[libcamera-devel] [PATCH] libcamera: v4l2_videodevice: Add crop/selection control.
Naushir Patuck
naush at raspberrypi.com
Mon Feb 3 12:42:54 CET 2020
Add control for cropping/selection on a V4L2 video device through
the VIDIOC_S_SELECTION ioctl. This is similar to the exising cropping
control available on V4L2 sub-devices.
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
src/libcamera/include/v4l2_videodevice.h | 5 +++
src/libcamera/v4l2_videodevice.cpp | 50 ++++++++++++++++++++++++
2 files changed, 55 insertions(+)
diff --git a/src/libcamera/include/v4l2_videodevice.h b/src/libcamera/include/v4l2_videodevice.h
index e4d35ab..5de4c65 100644
--- a/src/libcamera/include/v4l2_videodevice.h
+++ b/src/libcamera/include/v4l2_videodevice.h
@@ -200,6 +200,9 @@ public:
uint32_t toV4L2Fourcc(PixelFormat pixelFormat);
static uint32_t toV4L2Fourcc(PixelFormat pixelFormat, bool multiplanar);
+ int setCrop(Rectangle *rect);
+ int setCompose(Rectangle *rect);
+
protected:
std::string logPrefix() const;
@@ -213,6 +216,8 @@ private:
int getFormatSingleplane(V4L2DeviceFormat *format);
int setFormatSingleplane(V4L2DeviceFormat *format);
+ int setSelection(unsigned int target, Rectangle *rect);
+
std::vector<unsigned int> enumPixelformats();
std::vector<SizeRange> enumSizes(unsigned int pixelFormat);
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index 8226773..7914434 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -1499,6 +1499,56 @@ uint32_t V4L2VideoDevice::toV4L2Fourcc(PixelFormat pixelFormat, bool multiplanar
return 0;
}
+/**
+ * \brief Set a crop rectangle on the V4L2 video device node
+ * \param[inout] rect The rectangle describing the compose target area
+ * \return 0 on success or a negative error code otherwise
+ */
+int V4L2VideoDevice::setCrop( Rectangle *rect)
+{
+ return setSelection(V4L2_SEL_TGT_CROP, rect);
+}
+
+/**
+ * \brief Set a compose rectangle on the V4L2 video device node
+ * \param[inout] rect The rectangle describing the compose target area
+ * \return 0 on success or a negative error code otherwise
+ */
+int V4L2VideoDevice::setCompose(Rectangle *rect)
+{
+ return setSelection(V4L2_SEL_TGT_COMPOSE, rect);
+}
+
+int V4L2VideoDevice::setSelection(unsigned int target,
+ Rectangle *rect)
+{
+ struct v4l2_selection sel = {};
+
+ sel.type = bufferType_;
+ sel.target = target;
+ sel.flags = 0;
+
+ sel.r.left = rect->x;
+ sel.r.top = rect->y;
+ sel.r.width = rect->w;
+ sel.r.height = rect->h;
+
+ int ret = ioctl(VIDIOC_S_SELECTION, &sel);
+ if (ret < 0) {
+ LOG(V4L2, Error)
+ << "Unable to set rectangle " << target
+ << ": " << strerror(-ret);
+ return ret;
+ }
+
+ rect->x = sel.r.left;
+ rect->y = sel.r.top;
+ rect->w = sel.r.width;
+ rect->h = sel.r.height;
+
+ return 0;
+}
+
/**
* \class V4L2M2MDevice
* \brief Memory-to-Memory video device
--
2.17.1
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