diff options
Diffstat (limited to 'src/libcamera/v4l2_device.cpp')
| -rw-r--r-- | src/libcamera/v4l2_device.cpp | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp index 397029ac..515cbdfe 100644 --- a/src/libcamera/v4l2_device.cpp +++ b/src/libcamera/v4l2_device.cpp @@ -511,6 +511,43 @@ void V4L2Device::listControls() controls_ = std::move(ctrls); } +/** +* \brief Update the information for all device controls + * + * The V4L2Device class caches information about all controls supported by the + * device and exposes it through the controls() and controlInfo() functions. + * Control information may change at runtime, for instance when formats on a + * subdev are modified. When this occurs, this function can be used to refresh + * control information. The information is refreshed in-place, all pointers to + * v4l2_query_ext_ctrl instances previously returned by controlInfo() and + * iterators to the ControlInfoMap returned by controls() remain valid. + * + * Note that control information isn't refreshed automatically is it may be an + * expensive operation. The V4L2Device users are responsible for calling this + * function when required, based on their usage pattern of the class. + */ +void V4L2Device::updateControlInfo() +{ + for (auto &[controlId, info] : controls_) { + unsigned int id = controlId->id(); + + /* + * Assume controlInfo_ has a corresponding entry, as it has been + * generated by listControls(). + */ + struct v4l2_query_ext_ctrl &ctrl = controlInfo_[id]; + + if (ioctl(VIDIOC_QUERY_EXT_CTRL, &ctrl)) { + LOG(V4L2, Debug) + << "Could not refresh control " + << utils::hex(id); + continue; + } + + info = V4L2ControlInfo(ctrl); + } +} + /* * \brief Update the value of the first \a count V4L2 controls in \a ctrls using * values in \a v4l2Ctrls |