libcamera: controls: Reorder and update description of existing controls

Group AE, AWB, etc. controls together for accessibility.

Update descriptions for Contrast, Brightness, and Saturation controls.

Update the uvcvideo and vimc pipeline handlers to use the new
brightness, contrast and saturation units. UVC has no explicit units for
those controls, so map them with a best effort heuristic. For VIMC,
hardcode the control range based on knowledge of the driver
implementation for simplicity.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 23 insertions, 9 deletions

diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
index c5eea3a0..77de4c38 100644
--- a/src/libcamera/pipeline/vimc/vimc.cpp
+++ b/src/libcamera/pipeline/vimc/vimc.cpp
@@ -8,6 +8,7 @@
 #include <algorithm>
 #include <array>
 #include <iomanip>
+#include <math.h>
 #include <tuple>
 
 #include <linux/media-bus-format.h>
@@ -304,14 +305,24 @@ int PipelineHandlerVimc::processControls(VimcCameraData *data, Request *request)
 
 	for (auto it : request->controls()) {
 		unsigned int id = it.first;
-		ControlValue &value = it.second;
-
-		if (id == controls::Brightness)
-			controls.set(V4L2_CID_BRIGHTNESS, value);
-		else if (id == controls::Contrast)
-			controls.set(V4L2_CID_CONTRAST, value);
-		else if (id == controls::Saturation)
-			controls.set(V4L2_CID_SATURATION, value);
+		unsigned int offset;
+		uint32_t cid;
+
+		if (id == controls::Brightness) {
+			cid = V4L2_CID_BRIGHTNESS;
+			offset = 128;
+		} else if (id == controls::Contrast) {
+			cid = V4L2_CID_CONTRAST;
+			offset = 0;
+		} else if (id == controls::Saturation) {
+			cid = V4L2_CID_SATURATION;
+			offset = 0;
+		} else {
+			continue;
+		}
+
+		int32_t value = lroundf(it.second.get<float>() * 128 + offset);
+		controls.set(cid, utils::clamp(value, 0, 255));
 	}
 
 	for (const auto &ctrl : controls)
@@ -434,18 +445,21 @@ int VimcCameraData::init(MediaDevice *media)
 	ControlInfoMap::Map ctrls;
 
 	for (const auto &ctrl : controls) {
-		const ControlInfo &info = ctrl.second;
 		const ControlId *id;
+		ControlInfo info;
 
 		switch (ctrl.first->id()) {
 		case V4L2_CID_BRIGHTNESS:
 			id = &controls::Brightness;
+			info = ControlInfo{ { -1.0f }, { 1.0f }, { 0.0f } };
 			break;
 		case V4L2_CID_CONTRAST:
 			id = &controls::Contrast;
+			info = ControlInfo{ { 0.0f }, { 2.0f }, { 1.0f } };
 			break;
 		case V4L2_CID_SATURATION:
 			id = &controls::Saturation;
+			info = ControlInfo{ { 0.0f }, { 2.0f }, { 1.0f } };
 			break;
 		default:
 			continue;