diff options
Diffstat (limited to 'Documentation/DocBook/media')
-rw-r--r-- | Documentation/DocBook/media/v4l/common.xml | 2 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/compat.xml | 24 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/func-poll.xml | 35 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/v4l2.xml | 11 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml | 2 |
5 files changed, 61 insertions, 13 deletions
diff --git a/Documentation/DocBook/media/v4l/common.xml b/Documentation/DocBook/media/v4l/common.xml index 71f6bf9e735e..8b5e014224d6 100644 --- a/Documentation/DocBook/media/v4l/common.xml +++ b/Documentation/DocBook/media/v4l/common.xml @@ -110,7 +110,7 @@ makes no provisions to find these related devices. Some really complex devices use the Media Controller (see <xref linkend="media_controller" />) which can be used for this purpose. But most drivers do not use it, and while some code exists that uses sysfs to discover related devices -(see libmedia_dev in the <ulink url="http://git.linuxtv.org/v4l-utils/">v4l-utils</ulink> +(see libmedia_dev in the <ulink url="http://git.linuxtv.org/cgit.cgi/v4l-utils.git/">v4l-utils</ulink> git repository), there is no library yet that can provide a single API towards both Media Controller-based devices and devices that do not use the Media Controller. If you want to work on this please write to the linux-media mailing list: &v4l-ml;.</para> diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index eee6f0f4aa43..3a626d1b8f2e 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2545,6 +2545,30 @@ fields changed from _s32 to _u32. </orderedlist> </section> + <section> + <title>V4L2 in Linux 3.16</title> + <orderedlist> + <listitem> + <para>Added event V4L2_EVENT_SOURCE_CHANGE. + </para> + </listitem> + </orderedlist> + </section> + + <section> + <title>V4L2 in Linux 3.17</title> + <orderedlist> + <listitem> + <para>Extended &v4l2-pix-format;. Added format flags. + </para> + </listitem> + <listitem> + <para>Added compound control types and &VIDIOC-QUERY-EXT-CTRL;. + </para> + </listitem> + </orderedlist> + </section> + <section id="other"> <title>Relation of V4L2 to other Linux multimedia APIs</title> diff --git a/Documentation/DocBook/media/v4l/func-poll.xml b/Documentation/DocBook/media/v4l/func-poll.xml index 85cad8bff5ba..4c73f115219b 100644 --- a/Documentation/DocBook/media/v4l/func-poll.xml +++ b/Documentation/DocBook/media/v4l/func-poll.xml @@ -29,9 +29,12 @@ can suspend execution until the driver has captured data or is ready to accept data for output.</para> <para>When streaming I/O has been negotiated this function waits -until a buffer has been filled or displayed and can be dequeued with -the &VIDIOC-DQBUF; ioctl. When buffers are already in the outgoing -queue of the driver the function returns immediately.</para> +until a buffer has been filled by the capture device and can be dequeued +with the &VIDIOC-DQBUF; ioctl. For output devices this function waits +until the device is ready to accept a new buffer to be queued up with +the &VIDIOC-QBUF; ioctl for display. When buffers are already in the outgoing +queue of the driver (capture) or the incoming queue isn't full (display) +the function returns immediately.</para> <para>On success <function>poll()</function> returns the number of file descriptors that have been selected (that is, file descriptors @@ -44,10 +47,22 @@ Capture devices set the <constant>POLLIN</constant> and flags. When the function timed out it returns a value of zero, on failure it returns <returnvalue>-1</returnvalue> and the <varname>errno</varname> variable is set appropriately. When the -application did not call &VIDIOC-QBUF; or &VIDIOC-STREAMON; yet the +application did not call &VIDIOC-STREAMON; the <function>poll()</function> function succeeds, but sets the <constant>POLLERR</constant> flag in the -<structfield>revents</structfield> field.</para> +<structfield>revents</structfield> field. When the +application has called &VIDIOC-STREAMON; for a capture device but hasn't +yet called &VIDIOC-QBUF;, the <function>poll()</function> function +succeeds and sets the <constant>POLLERR</constant> flag in the +<structfield>revents</structfield> field. For output devices this +same situation will cause <function>poll()</function> to succeed +as well, but it sets the <constant>POLLOUT</constant> and +<constant>POLLWRNORM</constant> flags in the <structfield>revents</structfield> +field.</para> + + <para>If an event occurred (see &VIDIOC-DQEVENT;) then +<constant>POLLPRI</constant> will be set in the <structfield>revents</structfield> +field and <function>poll()</function> will return.</para> <para>When use of the <function>read()</function> function has been negotiated and the driver does not capture yet, the @@ -58,10 +73,18 @@ continuously (as opposed to, for example, still images) the function may return immediately.</para> <para>When use of the <function>write()</function> function has -been negotiated the <function>poll</function> function just waits +been negotiated and the driver does not stream yet, the +<function>poll</function> function starts streaming. When that fails +it returns a <constant>POLLERR</constant> as above. Otherwise it waits until the driver is ready for a non-blocking <function>write()</function> call.</para> + <para>If the caller is only interested in events (just +<constant>POLLPRI</constant> is set in the <structfield>events</structfield> +field), then <function>poll()</function> will <emphasis>not</emphasis> +start streaming if the driver does not stream yet. This makes it +possible to just poll for events and not for buffers.</para> + <para>All drivers implementing the <function>read()</function> or <function>write()</function> function or streaming I/O must also support the <function>poll()</function> function.</para> diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index f2f81f06a17b..7cfe618f754d 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -152,10 +152,11 @@ structs, ioctls) must be noted in more detail in the history chapter applications. --> <revision> - <revnumber>3.16</revnumber> - <date>2014-05-27</date> - <authorinitials>lp</authorinitials> - <revremark>Extended &v4l2-pix-format;. Added format flags. + <revnumber>3.17</revnumber> + <date>2014-08-04</date> + <authorinitials>lp, hv</authorinitials> + <revremark>Extended &v4l2-pix-format;. Added format flags. Added compound control types +and VIDIOC_QUERY_EXT_CTRL. </revremark> </revision> @@ -538,7 +539,7 @@ and discussions on the V4L mailing list.</revremark> </partinfo> <title>Video for Linux Two API Specification</title> - <subtitle>Revision 3.14</subtitle> + <subtitle>Revision 3.17</subtitle> <chapter id="common"> &sub-common; diff --git a/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml b/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml index 1ba9e999af3f..c62a7360719b 100644 --- a/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml +++ b/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml @@ -119,7 +119,7 @@ </row> <row> <entry>&v4l2-rect;</entry> - <entry><structfield>rect</structfield></entry> + <entry><structfield>r</structfield></entry> <entry>Selection rectangle, in pixels.</entry> </row> <row> |