[vlc-devel] [PATCH] add V4L2 video_output module

Rémi Denis-Courmont remi at remlab.net
Tue Jan 17 21:06:33 CET 2012

Le mardi 17 janvier 2012 21:47:49 Francois Cartegnie, vous avez écrit :
> Le 17/01/2012 19:16, Rémi Denis-Courmont a écrit :
> >> change_string_list( psz_profiles_values, psz_profiles_texts, 0 )
> > 
> > I don't think this makes no sense. The format restrictions depend on the
> > hardware, and retrieved through the V4L2 device driver.
> Except this module is mainly intended to be used with the linux loopback
> device, which will always answer positive to configuration requests.

That driver is non-standard, and it seems buggy. As far as I know the linux-
media guys, it is probably never going to get merged. V4L2 video output is 
meant to drive, well... video outputs. The analog TV out on some OMAP board is 
an example.

> We need in that particular case to be able to define a proper format
> that will be mirrored by the loopback device and exposed to the client app.

That is the client app problem. If the client app does not support the format, 
libv4l2 can convert on the fly. That is how V4L2 is meant to work.

Rémi Denis-Courmont

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