[MPlayer-G2-dev] Subtitles demuxer

[Arpi]

Hi,

> I started to do some g2 hacking with $SUBJ. I added subtitles stream to
> the demux_find_streams function and wrote a simple mpsub demuxer.
> 
> To test that i added a quick hack to test-play to show the subs on the
> terminal. Sadly i have atm no good movie / subtitle combination
> to do proper test about the sync but it seems to be ok.
> 
> The demuxer don't do autodetection atm so you have to force it :
> test-play -sub subfile -subdemuxer txtsub

the patch looks ok, i'll apply

> Now this is only a quick hack to have some thing comming out of the
> demuxer level. I'd like to know what are the plans for the subtitles
> decoding/filtering/output. If there are any ;)

plans: not really, i have only ideas.
someone really should sit down and design the API for subtitle/osd stuff.
maybe these 2 (osd and subs) shouldnt be mixed (keep them as 2 independent
layer).

what do we need:
- define subtitle stream formats (like ascii, html?, spu etc)
- maybe define subtitles decoder/filter/encoder layer (like vd/vf/ve in video/)
  sub filters may do things like subdelay/fps change, codepage conversion,
  word-wrapping etc. en/decoders may do spu<->bitmap conversion,
  text->bitmap->spu, spu->ocr->text :)

we also need to define the OSD api. it is harder.
wanted features, ideas:
- allow several independent osd "zones".
  for example it could allow putting osd (including subs) bellow & above the
  video image, but not over it, thus allowing full DR.
  or it could allow OSD to external LCD device or second display (for
  example playback video to TVout but display OSD on monitor/gui/lcd)
  or it could define osd zone over the image, and another bellow the image,
  so the over-image one will be scaled by BES (it could be used to display
  progress bar/volume symbols etc) the bellow one (unscaled) could be used
  for nice subtitles.
- it should support differential remove/draw, like in g1, so devices with
  hardware osd but slow osd-ram access (like DVB or PVR-350) could benefit.
- it should allow full control over osd to the UI, so UI can put its own
  messages. it would be better if the UI moves the subtitle osd to the osd
  engine, maybe via setting a callback.
- support for direct rendering compressed subs, ie. direct dvd->dxr3 spu
  transfer without decoding spu, osd engine, encoding. maybe it doesnt worth
  the extra complexity?


A'rpi / Astral & ESP-team

--
Developer of MPlayer G2, the Movie Framework for all - http://www.MPlayerHQ.hu