diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-audioout.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-audioout.rst | 86 |
1 files changed, 32 insertions, 54 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-audioout.rst b/Documentation/media/uapi/v4l/vidioc-g-audioout.rst index b1c1bfeb251e..d16ecbaddc59 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-audioout.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-audioout.rst @@ -15,9 +15,11 @@ VIDIOC_G_AUDOUT - VIDIOC_S_AUDOUT - Query or select the current audio output Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_audioout *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_G_AUDOUT, struct v4l2_audioout *argp ) + :name: VIDIOC_G_AUDOUT -.. cpp:function:: int ioctl( int fd, int request, const struct v4l2_audioout *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_S_AUDOUT, const struct v4l2_audioout *argp ) + :name: VIDIOC_S_AUDOUT Arguments @@ -26,9 +28,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_G_AUDOUT, VIDIOC_S_AUDOUT - ``argp`` @@ -36,7 +35,7 @@ Description =========== To query the current audio output applications zero out the ``reserved`` -array of a struct :ref:`v4l2_audioout <v4l2-audioout>` and call the +array of a struct :c:type:`v4l2_audioout` and call the ``VIDIOC_G_AUDOUT`` ioctl with a pointer to this structure. Drivers fill the rest of the structure or return an ``EINVAL`` error code when the device has no audio inputs, or none which combine with the current video @@ -45,68 +44,47 @@ output. Audio outputs have no writable properties. Nevertheless, to select the current audio output applications can initialize the ``index`` field and ``reserved`` array (which in the future may contain writable properties) -of a :ref:`struct v4l2_audioout <v4l2-audioout>` structure and call the +of a struct :c:type:`v4l2_audioout` structure and call the ``VIDIOC_S_AUDOUT`` ioctl. Drivers switch to the requested output or 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 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. -.. _v4l2-audioout: +.. c:type:: v4l2_audioout + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| .. flat-table:: struct v4l2_audioout :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __u32 - - - ``index`` - - - Identifies the audio output, set by the driver or application. - - - .. row 2 - - - __u8 - - - ``name``\ [32] - - - Name of the audio output, a NUL-terminated ASCII string, for - example: "Line Out". This information is intended for the user, - preferably the connector label on the device itself. - - - .. row 3 - - - __u32 - - - ``capability`` - - - Audio capability flags, none defined yet. Drivers must set this - field to zero. - - - .. row 4 - - - __u32 - - - ``mode`` - - - Audio mode, none defined yet. Drivers and applications (on - ``VIDIOC_S_AUDOUT``) must set this field to zero. - - - .. row 5 - - - __u32 - - - ``reserved``\ [2] - - - Reserved for future extensions. Drivers and applications must set - the array to zero. + * - __u32 + - ``index`` + - Identifies the audio output, set by the driver or application. + * - __u8 + - ``name``\ [32] + - Name of the audio output, a NUL-terminated ASCII string, for + example: "Line Out". This information is intended for the user, + preferably the connector label on the device itself. + * - __u32 + - ``capability`` + - Audio capability flags, none defined yet. Drivers must set this + field to zero. + * - __u32 + - ``mode`` + - Audio mode, none defined yet. Drivers and applications (on + ``VIDIOC_S_AUDOUT``) must set this field to zero. + * - __u32 + - ``reserved``\ [2] + - Reserved for future extensions. Drivers and applications must set + the array to zero. Return Value |