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authorLinus Torvalds2018-10-31 18:53:29 +0100
committerLinus Torvalds2018-10-31 18:53:29 +0100
commitb3491d8430dd25f0a4e00c33d60da22a9bd9d052 (patch)
treea3506967c871971bf9e5920dca5316c5346763df /Documentation/media/uapi/v4l
parentMerge branch 'akpm' (patches from Andrew) (diff)
parentmedia: dt-bindings: Document the Rockchip VPU bindings (diff)
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Merge tag 'media/v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull new experimental media request API from Mauro Carvalho Chehab: "A new media request API This API is needed to support device drivers that can dynamically change their parameters for each new frame. The latest versions of Google camera and codec HAL depends on such feature. At this stage, it supports only stateless codecs. It has been discussed for a long time (at least over the last 3-4 years), and we finally reached to something that seem to work. This series contain both the API and core changes required to support it and a new m2m decoder driver (cedrus). As the current API is still experimental, the only real driver using it (cedrus) was added at staging[1]. We intend to keep it there for a while, in order to test the API. Only when we're sure that this API works for other cases (like encoders), we'll move this driver out of staging and set the API into a stone. [1] We added support for the vivid virtual driver (used only for testing) to it too, as it makes easier to test the API for the ones that don't have the cedrus hardware" * tag 'media/v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (53 commits) media: dt-bindings: Document the Rockchip VPU bindings media: platform: Add Cedrus VPU decoder driver media: dt-bindings: media: Document bindings for the Cedrus VPU driver media: v4l: Add definition for the Sunxi tiled NV12 format media: v4l: Add definitions for MPEG-2 slice format and metadata media: videobuf2-core: Rework and rename helper for request buffer count media: v4l2-ctrls.c: initialize an error return code with zero media: v4l2-compat-ioctl32.c: add missing documentation for a field media: media-request: update documentation media: media-request: EPERM -> EACCES/EBUSY media: v4l2-ctrls: improve media_request_(un)lock_for_update media: v4l2-ctrls: use media_request_(un)lock_for_access media: media-request: add media_request_(un)lock_for_access media: vb2: set reqbufs/create_bufs capabilities media: videodev2.h: add new capabilities for buffer types media: buffer.rst: only set V4L2_BUF_FLAG_REQUEST_FD for QBUF media: v4l2-ctrls: return -EACCES if request wasn't completed media: media-request: return -EINVAL for invalid request_fds media: vivid: add request support media: vivid: add mc ...
Diffstat (limited to 'Documentation/media/uapi/v4l')
-rw-r--r--Documentation/media/uapi/v4l/buffer.rst29
-rw-r--r--Documentation/media/uapi/v4l/extended-controls.rst176
-rw-r--r--Documentation/media/uapi/v4l/pixfmt-compressed.rst16
-rw-r--r--Documentation/media/uapi/v4l/pixfmt-reserved.rst15
-rw-r--r--Documentation/media/uapi/v4l/vidioc-create-bufs.rst14
-rw-r--r--Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst59
-rw-r--r--Documentation/media/uapi/v4l/vidioc-qbuf.rst37
-rw-r--r--Documentation/media/uapi/v4l/vidioc-queryctrl.rst14
-rw-r--r--Documentation/media/uapi/v4l/vidioc-reqbufs.rst42
9 files changed, 382 insertions, 20 deletions
diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
index e2c85ddc990b..2e266d32470a 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -306,10 +306,23 @@ struct v4l2_buffer
- A place holder for future extensions. Drivers and applications
must set this to 0.
* - __u32
- - ``reserved``
+ - ``request_fd``
-
- - A place holder for future extensions. Drivers and applications
- must set this to 0.
+ - The file descriptor of the request to queue the buffer to. If the flag
+ ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will be
+ queued to this request. If the flag is not set, then this field will
+ be ignored.
+
+ The ``V4L2_BUF_FLAG_REQUEST_FD`` flag and this field are only used by
+ :ref:`ioctl VIDIOC_QBUF <VIDIOC_QBUF>` and ignored by other ioctls that
+ take a :c:type:`v4l2_buffer` as argument.
+
+ Applications should not set ``V4L2_BUF_FLAG_REQUEST_FD`` for any ioctls
+ other than :ref:`VIDIOC_QBUF <VIDIOC_QBUF>`.
+
+ If the device does not support requests, then ``EACCES`` will be returned.
+ If requests are supported but an invalid request file descriptor is
+ given, then ``EINVAL`` will be returned.
@@ -514,6 +527,11 @@ Buffer Flags
streaming may continue as normal and the buffer may be reused
normally. Drivers set this flag when the ``VIDIOC_DQBUF`` ioctl is
called.
+ * .. _`V4L2-BUF-FLAG-IN-REQUEST`:
+
+ - ``V4L2_BUF_FLAG_IN_REQUEST``
+ - 0x00000080
+ - This buffer is part of a request that hasn't been queued yet.
* .. _`V4L2-BUF-FLAG-KEYFRAME`:
- ``V4L2_BUF_FLAG_KEYFRAME``
@@ -589,6 +607,11 @@ Buffer Flags
the format. Any Any subsequent call to the
:ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl will not block anymore,
but return an ``EPIPE`` error code.
+ * .. _`V4L2-BUF-FLAG-REQUEST-FD`:
+
+ - ``V4L2_BUF_FLAG_REQUEST_FD``
+ - 0x00800000
+ - The ``request_fd`` field contains a valid file descriptor.
* .. _`V4L2-BUF-FLAG-TIMESTAMP-MASK`:
- ``V4L2_BUF_FLAG_TIMESTAMP_MASK``
diff --git a/Documentation/media/uapi/v4l/extended-controls.rst b/Documentation/media/uapi/v4l/extended-controls.rst
index 9f7312bf3365..65a1d873196b 100644
--- a/Documentation/media/uapi/v4l/extended-controls.rst
+++ b/Documentation/media/uapi/v4l/extended-controls.rst
@@ -1497,6 +1497,182 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
+.. _v4l2-mpeg-mpeg2:
+
+``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS (struct)``
+ Specifies the slice parameters (as extracted from the bitstream) for the
+ associated MPEG-2 slice data. This includes the necessary parameters for
+ configuring a stateless hardware decoding pipeline for MPEG-2.
+ The bitstream parameters are defined according to :ref:`mpeg2part2`.
+
+.. c:type:: v4l2_ctrl_mpeg2_slice_params
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_ctrl_mpeg2_slice_params
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u32
+ - ``bit_size``
+ - Size (in bits) of the current slice data.
+ * - __u32
+ - ``data_bit_offset``
+ - Offset (in bits) to the video data in the current slice data.
+ * - struct :c:type:`v4l2_mpeg2_sequence`
+ - ``sequence``
+ - Structure with MPEG-2 sequence metadata, merging relevant fields from
+ the sequence header and sequence extension parts of the bitstream.
+ * - struct :c:type:`v4l2_mpeg2_picture`
+ - ``picture``
+ - Structure with MPEG-2 picture metadata, merging relevant fields from
+ the picture header and picture coding extension parts of the bitstream.
+ * - __u8
+ - ``quantiser_scale_code``
+ - Code used to determine the quantization scale to use for the IDCT.
+ * - __u8
+ - ``backward_ref_index``
+ - Index for the V4L2 buffer to use as backward reference, used with
+ B-coded and P-coded frames.
+ * - __u8
+ - ``forward_ref_index``
+ - Index for the V4L2 buffer to use as forward reference, used with
+ B-coded frames.
+
+.. c:type:: v4l2_mpeg2_sequence
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_mpeg2_sequence
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u16
+ - ``horizontal_size``
+ - The width of the displayable part of the frame's luminance component.
+ * - __u16
+ - ``vertical_size``
+ - The height of the displayable part of the frame's luminance component.
+ * - __u32
+ - ``vbv_buffer_size``
+ - Used to calculate the required size of the video buffering verifier,
+ defined (in bits) as: 16 * 1024 * vbv_buffer_size.
+ * - __u8
+ - ``profile_and_level_indication``
+ - The current profile and level indication as extracted from the
+ bitstream.
+ * - __u8
+ - ``progressive_sequence``
+ - Indication that all the frames for the sequence are progressive instead
+ of interlaced.
+ * - __u8
+ - ``chroma_format``
+ - The chrominance sub-sampling format (1: 4:2:0, 2: 4:2:2, 3: 4:4:4).
+
+.. c:type:: v4l2_mpeg2_picture
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_mpeg2_picture
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u8
+ - ``picture_coding_type``
+ - Picture coding type for the frame covered by the current slice
+ (V4L2_MPEG2_PICTURE_CODING_TYPE_I, V4L2_MPEG2_PICTURE_CODING_TYPE_P or
+ V4L2_MPEG2_PICTURE_CODING_TYPE_B).
+ * - __u8
+ - ``f_code[2][2]``
+ - Motion vector codes.
+ * - __u8
+ - ``intra_dc_precision``
+ - Precision of Discrete Cosine transform (0: 8 bits precision,
+ 1: 9 bits precision, 2: 10 bits precision, 3: 11 bits precision).
+ * - __u8
+ - ``picture_structure``
+ - Picture structure (1: interlaced top field, 2: interlaced bottom field,
+ 3: progressive frame).
+ * - __u8
+ - ``top_field_first``
+ - If set to 1 and interlaced stream, top field is output first.
+ * - __u8
+ - ``frame_pred_frame_dct``
+ - If set to 1, only frame-DCT and frame prediction are used.
+ * - __u8
+ - ``concealment_motion_vectors``
+ - If set to 1, motion vectors are coded for intra macroblocks.
+ * - __u8
+ - ``q_scale_type``
+ - This flag affects the inverse quantization process.
+ * - __u8
+ - ``intra_vlc_format``
+ - This flag affects the decoding of transform coefficient data.
+ * - __u8
+ - ``alternate_scan``
+ - This flag affects the decoding of transform coefficient data.
+ * - __u8
+ - ``repeat_first_field``
+ - This flag affects the decoding process of progressive frames.
+ * - __u8
+ - ``progressive_frame``
+ - Indicates whether the current frame is progressive.
+
+``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION (struct)``
+ Specifies quantization matrices (as extracted from the bitstream) for the
+ associated MPEG-2 slice data.
+
+.. c:type:: v4l2_ctrl_mpeg2_quantization
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_ctrl_mpeg2_quantization
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u8
+ - ``load_intra_quantiser_matrix``
+ - One bit to indicate whether to load the ``intra_quantiser_matrix`` data.
+ * - __u8
+ - ``load_non_intra_quantiser_matrix``
+ - One bit to indicate whether to load the ``non_intra_quantiser_matrix``
+ data.
+ * - __u8
+ - ``load_chroma_intra_quantiser_matrix``
+ - One bit to indicate whether to load the
+ ``chroma_intra_quantiser_matrix`` data, only relevant for non-4:2:0 YUV
+ formats.
+ * - __u8
+ - ``load_chroma_non_intra_quantiser_matrix``
+ - One bit to indicate whether to load the
+ ``chroma_non_intra_quantiser_matrix`` data, only relevant for non-4:2:0
+ YUV formats.
+ * - __u8
+ - ``intra_quantiser_matrix[64]``
+ - The quantization matrix coefficients for intra-coded frames, in zigzag
+ scanning order. It is relevant for both luma and chroma components,
+ although it can be superseded by the chroma-specific matrix for
+ non-4:2:0 YUV formats.
+ * - __u8
+ - ``non_intra_quantiser_matrix[64]``
+ - The quantization matrix coefficients for non-intra-coded frames, in
+ zigzag scanning order. It is relevant for both luma and chroma
+ components, although it can be superseded by the chroma-specific matrix
+ for non-4:2:0 YUV formats.
+ * - __u8
+ - ``chroma_intra_quantiser_matrix[64]``
+ - The quantization matrix coefficients for the chominance component of
+ intra-coded frames, in zigzag scanning order. Only relevant for
+ non-4:2:0 YUV formats.
+ * - __u8
+ - ``chroma_non_intra_quantiser_matrix[64]``
+ - The quantization matrix coefficients for the chrominance component of
+ non-intra-coded frames, in zigzag scanning order. Only relevant for
+ non-4:2:0 YUV formats.
MFC 5.1 MPEG Controls
---------------------
diff --git a/Documentation/media/uapi/v4l/pixfmt-compressed.rst b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
index d04b18adac33..ba0f6c49d9bf 100644
--- a/Documentation/media/uapi/v4l/pixfmt-compressed.rst
+++ b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
@@ -60,6 +60,22 @@ Compressed Formats
- ``V4L2_PIX_FMT_MPEG2``
- 'MPG2'
- MPEG2 video elementary stream.
+ * .. _V4L2-PIX-FMT-MPEG2-SLICE:
+
+ - ``V4L2_PIX_FMT_MPEG2_SLICE``
+ - 'MG2S'
+ - MPEG-2 parsed slice data, as extracted from the MPEG-2 bitstream.
+ This format is adapted for stateless video decoders that implement a
+ MPEG-2 pipeline (using the :ref:`codec` and :ref:`media-request-api`).
+ Metadata associated with the frame to decode is required to be passed
+ through the ``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS`` control and
+ quantization matrices can optionally be specified through the
+ ``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION`` control.
+ See the :ref:`associated Codec Control IDs <v4l2-mpeg-mpeg2>`.
+ Exactly one output and one capture buffer must be provided for use with
+ this pixel format. The output buffer must contain the appropriate number
+ of macroblocks to decode a full corresponding frame to the matching
+ capture buffer.
* .. _V4L2-PIX-FMT-MPEG4:
- ``V4L2_PIX_FMT_MPEG4``
diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
index 38af1472a4b4..0c399858bda2 100644
--- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst
+++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
@@ -243,7 +243,20 @@ please make a proposal on the linux-media mailing list.
It is an opaque intermediate format and the MDP hardware must be
used to convert ``V4L2_PIX_FMT_MT21C`` to ``V4L2_PIX_FMT_NV12M``,
``V4L2_PIX_FMT_YUV420M`` or ``V4L2_PIX_FMT_YVU420``.
-
+ * .. _V4L2-PIX-FMT-SUNXI-TILED-NV12:
+
+ - ``V4L2_PIX_FMT_SUNXI_TILED_NV12``
+ - 'ST12'
+ - Two-planar NV12-based format used by the video engine found on Allwinner
+ (codenamed sunxi) platforms, with 32x32 tiles for the luminance plane
+ and 32x64 tiles for the chrominance plane. The data in each tile is
+ stored in linear order, within the tile bounds. Each tile follows the
+ previous one linearly in memory (from left to right, top to bottom).
+
+ The associated buffer dimensions are aligned to match an integer number
+ of tiles, resulting in 32-aligned resolutions for the luminance plane
+ and 16-aligned resolutions for the chrominance plane (with 2x2
+ subsampling).
.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
index a39e18d69511..eadf6f757fbf 100644
--- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
@@ -102,7 +102,19 @@ than the number requested.
- ``format``
- Filled in by the application, preserved by the driver.
* - __u32
- - ``reserved``\ [8]
+ - ``capabilities``
+ - Set by the driver. If 0, then the driver doesn't support
+ capabilities. In that case all you know is that the driver is
+ guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
+ other :c:type:`v4l2_memory` types. It will not support any others
+ capabilities. See :ref:`here <v4l2-buf-capabilities>` for a list of the
+ capabilities.
+
+ If you want to just query the capabilities without making any
+ other changes, then set ``count`` to 0, ``memory`` to
+ ``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
+ * - __u32
+ - ``reserved``\ [7]
- A place holder for future extensions. Drivers and applications
must set the array to zero.
diff --git a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
index 2011c2b2ee67..d9930fe776cf 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
@@ -95,6 +95,25 @@ appropriate. In the first case the new value is set in struct
is inappropriate (e.g. the given menu index is not supported by the menu
control), then this will also result in an ``EINVAL`` error code error.
+If ``request_fd`` is set to a not-yet-queued :ref:`request <media-request-api>`
+file descriptor and ``which`` is set to ``V4L2_CTRL_WHICH_REQUEST_VAL``,
+then the controls are not applied immediately when calling
+:ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, but instead are applied by
+the driver for the buffer associated with the same request.
+If the device does not support requests, then ``EACCES`` will be returned.
+If requests are supported but an invalid request file descriptor is given,
+then ``EINVAL`` will be returned.
+
+An attempt to call :ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` for a
+request that has already been queued will result in an ``EBUSY`` error.
+
+If ``request_fd`` is specified and ``which`` is set to
+``V4L2_CTRL_WHICH_REQUEST_VAL`` during a call to
+:ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, then it will return the
+values of the controls at the time of request completion.
+If the request is not yet completed, then this will result in an
+``EACCES`` error.
+
The driver will only set/get these controls if all control values are
correct. This prevents the situation where only some of the controls
were set/get. Only low-level errors (e. g. a failed i2c command) can
@@ -209,13 +228,17 @@ still cause this situation.
- ``which``
- Which value of the control to get/set/try.
``V4L2_CTRL_WHICH_CUR_VAL`` will return the current value of the
- control and ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
- value of the control.
+ control, ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
+ value of the control and ``V4L2_CTRL_WHICH_REQUEST_VAL`` indicates that
+ these controls have to be retrieved from a request or tried/set for
+ a request. In the latter case the ``request_fd`` field contains the
+ file descriptor of the request that should be used. If the device
+ does not support requests, then ``EACCES`` will be returned.
.. note::
- You can only get the default value of the control,
- you cannot set or try it.
+ When using ``V4L2_CTRL_WHICH_DEF_VAL`` be aware that you can only
+ get the default value of the control, you cannot set or try it.
For backwards compatibility you can also use a control class here
(see :ref:`ctrl-class`). In that case all controls have to
@@ -272,8 +295,15 @@ still cause this situation.
then you can call :ref:`VIDIOC_TRY_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` to try to discover the
actual control that failed the validation step. Unfortunately,
there is no ``TRY`` equivalent for :ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`.
+ * - __s32
+ - ``request_fd``
+ - File descriptor of the request to be used by this operation. Only
+ valid if ``which`` is set to ``V4L2_CTRL_WHICH_REQUEST_VAL``.
+ If the device does not support requests, then ``EACCES`` will be returned.
+ If requests are supported but an invalid request file descriptor is
+ given, then ``EINVAL`` will be returned.
* - __u32
- - ``reserved``\ [2]
+ - ``reserved``\ [1]
- Reserved for future extensions.
Drivers and applications must set the array to zero.
@@ -347,11 +377,14 @@ appropriately. The generic error codes are described at the
EINVAL
The struct :c:type:`v4l2_ext_control` ``id`` is
- invalid, the struct :c:type:`v4l2_ext_controls`
+ invalid, or the struct :c:type:`v4l2_ext_controls`
``which`` is invalid, or the struct
:c:type:`v4l2_ext_control` ``value`` was
inappropriate (e.g. the given menu index is not supported by the
- driver). This error code is also returned by the
+ driver), or the ``which`` field was set to ``V4L2_CTRL_WHICH_REQUEST_VAL``
+ but the given ``request_fd`` was invalid or ``V4L2_CTRL_WHICH_REQUEST_VAL``
+ is not supported by the kernel.
+ This error code is also returned by the
:ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` and :ref:`VIDIOC_TRY_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` ioctls if two or
more control values are in conflict.
@@ -362,7 +395,9 @@ ERANGE
EBUSY
The control is temporarily not changeable, possibly because another
applications took over control of the device function this control
- belongs to.
+ belongs to, or (if the ``which`` field was set to
+ ``V4L2_CTRL_WHICH_REQUEST_VAL``) the request was queued but not yet
+ completed.
ENOSPC
The space reserved for the control's payload is insufficient. The
@@ -370,5 +405,9 @@ ENOSPC
and this error code is returned.
EACCES
- Attempt to try or set a read-only control or to get a write-only
- control.
+ Attempt to try or set a read-only control, or to get a write-only
+ control, or to get a control from a request that has not yet been
+ completed.
+
+ Or the ``which`` field was set to ``V4L2_CTRL_WHICH_REQUEST_VAL`` but the
+ device does not support requests.
diff --git a/Documentation/media/uapi/v4l/vidioc-qbuf.rst b/Documentation/media/uapi/v4l/vidioc-qbuf.rst
index 9e448a4aa3aa..753b3b5946b1 100644
--- a/Documentation/media/uapi/v4l/vidioc-qbuf.rst
+++ b/Documentation/media/uapi/v4l/vidioc-qbuf.rst
@@ -65,7 +65,7 @@ To enqueue a :ref:`memory mapped <mmap>` buffer applications set the
with a pointer to this structure the driver sets the
``V4L2_BUF_FLAG_MAPPED`` and ``V4L2_BUF_FLAG_QUEUED`` flags and clears
the ``V4L2_BUF_FLAG_DONE`` flag in the ``flags`` field, or it returns an
-EINVAL error code.
+``EINVAL`` error code.
To enqueue a :ref:`user pointer <userp>` buffer applications set the
``memory`` field to ``V4L2_MEMORY_USERPTR``, the ``m.userptr`` field to
@@ -98,6 +98,28 @@ dequeued, until the :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` or
:ref:`VIDIOC_REQBUFS` ioctl is called, or until the
device is closed.
+The ``request_fd`` field can be used with the ``VIDIOC_QBUF`` ioctl to specify
+the file descriptor of a :ref:`request <media-request-api>`, if requests are
+in use. Setting it means that the buffer will not be passed to the driver
+until the request itself is queued. Also, the driver will apply any
+settings associated with the request for this buffer. This field will
+be ignored unless the ``V4L2_BUF_FLAG_REQUEST_FD`` flag is set.
+If the device does not support requests, then ``EACCES`` will be returned.
+If requests are supported but an invalid request file descriptor is given,
+then ``EINVAL`` will be returned.
+
+.. caution::
+ It is not allowed to mix queuing requests with queuing buffers directly.
+ ``EBUSY`` will be returned if the first buffer was queued directly and
+ then the application tries to queue a request, or vice versa. After
+ closing the file descriptor, calling
+ :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` or calling :ref:`VIDIOC_REQBUFS`
+ the check for this will be reset.
+
+ For :ref:`memory-to-memory devices <codec>` you can specify the
+ ``request_fd`` only for output buffers, not for capture buffers. Attempting
+ to specify this for a capture buffer will result in an ``EACCES`` error.
+
Applications call the ``VIDIOC_DQBUF`` ioctl to dequeue a filled
(capturing) or displayed (output) buffer from the driver's outgoing
queue. They just set the ``type``, ``memory`` and ``reserved`` fields of
@@ -133,7 +155,9 @@ EAGAIN
EINVAL
The buffer ``type`` is not supported, or the ``index`` is out of
bounds, or no buffers have been allocated yet, or the ``userptr`` or
- ``length`` are invalid.
+ ``length`` are invalid, or the ``V4L2_BUF_FLAG_REQUEST_FD`` flag was
+ set but the the given ``request_fd`` was invalid, or ``m.fd`` was
+ an invalid DMABUF file descriptor.
EIO
``VIDIOC_DQBUF`` failed due to an internal error. Can also indicate
@@ -153,3 +177,12 @@ EPIPE
``VIDIOC_DQBUF`` returns this on an empty capture queue for mem2mem
codecs if a buffer with the ``V4L2_BUF_FLAG_LAST`` was already
dequeued and no new buffers are expected to become available.
+
+EACCES
+ The ``V4L2_BUF_FLAG_REQUEST_FD`` flag was set but the device does not
+ support requests for the given buffer type.
+
+EBUSY
+ The first buffer was queued via a request, but the application now tries
+ to queue it directly, or vice versa (it is not permitted to mix the two
+ APIs).
diff --git a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
index 5bd26e8c9a1a..258f5813f281 100644
--- a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
+++ b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
@@ -424,8 +424,18 @@ See also the examples in :ref:`control`.
- any
- An unsigned 32-bit valued control ranging from minimum to maximum
inclusive. The step value indicates the increment between values.
-
-
+ * - ``V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS``
+ - n/a
+ - n/a
+ - n/a
+ - A struct :c:type:`v4l2_ctrl_mpeg2_slice_params`, containing MPEG-2
+ slice parameters for stateless video decoders.
+ * - ``V4L2_CTRL_TYPE_MPEG2_QUANTIZATION``
+ - n/a
+ - n/a
+ - n/a
+ - A struct :c:type:`v4l2_ctrl_mpeg2_quantization`, containing MPEG-2
+ quantization matrices for stateless video decoders.
.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
index 316f52c8a310..d4bbbb0c60e8 100644
--- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
@@ -88,10 +88,50 @@ any DMA in progress, an implicit
``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See
:c:type:`v4l2_memory`.
* - __u32
- - ``reserved``\ [2]
+ - ``capabilities``
+ - Set by the driver. If 0, then the driver doesn't support
+ capabilities. In that case all you know is that the driver is
+ guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support
+ other :c:type:`v4l2_memory` types. It will not support any others
+ capabilities.
+
+ If you want to query the capabilities with a minimum of side-effects,
+ then this can be called with ``count`` set to 0, ``memory`` set to
+ ``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
+ free any previously allocated buffers, so this is typically something
+ that will be done at the start of the application.
+ * - __u32
+ - ``reserved``\ [1]
- A place holder for future extensions. Drivers and applications
must set the array to zero.
+.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
+
+.. _v4l2-buf-capabilities:
+.. _V4L2-BUF-CAP-SUPPORTS-MMAP:
+.. _V4L2-BUF-CAP-SUPPORTS-USERPTR:
+.. _V4L2-BUF-CAP-SUPPORTS-DMABUF:
+.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS:
+
+.. cssclass:: longtable
+
+.. flat-table:: V4L2 Buffer Capabilities Flags
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 3 1 4
+
+ * - ``V4L2_BUF_CAP_SUPPORTS_MMAP``
+ - 0x00000001
+ - This buffer type supports the ``V4L2_MEMORY_MMAP`` streaming mode.
+ * - ``V4L2_BUF_CAP_SUPPORTS_USERPTR``
+ - 0x00000002
+ - This buffer type supports the ``V4L2_MEMORY_USERPTR`` streaming mode.
+ * - ``V4L2_BUF_CAP_SUPPORTS_DMABUF``
+ - 0x00000004
+ - This buffer type supports the ``V4L2_MEMORY_DMABUF`` streaming mode.
+ * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS``
+ - 0x00000008
+ - This buffer type supports :ref:`requests <media-request-api>`.
Return Value
============