[hedgehog90]

This problem regards the idx/sub format and no particular build or platform (although I've used the Windows x86 17.6 version for the purposes of this post).
Also I haven't tested .sup or any other graphics based subtitle formats.

With widescreen videos (wider than 16x9), I always prefer to have my subtitles just above the bottom black bar, at the bottom of the video image itself. Just as most blurays and dvds have their subtitles.

I've noticed with .idx/.sub subtitles within widescreen video containers (with equal dimensions to the video in the idx file), are stretched vertically to fill the screen, overlapping the black bars.
For the following pictures, I'm using a video with the dimensions 1920x818 playing on a 1080p display

Kodi (incorrectly stretched, overlapping black bars with subtitles of 2 or more lines):



VLC (correct):



SRT subtitles work just as I'd expect, obeying the setting value of 'Settings / Player / Language / Subtitle position on screen', otherwise aligning with the video calibration subtitile position setting.
These settings have no effect in idx/sub/sup subtitles though, as I assumed.

I can't imagine why anyone would want this as a default setting, so I assume it's a bug.
But just in case, is there any way to tell Kodi not to stretch idx/sub subtitiles like this? Or some sort of hacky/easy solution?

[Klojum]

Kodi (incorrectly stretched, overlapping black bars with subtitles of 2 or more lines):

You can change the subtitle position to "Bottom of video" instead of "Below video". That way subtitles are to be displayed inside the video. idx/sub or graphics subtitles may have a different outcome from the default srt subtitles.

Personally, I prefer to vertical-shift such video display to the top of the tv/monitor screen, and display all subtitles below the video. That way, all subtitles are fully displayed in the bottom black bar and not obstructed by any video part, and thus they are perfectly legible.

[hedgehog90]

The setting for the subtitle position (which I referred to in my post above) has no effect on idx/sub subtitles.
Although the individual captions are stored as small posterized images with positional values, they should be read by any interpreter/renderer as large images with lots of transparent pixels to fit the screen, as the idx states the precise resolution.
Therefore it makes some sense that the subtitle position setting in Kodi should have no effect on graphical subtitles.
Maybe there should be a boolean option called 'override idx/sub positioning' in the player settings for cases like this, so it will ignore all the positional data for each caption, centering it horizontally and vertically positioning it using the 'Subtitle position on screen' and/or video calibration setting. Shouldn't be difficult to implement.

But it still stands that even though the idx explicitly states the resolution of the container, instead of using it for the final step in rendering, or the video dimensions, the renderer stretches it to the display output resolution.
You can clearly see the stretching in the image I posted above, surely no one thinks that looks nicer than the correctly render subtitle?
It has to be a bug.

Again, if there's some sort of hack or fix to get around this, I'd love to know.

[Klojum]

Maybe there should be a boolean option called 'override idx/sub positioning', for cases like this.

There is such a setting for ASS/SSA subtitles, but apparently idx/sub is a different breed.

One quick fix perhaps is to use external .srt subtitles. They are less demanding. There are various subtitle converters available online for different subtitle formats. But this will only work if your subtitles aren't "burnt in" into the video.

[hedgehog90]

I'm not sure how to do it myself, but I would be grateful if someone could submit a bug report regarding this issue.  Nevermind, I sorted it out

I should also stress that it happens with PGS/.sup subtitles too.

[taxigps]

Need sample file to test.

I have tested some idx/sub subtitles, It works like this:

VLC (incorrect):


Kodi (correct):

[hedgehog90]

Hmm, very interesting!
The subtitles you're playing must have the size property (in the idx) as 1920x1080, even though the video has been cropped to remove the black bars (somewhere around 1920x800).
In my example, the subtitles' size property matches the video as I assumed was correct, but now I'm not sure.
VLC and Kodi interpret this differently, as to which is correct I have no idea. Should the size property match the original source dimensions or the cropped video dimensions?

I figured then that if I set the size value in the idx to 1920x1080 (instead of 1920x818) it should render perfectly on Kodi and squished in VLC, here's what I got though:

VLC:


Kodi:


As I suspected, VLC squishes the subtitles and Kodi now renders them correctly, however they are now both massively offset from the bottom of the frame.

When ripping blurays I always figured that the subtitle dimensions needed to match the video dimensions, using VLC as a way to test them, but now I'm not sure what's right or what's wrong.

Edit:
Here's a 1 minute segment from the video file I was testing on with the subtitles as they were (they're embedded):
https://drive.google.com/drive/folders/1...sp=sharing
I've also uploaded the idx/sub separately but the timing will be completely off to the video which is about 70 minutes into the film, where I got the original screenshots.

Edit2:
Finally got it working in Kodi using some freeware called BDSup2Sub, which I originally used to 'fix' the subtitles after ripping, by importing the subtitles as 1080p into the program, clicking 'Move All Captions', entering the video's aspect ratio and selecting 'move inside bounds', then clicking 'Move All':



Now I have the subtitles displaying in the same way as taxigps's screenshots showed on VLC and Kodi.

I'm still not sure what the correct settings for VobSub/PGS subtitles and cropped video files should be, all I know is VLC and Kodi treat them differently.
I'm still on the side of thinking VLC has the right idea, but I don't know for sure.
If someone could shed some light on this I'd really appreciate it.

[hedgehog90]

Another problem I've noticed with Kodi's way of doing it, is supposing that every graphics based subtitle was originally from a 1920x1080 (16:9) source, when some of my DVD rips are 720 x 576 (4:3)

If I play an untouched 4:3 DVD on Kodi I get horizontal stretching of subtitles because it assumes the aspect ratio of the subtitles are 16:9 / from a blu ray source.