#186 Some VobSub subtitles show up all black / palette issue?

[Jeppe Oland]

I found a somewhat strange problem with a VobSub file ....
Basically, if I create the IDX/SUB files and mux them into the MP4, the subtitles show as all black.
If I modify the colors slightly in the IDX file, the subtitles show correctly.

The original subtitle palette is:
palette: 000000, 828282, 828282, 828282, 828282, 828282, 828282, ffffff, 828282, bababa, 828282, 828282, 828282, 828282, 828282, 828282
(the color used for the subtitles is mostly index 9 = bababa).

If I modify 'bababa' to 'b9b9b9' or 'bbbbbb' the subtitles show correctly.

Possibly related: If I change the color to 'baba99' and then extract the VobSub from the MP4 again, the color now gets extracted as 'babb9b'.

If required, I can create a small test file and attach it.

[Jeppe Oland]

> If I modify 'bababa' to 'b9b9b9' or 'bbbbbb' the subtitles show correctly.

Or rather, they showed correctly in Windows Media Player Classic.
I just tried the file in XBMC 9.11, and the colors were wrong there.
(Could be an additional XBMC bug)

[Jean Le Feuvre]

Are you sure this is a bug in MP4Box muxing? If so, could you provide a sample sub/idx file as well as a correctly muxed MP4 version of it?