File 0002-libcamera-software_isp-Pass-correct-y-coordinate-to-.patch of Package libcamera

From d3aaab99a267c160cd67cc853b61a7d5d972ad0f Mon Sep 17 00:00:00 2001
From: Milan Zamazal <mzamazal@redhat.com>
Date: Thu, 21 Aug 2025 15:41:38 +0200
Subject: [PATCH 02/17] libcamera: software_isp: Pass correct y-coordinate to
 stats

The window set by SwStatsCpu::setWindow is relative to the processed
image area.  But debayering passes the processed line y-coordinate to
the stats relative to the whole image area.  This can result in
gathering stats from a wrong image area or in not gathering stats at
all.

Let's pass the correct y-coordinate to the stats processing methods.

Bug: https://bugs.libcamera.org/show_bug.cgi?id=280
Co-developed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
---
 src/libcamera/software_isp/debayer_cpu.cpp | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/libcamera/software_isp/debayer_cpu.cpp b/src/libcamera/software_isp/debayer_cpu.cpp
index bcc847ae6..185edd814 100644
--- a/src/libcamera/software_isp/debayer_cpu.cpp
+++ b/src/libcamera/software_isp/debayer_cpu.cpp
@@ -648,7 +648,7 @@ void DebayerCpu::memcpyNextLine(const uint8_t *linePointers[])
 
 void DebayerCpu::process2(const uint8_t *src, uint8_t *dst)
 {
-	unsigned int yEnd = window_.y + window_.height;
+	unsigned int yEnd = window_.height;
 	/* Holds [0] previous- [1] current- [2] next-line */
 	const uint8_t *linePointers[3];
 
@@ -664,12 +664,12 @@ void DebayerCpu::process2(const uint8_t *src, uint8_t *dst)
 		linePointers[1] = src + inputConfig_.stride;
 		linePointers[2] = src;
 		/* Last 2 lines also need special handling */
-		yEnd -= 2;
+		yEnd = (yEnd > 2 ? yEnd - 2 : 0);
 	}
 
 	setupInputMemcpy(linePointers);
 
-	for (unsigned int y = window_.y; y < yEnd; y += 2) {
+	for (unsigned int y = 0; y < yEnd; y += 2) {
 		shiftLinePointers(linePointers, src);
 		memcpyNextLine(linePointers);
 		stats_->processLine0(y, linePointers);
@@ -703,7 +703,7 @@ void DebayerCpu::process2(const uint8_t *src, uint8_t *dst)
 
 void DebayerCpu::process4(const uint8_t *src, uint8_t *dst)
 {
-	const unsigned int yEnd = window_.y + window_.height;
+	const unsigned int yEnd = window_.height;
 	/*
 	 * This holds pointers to [0] 2-lines-up [1] 1-line-up [2] current-line
 	 * [3] 1-line-down [4] 2-lines-down.
@@ -721,7 +721,7 @@ void DebayerCpu::process4(const uint8_t *src, uint8_t *dst)
 
 	setupInputMemcpy(linePointers);
 
-	for (unsigned int y = window_.y; y < yEnd; y += 4) {
+	for (unsigned int y = 0; y < yEnd; y += 4) {
 		shiftLinePointers(linePointers, src);
 		memcpyNextLine(linePointers);
 		stats_->processLine0(y, linePointers);
-- 
2.50.1