[libcamera-devel] [PATCH v1 08/10] ipa: raspberrypi: Generalise the focus algorithm

[Naushir Patuck]

Generalise the focus reporting algorithm code by removing any hard-coded
assumptions about the target hardware platform. Instead, the algorithm
code uses the generalised statistics structure to determine focus region
sizes.

Remove focus_status.h as it is no longer needed with this change.

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 src/ipa/raspberrypi/controller/focus_status.h | 20 -------------------
 src/ipa/raspberrypi/controller/rpi/focus.cpp  | 12 ++---------
 src/ipa/raspberrypi/raspberrypi.cpp           | 11 ++++++----
 3 files changed, 9 insertions(+), 34 deletions(-)
 delete mode 100644 src/ipa/raspberrypi/controller/focus_status.h

diff --git a/src/ipa/raspberrypi/controller/focus_status.h b/src/ipa/raspberrypi/controller/focus_status.h
deleted file mode 100644
index 8b74e59840c1..000000000000
--- a/src/ipa/raspberrypi/controller/focus_status.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: BSD-2-Clause */
-/*
- * Copyright (C) 2020, Raspberry Pi Ltd
- *
- * focus_status.h - focus measurement status
- */
-#pragma once
-
-#include <linux/bcm2835-isp.h>
-
-/*
- * The focus algorithm should post the following structure into the image's
- * "focus.status" metadata. Recall that it's only reporting focus (contrast)
- * measurements, it's not driving any kind of auto-focus algorithm!
- */
-
-struct FocusStatus {
-	unsigned int num;
-	uint32_t focusMeasures[FOCUS_REGIONS];
-};
diff --git a/src/ipa/raspberrypi/controller/rpi/focus.cpp b/src/ipa/raspberrypi/controller/rpi/focus.cpp
index ea3cc00e42c3..683d460ad6f7 100644
--- a/src/ipa/raspberrypi/controller/rpi/focus.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/focus.cpp
@@ -8,7 +8,6 @@
 
 #include <libcamera/base/log.h>
 
-#include "../focus_status.h"
 #include "focus.h"
 
 using namespace RPiController;
@@ -30,15 +29,8 @@ char const *Focus::name() const
 
 void Focus::process(StatisticsPtr &stats, Metadata *imageMetadata)
 {
-	FocusStatus status;
-	for (unsigned int i = 0; i < stats->focusRegions.numRegions(); i++)
-		status.focusMeasures[i] = stats->focusRegions.get(i).val;
-	status.num = stats->focusRegions.numRegions();
-	imageMetadata->set("focus.status", status);
-
-	LOG(RPiFocus, Debug)
-		<< "Focus contrast measure: "
-		<< (status.focusMeasures[5] + status.focusMeasures[6]) / 10;
+	/* Pass the stats directly to the IPA to report out to the application */
+	imageMetadata->set("focus.status", stats->focusRegions);
 }
 
 /* Register algorithm with the system. */
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index b6e5465ca32a..181512de74ad 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -50,7 +50,6 @@
 #include "denoise_algorithm.h"
 #include "denoise_status.h"
 #include "dpc_status.h"
-#include "focus_status.h"
 #include "geq_status.h"
 #include "lux_status.h"
 #include "metadata.h"
@@ -640,14 +639,18 @@ void IPARPi::reportMetadata(unsigned int ipaContext)
 					 static_cast<int32_t>(blackLevelStatus->blackLevelG),
 					 static_cast<int32_t>(blackLevelStatus->blackLevelB) });
 
-	FocusStatus *focusStatus = rpiMetadata.getLocked<FocusStatus>("focus.status");
-	if (focusStatus && focusStatus->num == 12) {
+	RPiController::FocusRegions *focusStatus =
+		rpiMetadata.getLocked<RPiController::FocusRegions>("focus.status");
+	if (focusStatus) {
+		libcamera::Size size = focusStatus->size();
 		/*
 		 * We get a 4x3 grid of regions by default. Calculate the average
 		 * FoM over the central two positions to give an overall scene FoM.
 		 * This can change later if it is not deemed suitable.
 		 */
-		int32_t focusFoM = (focusStatus->focusMeasures[5] + focusStatus->focusMeasures[6]) / 2;
+		ASSERT(size == Size(4, 3));
+		int32_t focusFoM = (focusStatus->get({ 1, 1 }).val +
+				    focusStatus->get({ 2, 1 }).val) / 2;
 		libcameraMetadata_.set(controls::FocusFoM, focusFoM);
 	}
 
-- 
2.34.1