[gst-devel] Re: Totem or no Totem was Re: GNOME Development Series Snapshot 2.3.0: "Mighty Atom"

Gustavo J. A. M. Carneiro gjc at inescporto.pt
Thu Apr 24 04:40:07 CEST 2003

  Can you tell me what exactly are the requirements for i18n
subtitling?  The text overlay plugin I'm working on receives UTF-8 text
as input and uses pango/freetype2 to do all rendering, so I guess it
should be able to render just about any text.
  Then we have the matter of subtitle file parsing, which should support
UTF-8.  Besides this, anything else I should be considering?

A Qui, 2003-04-24 às 03:24, Mario Sergio Fujikawa Ferreira escreveu:
> Hi,
> On Thu, Apr 24, 2003 at 12:26:22AM +0200, Thomas Vander Stichele wrote:
> > > On Wed, 2003-04-23 at 15:36, Bastien Nocera wrote:
> > > ...
> > > > You didn't get it at all. These are just subtitle formats, you can use
> > > > them on top of any video playable by the player. Ie. if I have an MPEG
> > > > file, and a subtitle file, I can have the subtitles synchronised with
> > > > the video. For all these formats, the specs are available.
> > > 
> >
> > This may be a stupid question, but who's going to promote this to content 
> > creators ? Who are these content creators ? And why aren't they using SMIL 
> > already ?
> > 
> > > If nothing else I would expect that some transformation software between
> > > SMIL and these formats could be put together.
> > 
> > same here - who's going to  write this software ?
> > 
> > I've been hearing about SMIL for a long time but I've never had to use it 
> > and I don't see a lot being done with it.
> 	I am going to provide a user point of view. I've done
> some research on computer based subtitling. I have used all of the
> usual subtitling formats available for Windows (and Unix via mplayer):
> Subrip, SubViewer, MicroDVD, SubStationAlpha and MPSub. Formats are
> chosen based on usability (available applications to edit and to
> view the subs) and on capability (changing font faces, styles,
> positioning, coloring).
> 	From the aforementioned, the easiest format to use is
> subrip. However, the most feature rich is SubStationAlpha since it
> allows you to pick placement on the screen (left, right, top, down),
> font assignment, font coloring, font styles, etc. However, none of
> these formats has l18n support. Which is a MAJOR drawback from a
> developer point of view.  Therefore, we cannot rely on any of them
> for wide deployment. SubStationAlpha developers could be contacted
> about adding l18n support since their format seems the most flexible.
> 	Okay, these were just subtitling formats. Using a good
> recent video player such as MPlayer, Zoom Player or avifile; you
> add subs to a video by simply telling the player where to find a
> suitable subtitle file in one of those aforementioned formats.
> Therefore, the use of these files does not interfere with the video
> in any way. You can use them with MPEG, AVI, OGM, etc.
> 	What about multimedia containers? Neither MPEG nor AVI have
> any support for embedding subtitles in the files. 
> 	- MPEG
> 		1) A MPEG file can have more than one MP2 audio
> 		   stream embedded but no subtitle streams.
> 		2) A SVCD can several MPEG files and subtitles for
> 		   them. Therefore, a SVCD can have a MPEG with
> 		   both several MP2 audio streams and several
> 		   subtitles. SVCD can support DVD-like chapters.
> 		3) However, one CAN'T tell which stream belongs to
> 		   which language. You have to check out if
> 		   audio/subtitle 1 is english, german, french,
> 		   etc.
> 	- AVI
> 		1) An AVI file can have more than one video/audio
> 		   stream embedded but no subtitle streams. Selecting
> 		   amongst the multiple video and audio streams
> 		   require specific software.
> 	- OGM
> 		1) Supports multiple audio, video, subtitle streams.
> 		2) Subtitle streams are currently limitted to
> 		   SubRipper/subrip format but plan is on the way
> 		   to add support for other formats.
> 		3) Supports DVD-like chapters.
> 		4) One can language identify any kind of stream.
> 		   Therefore, you can tell the language of an audio,
> 		   a video or a subtitle stream.
> 	Of course, I might be missing information here but you can
> have an idea. From a user perspective, all current subtitling formats
> should be supported. There are several implementations around as
> an example (mplayer for instance although not the best implementation
> for some of the formats, e.g., SubStationAlpha). Furthermore, there
> are many users wishing for such support. These should make it in
> the priority list.
> 	From a developers perspective, we should push the technology
> to support the next best thing. Therefore, adding support for OGM
> and trying to support/develop l18n capable subtitle formats not to
> mention MPEG4 containers (although they're not widely deployed yet
> not have been "de facto" established) which should be perfect for
> streaming. Not to mention this SMIL we keep hearing about but I
> have to yet see a real life example of it. These should make it in
> the "wish list". :)
> 	Well, I hope to have added a bit to the discussion. If you
> need more info, ask me and I'll try to answer though I'm just a
> small town user. :)
> 	Regards,
Gustavo João Alves Marques Carneiro
<gjc at inescporto.pt> <gustavo at users.sourceforge.net>

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