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  1. Member
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    So the way I have always done it (after ripping the DVD into separate episodes with DVDShrink) was to encode the vob file(s) with Handbrake/XMediaRecode/whatever. This is the part I get confused. These old TV shows have an aspect ratio of 4:3. The ripped episodes are 4:3 but have very thin black bars on each side which I crop out with a value of appx 10 on one side & 4 on the other (but this results in a smaller ratio than 4:3). I then manually enter an aspect ratio of 4:3 which slightly stretches the picture. I don't understand why there are always thin black bars on the sides of the picture. Have I been doing this wrong all along?
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  2. Member Cornucopia's Avatar
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    Those old TV episodes were likely mastered on Analog tape and then digitized using ITU standards. Which means the image you ripped from the DVD - the 720x480 - really only utilized 704x480 as it's visible program content area of 4:3, but because it is standard to use 720x480 for most DVD titles, they were padded prior to release.

    IIWY, I'd rip those, then crop 8pixels on each side (or if it happens to appear non-symmetrical, you could do 10+6 or 12+4, etc. - keeping even # of pixels).
    No need to stretch to 4:3 after. In fact, you SHOULDN'T. It unnecessarily adds blur (in addition to what the rest of your procedure is doing). It, for as close as you'll be able to determine, IS 4:3 (going from Analog to common digital formats doesn't ever do it exactly, due to a number of factors both analog & digital). Leave it as 720x480 non-square with the bars, or 704x480 non-square without the bars, or 640x480 square without the bars, depending upon your playback devices.

    Scott
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  3. Dinosaur Supervisor KarMa's Avatar
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    When you play a DVD, those black bars are designed not to be shown on a CRT TV. But overhang the left and right side.

    Any properly done 4:3 NTSC commercial DVD should be resized from 720x480 to 656x480 (including any black bars). And then crop off a total of 18 pixels from the left and right of the picture to get a perfect 640x480 (yes 18 instead of 16), if 640x480 is what you are aiming for. MeGui along with Avisynth make this process much easier, for me at least as it has the ITU 4:3 NTSC preset. Example http://i.imgur.com/hRXtaMb.jpg

    VHS has to deal with the same overscan as analog output DVD players, may want to look at the below
    https://forum.videohelp.com/threads/374912-Question-about-caputring-VHS-and-overscan
    https://forum.videohelp.com/threads/374875-VHS-capturing-and-resizing-for-correct-AR?p=...92#post2415692
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    Originally Posted by KarMa View Post
    When you play a DVD, those black bars are designed not to be shown on a CRT TV. But overhang the left and right side.
    Nonsense.

    Originally Posted by KarMa View Post
    Any properly done 4:3 NTSC commercial DVD should be resized from 720x480 to 656x480 (including any black bars). And then crop off a total of 18 pixels from the left and right of the picture to get a perfect 640x480 (yes 18 instead of 16), if 640x480 is what you are aiming for. MeGui along with Avisynth make this process much easier, for me at least as it has the ITU 4:3 NTSC preset. Example http://i.imgur.com/hRXtaMb.jpg
    Nonsense.

    VHS has to deal with the same overscan as analog output DVD players, may want to look at the below
    https://forum.videohelp.com/threads/374912-Question-about-caputring-VHS-and-overscan
    https://forum.videohelp.com/threads/374875-VHS-capturing-and-resizing-for-correct-AR?p=...92#post2415692[/QUOTE]More of same.

    Typical.
    - My sister Ann's brother
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  5. Dinosaur Supervisor KarMa's Avatar
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    Originally Posted by LMotlow View Post
    Originally Posted by KarMa View Post
    When you play a DVD, those black bars are designed not to be shown on a CRT TV. But overhang the left and right side.
    Nonsense.

    Originally Posted by KarMa View Post
    Any properly done 4:3 NTSC commercial DVD should be resized from 720x480 to 656x480 (including any black bars). And then crop off a total of 18 pixels from the left and right of the picture to get a perfect 640x480 (yes 18 instead of 16), if 640x480 is what you are aiming for. MeGui along with Avisynth make this process much easier, for me at least as it has the ITU 4:3 NTSC preset. Example http://i.imgur.com/hRXtaMb.jpg
    Nonsense.

    Originally Posted by KarMa View Post
    More of same.

    Typical.
    Who behaves like this

    I welcome a disagreement, but this unexplained "I'm right your wrong" argument helps no one.
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    Wait a minute, dude, you want an explanation opposing the butchering of video? OMG, not just clueless and blind, but nutty, too.

    One thing I've learned from videohelp over the past two years, 9 out of 10 times -- what not to do with video.
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  7. Dinosaur Supervisor KarMa's Avatar
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    Originally Posted by LMotlow View Post
    Wait a minute, dude, you want an explanation opposing the butchering of video? OMG, not just clueless and blind, but nutty, too.

    One thing I've learned from videohelp over the past two years, 9 out of 10 times -- what not to do with video.
    More of [the] same.
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  8. Member Cornucopia's Avatar
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    Maybe I'm missing something, but where I come from, 656 - 18 = 638, not 640.

    Scott
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  9. Dinosaur Supervisor KarMa's Avatar
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    Originally Posted by Cornucopia View Post
    Maybe I'm missing something, but where I come from, 656 - 18 = 638, not 640.

    Scott
    You are actually cropping on the 720x480, which then gets resized to your target resolution (640x480 for example). Resizing to ITU 4:3 without any cropping is 656x480. If you are targeting 640x480, then -18 gives you the lowest AR error %, at least according to MeGui.
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  10. Member
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    Thank you for all the feedback. So, basically, crop both sides and rencode as is without manually adjusting AR to 4:3?
    Last edited by smackyourfupa; 10th Dec 2015 at 23:54.
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  11. Member Cornucopia's Avatar
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    Well, that's MeGUI for you. If the title was digitized to ITU standards, the PAR is 10/11 whether the clip is padded to 720 or not (meaning a padded 720 clip is actually slightly wider than 4:3/16:9, even though it is marked as such). So to arrive at square pixel dimensions, one must undo those steps in reverse order and use the 10/11 scaling factor, which gives you 640x480 exactly, and hopefully 4:3 DAR exacly.

    Regardless, the "error" is really beyond most peoples' ability to discern, so I don't think it really matters which way you go. I just like it tidy. Of course, I could be wrong in that some titles may be digitized at 720 using ITU or at 704 using MPEG standards, and then all the assumptions wouldn't work.

    You seem to expect to resize, then crop, while what I am saying is you should crop then resize. Both should get you to the same destination. However, your L/R edges would have a bit of the black blended in, while mine wouldn't.

    Scott
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  12. Dinosaur Supervisor KarMa's Avatar
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    Originally Posted by Cornucopia View Post
    You seem to expect to resize, then crop, while what I am saying is you should crop then resize.
    I might not have been clear in the 9th post. Crop first on the 720x480, then resize it. That is what I was advocating.

    crop(8, 0, -10, 0)
    Spline64Resize(640,480) # Spline64 (Sharp)
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  13. Originally Posted by LMotlow View Post
    Wait a minute, dude, you want an explanation opposing the butchering of video? OMG, not just clueless and blind, but nutty, too.

    One thing I've learned from videohelp over the past two years, 9 out of 10 times -- what not to do with video.
    I wouldn't mind an explanation either.
    The black bars either side of a 4:3 DVD can't be seen on a CRT TV due to overscanning. Why are you claiming that's nonsense?
    If you're resizing a 4:3 NTSC DVD to square pixels, how should it be done?
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  14. Member hech54's Avatar
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    Much ado about........thin black lines.
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  15. Originally Posted by Cornucopia View Post
    Well, that's MeGUI for you. If the title was digitized to ITU standards, the PAR is 10/11 whether the clip is padded to 720 or not (meaning a padded 720 clip is actually slightly wider than 4:3/16:9, even though it is marked as such). So to arrive at square pixel dimensions, one must undo those steps in reverse order and use the 10/11 scaling factor, which gives you 640x480 exactly, and hopefully 4:3 DAR exacly.
    For the record (and I can't remember why there's a difference in the way the ITU PARs are calculated) if you look at the list of PARs here:
    https://www.doom9.org/showthread.php?p=1058927#post1058927
    MeGUI still uses the "Almost exact and commonly used ITU-PAR", or the second table of PARs.

    Also for the record, if it was up to me I'd switch to using the MPEG4 PARs, partly because I think they're more accurate, partly because they're the same PARs that can be selected in MeGUI's x264 encoder configuration, and partly because when --bluray-compat is added to the command line either MeGUI or x264 (I can't remember which) will automatically round the "ITU" PARs to MPEG4 PARs for Bluray compatibility. I assume most GUIs these days use the MPEG4 PARs. I've only checked two (Handbrake and StaxRip) and I'm pretty sure that's what they use.

    A while ago I did suggest that it might be a good idea for MeGUI to switch to MPEG4 PARS, but much to my surprise the only response I got was an argument about it.

    Not that it matters terribly much in respect to resizing, the difference between MeGUI's resizing and resizing using MPEG4 PARs is generally only a difference in width of a pixel or two.

    It is however, easy enough to create a couple of custom aspect ratios for MeGUI to use.

    In case it's not clear to everyone (calculated using the mpeg4 pixel aspect ratios):
    720x480 with a 10:11 pixel aspect ratio gives a display aspect ratio of 1.3636364 or 15:11.
    720x480 with a 40:33 pixel aspect ratio gives a display aspect ratio of 1.8181819 or 20:11.

    720x576 with a 12:11 pixel aspect ratio gives a display aspect ratio of 1.3636364 or 15:11.
    720x576 with a 16:11 pixel aspect ratio gives a display aspect ratio of 1.8181819 or 20:11.

    Therefore, the same 4:3 and 16:9 Input DARs can be used for both NTSC and PAL.

    Click image for larger version

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    (There was a small error in MeGUI's aspect ratio error calculations when using custom aspect ratios, and while I haven't re-tested it, I think it's been fixed).
    Last edited by hello_hello; 27th Dec 2015 at 23:37.
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