[gst-devel] GStreamer poor support for subtitles

[Tomasz Sałaciński]

Hello,

I wanted to ask about the status of bug 531166:

http://bugzilla.gnome.org/show_bug.cgi?id=531166

This bug is open for over a year now, and no information about it at
all. Is there any progress on that? Seeking the movie makes the
subtitles disappear for few seconds.

The second issue is bug 579516 - bad parsing of MicroDVD subtitles (it
assumes that subtitles is 24fps if not stated otherwise in subtitle
format). The bug is clearly here, someone (can't remember who, sorry)
stated that the FPS value MUST be written in subtitle file - which is
simply not true. 25 FPS movies don't have correct subtitles unless
someone puts:

{1}{1}25.000

in the subtitle file. Be aware that this entry is required in GStreamer
only. Xine, MPlayer, ffdshow and video players with their own subtitle
support work with these subtitles properly. ALL windows players don't
require this entry (they read FPS from the movie). Look at the comment
in mdvd parser - "is there a better way/assumption?"

My question is: is it the time for new subparse element? This element
can read only one line per file (that makes it simply unusable with
TMplayer subtitles, the support for this subtitle format is wrong at
this moment), and can't read properties from file, because it doesn't
have access to it (this is required for MicroDVD subtitles, that just
state the frame at which the subtitle should be shown - no matter if
it's 25fps or 30fps, we need to use current time and fps to compute when
to show the subtitle that should appear on 300th frame).

Also, subparse element supports only one subtitle stream.

Instead of patching bugs that have no value to casual user (of coure
they're imporant), should GStreamer focus on what casual users see? If
the movie subtitles work under Windows and don't work under GStreamer
(because we need to specify {1}{1}25.000), casual user thinks that
GStreamer just can't play this file (don't want to look at the code).


Just wanted to know if someone is taking care of this:) I think I don't
have enough knowledge to write new subparse2 element, but someone should
take a look at this. Instead, we'll just hear "Windows have better
support for this".

Didn't mention unscaled subtitles.