Subtitles to .MP4 that play on my settop BD player.

[cholla]

I want to put soft subtitles into a .mp4. If possible.
That will play on my settop BD player.

I have used the

-c:s mov_text

with ffmpeg.
Those subtitles work fine with a PC media player.
My settop BD does not recognize or play them.

I can put hard subtitles into an .mp4 but this is not what I want.

[cibo]

mp4 only support two shitty and outdated subtitles types, VobSub is the only one usable in the two.

If you plan to burn it to a disc, you must use PGS (BD SUP) subtitles. Nothing else will work, and mp4 containers are not the standard for Blu-ray. If you play the file from a USB stick, your best bet for compatibility is AVC video in mkv + srt subtitles.

[cholla]

I will be using a USB stick or external HDD.
I have found a fix for my BD player playing the file as .mkv that only has a few problems with chapter skip.
My BD player plays most files from a USP port it has.
I was not going to burn these files to a bluray disk.
I will give vobsub a try.
VobSub wanted a DVD .ifo to work with.