Re: [Totem] Browser plugin gstreamer

[Bastien Nocera <hadess hadess net>]

On Tue, 2008-08-19 at 19:55 +0300, Felipe Contreras wrote:
> On Tue, Aug 19, 2008 at 6:38 PM, Bastien Nocera <hadess hadess net> wrote:
> > On Tue, 2008-08-19 at 16:46 +0300, Felipe Contreras wrote:
> > <snip>
> >> >> Is playlist support a must-have feature? If so, probably should be
> >> >> handled by a GStreamer element. Fullscreen support should not be that
> >> >> difficult, but I leave that to somebody else.
> >> >
> >> > Yes, it's a must-have.
> >>
> >> If you are trying to emulate other plugins then yes, I see how that
> >> could be required.
> >
> > Even a plugin that doesn't try to support the APIs of those foreign
> > plugins will certainly need playlist support to be competitive...
> 
> Competitive against what?

Do you think website designers will use your plugin if it doesn't
support the basics? Your plugin would need to support enough features
for website developers to consider using it, otherwise they'll target
WMP or Quicktime, or possibly VLC if they're nice people.

>  I don't recall ever seeing a site embedding
> a playlist.

Pretty much all the websites using WMP, or Real as plugins will have
playlists. Quicktime also uses them (link references, metalinks as well
as movie redirections).

And if you want to play files in succession, you need playlist support.

>  Again, if it was really important I guess GStreamer should
> handle it.

It's already been discussed in bugzilla. Supporting playlists in
GStreamer is far too low down in the stack. Feel free to use the code in
totem-pl-parser to write an element and the API needed on top. But I
still don't see what that would buy us.

> >> > FWIW, you can probably have a complete web browser plugin in not much
> >> > space by packaging it properly in a sub-package.
> >> >
> >> > $(libdir)/mozilla/plugins/*
> >> > $(libexecdir)/totem-plugin-viewer
> >>
> >> This is one of the things I didn't like when I analyzed the totem
> >> plugin: why require an external process?
> >
> > Because video decoders are rubbish, and you don't want to do video
> > decoding in the same space as the web browser. A crafted video playing
> > inside the web browser could make it send your whole password wallet to
> > some website. With a separate program, it will just crash :)
> 
> Hmm, true. It seems to be a remote possibility to me, so I'm not sure
> if it's worth the trouble.

It's called security. It's only got to hurt once for it to be a problem.
Take a look at MPlayer's and Xine's recent CVE advisories, or even
Flash's. For it to be crafted to hurt might be unlikely, but crafted to
crash on some systems doesn't even have to be on purpose.

> If all the code is contained in the plugin then packaging becomes very
> easy: one file. Which I guess helps for plugin autoinstallation.

Why would it help plugin auto-installation. Whether it's one or three
files shouldn't make a difference to the installer (whatever it could
be), and Totem's browser plugin is already shipped by default on a good
number of distributions.

> >> > $(libdir)/libbaconvideowidget.so.0.0.0 (shared with Totem itself)
> >> > $(pkgdatadir)/mozilla-viewer.ui
> >> > $(pkgdatadir)/fullscreen.ui (shared with Totem itself)
> >> >
> >> > That comes in under a meg stripped...
> >>
> >> I guess it depends on what is required.
> >
> > Can certainly be smaller if you remove some of the compatibility
> > plugins.
> 
> I meant, if you are interested in simple playback (not emulating other
> plugins) then ideally the plugin can be contained in one file.

And which websites would use your plugin?

> Personally I would like to be able to install a plugin in my
> "~/.mozilla/plugins" directory, and not require anything else. Adding
> an application in the same directory to be run as a separate process
> seems reasonable too, but adding those .ui files doesn't appeal me.
> 
> All this discussion makes me wonder about some ideas:
> 
> a) Is it possible to pack all the "compatibility plugins" into a single plugin?

No, because browsers expect one plugin per shared library. You can't
have a single shared library have multiple names, descriptions (unless
you employ gross hacks including symbolic links...).

> b) Would it make sense to have a configuration to choose an
> application other than "totem-plugin-viewer"?

Why? The IPC API is very ad-hoc as well, and will probably change (or
have to change) to support more features.