Commit b6b6e678 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab

[media] docs-rst: better use the .. note:: tag

Change multi-line note tags to be more symetric, e. g. not starting
the text together witht the tag.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 18759441
...@@ -32,7 +32,9 @@ Arguments ...@@ -32,7 +32,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
Closes the cec device. Resources associated with the file descriptor are Closes the cec device. Resources associated with the file descriptor are
......
...@@ -38,7 +38,9 @@ Arguments ...@@ -38,7 +38,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
The :c:func:`ioctl()` function manipulates cec device parameters. The The :c:func:`ioctl()` function manipulates cec device parameters. The
......
...@@ -45,7 +45,9 @@ Arguments ...@@ -45,7 +45,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
To open a cec device applications call :c:func:`open()` with the To open a cec device applications call :c:func:`open()` with the
......
...@@ -29,7 +29,9 @@ Arguments ...@@ -29,7 +29,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
With the :c:func:`poll()` function applications can wait for CEC With the :c:func:`poll()` function applications can wait for CEC
......
...@@ -3,7 +3,9 @@ ...@@ -3,7 +3,9 @@
Introduction Introduction
============ ============
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
HDMI connectors provide a single pin for use by the Consumer Electronics HDMI connectors provide a single pin for use by the Consumer Electronics
......
...@@ -31,7 +31,9 @@ Arguments ...@@ -31,7 +31,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
All cec devices must support :ref:`ioctl CEC_ADAP_G_CAPS <CEC_ADAP_G_CAPS>`. To query All cec devices must support :ref:`ioctl CEC_ADAP_G_CAPS <CEC_ADAP_G_CAPS>`. To query
......
...@@ -35,7 +35,9 @@ Arguments ...@@ -35,7 +35,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
To query the current CEC logical addresses, applications call To query the current CEC logical addresses, applications call
......
...@@ -34,7 +34,9 @@ Arguments ...@@ -34,7 +34,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
To query the current physical address applications call To query the current physical address applications call
......
...@@ -32,7 +32,9 @@ Arguments ...@@ -32,7 +32,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
CEC devices can send asynchronous events. These can be retrieved by CEC devices can send asynchronous events. These can be retrieved by
......
...@@ -30,7 +30,9 @@ Arguments ...@@ -30,7 +30,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
By default any filehandle can use :ref:`CEC_TRANSMIT`, but in order to prevent By default any filehandle can use :ref:`CEC_TRANSMIT`, but in order to prevent
......
...@@ -33,7 +33,9 @@ Arguments ...@@ -33,7 +33,9 @@ Arguments
Description Description
=========== ===========
.. note:: This documents the proposed CEC API. This API is not yet finalized .. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module. and is currently only available as a staging kernel module.
To receive a CEC message the application has to fill in the To receive a CEC message the application has to fill in the
......
...@@ -17,7 +17,9 @@ using :ref:`FE_READ_STATUS`. ...@@ -17,7 +17,9 @@ using :ref:`FE_READ_STATUS`.
Signal statistics are provided via Signal statistics are provided via
:ref:`FE_GET_PROPERTY`. :ref:`FE_GET_PROPERTY`.
.. note:: Most statistics require the demodulator to be fully locked .. note::
Most statistics require the demodulator to be fully locked
(e. g. with FE_HAS_LOCK bit set). See (e. g. with FE_HAS_LOCK bit set). See
:ref:`Frontend statistics indicators <frontend-stat-properties>` for :ref:`Frontend statistics indicators <frontend-stat-properties>` for
more details. more details.
...@@ -8,7 +8,9 @@ ...@@ -8,7 +8,9 @@
Part II - Digital TV API Part II - Digital TV API
######################## ########################
.. note:: This API is also known as **DVB API**, although it is generic .. note::
This API is also known as **DVB API**, although it is generic
enough to support all digital TV standards. enough to support all digital TV standards.
**Version 5.10** **Version 5.10**
......
...@@ -20,7 +20,9 @@ Also, the union didn't have any space left to be expanded without ...@@ -20,7 +20,9 @@ Also, the union didn't have any space left to be expanded without
breaking userspace. So, the decision was to deprecate the legacy breaking userspace. So, the decision was to deprecate the legacy
union/struct based approach, in favor of a properties set approach. union/struct based approach, in favor of a properties set approach.
.. note:: On Linux DVB API version 3, setting a frontend were done via .. note::
On Linux DVB API version 3, setting a frontend were done via
:ref:`struct dvb_frontend_parameters <dvb-frontend-parameters>`. :ref:`struct dvb_frontend_parameters <dvb-frontend-parameters>`.
This got replaced on version 5 (also called "S2API", as this API were This got replaced on version 5 (also called "S2API", as this API were
added originally_enabled to provide support for DVB-S2), because the added originally_enabled to provide support for DVB-S2), because the
......
...@@ -9,7 +9,9 @@ Examples ...@@ -9,7 +9,9 @@ Examples
In this section we would like to present some examples for using the DVB In this section we would like to present some examples for using the DVB
API. API.
..note:: This section is out of date, and the code below won't even ..note::
This section is out of date, and the code below won't even
compile. Please refer to the compile. Please refer to the
`libdvbv5 <https://linuxtv.org/docs/libdvbv5/index.html>`__ for `libdvbv5 <https://linuxtv.org/docs/libdvbv5/index.html>`__ for
updated/recommended examples. updated/recommended examples.
......
...@@ -144,7 +144,9 @@ struct dvb_frontend_info ...@@ -144,7 +144,9 @@ struct dvb_frontend_info
- Capabilities supported by the frontend - Capabilities supported by the frontend
.. note:: The frequencies are specified in Hz for Terrestrial and Cable .. note::
The frequencies are specified in Hz for Terrestrial and Cable
systems. They're specified in kHz for Satellite systems systems. They're specified in kHz for Satellite systems
......
...@@ -40,7 +40,9 @@ used to check about the locking status of the frontend after being ...@@ -40,7 +40,9 @@ used to check about the locking status of the frontend after being
tuned. The ioctl takes a pointer to an integer where the status will be tuned. The ioctl takes a pointer to an integer where the status will be
written. written.
.. note:: The size of status is actually sizeof(enum fe_status), with .. note::
The size of status is actually sizeof(enum fe_status), with
varies according with the architecture. This needs to be fixed in the varies according with the architecture. This needs to be fixed in the
future. future.
......
...@@ -29,7 +29,9 @@ The frontend can be accessed through ``/dev/dvb/adapter?/frontend?``. ...@@ -29,7 +29,9 @@ The frontend can be accessed through ``/dev/dvb/adapter?/frontend?``.
Data types and ioctl definitions can be accessed by including Data types and ioctl definitions can be accessed by including
``linux/dvb/frontend.h`` in your application. ``linux/dvb/frontend.h`` in your application.
.. note:: Transmission via the internet (DVB-IP) is not yet handled by this .. note::
Transmission via the internet (DVB-IP) is not yet handled by this
API but a future extension is possible. API but a future extension is possible.
On Satellite systems, the API support for the Satellite Equipment On Satellite systems, the API support for the Satellite Equipment
......
...@@ -42,7 +42,9 @@ that prevents them to be used with some remotes. Wide band receiver might ...@@ -42,7 +42,9 @@ that prevents them to be used with some remotes. Wide band receiver might
also be more precise. On the other hand its disadvantage it usually also be more precise. On the other hand its disadvantage it usually
reduced range of reception. reduced range of reception.
.. note:: Wide band receiver might be implictly enabled if you enable .. note::
Wide band receiver might be implictly enabled if you enable
carrier reports. In that case it will be disabled as soon as you disable carrier reports. In that case it will be disabled as soon as you disable
carrier reports. Trying to disable wide band receiver while carrier carrier reports. Trying to disable wide band receiver while carrier
reports are active will do nothing. reports are active will do nothing.
......
...@@ -37,7 +37,9 @@ The :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` and ...@@ -37,7 +37,9 @@ The :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` and
:ref:`VIDIOC_G_AUDOUT <VIDIOC_G_AUDOUT>` ioctls report the current :ref:`VIDIOC_G_AUDOUT <VIDIOC_G_AUDOUT>` ioctls report the current
audio input and output, respectively. audio input and output, respectively.
.. note:: Note that, unlike :ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` and .. note::
Note that, unlike :ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` and
:ref:`VIDIOC_G_OUTPUT <VIDIOC_G_OUTPUT>` these ioctls return a :ref:`VIDIOC_G_OUTPUT <VIDIOC_G_OUTPUT>` these ioctls return a
structure as :ref:`VIDIOC_ENUMAUDIO` and structure as :ref:`VIDIOC_ENUMAUDIO` and
:ref:`VIDIOC_ENUMAUDOUT <VIDIOC_ENUMAUDOUT>` do, not just an index. :ref:`VIDIOC_ENUMAUDOUT <VIDIOC_ENUMAUDOUT>` do, not just an index.
......
...@@ -166,12 +166,15 @@ struct v4l2_buffer ...@@ -166,12 +166,15 @@ struct v4l2_buffer
output device because the application did not pass new data in output device because the application did not pass new data in
time. time.
.. note:: This may count the frames received e.g. over USB, without .. note::
This may count the frames received e.g. over USB, without
taking into account the frames dropped by the remote hardware due taking into account the frames dropped by the remote hardware due
to limited compression throughput or bus bandwidth. These devices to limited compression throughput or bus bandwidth. These devices
identify by not enumerating any video standards, see identify by not enumerating any video standards, see
:ref:`standard`. :ref:`standard`.
- .. row 10 - .. row 10
- __u32 - __u32
...@@ -299,7 +302,9 @@ struct v4l2_plane ...@@ -299,7 +302,9 @@ struct v4l2_plane
``bytesused`` will be set to the size of the plane (see the ``bytesused`` will be set to the size of the plane (see the
``length`` field of this struct) by the driver. ``length`` field of this struct) by the driver.
.. note:: Note that the actual image data starts at ``data_offset`` .. note::
Note that the actual image data starts at ``data_offset``
which may not be 0. which may not be 0.
- .. row 2 - .. row 2
...@@ -371,7 +376,9 @@ struct v4l2_plane ...@@ -371,7 +376,9 @@ struct v4l2_plane
field when ``type`` refers to a capture stream, applications when field when ``type`` refers to a capture stream, applications when
it refers to an output stream. it refers to an output stream.
.. note:: That data_offset is included in ``bytesused``. So the .. note::
That data_offset is included in ``bytesused``. So the
size of the image in the plane is ``bytesused``-``data_offset`` size of the image in the plane is ``bytesused``-``data_offset``
at offset ``data_offset`` from the start of the plane. at offset ``data_offset`` from the start of the plane.
......
...@@ -15,7 +15,9 @@ offset into a video signal. ...@@ -15,7 +15,9 @@ offset into a video signal.
Applications can use the following API to select an area in the video Applications can use the following API to select an area in the video
signal, query the default area and the hardware limits. signal, query the default area and the hardware limits.
.. note:: Despite their name, the :ref:`VIDIOC_CROPCAP <VIDIOC_CROPCAP>`, .. note::
Despite their name, the :ref:`VIDIOC_CROPCAP <VIDIOC_CROPCAP>`,
:ref:`VIDIOC_G_CROP <VIDIOC_G_CROP>` and :ref:`VIDIOC_S_CROP :ref:`VIDIOC_G_CROP <VIDIOC_G_CROP>` and :ref:`VIDIOC_S_CROP
<VIDIOC_G_CROP>` ioctls apply to input as well as output devices. <VIDIOC_G_CROP>` ioctls apply to input as well as output devices.
...@@ -38,7 +40,9 @@ support scaling or the :ref:`VIDIOC_G_CROP <VIDIOC_G_CROP>` and ...@@ -38,7 +40,9 @@ support scaling or the :ref:`VIDIOC_G_CROP <VIDIOC_G_CROP>` and
:ref:`VIDIOC_S_CROP <VIDIOC_G_CROP>` ioctls. Their size (and position :ref:`VIDIOC_S_CROP <VIDIOC_G_CROP>` ioctls. Their size (and position
where applicable) will be fixed in this case. where applicable) will be fixed in this case.
.. note:: All capture and output devices must support the .. note::
All capture and output devices must support the
:ref:`VIDIOC_CROPCAP <VIDIOC_CROPCAP>` ioctl such that applications :ref:`VIDIOC_CROPCAP <VIDIOC_CROPCAP>` ioctl such that applications
can determine if scaling takes place. can determine if scaling takes place.
...@@ -144,7 +148,9 @@ reopening a device, such that piping data into or out of a device will ...@@ -144,7 +148,9 @@ reopening a device, such that piping data into or out of a device will
work without special preparations. More advanced applications should work without special preparations. More advanced applications should
ensure the parameters are suitable before starting I/O. ensure the parameters are suitable before starting I/O.
.. note:: On the next two examples, a video capture device is assumed; .. note::
On the next two examples, a video capture device is assumed;
change ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` for other types of device. change ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` for other types of device.
Example: Resetting the cropping parameters Example: Resetting the cropping parameters
......
...@@ -21,7 +21,9 @@ for both capture and output to start the codec. ...@@ -21,7 +21,9 @@ for both capture and output to start the codec.
Video compression codecs use the MPEG controls to setup their codec Video compression codecs use the MPEG controls to setup their codec
parameters parameters
.. note:: The MPEG controls actually support many more codecs than .. note::
The MPEG controls actually support many more codecs than
just MPEG. See :ref:`mpeg-controls`. just MPEG. See :ref:`mpeg-controls`.
Memory-to-memory devices can often be used as a shared resource: you can Memory-to-memory devices can often be used as a shared resource: you can
......
...@@ -16,7 +16,9 @@ this interface, which borrows structures and ioctls of the ...@@ -16,7 +16,9 @@ this interface, which borrows structures and ioctls of the
The OSD function is accessible through the same character special file The OSD function is accessible through the same character special file
as the :ref:`Video Output <capture>` function. as the :ref:`Video Output <capture>` function.
.. note:: The default function of such a ``/dev/video`` device is video .. note::
The default function of such a ``/dev/video`` device is video
capturing or output. The OSD function is only available after calling capturing or output. The OSD function is only available after calling
the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl. the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl.
......
...@@ -19,7 +19,9 @@ video into a window. ...@@ -19,7 +19,9 @@ video into a window.
Video overlay devices are accessed through the same character special Video overlay devices are accessed through the same character special
files as :ref:`video capture <capture>` devices. files as :ref:`video capture <capture>` devices.
.. note:: The default function of a ``/dev/video`` device is video .. note::
The default function of a ``/dev/video`` device is video
capturing. The overlay function is only available after calling capturing. The overlay function is only available after calling
the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl. the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl.
...@@ -236,7 +238,9 @@ exceeded are undefined. [#f3]_ ...@@ -236,7 +238,9 @@ exceeded are undefined. [#f3]_
:ref:`VIDIOC_S_FBUF <VIDIOC_G_FBUF>`, :ref:`VIDIOC_S_FBUF <VIDIOC_G_FBUF>`,
:ref:`framebuffer-flags`). :ref:`framebuffer-flags`).
.. note:: This field was added in Linux 2.6.23, extending the .. note::
This field was added in Linux 2.6.23, extending the
structure. However the :ref:`VIDIOC_[G|S|TRY]_FMT <VIDIOC_G_FMT>` structure. However the :ref:`VIDIOC_[G|S|TRY]_FMT <VIDIOC_G_FMT>`
ioctls, which take a pointer to a :ref:`v4l2_format <v4l2-format>` ioctls, which take a pointer to a :ref:`v4l2_format <v4l2-format>`
parent structure with padding bytes at the end, are not affected. parent structure with padding bytes at the end, are not affected.
......
...@@ -14,7 +14,9 @@ at devices capable of receiving and/or transmitting RDS information. ...@@ -14,7 +14,9 @@ at devices capable of receiving and/or transmitting RDS information.
For more information see the core RDS standard :ref:`iec62106` and the For more information see the core RDS standard :ref:`iec62106` and the
RBDS standard :ref:`nrsc4`. RBDS standard :ref:`nrsc4`.
.. note:: Note that the RBDS standard as is used in the USA is almost .. note::
Note that the RBDS standard as is used in the USA is almost
identical to the RDS standard. Any RDS decoder/encoder can also handle identical to the RDS standard. Any RDS decoder/encoder can also handle
RBDS. Only some of the fields have slightly different meanings. See the RBDS. Only some of the fields have slightly different meanings. See the
RBDS standard for more information. RBDS standard for more information.
......
...@@ -184,7 +184,9 @@ Codec Control Reference ...@@ -184,7 +184,9 @@ Codec Control Reference
Below all controls within the Codec control class are described. First Below all controls within the Codec control class are described. First
the generic controls, then controls specific for certain hardware. the generic controls, then controls specific for certain hardware.
.. note:: These controls are applicable to all codecs and not just MPEG. The .. note::
These controls are applicable to all codecs and not just MPEG. The
defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG as the controls defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG as the controls
were originally made for MPEG codecs and later extended to cover all were originally made for MPEG codecs and later extended to cover all
encoding formats. encoding formats.
......
...@@ -78,7 +78,9 @@ Arguments ...@@ -78,7 +78,9 @@ Arguments
``MAP_SHARED`` allows applications to share the mapped memory with ``MAP_SHARED`` allows applications to share the mapped memory with
other (e. g. child-) processes. other (e. g. child-) processes.
.. note:: The Linux ``videobuf`` module which is used by some .. note::
The Linux ``videobuf`` module which is used by some
drivers supports only ``MAP_SHARED``. ``MAP_PRIVATE`` requests drivers supports only ``MAP_SHARED``. ``MAP_PRIVATE`` requests
copy-on-write semantics. V4L2 applications should not set the copy-on-write semantics. V4L2 applications should not set the
``MAP_PRIVATE``, ``MAP_DENYWRITE``, ``MAP_EXECUTABLE`` or ``MAP_ANON`` ``MAP_PRIVATE``, ``MAP_DENYWRITE``, ``MAP_EXECUTABLE`` or ``MAP_ANON``
......
...@@ -19,7 +19,9 @@ colorspace field of struct :ref:`v4l2_pix_format <v4l2-pix-format>` ...@@ -19,7 +19,9 @@ colorspace field of struct :ref:`v4l2_pix_format <v4l2-pix-format>`
or struct :ref:`v4l2_pix_format_mplane <v4l2-pix-format-mplane>` or struct :ref:`v4l2_pix_format_mplane <v4l2-pix-format-mplane>`
needs to be filled in. needs to be filled in.
.. note:: The default R'G'B' quantization is full range for all .. note::
The default R'G'B' quantization is full range for all
colorspaces except for BT.2020 which uses limited range R'G'B' colorspaces except for BT.2020 which uses limited range R'G'B'
quantization. quantization.
......
...@@ -538,7 +538,9 @@ projectors that use the DCI-P3 colorspace. The default transfer function ...@@ -538,7 +538,9 @@ projectors that use the DCI-P3 colorspace. The default transfer function
is ``V4L2_XFER_FUNC_DCI_P3``. The default Y'CbCr encoding is is ``V4L2_XFER_FUNC_DCI_P3``. The default Y'CbCr encoding is
``V4L2_YCBCR_ENC_709``. ``V4L2_YCBCR_ENC_709``.
.. note:: Note that this colorspace does not specify a .. note::
Note that this colorspace does not specify a
Y'CbCr encoding since it is not meant to be encoded to Y'CbCr. So this Y'CbCr encoding since it is not meant to be encoded to Y'CbCr. So this
default Y'CbCr encoding was picked because it is the HDTV encoding. The default Y'CbCr encoding was picked because it is the HDTV encoding. The
default Y'CbCr quantization is limited range. The chromaticities of the default Y'CbCr quantization is limited range. The chromaticities of the
...@@ -754,7 +756,9 @@ reference are: ...@@ -754,7 +756,9 @@ reference are:
- 0.316 - 0.316
.. note:: This colorspace uses Illuminant C instead of D65 as the white .. note::
This colorspace uses Illuminant C instead of D65 as the white
reference. To correctly convert an image in this colorspace to another reference. To correctly convert an image in this colorspace to another
that uses D65 you need to apply a chromatic adaptation algorithm such as that uses D65 you need to apply a chromatic adaptation algorithm such as
the Bradford method. the Bradford method.
...@@ -888,7 +892,9 @@ reference are identical to sRGB. The transfer function use is ...@@ -888,7 +892,9 @@ reference are identical to sRGB. The transfer function use is
with full range quantization where Y' is scaled to [0…255] and Cb/Cr are with full range quantization where Y' is scaled to [0…255] and Cb/Cr are
scaled to [-128…128] and then clipped to [-128…127]. scaled to [-128…128] and then clipped to [-128…127].
.. note:: The JPEG standard does not actually store colorspace .. note::
The JPEG standard does not actually store colorspace
information. So if something other than sRGB is used, then the driver information. So if something other than sRGB is used, then the driver
will have to set that information explicitly. Effectively will have to set that information explicitly. Effectively
``V4L2_COLORSPACE_JPEG`` can be considered to be an abbreviation for ``V4L2_COLORSPACE_JPEG`` can be considered to be an abbreviation for
......
...@@ -19,7 +19,9 @@ This format is similar to ...@@ -19,7 +19,9 @@ This format is similar to
has a depth of 16 bits. The least significant byte is stored at lower has a depth of 16 bits. The least significant byte is stored at lower
memory addresses (little-endian). memory addresses (little-endian).
..note:: The actual sampling precision may be lower than 16 bits, ..note::
The actual sampling precision may be lower than 16 bits,
for example 10 bits per pixel with values in tange 0 to 1023. for example 10 bits per pixel with values in tange 0 to 1023.
**Byte Order.** **Byte Order.**
......
...@@ -17,7 +17,9 @@ Description ...@@ -17,7 +17,9 @@ Description
This is a grey-scale image with a depth of 16 bits per pixel. The most This is a grey-scale image with a depth of 16 bits per pixel. The most
significant byte is stored at lower memory addresses (big-endian). significant byte is stored at lower memory addresses (big-endian).
.. note:: Tthe actual sampling precision may be lower than 16 bits, for .. note::
The actual sampling precision may be lower than 16 bits, for
example 10 bits per pixel with values in range 0 to 1023. example 10 bits per pixel with values in range 0 to 1023.
**Byte Order.** **Byte Order.**
......
...@@ -17,7 +17,9 @@ Description ...@@ -17,7 +17,9 @@ Description
This is a grey-scale image with a depth of 16 bits per pixel. The least This is a grey-scale image with a depth of 16 bits per pixel. The least
significant byte is stored at lower memory addresses (little-endian). significant byte is stored at lower memory addresses (little-endian).
.. note:: The actual sampling precision may be lower than 16 bits, for .. note::
The actual sampling precision may be lower than 16 bits, for
example 10 bits per pixel with values in range 0 to 1023. example 10 bits per pixel with values in range 0 to 1023.
**Byte Order.** **Byte Order.**
......
...@@ -41,7 +41,9 @@ output applications call the :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and ...@@ -41,7 +41,9 @@ output applications call the :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and
*received* standard can be sensed with the *received* standard can be sensed with the
:ref:`VIDIOC_QUERYSTD` ioctl. :ref:`VIDIOC_QUERYSTD` ioctl.
..note:: The parameter of all these ioctls is a pointer to a ..note::
The parameter of all these ioctls is a pointer to a
:ref:`v4l2_std_id <v4l2-std-id>` type (a standard set), *not* an :ref:`v4l2_std_id <v4l2-std-id>` type (a standard set), *not* an
index into the standard enumeration. Drivers must implement all video index into the standard enumeration. Drivers must implement all video
standard ioctls when the device has one or more video inputs or outputs. standard ioctls when the device has one or more video inputs or outputs.
......
...@@ -28,7 +28,9 @@ struct :ref:`v4l2_tuner <v4l2-tuner>` returned by :ref:`VIDIOC_G_TUNER <VIDIOC_G ...@@ -28,7 +28,9 @@ struct :ref:`v4l2_tuner <v4l2-tuner>` returned by :ref:`VIDIOC_G_TUNER <VIDIOC_G
also contains signal status information applicable when the tuner of the also contains signal status information applicable when the tuner of the
current video or radio input is queried. current video or radio input is queried.
.. note:: :ref:`VIDIOC_S_TUNER <VIDIOC_G_TUNER>` does not switch the .. note::
:ref:`VIDIOC_S_TUNER <VIDIOC_G_TUNER>` does not switch the
current tuner, when there is more than one at all. The tuner is solely current tuner, when there is more than one at all. The tuner is solely
determined by the current video input. Drivers must support both ioctls determined by the current video input. Drivers must support both ioctls
and set the ``V4L2_CAP_TUNER`` flag in the struct :ref:`v4l2_capability and set the ``V4L2_CAP_TUNER`` flag in the struct :ref:`v4l2_capability
......
...@@ -88,7 +88,9 @@ To start and stop capturing or output applications call the ...@@ -88,7 +88,9 @@ To start and stop capturing or output applications call the
:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` and :ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>` and
:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` ioctl. :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` ioctl.
.. note:: ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` removes all buffers from .. note::
ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` removes all buffers from
both queues and unlocks all buffers as a side effect. Since there is no both queues and unlocks all buffers as a side effect. Since there is no
notion of doing anything "now" on a multitasking system, if an notion of doing anything "now" on a multitasking system, if an
application needs to synchronize with another event it should examine application needs to synchronize with another event it should examine
......
...@@ -39,7 +39,9 @@ initialize the ``pad`` field to 0, zero the reserved array of struct ...@@ -39,7 +39,9 @@ initialize the ``pad`` field to 0, zero the reserved array of struct
``VIDIOC_DV_TIMINGS_CAP`` ioctl on a video node and the driver will fill ``VIDIOC_DV_TIMINGS_CAP`` ioctl on a video node and the driver will fill
in the structure. in the structure.
.. note:: Drivers may return different values after .. note::
Drivers may return different values after
switching the video input or output. switching the video input or output.
When implemented by the driver DV capabilities of subdevices can be When implemented by the driver DV capabilities of subdevices can be
......
...@@ -49,7 +49,9 @@ error code when the index is out of bounds. To enumerate all supported ...@@ -49,7 +49,9 @@ error code when the index is out of bounds. To enumerate all supported
DV timings, applications shall begin at index zero, incrementing by one DV timings, applications shall begin at index zero, incrementing by one
until the driver returns ``EINVAL``. until the driver returns ``EINVAL``.
.. note:: Drivers may enumerate a different set of DV timings after .. note::
Drivers may enumerate a different set of DV timings after
switching the video input or output. switching the video input or output.
When implemented by the driver DV timings of subdevices can be queried When implemented by the driver DV timings of subdevices can be queried
......
...@@ -40,7 +40,9 @@ fill the rest of the structure or return an ``EINVAL`` error code. All ...@@ -40,7 +40,9 @@ fill the rest of the structure or return an ``EINVAL`` error code. All
formats are enumerable by beginning at index zero and incrementing by formats are enumerable by beginning at index zero and incrementing by
one until ``EINVAL`` is returned. one until ``EINVAL`` is returned.
.. note:: After switching input or output the list of enumerated image .. note::
After switching input or output the list of enumerated image
formats may be different. formats may be different.
...@@ -51,7 +53,6 @@ one until ``EINVAL`` is returned. ...@@ -51,7 +53,6 @@ one until ``EINVAL`` is returned.
:stub-columns: 0 :stub-columns: 0
:widths: 1 1 2 :widths: 1 1 2
- .. row 1 - .. row 1
- __u32 - __u32
...@@ -113,7 +114,9 @@ one until ``EINVAL`` is returned. ...@@ -113,7 +114,9 @@ one until ``EINVAL`` is returned.
Several image formats are already defined by this specification in Several image formats are already defined by this specification in
:ref:`pixfmt`. :ref:`pixfmt`.
.. attention:: These codes are not the same as those used .. attention::
These codes are not the same as those used
in the Windows world. in the Windows world.
- .. row 7 - .. row 7
......
...@@ -73,7 +73,9 @@ the device supports. Only for the ``V4L2_FRMIVAL_TYPE_DISCRETE`` type ...@@ -73,7 +73,9 @@ the device supports. Only for the ``V4L2_FRMIVAL_TYPE_DISCRETE`` type
does it make sense to increase the index value to receive more frame does it make sense to increase the index value to receive more frame
intervals. intervals.
.. note:: The order in which the frame intervals are returned has no .. note::
The order in which the frame intervals are returned has no
special meaning. In particular does it not say anything about potential special meaning. In particular does it not say anything about potential
default frame intervals. default frame intervals.
......
...@@ -72,7 +72,9 @@ the ``type`` field to determine the type of frame size enumeration the ...@@ -72,7 +72,9 @@ the ``type`` field to determine the type of frame size enumeration the
device supports. Only for the ``V4L2_FRMSIZE_TYPE_DISCRETE`` type does device supports. Only for the ``V4L2_FRMSIZE_TYPE_DISCRETE`` type does
it make sense to increase the index value to receive more frame sizes. it make sense to increase the index value to receive more frame sizes.
.. note:: The order in which the frame sizes are returned has no special .. note::
The order in which the frame sizes are returned has no special
meaning. In particular does it not say anything about potential default meaning. In particular does it not say anything about potential default
format sizes. format sizes.
......
...@@ -129,7 +129,9 @@ of the corresponding tuner/modulator is set. ...@@ -129,7 +129,9 @@ of the corresponding tuner/modulator is set.
- :cspan:`2` The supported modulation systems of this frequency - :cspan:`2` The supported modulation systems of this frequency
band. See :ref:`band-modulation`. band. See :ref:`band-modulation`.
.. note:: Currently only one modulation system per frequency band .. note::
Currently only one modulation system per frequency band
is supported. More work will need to be done if multiple is supported. More work will need to be done if multiple
modulation systems are possible. Contact the linux-media modulation systems are possible. Contact the linux-media
mailing list mailing list
......
...@@ -41,7 +41,9 @@ structure or return an ``EINVAL`` error code when the index is out of ...@@ -41,7 +41,9 @@ structure or return an ``EINVAL`` error code when the index is out of
bounds. To enumerate all audio outputs applications shall begin at index bounds. To enumerate all audio outputs applications shall begin at index
zero, incrementing by one until the driver returns ``EINVAL``. zero, incrementing by one until the driver returns ``EINVAL``.
.. note:: Connectors on a TV card to loop back the received audio signal .. note::
Connectors on a TV card to loop back the received audio signal
to a sound card are not audio outputs in this sense. to a sound card are not audio outputs in this sense.
See :ref:`VIDIOC_G_AUDIOout <VIDIOC_G_AUDOUT>` for a description of struct See :ref:`VIDIOC_G_AUDIOout <VIDIOC_G_AUDOUT>` for a description of struct
......
...@@ -51,7 +51,9 @@ return the ``EINVAL`` error code when the index is out of bounds. This is a ...@@ -51,7 +51,9 @@ return the ``EINVAL`` error code when the index is out of bounds. This is a
write-only ioctl, it does not return the current audio output attributes write-only ioctl, it does not return the current audio output attributes
as ``VIDIOC_G_AUDOUT`` does. as ``VIDIOC_G_AUDOUT`` does.
.. note:: Connectors on a TV card to loop back the received audio signal .. note::
Connectors on a TV card to loop back the received audio signal
to a sound card are not audio outputs in this sense. to a sound card are not audio outputs in this sense.
......
...@@ -67,7 +67,9 @@ total number of available EDID blocks and it will return 0 without ...@@ -67,7 +67,9 @@ total number of available EDID blocks and it will return 0 without
copying any data. This is an easy way to discover how many EDID blocks copying any data. This is an easy way to discover how many EDID blocks
there are. there are.
.. note:: If there are no EDID blocks available at all, then .. note::
If there are no EDID blocks available at all, then
the driver will set ``blocks`` to 0 and it returns 0. the driver will set ``blocks`` to 0 and it returns 0.
To set the EDID blocks of a receiver the application has to fill in the To set the EDID blocks of a receiver the application has to fill in the
......
...@@ -127,7 +127,9 @@ still cause this situation. ...@@ -127,7 +127,9 @@ still cause this situation.
to a value large enough to store the payload result and ``ENOSPC`` is to a value large enough to store the payload result and ``ENOSPC`` is
returned. returned.
.. note:: For string controls, this ``size`` field should .. note::
For string controls, this ``size`` field should
not be confused with the length of the string. This field refers not be confused with the length of the string. This field refers
to the size of the memory that contains the string. The actual to the size of the memory that contains the string. The actual
*length* of the string may well be much smaller. *length* of the string may well be much smaller.
...@@ -265,7 +267,9 @@ still cause this situation. ...@@ -265,7 +267,9 @@ still cause this situation.
control and ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default control and ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
value of the control. value of the control.
.. note:: You can only get the default value of the control, .. note::
You can only get the default value of the control,
you cannot set or try it. you cannot set or try it.
For backwards compatibility you can also use a control class here For backwards compatibility you can also use a control class here
......
...@@ -130,7 +130,9 @@ To change the radio frequency the ...@@ -130,7 +130,9 @@ To change the radio frequency the
shall be modulated. It contains a set of flags as defined in shall be modulated. It contains a set of flags as defined in
:ref:`modulator-txsubchans`. :ref:`modulator-txsubchans`.
.. note:: The tuner ``rxsubchans`` flags are reused, but the .. note::
The tuner ``rxsubchans`` flags are reused, but the
semantics are different. Video output devices semantics are different. Video output devices
are assumed to have an analog or PCM audio input with 1-3 are assumed to have an analog or PCM audio input with 1-3
channels. The ``txsubchans`` flags select one or more channels channels. The ``txsubchans`` flags select one or more channels
......
...@@ -40,7 +40,9 @@ output device, applications initialize the ``type`` field of a struct ...@@ -40,7 +40,9 @@ output device, applications initialize the ``type`` field of a struct
driver fills in the remaining fields or returns an ``EINVAL`` error code if driver fills in the remaining fields or returns an ``EINVAL`` error code if
the sliced VBI API is unsupported or ``type`` is invalid. the sliced VBI API is unsupported or ``type`` is invalid.
.. note:: The ``type`` field was added, and the ioctl changed from read-only .. note::
The ``type`` field was added, and the ioctl changed from read-only
to write-read, in Linux 2.6.19. to write-read, in Linux 2.6.19.
......
...@@ -391,7 +391,9 @@ To change the radio frequency the ...@@ -391,7 +391,9 @@ To change the radio frequency the
carrier for a monaural secondary language. Only carrier for a monaural secondary language. Only
``V4L2_TUNER_ANALOG_TV`` tuners can have this capability. ``V4L2_TUNER_ANALOG_TV`` tuners can have this capability.
.. note:: The ``V4L2_TUNER_CAP_LANG2`` and ``V4L2_TUNER_CAP_SAP`` .. note::
The ``V4L2_TUNER_CAP_LANG2`` and ``V4L2_TUNER_CAP_SAP``
flags are synonyms. ``V4L2_TUNER_CAP_SAP`` applies when the tuner flags are synonyms. ``V4L2_TUNER_CAP_SAP`` applies when the tuner
supports the ``V4L2_STD_NTSC_M`` video standard. supports the ``V4L2_STD_NTSC_M`` video standard.
...@@ -502,7 +504,9 @@ To change the radio frequency the ...@@ -502,7 +504,9 @@ To change the radio frequency the
- The tuner receives a Second Audio Program. - The tuner receives a Second Audio Program.
.. note:: The ``V4L2_TUNER_SUB_LANG2`` and ``V4L2_TUNER_SUB_SAP`` .. note::
The ``V4L2_TUNER_SUB_LANG2`` and ``V4L2_TUNER_SUB_SAP``
flags are synonyms. The ``V4L2_TUNER_SUB_SAP`` flag applies flags are synonyms. The ``V4L2_TUNER_SUB_SAP`` flag applies
when the current video standard is ``V4L2_STD_NTSC_M``. when the current video standard is ``V4L2_STD_NTSC_M``.
......
...@@ -137,7 +137,9 @@ EIO ...@@ -137,7 +137,9 @@ EIO
``VIDIOC_DQBUF`` failed due to an internal error. Can also indicate ``VIDIOC_DQBUF`` failed due to an internal error. Can also indicate
temporary problems like signal loss. temporary problems like signal loss.
.. note:: The driver might dequeue an (empty) buffer despite returning .. note::
The driver might dequeue an (empty) buffer despite returning
an error, or even stop capturing. Reusing such buffer may be unsafe an error, or even stop capturing. Reusing such buffer may be unsafe
though and its details (e.g. ``index``) may not be returned either. though and its details (e.g. ``index``) may not be returned either.
It is recommended that drivers indicate recoverable errors by setting It is recommended that drivers indicate recoverable errors by setting
......
...@@ -39,7 +39,9 @@ similar to sensing the video standard. To do so, applications call ...@@ -39,7 +39,9 @@ similar to sensing the video standard. To do so, applications call
:ref:`v4l2_dv_timings <v4l2-dv-timings>`. Once the hardware detects :ref:`v4l2_dv_timings <v4l2-dv-timings>`. Once the hardware detects
the timings, it will fill in the timings structure. the timings, it will fill in the timings structure.
.. note:: Drivers shall *not* switch timings automatically if new .. note::
Drivers shall *not* switch timings automatically if new
timings are detected. Instead, drivers should send the timings are detected. Instead, drivers should send the
``V4L2_EVENT_SOURCE_CHANGE`` event (if they support this) and expect ``V4L2_EVENT_SOURCE_CHANGE`` event (if they support this) and expect
that userspace will take action by calling :ref:`VIDIOC_QUERY_DV_TIMINGS`. that userspace will take action by calling :ref:`VIDIOC_QUERY_DV_TIMINGS`.
......
...@@ -84,7 +84,9 @@ fills the rest of the structure or returns an ``EINVAL`` error code when the ...@@ -84,7 +84,9 @@ fills the rest of the structure or returns an ``EINVAL`` error code when the
:ref:`v4l2_queryctrl <v4l2-queryctrl>` ``minimum`` to ``maximum``, :ref:`v4l2_queryctrl <v4l2-queryctrl>` ``minimum`` to ``maximum``,
inclusive. inclusive.
.. note:: It is possible for ``VIDIOC_QUERYMENU`` to return .. note::
It is possible for ``VIDIOC_QUERYMENU`` to return
an ``EINVAL`` error code for some indices between ``minimum`` and an ``EINVAL`` error code for some indices between ``minimum`` and
``maximum``. In that case that particular menu item is not supported by ``maximum``. In that case that particular menu item is not supported by
this driver. Also note that the ``minimum`` value is not necessarily 0. this driver. Also note that the ``minimum`` value is not necessarily 0.
...@@ -188,7 +190,9 @@ See also the examples in :ref:`control`. ...@@ -188,7 +190,9 @@ See also the examples in :ref:`control`.
``_BITMASK``, ``_MENU`` or ``_INTEGER_MENU`` control. Not valid ``_BITMASK``, ``_MENU`` or ``_INTEGER_MENU`` control. Not valid
for other types of controls. for other types of controls.
.. note:: Drivers reset controls to their default value only when .. note::
Drivers reset controls to their default value only when
the driver is first loaded, never afterwards. the driver is first loaded, never afterwards.
- .. row 8 - .. row 8
...@@ -306,7 +310,9 @@ See also the examples in :ref:`control`. ...@@ -306,7 +310,9 @@ See also the examples in :ref:`control`.
``_BOOLEAN``, ``_BITMASK``, ``_MENU``, ``_INTEGER_MENU``, ``_U8`` ``_BOOLEAN``, ``_BITMASK``, ``_MENU``, ``_INTEGER_MENU``, ``_U8``
or ``_U16`` control. Not valid for other types of controls. or ``_U16`` control. Not valid for other types of controls.
.. note:: Drivers reset controls to their default value only when .. note::
Drivers reset controls to their default value only when
the driver is first loaded, never afterwards. the driver is first loaded, never afterwards.
- .. row 8 - .. row 8
...@@ -728,7 +734,9 @@ See also the examples in :ref:`control`. ...@@ -728,7 +734,9 @@ See also the examples in :ref:`control`.
case the hardware calculates the gain value based on the lighting case the hardware calculates the gain value based on the lighting
conditions which can change over time. conditions which can change over time.
.. note:: Setting a new value for a volatile control will have no .. note::
Setting a new value for a volatile control will have no
effect and no ``V4L2_EVENT_CTRL_CH_VALUE`` will be sent, unless effect and no ``V4L2_EVENT_CTRL_CH_VALUE`` will be sent, unless
the ``V4L2_CTRL_FLAG_EXECUTE_ON_WRITE`` flag (see below) is the ``V4L2_CTRL_FLAG_EXECUTE_ON_WRITE`` flag (see below) is
also set. Otherwise the new value will just be ignored. also set. Otherwise the new value will just be ignored.
......
...@@ -43,7 +43,9 @@ will return V4L2_STD_UNKNOWN. When detection is not possible or fails, ...@@ -43,7 +43,9 @@ will return V4L2_STD_UNKNOWN. When detection is not possible or fails,
the set must contain all standards supported by the current video input the set must contain all standards supported by the current video input
or output. or output.
.. note:: Drivers shall *not* switch the video standard .. note::
Drivers shall *not* switch the video standard
automatically if a new video standard is detected. Instead, drivers automatically if a new video standard is detected. Instead, drivers
should send the ``V4L2_EVENT_SOURCE_CHANGE`` event (if they support should send the ``V4L2_EVENT_SOURCE_CHANGE`` event (if they support
this) and expect that userspace will take action by calling this) and expect that userspace will take action by calling
......
...@@ -76,7 +76,9 @@ then 0 is returned. Nothing happens in the case of ``VIDIOC_STREAMON``, ...@@ -76,7 +76,9 @@ then 0 is returned. Nothing happens in the case of ``VIDIOC_STREAMON``,
but ``VIDIOC_STREAMOFF`` will return queued buffers to their starting but ``VIDIOC_STREAMOFF`` will return queued buffers to their starting
state as mentioned above. state as mentioned above.
.. note:: Applications can be preempted for unknown periods right before .. note::
Applications can be preempted for unknown periods right before
or after the ``VIDIOC_STREAMON`` or ``VIDIOC_STREAMOFF`` calls, there is or after the ``VIDIOC_STREAMON`` or ``VIDIOC_STREAMOFF`` calls, there is
no notion of starting or stopping "now". Buffer timestamps can be used no notion of starting or stopping "now". Buffer timestamps can be used
to synchronize with other events. to synchronize with other events.
......
...@@ -54,7 +54,9 @@ using the :ref:`VIDIOC_DQEVENT` ioctl. ...@@ -54,7 +54,9 @@ using the :ref:`VIDIOC_DQEVENT` ioctl.
- Type of the event, see :ref:`event-type`. - Type of the event, see :ref:`event-type`.
.. note:: ``V4L2_EVENT_ALL`` can be used with .. note::
``V4L2_EVENT_ALL`` can be used with
:ref:`VIDIOC_UNSUBSCRIBE_EVENT <VIDIOC_SUBSCRIBE_EVENT>` for :ref:`VIDIOC_UNSUBSCRIBE_EVENT <VIDIOC_SUBSCRIBE_EVENT>` for
unsubscribing all events at once. unsubscribing all events at once.
......
...@@ -586,6 +586,7 @@ Cards ...@@ -586,6 +586,7 @@ Cards
----- -----
.. note:: .. note::
For a more updated list, please check For a more updated list, please check
https://linuxtv.org/wiki/index.php/Hardware_Device_Information https://linuxtv.org/wiki/index.php/Hardware_Device_Information
......
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