ipa: raspberrypi: Move initial frame drop decision to AGC/AWB

Previously the CamHelper was returning the number of frames to drop
(on account of AGC/AWB converging). This wasn't really appropriate,
it's better for the algorithms to do it as they know how many frames
they might need.

The CamHelper::HideFramesStartup method should now just be returning
the number of frames to hide because they're bad/invalid in some way,
not worrying about the AGC/AWB. For many sensors, the correct value
for this is zero. But the ov5647 needs updating as it must return 2.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-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, 28 insertions, 0 deletions

diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 8acab85e..80140021 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -194,6 +194,34 @@ int IPARPi::start(const IPAOperationData &data, IPAOperationData *result)
 	if (firstStart_) {
 		dropFrame = helper_->HideFramesStartup();
 		mistrustCount_ = helper_->MistrustFramesStartup();
+
+		/*
+		 * Query the AGC/AWB for how many frames they may take to
+		 * converge sufficiently. Where these numbers are non-zero
+		 * we must allow for the frames with bad statistics
+		 * (mistrustCount_) that they won't see. But if zero (i.e.
+		 * no convergence necessary), no frames need to be dropped.
+		 */
+		unsigned int agcConvergenceFrames = 0;
+		RPiController::AgcAlgorithm *agc = dynamic_cast<RPiController::AgcAlgorithm *>(
+			controller_.GetAlgorithm("agc"));
+		if (agc) {
+			agcConvergenceFrames = agc->GetConvergenceFrames();
+			if (agcConvergenceFrames)
+				agcConvergenceFrames += mistrustCount_;
+		}
+
+		unsigned int awbConvergenceFrames = 0;
+		RPiController::AwbAlgorithm *awb = dynamic_cast<RPiController::AwbAlgorithm *>(
+			controller_.GetAlgorithm("awb"));
+		if (awb) {
+			awbConvergenceFrames = awb->GetConvergenceFrames();
+			if (awbConvergenceFrames)
+				awbConvergenceFrames += mistrustCount_;
+		}
+
+		dropFrame = std::max({ dropFrame, agcConvergenceFrames, awbConvergenceFrames });
+		LOG(IPARPI, Debug) << "Drop " << dropFrame << " frames on startup";
 	} else {
 		dropFrame = helper_->HideFramesModeSwitch();
 		mistrustCount_ = helper_->MistrustFramesModeSwitch();