Hi Ladis,

On Mon, 2003-09-29 at 14:01, Ladislav Michl wrote:
> in short VIDIOCGCAPTURE and VIDIOCSCAPTURE ioctl using struct video_capture
> should be used to set capture window while VIDIOCGWIN and VIDIOCSWIN using
> struct video_window should be used to set overlay window.

No, the API documentation that you're reading is wrong. The drivers are
right. VIDIOC[SG]WIN are indeed for overlay. However, VIDIOC[SG]CAPTURE
are for hardware **MPEG** capture, not for raw capture. Raw capture
format using the streaming (mmap) interface in v4l1 is controlled by the
video_mmap struct. And I know this sucks, that's why it was improved in
v4l2. I'm just guessing here, but I think you should really read the
v4l2 documentation and use v4l2 instead. v4l1 is old, obsolete and can't
do too many things.

> I'd like also to know how should continuous capture work (via mmap). Using
> existing drivers as example it no longer option for me :-(

Well, VIDIOCMCAPTURE, VIDIOCSYNC for queue/sync cycles, and mmap or
memory mapping. Here, too, I suggest to use v4l2. It works the same
(VIDIOC_QBUF and VIDIOC_DQBUF for queue/sync), but format setting is
separated from the actual capture cycle, which is (imo) a lot easier to
implement in drivers.

Either way, the drivers are correct. You should use them as a reference
if the documentation is incomplete.

HTH,

Ronald

-- 
Ronald Bultje <[EMAIL PROTECTED]>
Linux Video/Multimedia developer


--
video4linux-list mailing list
Unsubscribe mailto:[EMAIL PROTECTED]
https://www.redhat.com/mailman/listinfo/video4linux-list

Reply via email to