Changing aspect ratio in MKVToolNix

[Rosinmanden]

Hi all

First question here, hope you can help

I've recently ripped my entire DVD/Blu ray library using MakeMKV, and streaming via Plex.

I've noticed that a few of my DVD's have a weird aspect ratio, where there are black bars both at the top and bottom as well as the sides.
Using MKVToolNix I can see that the original aspect ratio is 720x526 pixels.

I've tried converting it to 16:9 in MKVToolNix by changing the MPEG 1/2 codec, and under "video properties" changing the "Set aspect ratio" to 16:9.
After converting, the aspect ratio remains exactly the same at 720x526.

Does anyone have any advice on how to get MKVToolNix to actually convert the aspect ratio, or know of any other programs that does the same?

Thanks in advance

[davexnet]

The display aspect ratio is not necessarily the same as the physical pixels.
The player will stretch the video to conform to the "set aspect ratio" if this is is set

[jagabo]

The player will stretch the video to conform to the "set aspect ratio" if this is is set

And not all players will respond to MVK aspect ratio flags. The MPEG 2 stream still includes its own display aspect ratio flags -- which will be 16:9 or 4:3.

[Alwyn]

Something's sus if there are black bars on all sides. That doesn't sound like an aspect ratio issue to me. I would expect the viewing device/software to at least "fill" the sides, or the top; either it's either letterboxed or pillarboxed, but it can't be both unless the file is encoded that way with physical black video.

[ProWo]

The video is probably encoded with physical black bars on all sides.
To verify this, you can use clever FFmpeg-GUI with crop detection to detect the effective video image in the video frame, which in your case is certainly not 720x526.
After that you can re-encode the video correctly.
The best would be to cut out 30 seconds of your video with Avidemux and post it here.
Then we could take a closer look.

[Alwyn]

Or you can just use VLC player and drag one side in until the video starts compressing. If it compresses before the VLC edge/mouse gets to the visible video edge, you've got black side bars. Do the same with the top edge to spot black top/bottom bars.

[Rosinmanden]

Hi

I just tried to pop in one of the "affected" dvd's, just to see what format I get, and I get the format you see in the top picture.
That is also the format I see, when viewing the ripped file, either on my computer or via Plex

But at least on my PS4, I get the option to choose between "Full" and "Zoom" as well, which at least makes it watchable. Though "Zoom" cuts off the bottom part of the subtitles.

[jagabo]

You have a ~2.24:1 movie letterboxed in a 4:3 DVD frame. The black bars above and below the picture are part of the DVD frame. When you play that the 4:3 DVD frame, including the black bars at the top and bottom, fills the height of the TV and the rest of the 16:9 TV frame is filled with black pillarbox bars. The top image is exactly what one expects to see. If you don't want the pillarbox bars you have to crop away the letterbox bars from the DVD frame and reencode the video.

See the example images in this post: https://forum.videohelp.com/threads/405115-Video-top-bottom-blackbar-cropping-question#post2651710

[Ennio]

The 720x526 resolution still strikes me as strange. No matter if I'd read it as real pixels or aspect ratio. Can somebody tell if/where it's a commonly used value, coming from dvd?

As a sidenote: Assuming that the tv is displaying the same frame but with different zoom settings on PS4 player, I do wonder whether it's the tv or PS4 showing less of that frame in the first picture.
Which you can notice best at the utter right of the frame.

[jagabo]

The 720x526 resolution still strikes me as strange.

My guess is the OP just remembered incorrectly and it is really 720x576.

[Rosinmanden]

The 720x526 resolution still strikes me as strange.

My guess is the OP just remembered incorrectly and it is really 720x576.

Yeah, sorry about that. It's 720x576

[Alwyn]

The 720x526 resolution still strikes me as strange. No matter if I'd read it as real pixels or aspect ratio. Can somebody tell if/where it's a commonly used value, coming from dvd?

If this is PAL, 720x576 is the normal DVD frame size. It will be coded either 4:3 or 16:9. See Jagabo's post #8.

[netmask56]

Fire up an ancient program IFOEdit and check out the settings used. https://www.videohelp.com/software/IfoEdit

[ingsoc]

i have tried to set 3/2 aspect ratio that is not on the listbox. Also i tried to apply the same via header editor. In the smart tv all changes i do that way make not changes in the aspect ratio. I tried mkvtoolnix versions 68 and 82, both with same results. I wonder if mkvtoonix is just ignoring 3/2 aspect ratio because not on its listbox.

Any ideas how to achieve it ?

[davexnet]

i have tried to set 3/2 aspect ratio that is not on the listbox. Also i tried to apply the same via header editor. In the smart tv all changes i do that way make not changes in the aspect ratio. I tried mkvtoolnix versions 68 and 82, both with same results. I wonder if mkvtoonix is just ignoring 3/2 aspect ratio because not on its listbox.

Any ideas how to achieve it ?

What is the resolution of the source file?

In general, you can type in 1.5 to get 3:2

[ingsoc]

i have tried to set 3/2 aspect ratio that is not on the listbox. Also i tried to apply the same via header editor. In the smart tv all changes i do that way make not changes in the aspect ratio. I tried mkvtoolnix versions 68 and 82, both with same results. I wonder if mkvtoonix is just ignoring 3/2 aspect ratio because not on its listbox.

Any ideas how to achieve it ?

What is the resolution of the source file?

In general, you can type in 1.5 to get 3:2

1440x1080

[davexnet]

Just put in 1.5 in the "set aspect ratio" box, as I alluded to above.
You can also try 1620 / 1080 in the width/height boxes

[ingsoc]

^ I already tried that, none way made it works. Yes with the pc player, but not with the smart tv. When adding that 1.5, the result will be that mkvtoolnix will set that 1620 x 1080, that seems no valid for the smart tvs, samsung at least. Doing the same, and more, with header editor, result the same. Only solution to make it works was using ffmpeg with that clever gui made by ProWo

I still think that mkvtoolnix is failing because no 3:2 or 1.5 in the listbox as valid values...

[Ennio]

Only solution to make it works was using ffmpeg with that clever gui made by ProWo

May I ask what you did exactly with clever FFmpeg?

I still think that mkvtoolnix is failing because no 3:2 or 1.5 in the listbox as valid values...

I've seen video with 1440x1080 resolution which is authored to either 16:9 or 4:3 display aspect ratio. Never with 3:2 though, which uncommon value can be something the tv (internal player) can't handle properly. Where I wonder if it can read DAR headers in matroska video in the first place.
Maybe remuxing to another container may help.

[davexnet]

The method in MKVtoolnix works fine, it is the TV that is ignoring the A/R setting to 3:2.
The actual pixels in the file are still sized @ 1440x1080, all MKVtoolnix is doing is setting an indicator
in the header and/or the stream itself that it should be stretched upon playback.

It works properly in my LG TV.

In your case, you may have to re-encode the file and set the resolution to the display size you want

[ingsoc]

^^ no, mkvtoolnix is not working well doing that. In header editor you will see how there is a difference on the result from clever ffmpeg and result from mkvtoolnix. And the smart tv knows it. If there is some tv model that works, that is lucky, but results are not the same.

About reenconde, is that joke ?

[davexnet]

About reenconde, is that joke ?

No it's not a joke, it's a common thing for those with older TV's.

What header editor? MKVtoolnix? I see the video display width, are you talking about something else?

Clever FFmpeg GUI is using "-aspect 1.5" in it's command line, I assume this is responsible for the extra info
in "video display unit", "video display height" and "video display width"