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  1. Hello,

    I have this video that I wish to change its display aspect ratio. Regardless of which software or method I used, it will not allow me to change it. Why? Which field did the original encoder modify to prevent changing of its display aspect ratio? How if there is any way to change it?

    Below is some info about the video.

    General
    Complete name : Video.avi
    Format : AVI
    Format/Info : Audio Video Interleave
    File size : 837 MiB
    Duration : 13mn 41s
    Overall bit rate : 8 551 Kbps
    Movie name : Video
    Writing application : Lavf54.3.100

    Video
    ID : 0
    Format : MPEG-4 Visual
    Format profile : Simple@L1
    Format settings, BVOP : No
    Format settings, QPel : No
    Format settings, GMC : No warppoints
    Format settings, Matrix : Default (H.263)
    Codec ID : XVID
    Codec ID/Hint : XviD
    Duration : 13mn 41s
    Bit rate : 8 411 Kbps
    Width : 1 920 pixels
    Height : 1 080 pixels
    Display aspect ratio : 16:9
    Frame rate : 23.976 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Progressive
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.169
    Stream size : 823 MiB (98%)
    Writing library : Lavc54.15.100

    Audio
    ID : 1
    Format : MPEG Audio
    Format version : Version 1
    Format profile : Layer 3
    Mode : Joint stereo
    Mode extension : MS Stereo
    Codec ID : 55
    Codec ID/Hint : MP3
    Duration : 13mn 41s
    Bit rate mode : Constant
    Bit rate : 128 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48.0 KHz
    Compression mode : Lossy
    Stream size : 12.5 MiB (1%)
    Alignment : Aligned on interleaves
    Interleave, duration : 24 ms (0.58 video frame)
    Interleave, preload duration : 24 ms
    Writing library : LAME3.99.5


    Thanks in advance for your help!

    Eric
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  2. for xvid/avi you can use mpeg4modifier

    but 16:9 for 1920x1080 looks correct, unless your source was "off" or you did something weird

    or you can rewrap into mkv with mkvtoolnix and force a DAR
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  3. Originally Posted by poisondeathray View Post
    for xvid/avi you can use mpeg4modifier

    but 16:9 for 1920x1080 looks correct, unless your source was "off" or you did something weird

    or you can rewrap into mkv with mkvtoolnix and force a DAR

    The numbers are 16:9, but the pictures rather look like 4:3. Even if I expand it the full-screen mode, the pictures do not fill the full screen, only half of the screen.

    I just tried mpeg4modifier, but still no luck.
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  4. What were the source video characteristics? Was it distorted to begin with?

    Are objects distorted? Does a circle (e.g. like a car tire) look like a circle or oval ? If there is no distortion, maybe it's pillarboxed content (supposed to be 4:3?)
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  5. Originally Posted by poisondeathray View Post
    What were the source video characteristics? Was it distorted to begin with?

    Are objects distorted? Does a circle (e.g. like a car tire) look like a circle or oval ? If there is no distortion, maybe it's pillarboxed content (supposed to be 4:3?)
    The source video (Video.wmv) were 16:9, but look like 4:3 as well. Everything looked normal. I used AVS Video Converter and its crop scale option. No matter how I move the bar, the display will not change.
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  6. So there was distortion on playback? People look "skinny" and horizontally squished ?

    What were the WMV characteristics? Was it encoded at 1440x1080 frame size? What does mediainfo say about the source videos?

    I guess it was decoded incorrectly, you can use wmvarchanger to "fix" the wmv, then encode. I've seen a few cases like that

    Or you can do the crop and resize properly in avisynth or vdub. AVS video converter probably didn't do it correctly

    To fix it after the fact, you would have to set the DAR in mpeg4modifier to something wider than 16:9 to overcompensate


    EDIT:
    The source video (Video.wmv) were 16:9, but look like 4:3 as well. Everything looked normal.
    Ok , I'm not sure if I'm on the same page

    "everything looked normal" ???? So you mean no distortion?

    So was it encoded pillarboxed?
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  7. If it's 4:3 content, and there is no distortion , then it's supposed to be pillarboxed (black bars on the left and right) when watching on a 16:9 HDTV display
    http://en.wikipedia.org/wiki/Pillarbox

    The only way you "fill the screen " to 16:9 is if YOU cause the distortion, ie. stretch it so people look fat (=BAD) , or you "zoom in" and you lose picture area (=BAD)

    Usually the only reason you change the AR is if there was distortion to begin with (e.g. circles look like "ovals")
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  8. It's not the what, but rather the how. The original video has pillar boxes. I want to remove these pillar boxes and have the sides filled with pictures, but regardless of which software I used, it would let me do that! This lead me to think there might be a field that the original encoder has set to prevent the changing of the display ratio.

    I want to learn the how.
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  9. Originally Posted by ericdunn View Post
    It's not the what, but rather the how. The original video has pillar boxes. I want to remove these pillar boxes and have the sides filled with pictures, but regardless of which software I used, it would let me do that! This lead me to think there might be a field that the original encoder has set to prevent the changing of the display ratio.

    I want to learn the how.

    If there is no distortion , then you don't change the AR. You don't "remove" the pillar boxes, because you would have to add them back (or add pictures back since you want the sides filled with pictures). Even if you don't add them back (ie. you crop to 4:3 AR), the display (your TV or monitor) will add them back

    You use another program (e.g. a video editor) to "cover" the pillarbox area with something. You can use something like Sony Vegas, Adobe Premiere Pro, even free ones like avisynth
    https://www.videohelp.com/tools/sections/video-editors-advanced
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  10. mpeg4modifier is supposed to change attributes such as DAR, but even it does not change. The pictures still look like 4:3 with the pillar boxes on each side, after I changed it to 16:9.
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  11. Originally Posted by ericdunn View Post
    mpeg4modifier is supposed to change attributes such as DAR, but even it does not change. The pictures still look like 4:3 with the pillar boxes on each side, after I changed it to 16:9.

    That's supposed to happen, because the pillarbars are encoded into the 1920x1080 frame . The DAR is 16:9 eitherway so nothing is changed. The programs have no way of knowing what the actual content is - they cannot distinguish between 4:3 pillar boxed content. All they see is 1920x1080 frame size

    If you were going this route you would have to enter a DAR value wider than 16:9 to stretch and distort the picture - but again you dont' want to do that, people will be stretched and fat
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  12. Let me put another way, even when I tried to crop half of the picture out it would not let me. Do you understand what the problem is now? I believe it's something the original encoder did to prevent it.

    Anyways, it's now a huge issue. I can live with the current display. I just wanted to learn the cause behind it. I don't want to spend a lot of time circling around the point without learning the issue.

    Thanks for your help anyways!
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  13. Member Cornucopia's Avatar
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    Yeah, you want to crop off the pillarboxing (240 on each side L + R for a total loss of 480 pixels in width). This will leave you with a TRUE ACTIVE image of 1440x1080, with a PAR of 1:1 and a DAR of 4:3.
    Then you change the DAR from 4:3 to 16:9 (or PAR from 1:1 to 4:3). Save.
    Now your image will fill the screen.
    But like pdr said, it will be wrong because it will stretch all the objects into FAT, SQUAT objects (unless that's what you really want??!!!)

    If that ISN'T what you really want, then you skip the DAR change and save as-is 1440x1080 with 4:3 DAR (or just use the original).
    Open that in an NLE/editor/compositor and put additional pictures on top of the blank areas and render/encode the new master as 1920x1080 16:9.

    Scott

    Note: mpeg4modifier does not "CROP". You want to use an NLE/editor/compositor, or processor/convert like AVISynth, Virtualdub, etc.
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  14. Originally Posted by ericdunn View Post
    Let me put another way, even when I tried to crop half of the picture out it would not let me. Do you understand what the problem is now? I believe it's something the original encoder did to prevent it.

    Anyways, it's now a huge issue. I can live with the current display. I just wanted to learn the cause behind it. I don't want to spend a lot of time circling around the point without learning the issue.

    Thanks for your help anyways!

    It's not something the encoder did to prevent it, it's just that you are watching 4:3 content on a 16:9 display.

    Sorry I'm doing a poor job of explaining it.

    Even if you cropped it, encoded it as 1440x1080 (cropped the pillar box sides off), when you watch it on a 1920x1080 display, the display will add the bars back. Think of it as a window with size 1920x1080. How do yo u fit something 1440x1080 into that? It fits perfectly with pillarbox bars.

    The only (bad) ways around this are either to zoom in, or distort the image. It's just math. In fact you can set your TV or display to zoom in and see what is happening. Even software players have this option
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  15. Member Cornucopia's Avatar
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    @ericdunn,
    maybe you want to Zoom In?

    Scott
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  16. The bottom line is you don't really want to change the actual picture aspect ratio when encoding. You can change the dimensions of the video itself by removing some of it when encoding, but the shape of objects in the video which remains should never change as any change is a distortion of the picture. A lot of encoding software will actually try to save you from yourself by preventing that distortion from happening, so if you encode a 4:3 picture while specifying a 16:9 output aspect ratio, the software may automatically include/add pillar boxes to the sides, giving you an "overall" 16:9 aspect ratio as you requested, while keeping the original 4:3 video intact within. In your case it seems that's how the original video was encoded.

    If you want a 4:3 picture to fill a 16:9 screen (and it seems you basically have a video which contains an active picture area with dimensions of 4:3), you have to manually remove enough of the picture from the top and the bottom until what's left fills a 16:9 screen without the necessity of stretching it, but generally it's better to accept the original video is 4:3 rather than remove a noticeable amount from the top and/or the bottom. If that's what you were attempting to do when you said you unsuccessfully tried to crop out half the picture, then it's a different story because while it's far from ideal it should be easy to do. If however cropping out half of the picture means you were simply cropping the black bars from the sides, then the only way the remaining 4:3 picture could fill a 16:9 screen is if it was stretched lengthways, which as I said is quite often the type of picture distortion some encoding software will deliberately try to prevent.
    Last edited by hello_hello; 24th May 2012 at 01:51.
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  17. > If you want a 4:3 picture to fill a 16:9 screen

    This is preciously what I want.

    > you have to manually remove enough of the picture from the top and the bottom until what's left fills a 16:9 screen without the necessity of stretching it,

    I tried that (using FFmpeg's crop parameter) and it would not allow me. THIS IS the problem and the reason I posted my question is to find out why this is and NOT if I should do it and what the consequences will be. Using a a different scenario: A smoker whose lighter is not working. He asks lighter experts what is wrong with the lighter, but they tell him that he should not smoker because it's bad for the health. I'm here to ask why the lighter is not working and how to fix it, instead getting people tell me that I should not smoke (should not change the aspect ratio).
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  18. Originally Posted by ericdunn View Post
    I tried that (using FFmpeg's crop parameter) and it would not allow me. THIS IS the problem and the reason I posted my question is to find out why this is and NOT if I should do it and what the consequences will be. Using a a different scenario: A smoker whose lighter is not working. He asks lighter experts what is wrong with the lighter, but they tell him that he should not smoker because it's bad for the health. I'm here to ask why the lighter is not working and how to fix it, instead getting people tell me that I should not smoke (should not change the aspect ratio).
    Well in your first post you simply asked how to change the aspect ratio of the video, which to most of the people here would mean taking an existing video and simply changing the dimensions with which it displays on playback. Based on that description nobody was telling you not to smoke, only trying to confirm whether your lighter's broken when it appears you're holding a flashlight. Then you explained how you want to remove the pillar boxes from the sides and have the whole picture fill the screen without mentioning any further cropping, which to use your analogy again seems a bit like asking why your lighter's broken while you're standing in the rain.
    The closest anybody has come to telling you not to smoke would probably have been my post when I said it's not ideal, but that was while trying to explain the different ways to use a lighter in the hope you'd finally describe the process you're using well enough to determine if it's actually broken.

    Someone else may be able to help you with your problem. I'm actually a smoker myself but unfortunately I've never used your brand of lighter.....
    Last edited by hello_hello; 24th May 2012 at 23:13.
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  19. Originally Posted by ericdunn View Post
    > If you want a 4:3 picture to fill a 16:9 screen

    This is preciously what I want.

    > you have to manually remove enough of the picture from the top and the bottom until what's left fills a 16:9 screen without the necessity of stretching it,

    I tried that (using FFmpeg's crop parameter) and it would not allow me. THIS IS the problem and the reason I posted my question is to find out why this is and NOT if I should do it and what the consequences will be. Using a a different scenario: A smoker whose lighter is not working. He asks lighter experts what is wrong with the lighter, but they tell him that he should not smoker because it's bad for the health. I'm here to ask why the lighter is not working and how to fix it, instead getting people tell me that I should not smoke (should not change the aspect ratio).
    The lighter works.

    To confirm, you to want zoom in (you don't mind losing active picture area - you might cut off someone's head depending on the framing)?. You can do this in something like avisynth, vdub, avidemux, or any NLE

    Essentially what you are doing is scaling the video up larger than the original 1920x1080 window frame, then cropping it back to the 1920x1080 window size

    These images are scaled down in proportion just for illustrative purposes. I added a circle to show AR proprotion scale. Note The DAR isn't altered (in both cases it's 16:9 , for the original, and when you zoom in) , The PAR isn't altered either , so you 're not changing the DAR as your title is misleading

    Display Aspect Ratio = Frame Aspect Ratio x Pixel Aspect Ratio

    You can thing of FAR as w:h of the dimensions of the actual encoded video, and PAR as the w:h of the pixels (it's also called SAR or sample aspect ratio in some terminology)

    In both cases, the FAR is 1920x1080, and the PAR is 1:1 square pixels , and by math the DAR is 16:9.

    16/9 = 1920/1080 x 1/1

    Notice that even though you have 4:3 letterbox content that doesn't even come into the equation. The tools don't analyze the actual content. A black letter box pixel is the same thing to them as a green pixel. This is the answer to your question. When you enter 16:9 in your various tools, nothing changes - Nothing is supposed to!





    1) Original pillarbox

    Click image for larger version

Name:	1 Normal Pillarbox.jpg
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ID:	12542

    2) zoom in = lose active picture area, also upscaling will make picture softer

    Click image for larger version

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    3) distort stretch = make people fat
    Click image for larger version

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ID:	12541


    4) the 4th technique isn't shown, it's covering the black pillarbox with something else, like a mirrored edge or something
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  20. So assuming you wanted the zoom technique, the values you would use for perfect* pillarbox: (sometimes it might not be "perfect", perfect would give you 1440x1080 exactly if you cropped the pillarbars)

    I don't do this very often (or at all, obviously ), but I think these numbers are correct, as I tested an example:
    1) Scale to 2560x1440 (I got this by multiply each dimension by 4/3)
    2) Crop 320 on each of the left and right (640 total) , and 180 each from the top and bottom (360 total) . This will give you 1920x1080

    So if it's not perfect 4:3 content, then you might have to adjust the values. Or if you use a NLE you can visually do it on the fly

    Cheers
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  21. poisondeathray: Thank u for providing the pictures for illustration. Basically I would like to get from 1) Original pillarbox to 2) or 3) (with the pillar boxes gone.)

    With other videos I have I can use AVS4YOU and its crop slider bar to remove the pillar boxes in the resultant video. It's that simple. But, with this particular video, when I move the AVS4YOU slider bar, the picture stay the same (as in picture 1). This has led me to believe that the original encoder might have done something unusual. I will try avisynth, vdub, avidemux as you have suggested. btw, what does NLE stand for?

    Thank everyone for your help and patience!

    Regards,

    Eric
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  22. Originally Posted by poisondeathray View Post
    So assuming you wanted the zoom technique, the values you would use for perfect* pillarbox: (sometimes it might not be "perfect", perfect would give you 1440x1080 exactly if you cropped the pillarbars)

    I don't do this very often (or at all, obviously ), but I think these numbers are correct, as I tested an example:
    1) Scale to 2560x1440 (I got this by multiply each dimension by 4/3)
    2) Crop 320 on each of the left and right (640 total) , and 180 each from the top and bottom (360 total) . This will give you 1920x1080

    So if it's not perfect 4:3 content, then you might have to adjust the values. Or if you use a NLE you can visually do it on the fly

    Cheers
    This is what I did! Cropping 320 on each side with FFmpeg's -vf crop=width:height:y parameter. AND the black pillar boxes remain in the resultant video, as if no command has ever been performed on the source video.

    I will try it again using the other software you suggested.

    Thx!
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  23. Originally Posted by ericdunn View Post

    This is what I did! Cropping 320 on each side with FFmpeg's -vf crop=width:height:y parameter. AND the black pillar boxes remain in the resultant video, as if no command has ever been performed on the source video.
    Bud did you scale as well? If you cropped without scaling and encoded at 1920x1080, the pillarbox would come back.

    Cropping 320 on each side would give you 1440x1080 with PAR of 1:1. Notice that the DAR is the correct value of 4:3 for the active image area (the pillars have been cropped) . Think of it as 4:3 content inside a 4:3 box (it fits perfectly)
    4/3 = 1440/1080 x1:1

    So watching that on a 16:9 HDTV, the TV would put the pillarbox back in order to preserve the image (undistorted)





    This has led me to believe that the original encoder might have done something unusual. I will try avisynth, vdub, avidemux as you have suggested. btw, what does NLE stand for?
    There might be something else going on, but I doubt it since you said there was no distortion, just pillar box. But WMV can have weird AR issues that sometimes need fixing (I mentioned WMVARChanger earlier). If you want to provide a small sample e.g. cut with asfbin, we can verify what is going on

    NLE = non linear editor. Something like Sony vegas, premiere pro. You have a nice GUI where you can resize and see what you're doing with realtime feedback. So if it's not exactly 1440x1080 active image area, you will see it and scale accordingly. ie. you can see exactly what you are doing

    Something like avisynth or ffmpeg don't have real gui's and are more difficult to use, no realtime feedback. (You can use avspmod for avisynth, push f5 for preview).
    Last edited by poisondeathray; 25th May 2012 at 00:46.
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