolution non mod 16 it was always a black blank box in my player with nothing but audio working. They worked in Media Player Classic and VLC though. I wanted it to work in regular windows media player though.

I encoded with Me-Gui and used MKV Merge to make into an MKV file.

I tried 852x480 and 850x480 before on another dvd and it didnt work, it was all black so I had to make it 848x480 according to people on here several months back because mod16 was needed. Im betting if I make it 640x472 it would do the same thing.

hows your works is a miracle to me.

[jagabo]

Well anytime I ever made the resolution non mod 16 it was always a black blank box in my player with nothing but audio working. They worked in Media Player Classic and VLC though. I wanted it to work in regular windows media player though.

What h.264 decoder are you using? I haven't seen any problems with mod4 or mod8 in five years.

[darkdream787]

Well anytime I ever made the resolution non mod 16 it was always a black blank box in my player with nothing but audio working. They worked in Media Player Classic and VLC though. I wanted it to work in regular windows media player though.

What h.264 decoder are you using? I haven't seen any problems with mod4 or mod8 in five years.

I dunno, I didnt know there were different kinds of h.264.


x264? I use Me-Gui but I can provide all of the settings on a screenshot if needed.

Perhaps it was the version of MKV Merge I had back then?