On Fri, 13 Feb 2009 13:57:45 +0100
Hans Verkuil <hverk...@xs4all.nl> wrote:

> Hi Hans,
> 
> I've developed a converter for the HM12 format (produced by Conexant MPEG 
> encoders as used in the ivtv and cx18 drivers).
> 
> But libv4l2 has a problem in its implementation of v4l2_read: it assumes 
> that the driver can always do streaming. However, that is not the case for 
> some drivers, including cx18 and ivtv. These drivers only implement read() 
> functionality and no streaming.
> 
> Can you as a minimum modify libv4l2 so that it will check for this case? The 
> best solution would be that libv4l2 can read HM12 from the driver and 
> convert it on the fly. But currently it tries to convert HM12 by starting 
> to stream, and that produces an error.
> 
> This bug needs to be fixed first before I can contribute my HM12 converter.

Hans Verkuil,

I think it would be valuable if you could convert the drivers to use videobuf.
There's currently a videobuf variation for devices that don't support
scatter/gather dma transfers. By using videobuf, the mmap() methods (and also
overlay, if you want) will be supported.


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

Reply via email to