[MPlayer-dev-eng] [PATCH] libmenu subtitles selector

[Alban Bedel]

On Tue, 08 May 2007 23:35:36 +0200
Benjamin Zores <ben at geexbox.org> wrote:

> Alban Bedel a écrit :
> 
> > The basic idea (having a/v/sid selection) is fine, but to be honest it's
> > exactly the kind of implementation i wanted to avoid from the start.
> > It's too tied to the internal of the current track selection, partialy
> > duplicating code wich as Nico said is very messy.
> 
> I know but we (at GeeXboX) use libmenu OSD as the whole GUI for the 
> system and these feature needed to be provided by some way.
> Though, as you can see in the patch, there's no generic way to implement 
> the features (i mean we have code specific to mkv, to ogg, to dvd ...) 
> which isn't really nice but it was the only way to do (this code is more 
> than 3 years old but has been ported over time ...).
> Now with MPContext, things might change a bit.

It definitly changed quiet a lot with the property API. As you know
it is already possible to select a/v/s tracks from the menu. And w/o
using any specific code, just the property API in a generic way.
The only missing thing is a way to get all possible values of a property
at once. Then a simple generic track description can be used for all
a/v/s and a single menu is needed.

> > It so happend i was recently reviving an old patch of mine (audio
> > visualisation with goom :) and it got me back again in hacking
> > mplayer.
> 
> Have some code to share on that ?

Sure, i plan to post a RFC patch this week. Basicaly it is just a demuxer
(implemented outside of libmpdemux) using another demuxer as input and
outputing the decoded audio as both audio and video. The visuals is then
just a codec like any other.

> > One idea i had would be to allow menu generated from script and/or
> > loaded at runtime. Thus allowing frontends to do things like
> > autodetecting what media is in a drive (cdda, vcd, dvd, etc) and
> > then showing the right menu. Currently just an idea but i think
> > it might be worth exploring.
> 
> Aurel and myself started working on such a thing a long time ago (years)
> but it wasn't the best technical solution. It'll result in bloating even 
> more libmenu that it currently is.

The biggest pb imho would be to do it in a portable way. However just
allowing to load new menu definitions at run-time should be trivial.
Now if that would be really that useful is another question.

> > Another thing i had in mind was to perhaps add a basic mouse support.
> 
> That however might be interesting, maybe not that hard to do either, 
> considering that each menu item has a box. You just need to calculate if 
> the mise position belongs to one of these boxes (dvdnav already has 
> support for mouse movement iirc).

Yep, i'm planning on using the dvdnav commands. However, on a slightly
off topic note, this again make libvo dependent on libinput wich i have
always been against. The real solution would be to change the libvo API
a bit to use some event struct instead of just keycodes.

> > Currently i'm working on the metadata stuff wich is imho too limited.
> > What i'd like is a nice integration with the rest of the properties
> > API. I did a quick hack last night but it still need some work.
> 
> Please send even a rough patch when possible.

I expect to have something ready tomorrow.

> > Track selection shouldn't be a problem thanks to the recent work that
> > went in cleaning the player core. However chapter (and stream stuff
> > in general) is probably still not easy. The biggest obstacle is the
> > cache which make it near to impossible to reliably use control on the
> > stream at run time. There are solutions but they are either, hard to
> > implement in a nice and portable way (IPC), or are going to be hard to
> > get accepted by everybody (using threads for the cache).
> 
> What does cache has to do with that ?
> As long as the movie is started you have access to all of its 
> chapter/sid/aid/track/... info.

The cache use a fork, this mean the controls don't end-up at the stream
that is actually reading. So to just read stuff that is computed when
the stream is opened that's ok, but anything more advanced just can't
work.

	Albeu