Markus Heiser | 5377d91 | 2016-06-30 15:18:56 +0200 | [diff] [blame^] | 1 | .. -*- coding: utf-8; mode: rst -*- |
| 2 | |
| 3 | .. _vidioc-enumoutput: |
| 4 | |
| 5 | *********************** |
| 6 | ioctl VIDIOC_ENUMOUTPUT |
| 7 | *********************** |
| 8 | |
| 9 | *man VIDIOC_ENUMOUTPUT(2)* |
| 10 | |
| 11 | Enumerate video outputs |
| 12 | |
| 13 | |
| 14 | Synopsis |
| 15 | ======== |
| 16 | |
| 17 | .. c:function:: int ioctl( int fd, int request, struct v4l2_output *argp ) |
| 18 | |
| 19 | Arguments |
| 20 | ========= |
| 21 | |
| 22 | ``fd`` |
| 23 | File descriptor returned by :ref:`open() <func-open>`. |
| 24 | |
| 25 | ``request`` |
| 26 | VIDIOC_ENUMOUTPUT |
| 27 | |
| 28 | ``argp`` |
| 29 | |
| 30 | |
| 31 | Description |
| 32 | =========== |
| 33 | |
| 34 | To query the attributes of a video outputs applications initialize the |
| 35 | ``index`` field of struct :ref:`v4l2_output <v4l2-output>` and call |
| 36 | the ``VIDIOC_ENUMOUTPUT`` ioctl with a pointer to this structure. |
| 37 | Drivers fill the rest of the structure or return an EINVAL error code |
| 38 | when the index is out of bounds. To enumerate all outputs applications |
| 39 | shall begin at index zero, incrementing by one until the driver returns |
| 40 | EINVAL. |
| 41 | |
| 42 | |
| 43 | .. _v4l2-output: |
| 44 | |
| 45 | .. flat-table:: struct v4l2_output |
| 46 | :header-rows: 0 |
| 47 | :stub-columns: 0 |
| 48 | :widths: 1 1 2 |
| 49 | |
| 50 | |
| 51 | - .. row 1 |
| 52 | |
| 53 | - __u32 |
| 54 | |
| 55 | - ``index`` |
| 56 | |
| 57 | - Identifies the output, set by the application. |
| 58 | |
| 59 | - .. row 2 |
| 60 | |
| 61 | - __u8 |
| 62 | |
| 63 | - ``name``\ [32] |
| 64 | |
| 65 | - Name of the video output, a NUL-terminated ASCII string, for |
| 66 | example: "Vout". This information is intended for the user, |
| 67 | preferably the connector label on the device itself. |
| 68 | |
| 69 | - .. row 3 |
| 70 | |
| 71 | - __u32 |
| 72 | |
| 73 | - ``type`` |
| 74 | |
| 75 | - Type of the output, see :ref:`output-type`. |
| 76 | |
| 77 | - .. row 4 |
| 78 | |
| 79 | - __u32 |
| 80 | |
| 81 | - ``audioset`` |
| 82 | |
| 83 | - Drivers can enumerate up to 32 video and audio outputs. This field |
| 84 | shows which audio outputs were selectable as the current output if |
| 85 | this was the currently selected video output. It is a bit mask. |
| 86 | The LSB corresponds to audio output 0, the MSB to output 31. Any |
| 87 | number of bits can be set, or none. |
| 88 | |
| 89 | When the driver does not enumerate audio outputs no bits must be |
| 90 | set. Applications shall not interpret this as lack of audio |
| 91 | support. Drivers may automatically select audio outputs without |
| 92 | enumerating them. |
| 93 | |
| 94 | For details on audio outputs and how to select the current output |
| 95 | see :ref:`audio`. |
| 96 | |
| 97 | - .. row 5 |
| 98 | |
| 99 | - __u32 |
| 100 | |
| 101 | - ``modulator`` |
| 102 | |
| 103 | - Output devices can have zero or more RF modulators. When the |
| 104 | ``type`` is ``V4L2_OUTPUT_TYPE_MODULATOR`` this is an RF connector |
| 105 | and this field identifies the modulator. It corresponds to struct |
| 106 | :ref:`v4l2_modulator <v4l2-modulator>` field ``index``. For |
| 107 | details on modulators see :ref:`tuner`. |
| 108 | |
| 109 | - .. row 6 |
| 110 | |
| 111 | - :ref:`v4l2_std_id <v4l2-std-id>` |
| 112 | |
| 113 | - ``std`` |
| 114 | |
| 115 | - Every video output supports one or more different video standards. |
| 116 | This field is a set of all supported standards. For details on |
| 117 | video standards and how to switch see :ref:`standard`. |
| 118 | |
| 119 | - .. row 7 |
| 120 | |
| 121 | - __u32 |
| 122 | |
| 123 | - ``capabilities`` |
| 124 | |
| 125 | - This field provides capabilities for the output. See |
| 126 | :ref:`output-capabilities` for flags. |
| 127 | |
| 128 | - .. row 8 |
| 129 | |
| 130 | - __u32 |
| 131 | |
| 132 | - ``reserved``\ [3] |
| 133 | |
| 134 | - Reserved for future extensions. Drivers must set the array to |
| 135 | zero. |
| 136 | |
| 137 | |
| 138 | |
| 139 | .. _output-type: |
| 140 | |
| 141 | .. flat-table:: Output Type |
| 142 | :header-rows: 0 |
| 143 | :stub-columns: 0 |
| 144 | :widths: 3 1 4 |
| 145 | |
| 146 | |
| 147 | - .. row 1 |
| 148 | |
| 149 | - ``V4L2_OUTPUT_TYPE_MODULATOR`` |
| 150 | |
| 151 | - 1 |
| 152 | |
| 153 | - This output is an analog TV modulator. |
| 154 | |
| 155 | - .. row 2 |
| 156 | |
| 157 | - ``V4L2_OUTPUT_TYPE_ANALOG`` |
| 158 | |
| 159 | - 2 |
| 160 | |
| 161 | - Analog baseband output, for example Composite / CVBS, S-Video, |
| 162 | RGB. |
| 163 | |
| 164 | - .. row 3 |
| 165 | |
| 166 | - ``V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY`` |
| 167 | |
| 168 | - 3 |
| 169 | |
| 170 | - [?] |
| 171 | |
| 172 | |
| 173 | |
| 174 | .. _output-capabilities: |
| 175 | |
| 176 | .. flat-table:: Output capabilities |
| 177 | :header-rows: 0 |
| 178 | :stub-columns: 0 |
| 179 | :widths: 3 1 4 |
| 180 | |
| 181 | |
| 182 | - .. row 1 |
| 183 | |
| 184 | - ``V4L2_OUT_CAP_DV_TIMINGS`` |
| 185 | |
| 186 | - 0x00000002 |
| 187 | |
| 188 | - This output supports setting video timings by using |
| 189 | VIDIOC_S_DV_TIMINGS. |
| 190 | |
| 191 | - .. row 2 |
| 192 | |
| 193 | - ``V4L2_OUT_CAP_STD`` |
| 194 | |
| 195 | - 0x00000004 |
| 196 | |
| 197 | - This output supports setting the TV standard by using |
| 198 | VIDIOC_S_STD. |
| 199 | |
| 200 | - .. row 3 |
| 201 | |
| 202 | - ``V4L2_OUT_CAP_NATIVE_SIZE`` |
| 203 | |
| 204 | - 0x00000008 |
| 205 | |
| 206 | - This output supports setting the native size using the |
| 207 | ``V4L2_SEL_TGT_NATIVE_SIZE`` selection target, see |
| 208 | :ref:`v4l2-selections-common`. |
| 209 | |
| 210 | |
| 211 | |
| 212 | Return Value |
| 213 | ============ |
| 214 | |
| 215 | On success 0 is returned, on error -1 and the ``errno`` variable is set |
| 216 | appropriately. The generic error codes are described at the |
| 217 | :ref:`Generic Error Codes <gen-errors>` chapter. |
| 218 | |
| 219 | EINVAL |
| 220 | The struct :ref:`v4l2_output <v4l2-output>` ``index`` is out of |
| 221 | bounds. |
| 222 | |
| 223 | |
| 224 | .. ------------------------------------------------------------------------------ |
| 225 | .. This file was automatically converted from DocBook-XML with the dbxml |
| 226 | .. library (https://github.com/return42/sphkerneldoc). The origin XML comes |
| 227 | .. from the linux kernel, refer to: |
| 228 | .. |
| 229 | .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook |
| 230 | .. ------------------------------------------------------------------------------ |