Subtitle used as matte mask

[spoRv]

I tried to use a properly made png file, with black bars top and bottom, and alpha channel in the middle, to make a "trick", using that as a subtitle.

It worked somehow... first, the xml test file:
<?xml version="1.0" encoding="UTF-8"?>
<BDN Version="0.93" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="BD-03-006-0093b BDN File Format.xsd">
<Description>
<Name Title="Non-open-matte" Content=""/>
<Language Code="non"/>
<Format VideoFormat="1080p" FrameRate="23.976" DropFrame="False"/>
<Events Type="Graphic" FirstEventInTC="00:00:10:00" LastEventOutTC="00:00:50:00" NumberofEvents="4"/>
</Description>
<Events>
<Event InTC="00:00:10:000" OutTC="00:00:20:000" Forced="False">
<Graphic Width="1920" Height="1080" X="0" Y="0">blackbars.png</Graphic>
</Event>
<Event InTC="00:00:20:001" OutTC="00:00:30:000" Forced="False">
<Graphic Width="1920" Height="1080" X="0" Y="0">blackbars.png</Graphic>
</Event>
<Event InTC="00:00:30:001" OutTC="00:00:40:000" Forced="False">
<Graphic Width="1920" Height="1080" X="0" Y="0">blackbars.png</Graphic>
</Event>
<Event InTC="00:00:40:001" OutTC="00:00:50:000" Forced="False">
<Graphic Width="1920" Height="1080" X="0" Y="0">blackbars.png</Graphic>
</Event>
</Events>
</BDN>


Then, input this file to BDSup2Sub and exported as .sup file; at the end, muxed it along with the open matte clip in tsmuxer (both old and new version).

Result: it works only in VLC, when muxed to .ts file; the black bars are grey, and they diseappear for few frames where there are subtitle change. (MPC doesn't even recognize there is a subtitle track...)

I chose to not do a single subtitle that last the entire movie lenght, because when ff/rew or activated the subs, it doesn't work.

So, problems to be solved:
1) find a way to work in every player, or at least in VLC and MPC -> solved!
2) turn the grey into black -> solved!
3) avoid the jump at subtitle event change -> partially solved, it works with MPV and SMPlayer.

Thanks for your help!

[spoRv]

I solved point #2 using BDSupEdit.

Point #1 is relatively important, as at least there is one free player (Leawo BD player) that recognize these kind of subs.

Now the most important thing it to solve #3: get continuous subtitles without a pause between them; I'm pretty sure it's possible, but I have no idea how to solve this problem... :(

[spoRv]

Point 1 solved - just use TSmuxer and avoid cutting...
Point 3 partially solved - the jumps don't occur on MPV and SMPlayer

Must add that if you want, for example, get black bars AND normal subtitles, SMPlayer allows that.

During all these tests, I've discovered another way to use this hack, but this is another story... if someone is interested, though, just reply to this thread.