[libcamera-devel] [RFC PATCH 2/5] ipa: rpi: Make parsePdafData() available in the CamHelper class

[Umang Jain]

parsePdafData() parses the PDAF section of the sensor's embedded data
and the parsing logic is generic to all PDAF-supported sensors.
Once the PDAF-specific buffer section is identified correctly, any
sensor should be able to use this helper in order parse its PDAF data.

No functional changes intended in this patch.

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
 src/ipa/rpi/cam_helper/cam_helper.cpp        | 29 +++++++++++++++
 src/ipa/rpi/cam_helper/cam_helper.h          |  6 ++++
 src/ipa/rpi/cam_helper/cam_helper_imx708.cpp | 37 --------------------
 3 files changed, 35 insertions(+), 37 deletions(-)

diff --git a/src/ipa/rpi/cam_helper/cam_helper.cpp b/src/ipa/rpi/cam_helper/cam_helper.cpp
index ddd5e9a4..e9e0c496 100644
--- a/src/ipa/rpi/cam_helper/cam_helper.cpp
+++ b/src/ipa/rpi/cam_helper/cam_helper.cpp
@@ -253,6 +253,35 @@ void CamHelper::parseEmbeddedData(Span<const uint8_t> buffer,
 	metadata.set("device.status", deviceStatus);
 }
 
+bool CamHelper::parsePdafData(Span<const uint8_t> &data, unsigned bpp, PdafRegions &pdaf)
+{
+	const uint8_t *ptr = data.data();
+	unsigned int len = data.size();
+	size_t step = bpp >> 1; /* bytes per PDAF grid entry */
+
+	if (bpp < 10 || bpp > 12 || len < 194 * step || ptr[0] != 0 || ptr[1] >= 0x40) {
+		LOG(IPARPI, Error) << "PDAF data in unsupported format";
+		return false;
+	}
+
+	pdaf.init({ pdafStatsCols, pdafStatsRows });
+
+	ptr += 2 * step;
+	for (unsigned i = 0; i < pdafStatsRows; ++i) {
+		for (unsigned j = 0; j < pdafStatsCols; ++j) {
+			unsigned c = (ptr[0] << 3) | (ptr[1] >> 5);
+			int p = (((ptr[1] & 0x0f) - (ptr[1] & 0x10)) << 6) | (ptr[2] >> 2);
+			PdafData pdafData;
+			pdafData.conf = c;
+			pdafData.phase = c ? p : 0;
+			pdaf.set(libcamera::Point(j, i), { pdafData, 1, 0 });
+			ptr += step;
+		}
+	}
+
+	return true;
+}
+
 void CamHelper::populateMetadata([[maybe_unused]] const MdParser::RegisterMap &registers,
 				 [[maybe_unused]] Metadata &metadata) const
 {
diff --git a/src/ipa/rpi/cam_helper/cam_helper.h b/src/ipa/rpi/cam_helper/cam_helper.h
index 58a4b202..705796a2 100644
--- a/src/ipa/rpi/cam_helper/cam_helper.h
+++ b/src/ipa/rpi/cam_helper/cam_helper.h
@@ -16,6 +16,7 @@
 #include "controller/camera_mode.h"
 #include "controller/controller.h"
 #include "controller/metadata.h"
+#include "controller/pdaf_data.h"
 #include "md_parser.h"
 
 #include "libcamera/internal/v4l2_videodevice.h"
@@ -101,11 +102,16 @@ public:
 	virtual unsigned int mistrustFramesModeSwitch() const;
 
 protected:
+	static bool parsePdafData(libcamera::Span<const uint8_t> &pdafData, unsigned bpp,
+				  PdafRegions &pdaf);
 	void parseEmbeddedData(libcamera::Span<const uint8_t> buffer,
 			       Metadata &metadata);
 	virtual void populateMetadata(const MdParser::RegisterMap &registers,
 				      Metadata &metadata) const;
 
+	static constexpr int pdafStatsRows = 12;
+	static constexpr int pdafStatsCols = 16;
+
 	std::unique_ptr<MdParser> parser_;
 	CameraMode mode_;
 
diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
index b24ee643..d0382d63 100644
--- a/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
@@ -12,8 +12,6 @@
 
 #include <libcamera/base/log.h>
 
-#include "controller/pdaf_data.h"
-
 #include "cam_helper.h"
 #include "md_parser.h"
 
@@ -72,15 +70,9 @@ private:
 	/* Largest long exposure scale factor given as a left shift on the frame length. */
 	static constexpr int longExposureShiftMax = 7;
 
-	static constexpr int pdafStatsRows = 12;
-	static constexpr int pdafStatsCols = 16;
-
 	void populateMetadata(const MdParser::RegisterMap &registers,
 			      Metadata &metadata) const override;
 
-	static bool parsePdafData(libcamera::Span<const uint8_t> &pdafData, unsigned bpp,
-				  PdafRegions &pdaf);
-
 	bool parseAEHist(const uint8_t *ptr, size_t len, unsigned bpp);
 	void putAGCStatistics(StatisticsPtr stats);
 
@@ -243,35 +235,6 @@ void CamHelperImx708::populateMetadata(const MdParser::RegisterMap &registers,
 	metadata.set("device.status", deviceStatus);
 }
 
-bool CamHelperImx708::parsePdafData(Span<const uint8_t> &data, unsigned bpp, PdafRegions &pdaf)
-{
-	const uint8_t *ptr = data.data();
-	unsigned int len = data.size();
-	size_t step = bpp >> 1; /* bytes per PDAF grid entry */
-
-	if (bpp < 10 || bpp > 12 || len < 194 * step || ptr[0] != 0 || ptr[1] >= 0x40) {
-		LOG(IPARPI, Error) << "PDAF data in unsupported format";
-		return false;
-	}
-
-	pdaf.init({ pdafStatsCols, pdafStatsRows });
-
-	ptr += 2 * step;
-	for (unsigned i = 0; i < pdafStatsRows; ++i) {
-		for (unsigned j = 0; j < pdafStatsCols; ++j) {
-			unsigned c = (ptr[0] << 3) | (ptr[1] >> 5);
-			int p = (((ptr[1] & 0x0F) - (ptr[1] & 0x10)) << 6) | (ptr[2] >> 2);
-			PdafData pdafData;
-			pdafData.conf = c;
-			pdafData.phase = c ? p : 0;
-			pdaf.set(libcamera::Point(j, i), { pdafData, 1, 0 });
-			ptr += step;
-		}
-	}
-
-	return true;
-}
-
 bool CamHelperImx708::parseAEHist(const uint8_t *ptr, size_t len, unsigned bpp)
 {
 	static constexpr unsigned int PipelineBits = Statistics::NormalisationFactorPow2;
-- 
2.39.1