Hi Nicolas,
On Sun, Mar 25, 2007 at 12:08:58PM +0200, Nicolas Boulay wrote:
> So what is the "right" way of using mmap?
I assume you use the V4L2 interface:
First you request some buffers from the driver:
m_req.count = 2;
m_req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
m_req.memory = V4L2_MEMORY_MMAP;
ioctl (m_fd, VIDIOC_REQBUFS, &m_req)
Then you query each buffer:
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = buffer_index;
ioctl (m_fd, VIDIOC_QUERYBUF, &buf)
Now you have the buffer length in the v4l2_buffer structure. Ready to
mmap:
mmap (NULL, buf.length, PROT_READ|PROT_WRITE,
MAP_SHARED, m_fd, buf.m.offset);
I hope this sheds some light onto your problem.
Gregor
_______________________________________________
pwc mailing list
[email protected]
http://lists.saillard.org/mailman/listinfo/pwc
