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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-30 11:08:53 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-30 11:08:53 +0400 |
commit | 664a41b8a91bf78a01a751e15175e0008977685a (patch) | |
tree | d9dc15c83400ad2dfb430ff27ae3e7fdc9395856 /Documentation/DocBook/media/v4l/vidioc-streamon.xml | |
parent | 983236b5741e557451f3ed4ec5ebf1f62a5b2c15 (diff) | |
parent | ee2ce3a0b43d14d792d34cf88e7bc2091096744b (diff) | |
download | linux-664a41b8a91bf78a01a751e15175e0008977685a.tar.xz |
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (430 commits)
[media] ir-mce_kbd-decoder: include module.h for its facilities
[media] ov5642: include module.h for its facilities
[media] em28xx: Fix DVB-C maxsize for em2884
[media] tda18271c2dd: Fix saw filter configuration for DVB-C @6MHz
[media] v4l: mt9v032: Fix Bayer pattern
[media] V4L: mt9m111: rewrite set_pixfmt
[media] V4L: mt9m111: fix missing return value check mt9m111_reg_clear
[media] V4L: initial driver for ov5642 CMOS sensor
[media] V4L: sh_mobile_ceu_camera: fix Oops when USERPTR mapping fails
[media] V4L: soc-camera: remove soc-camera bus and devices on it
[media] V4L: soc-camera: un-export the soc-camera bus
[media] V4L: sh_mobile_csi2: switch away from using the soc-camera bus notifier
[media] V4L: add media bus configuration subdev operations
[media] V4L: soc-camera: group struct field initialisations together
[media] V4L: soc-camera: remove now unused soc-camera specific PM hooks
[media] V4L: pxa-camera: switch to using standard PM hooks
[media] NetUP Dual DVB-T/C CI RF: force card hardware revision by module param
[media] Don't OOPS if videobuf_dvb_get_frontend return NULL
[media] NetUP Dual DVB-T/C CI RF: load firmware according card revision
[media] omap3isp: Support configurable HS/VS polarities
...
Fix up conflicts:
- arch/arm/mach-omap2/board-rx51-peripherals.c:
cleanup regulator supply definitions in mach-omap2
vs
OMAP3: RX-51: define vdds_csib regulator supply
- drivers/staging/tm6000/tm6000-alsa.c (trivial)
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-streamon.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-streamon.xml | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-streamon.xml b/Documentation/DocBook/media/v4l/vidioc-streamon.xml new file mode 100644 index 000000000000..81cca4569050 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-streamon.xml @@ -0,0 +1,107 @@ +<refentry id="vidioc-streamon"> + <refmeta> + <refentrytitle>ioctl VIDIOC_STREAMON, VIDIOC_STREAMOFF</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_STREAMON</refname> + <refname>VIDIOC_STREAMOFF</refname> + <refpurpose>Start or stop streaming I/O</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>const int *<parameter>argp</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Arguments</title> + + <variablelist> + <varlistentry> + <term><parameter>fd</parameter></term> + <listitem> + <para>&fd;</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>request</parameter></term> + <listitem> + <para>VIDIOC_STREAMON, VIDIOC_STREAMOFF</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>The <constant>VIDIOC_STREAMON</constant> and +<constant>VIDIOC_STREAMOFF</constant> ioctl start and stop the capture +or output process during streaming (<link linkend="mmap">memory +mapping</link> or <link linkend="userp">user pointer</link>) I/O.</para> + + <para>Specifically the capture hardware is disabled and no input +buffers are filled (if there are any empty buffers in the incoming +queue) until <constant>VIDIOC_STREAMON</constant> has been called. +Accordingly the output hardware is disabled, no video signal is +produced until <constant>VIDIOC_STREAMON</constant> has been called. +The ioctl will succeed only when at least one output buffer is in the +incoming queue.</para> + + <para>The <constant>VIDIOC_STREAMOFF</constant> ioctl, apart of +aborting or finishing any DMA in progress, unlocks any user pointer +buffers locked in physical memory, and it removes all buffers from the +incoming and outgoing queues. That means all images captured but not +dequeued yet will be lost, likewise all images enqueued for output but +not transmitted yet. I/O returns to the same state as after calling +&VIDIOC-REQBUFS; and can be restarted accordingly.</para> + + <para>Both ioctls take a pointer to an integer, the desired buffer or +stream type. This is the same as &v4l2-requestbuffers; +<structfield>type</structfield>.</para> + + <para>Note applications can be preempted for unknown periods right +before or after the <constant>VIDIOC_STREAMON</constant> or +<constant>VIDIOC_STREAMOFF</constant> calls, there is no notion of +starting or stopping "now". Buffer timestamps can be used to +synchronize with other events.</para> + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The buffer<structfield>type</structfield> is not supported, + or no buffers have been allocated (memory mapping) or enqueued + (output) yet.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EPIPE</errorcode></term> + <listitem> + <para>The driver implements <link + linkend="pad-level-formats">pad-level format configuration</link> and + the pipeline configuration is invalid. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |