diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
index 641ba18f..b24ee643 100644
--- a/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
+++ b/src/ipa/rpi/cam_helper/cam_helper_imx708.cpp
@@ -42,6 +42,9 @@ constexpr std::initializer_list<uint32_t> registerList =
 	{ expHiReg, expLoReg, gainHiReg, gainLoReg, lineLengthHiReg,
 	  lineLengthLoReg, frameLengthHiReg, frameLengthLoReg, temperatureReg };
 
+/* PDAF data is expect to occupy the third scanline of embedded data. */
+constexpr uint32_t pdafLineOffsetImx708 = 2;
+
 class CamHelperImx708 : public CamHelper
 {
 public:
@@ -75,7 +78,7 @@ private:
 	void populateMetadata(const MdParser::RegisterMap &registers,
 			      Metadata &metadata) const override;
 
-	static bool parsePdafData(const uint8_t *ptr, size_t len, unsigned bpp,
+	static bool parsePdafData(libcamera::Span<const uint8_t> &pdafData, unsigned bpp,
 				  PdafRegions &pdaf);
 
 	bool parseAEHist(const uint8_t *ptr, size_t len, unsigned bpp);
@@ -116,17 +119,16 @@ void CamHelperImx708::prepare(libcamera::Span<const uint8_t> buffer, Metadata &m
 
 	parseEmbeddedData(buffer, metadata);
 
-	/*
-	 * Parse PDAF data, which we expect to occupy the third scanline
-	 * of embedded data. As PDAF is quite sensor-specific, it's parsed here.
-	 */
+	/* Parse sensor-specific PDAF data. */
 	size_t bytesPerLine = (mode_.width * mode_.bitdepth) >> 3;
+	size_t pdafDataOffset = pdafLineOffsetImx708 * bytesPerLine;
 
-	if (buffer.size() > 2 * bytesPerLine) {
+	if (buffer.size() > pdafDataOffset) {
 		PdafRegions pdaf;
-		if (parsePdafData(&buffer[2 * bytesPerLine],
-				  buffer.size() - 2 * bytesPerLine,
-				  mode_.bitdepth, pdaf))
+		libcamera::Span<const uint8_t> pdafData{ &buffer[pdafDataOffset],
+							 buffer.size() - pdafDataOffset };
+
+		if (parsePdafData(pdafData, mode_.bitdepth, pdaf))
 			metadata.set("pdaf.regions", pdaf);
 	}
 
@@ -241,9 +243,10 @@ void CamHelperImx708::populateMetadata(const MdParser::RegisterMap &registers,
 	metadata.set("device.status", deviceStatus);
 }
 
-bool CamHelperImx708::parsePdafData(const uint8_t *ptr, size_t len,
-				    unsigned bpp, PdafRegions &pdaf)
+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) {