From 0e36d26dad1143877d2cccb588e630271b3bc9b4 Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Wed, 22 Apr 2020 09:46:05 +0200 Subject: libcamera: v4l2_subdevice: Implement getSelection() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement V4L2Subdevice::getSelection() to support retrieving selection rectangles from the V4L2 subdevice. Reviewed-by: Niklas Söderlund Reviewed-by: Laurent Pinchart Signed-off-by: Jacopo Mondi --- src/libcamera/include/v4l2_subdevice.h | 2 ++ src/libcamera/v4l2_subdevice.cpp | 36 ++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h index 9a5c812d..27ba5b17 100644 --- a/src/libcamera/include/v4l2_subdevice.h +++ b/src/libcamera/include/v4l2_subdevice.h @@ -46,6 +46,8 @@ public: const MediaEntity *entity() const { return entity_; } + int getSelection(unsigned int pad, unsigned int target, + Rectangle *rect); int setSelection(unsigned int pad, unsigned int target, Rectangle *rect); diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp index e8623d58..06bc430f 100644 --- a/src/libcamera/v4l2_subdevice.cpp +++ b/src/libcamera/v4l2_subdevice.cpp @@ -133,6 +133,42 @@ int V4L2Subdevice::open() * \return The subdevice's associated media entity. */ +/** + * \brief Get selection rectangle \a rect for \a target + * \param[in] pad The 0-indexed pad number the rectangle is retrieved from + * \param[in] target The selection target defined by the V4L2_SEL_TGT_* flags + * \param[out] rect The retrieved selection rectangle + * + * \todo Define a V4L2SelectionTarget enum for the selection target + * + * \return 0 on success or a negative error code otherwise + */ +int V4L2Subdevice::getSelection(unsigned int pad, unsigned int target, + Rectangle *rect) +{ + struct v4l2_subdev_selection sel = {}; + + sel.which = V4L2_SUBDEV_FORMAT_ACTIVE; + sel.pad = pad; + sel.target = target; + sel.flags = 0; + + int ret = ioctl(VIDIOC_SUBDEV_G_SELECTION, &sel); + if (ret < 0) { + LOG(V4L2, Error) + << "Unable to get rectangle " << target << " on pad " + << pad << ": " << strerror(-ret); + return ret; + } + + rect->x = sel.r.left; + rect->y = sel.r.top; + rect->width = sel.r.width; + rect->height = sel.r.height; + + return 0; +} + /** * \brief Set selection rectangle \a rect for \a target * \param[in] pad The 0-indexed pad number the rectangle is to be applied to -- cgit v1.2.1