Re: [PATCH/RFC 1/4] V4L: add three new ioctl()s for multi-size videobuffer management

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tuesday 05 April 2011 14:40:16 Hans Verkuil wrote:
> On Tuesday, April 05, 2011 14:02:17 Laurent Pinchart wrote:
> > On Monday 04 April 2011 10:06:47 Hans Verkuil wrote:
> > > > On Mon, 4 Apr 2011, Hans Verkuil wrote:
> > > >> On Friday, April 01, 2011 10:13:02 Guennadi Liakhovetski wrote:
> > [snip]
> > 
> > > BTW, REQBUFS and CREATE/DESTROY_BUFS should definitely co-exist.
> > > REQBUFS is compulsory, while CREATE/DESTROY are optional.
> > 
> > Drivers must support REQBUFS and should support CREATE/DESTROY, but I
> > think applications should not be allowed to mix calls.
> 
> Why not? The videobuf2-core.c implementation shouldn't care about that, so
> I don't see why userspace should care.

Because it makes the API semantics much more complex to define. We would have 
to precisely define interactions between REQBUFS and CREATE/DESTROY. That will 
be error-prone, for very little benefits (if any at all). If an application is 
aware of the CREATE/DESTROY ioctls and wants to use them, why would it need to 
use REQBUFS ?

-- 
Regards,

Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux