diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/tuner.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/tuner.rst | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/Documentation/media/uapi/v4l/tuner.rst b/Documentation/media/uapi/v4l/tuner.rst index 37eb4b9..ad117b0 100644 --- a/Documentation/media/uapi/v4l/tuner.rst +++ b/Documentation/media/uapi/v4l/tuner.rst @@ -13,7 +13,7 @@ Tuners Video input devices can have one or more tuners demodulating a RF signal. Each tuner is associated with one or more video inputs, depending on the number of RF connectors on the tuner. The ``type`` -field of the respective struct :ref:`v4l2_input <v4l2-input>` +field of the respective struct :c:type:`v4l2_input` returned by the :ref:`VIDIOC_ENUMINPUT` ioctl is set to ``V4L2_INPUT_TYPE_TUNER`` and its ``tuner`` field contains the index number of the tuner. @@ -24,15 +24,17 @@ inputs. To query and change tuner properties applications use the :ref:`VIDIOC_G_TUNER <VIDIOC_G_TUNER>` and :ref:`VIDIOC_S_TUNER <VIDIOC_G_TUNER>` ioctls, respectively. The -struct :ref:`v4l2_tuner <v4l2-tuner>` returned by :ref:`VIDIOC_G_TUNER <VIDIOC_G_TUNER>` +struct :c:type:`v4l2_tuner` returned by :ref:`VIDIOC_G_TUNER <VIDIOC_G_TUNER>` also contains signal status information applicable when the tuner of the 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 determined by the current video input. Drivers must support both ioctls - and set the ``V4L2_CAP_TUNER`` flag in the struct :ref:`v4l2_capability - <v4l2-capability>` returned by the :ref:`VIDIOC_QUERYCAP` ioctl when the + and set the ``V4L2_CAP_TUNER`` flag in the struct :c:type:`v4l2_capability` + returned by the :ref:`VIDIOC_QUERYCAP` ioctl when the device has one or more tuners. @@ -44,7 +46,7 @@ video signal for radiation or connection to the antenna input of a TV set or video recorder. Each modulator is associated with one or more video outputs, depending on the number of RF connectors on the modulator. The ``type`` field of the respective struct -:ref:`v4l2_output <v4l2-output>` returned by the +:c:type:`v4l2_output` returned by the :ref:`VIDIOC_ENUMOUTPUT` ioctl is set to ``V4L2_OUTPUT_TYPE_MODULATOR`` and its ``modulator`` field contains the index number of the modulator. @@ -66,7 +68,7 @@ To query and change modulator properties applications use the is more than one at all. The modulator is solely determined by the current video output. Drivers must support both ioctls and set the ``V4L2_CAP_MODULATOR`` flag in the struct -:ref:`v4l2_capability <v4l2-capability>` returned by the +:c:type:`v4l2_capability` returned by the :ref:`VIDIOC_QUERYCAP` ioctl when the device has one or more modulators. @@ -77,7 +79,7 @@ Radio Frequency To get and set the tuner or modulator radio frequency applications use the :ref:`VIDIOC_G_FREQUENCY <VIDIOC_G_FREQUENCY>` and :ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl which both take -a pointer to a struct :ref:`v4l2_frequency <v4l2-frequency>`. These +a pointer to a struct :c:type:`v4l2_frequency`. These ioctls are used for TV and radio devices alike. Drivers must support both ioctls when the tuner or modulator ioctls are supported, or when the device is a radio device. |