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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
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Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _VIDIOC_G_DV_TIMINGS:
+
+**********************************************
+ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS
+**********************************************
+
+Name
+====
+
+VIDIOC_G_DV_TIMINGS - VIDIOC_S_DV_TIMINGS - VIDIOC_SUBDEV_G_DV_TIMINGS - VIDIOC_SUBDEV_S_DV_TIMINGS - Get or set DV timings for input or output
+
+Synopsis
+========
+
+.. c:macro:: VIDIOC_G_DV_TIMINGS
+
+``int ioctl(int fd, VIDIOC_G_DV_TIMINGS, struct v4l2_dv_timings *argp)``
+
+.. c:macro:: VIDIOC_S_DV_TIMINGS
+
+``int ioctl(int fd, VIDIOC_S_DV_TIMINGS, struct v4l2_dv_timings *argp)``
+
+.. c:macro:: VIDIOC_SUBDEV_G_DV_TIMINGS
+
+``int ioctl(int fd, VIDIOC_SUBDEV_G_DV_TIMINGS, struct v4l2_dv_timings *argp)``
+
+.. c:macro:: VIDIOC_SUBDEV_S_DV_TIMINGS
+
+``int ioctl(int fd, VIDIOC_SUBDEV_S_DV_TIMINGS, struct v4l2_dv_timings *argp)``
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :c:func:`open()`.
+
+``argp``
+ Pointer to struct :c:type:`v4l2_dv_timings`.
+
+Description
+===========
+
+To set DV timings for the input or output, applications use the
+:ref:`VIDIOC_S_DV_TIMINGS <VIDIOC_G_DV_TIMINGS>` ioctl and to get the current timings,
+applications use the :ref:`VIDIOC_G_DV_TIMINGS <VIDIOC_G_DV_TIMINGS>` ioctl. The detailed timing
+information is filled in using the structure struct
+:c:type:`v4l2_dv_timings`. These ioctls take a
+pointer to the struct :c:type:`v4l2_dv_timings`
+structure as argument. If the ioctl is not supported or the timing
+values are not correct, the driver returns ``EINVAL`` error code.
+
+Calling ``VIDIOC_SUBDEV_S_DV_TIMINGS`` on a subdev device node that has been
+registered in read-only mode is not allowed. An error is returned and the errno
+variable is set to ``-EPERM``.
+
+The ``linux/v4l2-dv-timings.h`` header can be used to get the timings of
+the formats in the :ref:`cea861` and :ref:`vesadmt` standards. If
+the current input or output does not support DV timings (e.g. if
+:ref:`VIDIOC_ENUMINPUT` does not set the
+``V4L2_IN_CAP_DV_TIMINGS`` flag), then ``ENODATA`` error code is returned.
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+EINVAL
+ This ioctl is not supported, or the :ref:`VIDIOC_S_DV_TIMINGS <VIDIOC_G_DV_TIMINGS>`
+ parameter was unsuitable.
+
+ENODATA
+ Digital video timings are not supported for this input or output.
+
+EBUSY
+ The device is busy and therefore can not change the timings.
+
+EPERM
+ ``VIDIOC_SUBDEV_S_DV_TIMINGS`` has been called on a read-only subdevice.
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. c:type:: v4l2_bt_timings
+
+.. flat-table:: struct v4l2_bt_timings
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u32
+ - ``width``
+ - Width of the active video in pixels.
+ * - __u32
+ - ``height``
+ - Height of the active video frame in lines. So for interlaced
+ formats the height of the active video in each field is
+ ``height``/2.
+ * - __u32
+ - ``interlaced``
+ - Progressive (``V4L2_DV_PROGRESSIVE``) or interlaced (``V4L2_DV_INTERLACED``).
+ * - __u32
+ - ``polarities``
+ - This is a bit mask that defines polarities of sync signals. bit 0
+ (``V4L2_DV_VSYNC_POS_POL``) is for vertical sync polarity and bit
+ 1 (``V4L2_DV_HSYNC_POS_POL``) is for horizontal sync polarity. If
+ the bit is set (1) it is positive polarity and if is cleared (0),
+ it is negative polarity.
+ * - __u64
+ - ``pixelclock``
+ - Pixel clock in Hz. Ex. 74.25MHz->74250000
+ * - __u32
+ - ``hfrontporch``
+ - Horizontal front porch in pixels
+ * - __u32
+ - ``hsync``
+ - Horizontal sync length in pixels
+ * - __u32
+ - ``hbackporch``
+ - Horizontal back porch in pixels
+ * - __u32
+ - ``vfrontporch``
+ - Vertical front porch in lines. For interlaced formats this refers
+ to the odd field (aka field 1).
+ * - __u32
+ - ``vsync``
+ - Vertical sync length in lines. For interlaced formats this refers
+ to the odd field (aka field 1).
+ * - __u32
+ - ``vbackporch``
+ - Vertical back porch in lines. For interlaced formats this refers
+ to the odd field (aka field 1).
+ * - __u32
+ - ``il_vfrontporch``
+ - Vertical front porch in lines for the even field (aka field 2) of
+ interlaced field formats. Must be 0 for progressive formats.
+ * - __u32
+ - ``il_vsync``
+ - Vertical sync length in lines for the even field (aka field 2) of
+ interlaced field formats. Must be 0 for progressive formats.
+ * - __u32
+ - ``il_vbackporch``
+ - Vertical back porch in lines for the even field (aka field 2) of
+ interlaced field formats. Must be 0 for progressive formats.
+ * - __u32
+ - ``standards``
+ - The video standard(s) this format belongs to. This will be filled
+ in by the driver. Applications must set this to 0. See
+ :ref:`dv-bt-standards` for a list of standards.
+ * - __u32
+ - ``flags``
+ - Several flags giving more information about the format. See
+ :ref:`dv-bt-flags` for a description of the flags.
+ * - struct :c:type:`v4l2_fract`
+ - ``picture_aspect``
+ - The picture aspect if the pixels are not square. Only valid if the
+ ``V4L2_DV_FL_HAS_PICTURE_ASPECT`` flag is set.
+ * - __u8
+ - ``cea861_vic``
+ - The Video Identification Code according to the CEA-861 standard.
+ Only valid if the ``V4L2_DV_FL_HAS_CEA861_VIC`` flag is set.
+ * - __u8
+ - ``hdmi_vic``
+ - The Video Identification Code according to the HDMI standard.
+ Only valid if the ``V4L2_DV_FL_HAS_HDMI_VIC`` flag is set.
+ * - __u8
+ - ``reserved[46]``
+ - Reserved for future extensions. Drivers and applications must set
+ the array to zero.
+
+.. tabularcolumns:: |p{3.5cm}|p{3.5cm}|p{7.0cm}|p{3.5cm}|
+
+.. c:type:: v4l2_dv_timings
+
+.. flat-table:: struct v4l2_dv_timings
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u32
+ - ``type``
+ - Type of DV timings as listed in :ref:`dv-timing-types`.
+ * - union {
+ - (anonymous)
+ * - struct :c:type:`v4l2_bt_timings`
+ - ``bt``
+ - Timings defined by BT.656/1120 specifications
+ * - __u32
+ - ``reserved``\ [32]
+ -
+ * - }
+ -
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. _dv-timing-types:
+
+.. flat-table:: DV Timing types
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - Timing type
+ - value
+ - Description
+ * -
+ -
+ -
+ * - ``V4L2_DV_BT_656_1120``
+ - 0
+ - BT.656/1120 timings
+
+.. tabularcolumns:: |p{4.5cm}|p{12.8cm}|
+
+.. _dv-bt-standards:
+
+.. flat-table:: DV BT Timing standards
+ :header-rows: 0
+ :stub-columns: 0
+
+ * - Timing standard
+ - Description
+ * - ``V4L2_DV_BT_STD_CEA861``
+ - The timings follow the CEA-861 Digital TV Profile standard
+ * - ``V4L2_DV_BT_STD_DMT``
+ - The timings follow the VESA Discrete Monitor Timings standard
+ * - ``V4L2_DV_BT_STD_CVT``
+ - The timings follow the VESA Coordinated Video Timings standard
+ * - ``V4L2_DV_BT_STD_GTF``
+ - The timings follow the VESA Generalized Timings Formula standard
+ * - ``V4L2_DV_BT_STD_SDI``
+ - The timings follow the SDI Timings standard.
+ There are no horizontal syncs/porches at all in this format.
+ Total blanking timings must be set in hsync or vsync fields only.
+
+.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|
+
+.. _dv-bt-flags:
+
+.. flat-table:: DV BT Timing flags
+ :header-rows: 0
+ :stub-columns: 0
+
+ * - Flag
+ - Description
+ * - ``V4L2_DV_FL_REDUCED_BLANKING``
+ - CVT/GTF specific: the timings use reduced blanking (CVT) or the
+ 'Secondary GTF' curve (GTF). In both cases the horizontal and/or
+ vertical blanking intervals are reduced, allowing a higher
+ resolution over the same bandwidth. This is a read-only flag,
+ applications must not set this.
+ * - ``V4L2_DV_FL_CAN_REDUCE_FPS``
+ - CEA-861 specific: set for CEA-861 formats with a framerate that is
+ a multiple of six. These formats can be optionally played at 1 /
+ 1.001 speed to be compatible with 60 Hz based standards such as
+ NTSC and PAL-M that use a framerate of 29.97 frames per second. If
+ the transmitter can't generate such frequencies, then the flag
+ will also be cleared. This is a read-only flag, applications must
+ not set this.
+ * - ``V4L2_DV_FL_REDUCED_FPS``
+ - CEA-861 specific: only valid for video transmitters or video
+ receivers that have the ``V4L2_DV_FL_CAN_DETECT_REDUCED_FPS``
+ set. This flag is cleared otherwise. It is also only valid for
+ formats with the ``V4L2_DV_FL_CAN_REDUCE_FPS`` flag set, for other
+ formats the flag will be cleared by the driver.
+
+ If the application sets this flag for a transmitter, then the
+ pixelclock used to set up the transmitter is divided by 1.001 to
+ make it compatible with NTSC framerates. If the transmitter can't
+ generate such frequencies, then the flag will be cleared.
+
+ If a video receiver detects that the format uses a reduced framerate,
+ then it will set this flag to signal this to the application.
+ * - ``V4L2_DV_FL_HALF_LINE``
+ - Specific to interlaced formats: if set, then the vertical
+ frontporch of field 1 (aka the odd field) is really one half-line
+ longer and the vertical backporch of field 2 (aka the even field)
+ is really one half-line shorter, so each field has exactly the
+ same number of half-lines. Whether half-lines can be detected or
+ used depends on the hardware.
+ * - ``V4L2_DV_FL_IS_CE_VIDEO``
+ - If set, then this is a Consumer Electronics (CE) video format.
+ Such formats differ from other formats (commonly called IT
+ formats) in that if R'G'B' encoding is used then by default the
+ R'G'B' values use limited range (i.e. 16-235) as opposed to full
+ range (i.e. 0-255). All formats defined in CEA-861 except for the
+ 640x480p59.94 format are CE formats.
+ * - ``V4L2_DV_FL_FIRST_FIELD_EXTRA_LINE``
+ - Some formats like SMPTE-125M have an interlaced signal with a odd
+ total height. For these formats, if this flag is set, the first
+ field has the extra line. Else, it is the second field.
+ * - ``V4L2_DV_FL_HAS_PICTURE_ASPECT``
+ - If set, then the picture_aspect field is valid. Otherwise assume that
+ the pixels are square, so the picture aspect ratio is the same as the
+ width to height ratio.
+ * - ``V4L2_DV_FL_HAS_CEA861_VIC``
+ - If set, then the cea861_vic field is valid and contains the Video
+ Identification Code as per the CEA-861 standard.
+ * - ``V4L2_DV_FL_HAS_HDMI_VIC``
+ - If set, then the hdmi_vic field is valid and contains the Video
+ Identification Code as per the HDMI standard (HDMI Vendor Specific
+ InfoFrame).
+ * - ``V4L2_DV_FL_CAN_DETECT_REDUCED_FPS``
+ - CEA-861 specific: only valid for video receivers, the flag is
+ cleared by transmitters.
+ If set, then the hardware can detect the difference between
+ regular framerates and framerates reduced by 1000/1001. E.g.:
+ 60 vs 59.94 Hz, 30 vs 29.97 Hz or 24 vs 23.976 Hz.