Apparently not everyone upgraded from the original LIVE to the SMP and thus did not browse the LIVE forums. For all the people who missed my original thread on WDTV LIVE subtitle issues here’s the gist on what’s what with the SMP:
Animated subs are not displayed
Found e.g. in the ‘Men in Black’ DVD and ‘Lord of the Rings’ BD commentary streams. When cycling through streams even the stream name of these subs is not depicted but listed as ‘unknown’.
Subs ripped with MakeMKV are not displayed ( fixed as of MakeMKV 1.7.8, use WDTV profile )
MakeMKV does not compress PGS subs with zlib which are the only subs that work on the SMP. Mediainfo lists compressed subs as ‘Muxing mode: zlib’.
Solution: bug Mike to add zlib compression to MakeMKV, bug WD to support uncompressed subs
Workaround: remux MKVs with MKVToolnix which automatically compresses them. This is not related to the ‘header removal compression’ setting (which has been fixed on the WDTVs but should be disabled nevertheless cause it confuses various standalones and only saves a few MB anyway).
Unlike other players the SMP allows for adjustment of text subtitles (SRT, SSA/A SS) only. Pressing option on the remote allows you to enter a menu where you can change position & size, color, coding but not timings (which somehow got dropped from the LIVE).