On Fri, 13 Feb 2009 13:57:45 +0100 Hans Verkuil <hverkuil@xxxxxxxxx> 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
