Julien Isorce 61ae84b50d v4l2: add support for multi-planar V4L2 API
This api is in linux kernel since version 2.6.39,
and present in all version 3.

The commit that adds the API in master branch of the
linux kernel source is:
f8f3914cf9

v4l2 doc: "Some devices require data for each input
or output video frame to be placed in discontiguous
memory buffers"

There are newer structures 'struct v4l2_pix_format_mplane'
and 'struct v4l2_plane'.
So the pixel format is not setup with the same API when using
multi-planar.

Also for gst-v4l2, one of the difference is that in GstV4l2Meta
there are now one mem pointer for each maped plane.

When not using multi-planar, this commit takes care of keeping
the same code path than previously. So that the 2 cases are
in two different blocks triggered from V4L2_TYPE_IS_MULTIPLANAR.

Fixes bug https://bugzilla.gnome.org/show_bug.cgi?id=712754
2013-12-04 09:27:20 +00:00
..
2013-09-01 21:18:38 +01:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00
2007-02-22 14:35:28 +00:00
2012-11-04 00:07:18 +00:00
2012-11-04 00:07:18 +00:00

v4l2 plugins
============

The idea is a bit the same as the idea for the v4l1 plugins. We want
one generic v4l2element, and a few child objects (probably only two:
v4l2src and v4l2sink):

                /-------- v4l2src
v4l2element ---=
                \-------- v4l2sink

Both v4l2src and v4l2sink have a uncompressed and a compressed
recording-/playback-mode. Since this is all part of v4l2, the 'client'
of these elements, i.e. an application using v4l2src/v4l2sink, will
hardly notice this. All capsnego stuff is done inside, and the plugin
knows which formats are compressed and which are not.

Please note that the v4l1 and the v4l2 plugins are *not* compatible
concerning properties. Naming has been kept the same where possible,
but in some cases, properties had to be removed or added to make
full use of v4l2.

V4L2 API: http://linux.bytesex.org/v4l2/.
          http://v4l2spec.bytesex.org/
          /usr/include/linux/videodev2.h or

Kernel patches available from
          http://dl.bytesex.org/patches/.

Articles:
          http://lwn.net/Articles/203924/