Re: [PATCH 1/1] V4L: stk11xx, add a new webcam driver

[Thierry Merle <thierry.merle@free.fr>]

Thierry Merle a écrit :
> Mauro Carvalho Chehab a écrit :
> > > > As Luca pointed, if we add conversion for one driver, we should add 
> > > > for
> > > > the rest.
> > > >
> > > > Instead, it would be better if Jiri sends the decoding and the 
> > > > rescaling
> > > > stuff as a patch to v4l2-apps/lib, starting the API decoding library.
> > > > Once we have a library, we can ask the userspace developers to use it
> > > > for the formats not recognized by their userspace apps.
> > > >
> > > >       
> > > I think it would be better to evaluate existing solutions (eg. libpw).
> > >     
> >
> > Agreed. Volunteers?
> >
> >   
> Hi Mauro and Markus,
> Just to summ up what I understood we need:
>
> What do we need in userspace, only for v4l (dvb is not concerned):
> - colorspace translations
> - filters that be done in hardware if the selected hardware can, 
> otherwise software plugin
> - decompression algorithm like stk11xx or usbvision (the decompression 
> algorithm is in kernelspace since it is of linear complexity but shall 
> be moved to userspace)
>
> Using pwlib will not mean that application developers will use pwlib 
> to decode v4l driver outputs.
> C bindings are much more popular than C++ bindings and do not prevent 
> object oriented design.
> Application developers implement their own codecs.
> As an example, every application do deinterlacing internally or not...
> Application developers will probably not use pwlib v4l extensions 
> because they will prefer to write adapted codecs for their framework.
>
> Much more important for me is to see the actual specification of the 
> needed v4l extensions points, with advice/participation of 
> application/codec developers.
As an example, we could empacket frames with a header containing 
audio/video format as it is done for MPEG streams.
Is it possible without breaking the current ABI?
Do application developers would cope with that?
> Thierry

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/