[vlc] Issues with subtitles with the Python bindings

[Mike Fabre]

I got some help with this issue in the IRC channel, but didn't manage
to solve the problem. Hopefully I can get some more help here.

I've got an RTP stream with zvbi subtitles that all works find in the
standard VLC GUI, I select the right subtitles track in Video->Subtitles
and it starts appearing on the screen. However when using the Python
bindings for VLC with the same RTP stream, the subtitles track is
recognized, and there's no errors raised when setting the subtitles
track but no subtitles start rendering on the video. Both the GUI and
the Python bindings work fine when using .avi file with .srt or .idx &
.sub files.

The logs from when everything works fine indicates that VLC loads the
necessary demux module to read the subtitles (telx/zvbi/vobsub) and then
shortly after it loads the blend module. However when Python fails with
the zvbi subtitles it loads the zvbi module, but never even tries to
load the blend module. Is the GUI doing something hacky to load the
blend module itself when the VLC library won't?

-- 
Mike Fabre