Allow to stack secondary subtitles on bottom of screen

[teohhanhui]

Expected behavior of the wanted feature

Being able to stack the secondary subtitles on top or below the primary subtitles, both at the bottom of the screen.

The effect should be like no. 5 in this blog post: https://www.raymond.cc/blog/playing-two-subtitles-at-the-same-time-in-dvd-player-and-computer/ but without having to merge multiple subtitles files into one.

This kind of multilingual display of subtitles is very common in Malaysia where I come from. In the cinema, an English movie would typically have Malay and Chinese subtitles at the same time, both displayed at the bottom of the screen. A non-English/Malay/Chinese movie might sometimes even have English, Malay and Chinese subtitles all at the same time.

Can't find a Malaysian example, but here's one from Hong Kong: https://www.scmp.com/magazines/hk-magazine/article/2037102/ask-mr-know-it-all-why-do-all-films-hong-kong-have-subtitles

Alternative behavior of the wanted feature

N/A

Log file

N/A

[link-webcreations]

It would be lovely!

[ghost]

Technically hard, because "secondary" subs are renderered completely separately. Both are renderered into the video without knowing about each other. To stack them you'd need to handle them by the same renderer, which may be significantly harder.

For now, you may need to write a script or so that produces a merged subtitle file.

[felagund]

What about allowing the user to move the secondary subtitles manually? It would have a downside that with two one-line subtitles, there would be a gap, but still better than nothing.

[Asraelite]

For anyone else looking to just be able to manually position secondary subtitles for now, I made a quick and dirty patch:

https://gist.github.com/Asraelite/17795f07f6f71d768a3206eed5e90119

Apply it with git apply -3 mpv_secondary_sub_position.diff and build, then you can use the flag --secondary-sub-pos=90.