Synopsis
========
-.. cpp:function:: int ioctl( int fd, int request, struct v4l2_encoder_cmd *argp )
+.. c:function:: int ioctl( int fd, VIDIOC_ENCODER_CMD, struct v4l2_encoder_cmd *argp )
+ :name: VIDIOC_ENCODER_CMD
+
+.. c:function:: int ioctl( int fd, VIDIOC_TRY_ENCODER_CMD, struct v4l2_encoder_cmd *argp )
+ :name: VIDIOC_TRY_ENCODER_CMD
Arguments
``fd``
File descriptor returned by :ref:`open() <func-open>`.
-``request``
- VIDIOC_ENCODER_CMD, VIDIOC_TRY_ENCODER_CMD
-
``argp``
executing it.
To send a command applications must initialize all fields of a struct
-:ref:`v4l2_encoder_cmd <v4l2-encoder-cmd>` and call
+:c:type:`v4l2_encoder_cmd` and call
``VIDIOC_ENCODER_CMD`` or ``VIDIOC_TRY_ENCODER_CMD`` with a pointer to
this structure.
introduced in Linux 2.6.21.
-.. _v4l2-encoder-cmd:
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. c:type:: v4l2_encoder_cmd
.. flat-table:: struct v4l2_encoder_cmd
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
+ * - __u32
+ - ``cmd``
+ - The encoder command, see :ref:`encoder-cmds`.
+ * - __u32
+ - ``flags``
+ - Flags to go with the command, see :ref:`encoder-flags`. If no
+ flags are defined for this command, drivers and applications must
+ set this field to zero.
+ * - __u32
+ - ``data``\ [8]
+ - Reserved for future extensions. Drivers and applications must set
+ the array to zero.
- - .. row 1
-
- - __u32
-
- - ``cmd``
-
- - The encoder command, see :ref:`encoder-cmds`.
-
- - .. row 2
-
- - __u32
-
- - ``flags``
-
- - Flags to go with the command, see :ref:`encoder-flags`. If no
- flags are defined for this command, drivers and applications must
- set this field to zero.
-
- - .. row 3
-
- - __u32
-
- - ``data``\ [8]
-
- - Reserved for future extensions. Drivers and applications must set
- the array to zero.
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
.. _encoder-cmds:
:stub-columns: 0
:widths: 3 1 4
-
- - .. row 1
-
- - ``V4L2_ENC_CMD_START``
-
- - 0
-
- - Start the encoder. When the encoder is already running or paused,
- this command does nothing. No flags are defined for this command.
-
- - .. row 2
-
- - ``V4L2_ENC_CMD_STOP``
-
- - 1
-
- - Stop the encoder. When the ``V4L2_ENC_CMD_STOP_AT_GOP_END`` flag
- is set, encoding will continue until the end of the current *Group
- Of Pictures*, otherwise encoding will stop immediately. When the
- encoder is already stopped, this command does nothing. mem2mem
- encoders will send a ``V4L2_EVENT_EOS`` event when the last frame
- has been encoded and all frames are ready to be dequeued and will
- set the ``V4L2_BUF_FLAG_LAST`` buffer flag on the last buffer of
- the capture queue to indicate there will be no new buffers
- produced to dequeue. This buffer may be empty, indicated by the
- driver setting the ``bytesused`` field to 0. Once the
- ``V4L2_BUF_FLAG_LAST`` flag was set, the
- :ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl will not block anymore,
- but return an ``EPIPE`` error code.
-
- - .. row 3
-
- - ``V4L2_ENC_CMD_PAUSE``
-
- - 2
-
- - Pause the encoder. When the encoder has not been started yet, the
- driver will return an ``EPERM`` error code. When the encoder is
- already paused, this command does nothing. No flags are defined
- for this command.
-
- - .. row 4
-
- - ``V4L2_ENC_CMD_RESUME``
-
- - 3
-
- - Resume encoding after a PAUSE command. When the encoder has not
- been started yet, the driver will return an ``EPERM`` error code. When
- the encoder is already running, this command does nothing. No
- flags are defined for this command.
-
-
+ * - ``V4L2_ENC_CMD_START``
+ - 0
+ - Start the encoder. When the encoder is already running or paused,
+ this command does nothing. No flags are defined for this command.
+ * - ``V4L2_ENC_CMD_STOP``
+ - 1
+ - Stop the encoder. When the ``V4L2_ENC_CMD_STOP_AT_GOP_END`` flag
+ is set, encoding will continue until the end of the current *Group
+ Of Pictures*, otherwise encoding will stop immediately. When the
+ encoder is already stopped, this command does nothing. mem2mem
+ encoders will send a ``V4L2_EVENT_EOS`` event when the last frame
+ has been encoded and all frames are ready to be dequeued and will
+ set the ``V4L2_BUF_FLAG_LAST`` buffer flag on the last buffer of
+ the capture queue to indicate there will be no new buffers
+ produced to dequeue. This buffer may be empty, indicated by the
+ driver setting the ``bytesused`` field to 0. Once the
+ ``V4L2_BUF_FLAG_LAST`` flag was set, the
+ :ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl will not block anymore,
+ but return an ``EPIPE`` error code.
+ * - ``V4L2_ENC_CMD_PAUSE``
+ - 2
+ - Pause the encoder. When the encoder has not been started yet, the
+ driver will return an ``EPERM`` error code. When the encoder is
+ already paused, this command does nothing. No flags are defined
+ for this command.
+ * - ``V4L2_ENC_CMD_RESUME``
+ - 3
+ - Resume encoding after a PAUSE command. When the encoder has not
+ been started yet, the driver will return an ``EPERM`` error code. When
+ the encoder is already running, this command does nothing. No
+ flags are defined for this command.
+
+
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
.. _encoder-flags:
:stub-columns: 0
:widths: 3 1 4
-
- - .. row 1
-
- - ``V4L2_ENC_CMD_STOP_AT_GOP_END``
-
- - 0x0001
-
- - Stop encoding at the end of the current *Group Of Pictures*,
- rather than immediately.
+ * - ``V4L2_ENC_CMD_STOP_AT_GOP_END``
+ - 0x0001
+ - Stop encoding at the end of the current *Group Of Pictures*,
+ rather than immediately.
Return Value
projects / cascardo / linux.git / blobdiff