ipa: raspberrypi: Limit the calculated vblank based on the sensor mode

The existing framerate/vblank calculations did not account for the
sensor mode limits. This commit extracts vblank limits from the sensor
v4l2 controls, and stores it in the camera modes structure.

Exposure and vblank value calculations now use values clamped to the
sensor mode limits. The libcamera::controls::FrameDurations metadata
return values now reflect the minimum and maximum after clamping.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 34 insertions, 16 deletions

diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index a1b9433b..85aee6f7 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -102,6 +102,7 @@ private:
 	void reportMetadata();
 	bool parseEmbeddedData(unsigned int bufferId, struct DeviceStatus &deviceStatus);
 	void processStats(unsigned int bufferId);
+	void applyFrameDurations(double minFrameDuration, double maxFrameDuration);
 	void applyAGC(const struct AgcStatus *agcStatus, ControlList &ctrls);
 	void applyAWB(const struct AwbStatus *awbStatus, ControlList &ctrls);
 	void applyDG(const struct AgcStatus *dgStatus, ControlList &ctrls);
@@ -279,6 +280,13 @@ void IPARPi::setMode(const CameraSensorInfo &sensorInfo)
 	 * the line length in pixels and the pixel rate.
 	 */
 	mode_.line_length = 1e9 * sensorInfo.lineLength / sensorInfo.pixelRate;
+
+	/*
+	 * Set the frame length limits for the mode to ensure exposure and
+	 * framerate calculations are clipped appropriately.
+	 */
+	mode_.min_frame_length = sensorInfo.minFrameLength;
+	mode_.max_frame_length = sensorInfo.maxFrameLength;
 }
 
 void IPARPi::configure(const CameraSensorInfo &sensorInfo,
@@ -384,8 +392,8 @@ void IPARPi::configure(const CameraSensorInfo &sensorInfo,
 		controller_.Initialise();
 		controllerInit_ = true;
 
-		minFrameDuration_ = defaultMinFrameDuration;
-		maxFrameDuration_ = defaultMaxFrameDuration;
+		/* Supply initial values for frame durations. */
+		applyFrameDurations(defaultMinFrameDuration, defaultMaxFrameDuration);
 
 		/* Supply initial values for gain and exposure. */
 		ControlList ctrls(sensorCtrls_);
@@ -877,20 +885,7 @@ void IPARPi::queueRequest(const ControlList &controls)
 
 		case controls::FRAME_DURATIONS: {
 			auto frameDurations = ctrl.second.get<Span<const int64_t>>();
-
-			/* This will be applied once AGC recalculations occur. */
-			minFrameDuration_ = frameDurations[0] ? frameDurations[0] : defaultMinFrameDuration;
-			maxFrameDuration_ = frameDurations[1] ? frameDurations[1] : defaultMaxFrameDuration;
-			maxFrameDuration_ = std::max(maxFrameDuration_, minFrameDuration_);
-
-			/*
-			 * \todo The values returned in the metadata below must be
-			 * correctly clipped by what the sensor mode supports and
-			 * what the AGC exposure mode or manual shutter speed limits
-			 */
-			libcameraMetadata_.set(controls::FrameDurations,
-					       { static_cast<int64_t>(minFrameDuration_),
-						 static_cast<int64_t>(maxFrameDuration_) });
+			applyFrameDurations(frameDurations[0], frameDurations[1]);
 			break;
 		}
 
@@ -1049,6 +1044,29 @@ void IPARPi::applyAWB(const struct AwbStatus *awbStatus, ControlList &ctrls)
 		  static_cast<int32_t>(awbStatus->gain_b * 1000));
 }
 
+void IPARPi::applyFrameDurations(double minFrameDuration, double maxFrameDuration)
+{
+	const double minSensorFrameDuration = 1e-3 * mode_.min_frame_length * mode_.line_length;
+	const double maxSensorFrameDuration = 1e-3 * mode_.max_frame_length * mode_.line_length;
+
+	/*
+	 * This will only be applied once AGC recalculations occur.
+	 * The values may be clamped based on the sensor mode capabilities as well.
+	 */
+	minFrameDuration_ = minFrameDuration ? minFrameDuration : defaultMaxFrameDuration;
+	maxFrameDuration_ = maxFrameDuration ? maxFrameDuration : defaultMinFrameDuration;
+	minFrameDuration_ = std::clamp(minFrameDuration_,
+				       minSensorFrameDuration, maxSensorFrameDuration);
+	maxFrameDuration_ = std::clamp(maxFrameDuration_,
+				       minSensorFrameDuration, maxSensorFrameDuration);
+	maxFrameDuration_ = std::max(maxFrameDuration_, minFrameDuration_);
+
+	/* Return the validated limits out though metadata. */
+	libcameraMetadata_.set(controls::FrameDurations,
+			       { static_cast<int64_t>(minFrameDuration_),
+				 static_cast<int64_t>(maxFrameDuration_) });
+}
+
 void IPARPi::applyAGC(const struct AgcStatus *agcStatus, ControlList &ctrls)
 {
 	int32_t gainCode = helper_->GainCode(agcStatus->analogue_gain);