From 4cb3380f4d5615f041ed5698eb1fd12b2e46a720 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Wed, 25 Sep 2024 20:56:52 +0300 Subject: libcamera: v4l2_videodevice: Add getSelection() function The V4L2VideoDevice class implements setSelection() but not getSelection(). The latter is useful for instance to query crop bounds. Implement the function. Signed-off-by: Laurent Pinchart Reviewed-by: Umang Jain Reviewed-by: Jacopo Mondi --- include/libcamera/internal/v4l2_videodevice.h | 1 + src/libcamera/v4l2_videodevice.cpp | 32 +++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h index 9057be08..f021c2a0 100644 --- a/include/libcamera/internal/v4l2_videodevice.h +++ b/include/libcamera/internal/v4l2_videodevice.h @@ -208,6 +208,7 @@ public: int setFormat(V4L2DeviceFormat *format); Formats formats(uint32_t code = 0); + int getSelection(unsigned int target, Rectangle *rect); int setSelection(unsigned int target, Rectangle *rect); int allocateBuffers(unsigned int count, diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 93cb1697..14eba056 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -1214,6 +1214,38 @@ std::vector V4L2VideoDevice::enumSizes(V4L2PixelFormat pixelFormat) return sizes; } +/** + * \brief Get the selection rectangle for \a target + * \param[in] target The selection target defined by the V4L2_SEL_TGT_* flags + * \param[out] rect The selection rectangle to retrieve + * + * \todo Define a V4L2SelectionTarget enum for the selection target + * + * \return 0 on success or a negative error code otherwise + */ +int V4L2VideoDevice::getSelection(unsigned int target, Rectangle *rect) +{ + struct v4l2_selection sel = {}; + + sel.type = bufferType_; + sel.target = target; + sel.flags = 0; + + int ret = ioctl(VIDIOC_G_SELECTION, &sel); + if (ret < 0) { + LOG(V4L2, Error) << "Unable to get rectangle " << target + << ": " << 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 a selection rectangle \a rect for \a target * \param[in] target The selection target defined by the V4L2_SEL_TGT_* flags -- cgit v1.2.1