diff options
Diffstat (limited to 'Documentation/DocBook')
| -rw-r--r-- | Documentation/DocBook/media/Makefile | 4 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/compat.xml | 9 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/dev-subdev.xml | 202 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/v4l2.xml | 15 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml | 228 |
5 files changed, 432 insertions, 26 deletions
diff --git a/Documentation/DocBook/media/Makefile b/Documentation/DocBook/media/Makefile index 6628b4b9cac4..362520992ced 100644 --- a/Documentation/DocBook/media/Makefile +++ b/Documentation/DocBook/media/Makefile @@ -70,6 +70,8 @@ IOCTLS = \ VIDIOC_SUBDEV_ENUM_MBUS_CODE \ VIDIOC_SUBDEV_ENUM_FRAME_SIZE \ VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL \ + VIDIOC_SUBDEV_G_SELECTION \ + VIDIOC_SUBDEV_S_SELECTION \ TYPES = \ $(shell perl -ne 'print "$$1 " if /^typedef\s+[^\s]+\s+([^\s]+)\;/' $(srctree)/include/linux/videodev2.h) \ @@ -193,7 +195,7 @@ DVB_DOCUMENTED = \ # install_media_images = \ - $(Q)cp $(OBJIMGFILES) $(MEDIA_OBJ_DIR)/media_api + $(Q)cp $(OBJIMGFILES) $(MEDIA_SRC_DIR)/v4l/*.svg $(MEDIA_OBJ_DIR)/media_api $(MEDIA_OBJ_DIR)/%: $(MEDIA_SRC_DIR)/%.b64 $(Q)base64 -d $< >$@ diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index d881520e1a54..0fc74ca81f0f 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2417,6 +2417,11 @@ details.</para> <para>Added integer menus, the new type will be V4L2_CTRL_TYPE_INTEGER_MENU.</para> </listitem> + <listitem> + <para>Added selection API for V4L2 subdev interface: + &VIDIOC-SUBDEV-G-SELECTION; and + &VIDIOC-SUBDEV-S-SELECTION;.</para> + </listitem> </orderedlist> </section> @@ -2533,6 +2538,10 @@ ioctls.</para> <listitem> <para>Selection API. <xref linkend="selection-api" /></para> </listitem> + <listitem> + <para>Sub-device selection API: &VIDIOC-SUBDEV-G-SELECTION; + and &VIDIOC-SUBDEV-S-SELECTION; ioctls.</para> + </listitem> </itemizedlist> </section> diff --git a/Documentation/DocBook/media/v4l/dev-subdev.xml b/Documentation/DocBook/media/v4l/dev-subdev.xml index 0916a7343a16..4afcbbec5eda 100644 --- a/Documentation/DocBook/media/v4l/dev-subdev.xml +++ b/Documentation/DocBook/media/v4l/dev-subdev.xml @@ -76,11 +76,12 @@ <wordasword>format</wordasword> means the combination of media bus data format, frame width and frame height.</para></note> - <para>Image formats are typically negotiated on video capture and output - devices using the <link linkend="crop">cropping and scaling</link> ioctls. - The driver is responsible for configuring every block in the video pipeline - according to the requested format at the pipeline input and/or - output.</para> + <para>Image formats are typically negotiated on video capture and + output devices using the format and <link + linkend="vidioc-subdev-g-selection">selection</link> ioctls. The + driver is responsible for configuring every block in the video + pipeline according to the requested format at the pipeline input + and/or output.</para> <para>For complex devices, such as often found in embedded systems, identical image sizes at the output of a pipeline can be achieved using @@ -276,11 +277,11 @@ </section> <section> - <title>Cropping and scaling</title> + <title>Selections: cropping, scaling and composition</title> <para>Many sub-devices support cropping frames on their input or output pads (or possible even on both). Cropping is used to select the area of - interest in an image, typically on a video sensor or video decoder. It can + interest in an image, typically on an image sensor or a video decoder. It can also be used as part of digital zoom implementations to select the area of the image that will be scaled up.</para> @@ -288,26 +289,179 @@ &v4l2-rect; by the coordinates of the top left corner and the rectangle size. Both the coordinates and sizes are expressed in pixels.</para> - <para>The crop rectangle is retrieved and set using the - &VIDIOC-SUBDEV-G-CROP; and &VIDIOC-SUBDEV-S-CROP; ioctls. Like for pad - formats, drivers store try and active crop rectangles. The format - negotiation mechanism applies to crop settings as well.</para> - - <para>On input pads, cropping is applied relatively to the current pad - format. The pad format represents the image size as received by the - sub-device from the previous block in the pipeline, and the crop rectangle - represents the sub-image that will be transmitted further inside the - sub-device for processing. The crop rectangle be entirely containted - inside the input image size.</para> - - <para>Input crop rectangle are reset to their default value when the input - image format is modified. Drivers should use the input image size as the - crop rectangle default value, but hardware requirements may prevent this. - </para> + <para>As for pad formats, drivers store try and active + rectangles for the selection targets of ACTUAL type <xref + linkend="v4l2-subdev-selection-targets">.</xref></para> + + <para>On sink pads, cropping is applied relative to the + current pad format. The pad format represents the image size as + received by the sub-device from the previous block in the + pipeline, and the crop rectangle represents the sub-image that + will be transmitted further inside the sub-device for + processing.</para> + + <para>The scaling operation changes the size of the image by + scaling it to new dimensions. The scaling ratio isn't specified + explicitly, but is implied from the original and scaled image + sizes. Both sizes are represented by &v4l2-rect;.</para> + + <para>Scaling support is optional. When supported by a subdev, + the crop rectangle on the subdev's sink pad is scaled to the + size configured using the &VIDIOC-SUBDEV-S-SELECTION; IOCTL + using <constant>V4L2_SUBDEV_SEL_COMPOSE_ACTUAL</constant> + selection target on the same pad. If the subdev supports scaling + but not composing, the top and left values are not used and must + always be set to zero.</para> + + <para>On source pads, cropping is similar to sink pads, with the + exception that the source size from which the cropping is + performed, is the COMPOSE rectangle on the sink pad. In both + sink and source pads, the crop rectangle must be entirely + contained inside the source image size for the crop + operation.</para> + + <para>The drivers should always use the closest possible + rectangle the user requests on all selection targets, unless + specifically told otherwise. + <constant>V4L2_SUBDEV_SEL_FLAG_SIZE_GE</constant> and + <constant>V4L2_SUBDEV_SEL_FLAG_SIZE_LE</constant> flags may be + used to round the image size either up or down. <xref + linkend="v4l2-subdev-selection-flags"></xref></para> + </section> + + <section> + <title>Types of selection targets</title> + + <section> + <title>ACTUAL targets</title> + + <para>ACTUAL targets reflect the actual hardware configuration + at any point of time. There is a BOUNDS target + corresponding to every ACTUAL.</para> + </section> + + <section> + <title>BOUNDS targets</title> + + <para>BOUNDS targets is the smallest rectangle that contains + all valid ACTUAL rectangles. It may not be possible to set the + ACTUAL rectangle as large as the BOUNDS rectangle, however. + This may be because e.g. a sensor's pixel array is not + rectangular but cross-shaped or round. The maximum size may + also be smaller than the BOUNDS rectangle.</para> + </section> - <para>Cropping behaviour on output pads is not defined.</para> + </section> + + <section> + <title>Order of configuration and format propagation</title> + + <para>Inside subdevs, the order of image processing steps will + always be from the sink pad towards the source pad. This is also + reflected in the order in which the configuration must be + performed by the user: the changes made will be propagated to + any subsequent stages. If this behaviour is not desired, the + user must set + <constant>V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG</constant> flag. This + flag causes no propagation of the changes are allowed in any + circumstances. This may also cause the accessed rectangle to be + adjusted by the driver, depending on the properties of the + underlying hardware.</para> + + <para>The coordinates to a step always refer to the actual size + of the previous step. The exception to this rule is the source + compose rectangle, which refers to the sink compose bounds + rectangle --- if it is supported by the hardware.</para> + + <orderedlist> + <listitem>Sink pad format. The user configures the sink pad + format. This format defines the parameters of the image the + entity receives through the pad for further processing.</listitem> + + <listitem>Sink pad actual crop selection. The sink pad crop + defines the crop performed to the sink pad format.</listitem> + + <listitem>Sink pad actual compose selection. The size of the + sink pad compose rectangle defines the scaling ratio compared + to the size of the sink pad crop rectangle. The location of + the compose rectangle specifies the location of the actual + sink compose rectangle in the sink compose bounds + rectangle.</listitem> + + <listitem>Source pad actual crop selection. Crop on the source + pad defines crop performed to the image in the sink compose + bounds rectangle.</listitem> + + <listitem>Source pad format. The source pad format defines the + output pixel format of the subdev, as well as the other + parameters with the exception of the image width and height. + Width and height are defined by the size of the source pad + actual crop selection.</listitem> + </orderedlist> + + <para>Accessing any of the above rectangles not supported by the + subdev will return <constant>EINVAL</constant>. Any rectangle + referring to a previous unsupported rectangle coordinates will + instead refer to the previous supported rectangle. For example, + if sink crop is not supported, the compose selection will refer + to the sink pad format dimensions instead.</para> + + <figure id="subdev-image-processing-crop"> + <title>Image processing in subdevs: simple crop example</title> + <mediaobject> + <imageobject> + <imagedata fileref="subdev-image-processing-crop.svg" + format="SVG" scale="200" /> + </imageobject> + </mediaobject> + </figure> + + <para>In the above example, the subdev supports cropping on its + sink pad. To configure it, the user sets the media bus format on + the subdev's sink pad. Now the actual crop rectangle can be set + on the sink pad --- the location and size of this rectangle + reflect the location and size of a rectangle to be cropped from + the sink format. The size of the sink crop rectangle will also + be the size of the format of the subdev's source pad.</para> + + <figure id="subdev-image-processing-scaling-multi-source"> + <title>Image processing in subdevs: scaling with multiple sources</title> + <mediaobject> + <imageobject> + <imagedata fileref="subdev-image-processing-scaling-multi-source.svg" + format="SVG" scale="200" /> + </imageobject> + </mediaobject> + </figure> + + <para>In this example, the subdev is capable of first cropping, + then scaling and finally cropping for two source pads + individually from the resulting scaled image. The location of + the scaled image in the cropped image is ignored in sink compose + target. Both of the locations of the source crop rectangles + refer to the sink scaling rectangle, independently cropping an + area at location specified by the source crop rectangle from + it.</para> + + <figure id="subdev-image-processing-full"> + <title>Image processing in subdevs: scaling and composition + with multiple sinks and sources</title> + <mediaobject> + <imageobject> + <imagedata fileref="subdev-image-processing-full.svg" + format="SVG" scale="200" /> + </imageobject> + </mediaobject> + </figure> + + <para>The subdev driver supports two sink pads and two source + pads. The images from both of the sink pads are individually + cropped, then scaled and further composed on the composition + bounds rectangle. From that, two independent streams are cropped + and sent out of the subdev from the source pads.</para> </section> + </section> &sub-subdev-formats; diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index 864ba5d6873d..fbf808d242f7 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -96,6 +96,17 @@ Remote Controller chapter.</contrib> </address> </affiliation> </author> + + <author> + <firstname>Sakari</firstname> + <surname>Ailus</surname> + <contrib>Subdev selections API.</contrib> + <affiliation> + <address> + <email>sakari.ailus@iki.fi</email> + </address> + </affiliation> + </author> </authorgroup> <copyright> @@ -131,7 +142,8 @@ applications. --> <revnumber>3.5</revnumber> <date>2012-04-02</date> <authorinitials>sa</authorinitials> - <revremark>Added V4L2_CTRL_TYPE_INTEGER_MENU. + <revremark>Added V4L2_CTRL_TYPE_INTEGER_MENU and V4L2 subdev + selections API. </revremark> </revision> @@ -548,6 +560,7 @@ and discussions on the V4L mailing list.</revremark> &sub-subdev-g-crop; &sub-subdev-g-fmt; &sub-subdev-g-frame-interval; + &sub-subdev-g-selection; &sub-subscribe-event; <!-- End of ioctls. --> &sub-mmap; diff --git a/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml b/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml new file mode 100644 index 000000000000..208e9f0da3f3 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-subdev-g-selection.xml @@ -0,0 +1,228 @@ +<refentry id="vidioc-subdev-g-selection"> + <refmeta> + <refentrytitle>ioctl VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_SUBDEV_G_SELECTION</refname> + <refname>VIDIOC_SUBDEV_S_SELECTION</refname> + <refpurpose>Get or set selection rectangles on a subdev pad</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>struct v4l2_subdev_selection *<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_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <note> + <title>Experimental</title> + <para>This is an <link linkend="experimental">experimental</link> + interface and may change in the future.</para> + </note> + + <para>The selections are used to configure various image + processing functionality performed by the subdevs which affect the + image size. This currently includes cropping, scaling and + composition.</para> + + <para>The selection API replaces <link + linkend="vidioc-subdev-g-crop">the old subdev crop API</link>. All + the function of the crop API, and more, are supported by the + selections API.</para> + + <para>See <xref linkend="subdev"></xref> for + more information on how each selection target affects the image + processing pipeline inside the subdevice.</para> + + <section> + <title>Types of selection targets</title> + + <para>There are two types of selection targets: actual and bounds. + The ACTUAL targets are the targets which configure the hardware. + The BOUNDS target will return a rectangle that contain all + possible ACTUAL rectangles.</para> + </section> + + <section> + <title>Discovering supported features</title> + + <para>To discover which targets are supported, the user can + perform <constant>VIDIOC_SUBDEV_G_SELECTION</constant> on them. + Any unsupported target will return + <constant>EINVAL</constant>.</para> + </section> + + <table pgwide="1" frame="none" id="v4l2-subdev-selection-targets"> + <title>V4L2 subdev selection targets</title> + <tgroup cols="3"> + &cs-def; + <tbody valign="top"> + <row> + <entry><constant>V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL</constant></entry> + <entry>0x0000</entry> + <entry>Actual crop. Defines the cropping + performed by the processing step.</entry> + </row> + <row> + <entry><constant>V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS</constant></entry> + <entry>0x0002</entry> + <entry>Bounds of the crop rectangle.</entry> + </row> + <row> + <entry><constant>V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL</constant></entry> + <entry>0x0100</entry> + <entry>Actual compose rectangle. Used to configure scaling + on sink pads and composition on source pads.</entry> + </row> + <row> + <entry><constant>V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS</constant></entry> + <entry>0x0102</entry> + <entry>Bounds of the compose rectangle.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="v4l2-subdev-selection-flags"> + <title>V4L2 subdev selection flags</title> + <tgroup cols="3"> + &cs-def; + <tbody valign="top"> + <row> + <entry><constant>V4L2_SUBDEV_SEL_FLAG_SIZE_GE</constant></entry> + <entry>(1 << 0)</entry> <entry>Suggest the driver it + should choose greater or equal rectangle (in size) than + was requested. Albeit the driver may choose a lesser size, + it will only do so due to hardware limitations. Without + this flag (and + <constant>V4L2_SUBDEV_SEL_FLAG_SIZE_LE</constant>) the + behaviour is to choose the closest possible + rectangle.</entry> + </row> + <row> + <entry><constant>V4L2_SUBDEV_SEL_FLAG_SIZE_LE</constant></entry> + <entry>(1 << 1)</entry> <entry>Suggest the driver it + should choose lesser or equal rectangle (in size) than was + requested. Albeit the driver may choose a greater size, it + will only do so due to hardware limitations.</entry> + </row> + <row> + <entry><constant>V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG</constant></entry> + <entry>(1 << 2)</entry> + <entry>The configuration should not be propagated to any + further processing steps. If this flag is not given, the + configuration is propagated inside the subdevice to all + further processing steps.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="v4l2-subdev-selection"> + <title>struct <structname>v4l2_subdev_selection</structname></title> + <tgroup cols="3"> + &cs-str; + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>which</structfield></entry> + <entry>Active or try selection, from + &v4l2-subdev-format-whence;.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>pad</structfield></entry> + <entry>Pad number as reported by the media framework.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>target</structfield></entry> + <entry>Target selection rectangle. See + <xref linkend="v4l2-subdev-selection-targets">.</xref>.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry>Flags. See + <xref linkend="v4l2-subdev-selection-flags">.</xref></entry> + </row> + <row> + <entry>&v4l2-rect;</entry> + <entry><structfield>rect</structfield></entry> + <entry>Selection rectangle, in pixels.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[8]</entry> + <entry>Reserved for future extensions. Applications and drivers must + set the array to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EBUSY</errorcode></term> + <listitem> + <para>The selection rectangle can't be changed because the + pad is currently busy. This can be caused, for instance, by + an active video stream on the pad. The ioctl must not be + retried without performing another action to fix the problem + first. Only returned by + <constant>VIDIOC_SUBDEV_S_SELECTION</constant></para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The &v4l2-subdev-selection; + <structfield>pad</structfield> references a non-existing + pad, the <structfield>which</structfield> field references a + non-existing format, or the selection target is not + supported on the given subdev pad.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |
