libcamera: formats: add numPlanes helper

Determine the number of planes used by a format by counting the number
of PixelFormatPlaneInfo entries with a valid entry.

Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
index a51e9681..ebaae9be 100644
--- a/src/libcamera/formats.cpp
+++ b/src/libcamera/formats.cpp
@@ -821,4 +821,22 @@ PixelFormatInfo::frameSize(const Size &size,
 	return sum;
 }
 
+/**
+ * \brief Retrieve the number of planes represented by the format
+ * \return The number of planes used by the format
+ */
+unsigned int PixelFormatInfo::numPlanes() const
+{
+	unsigned int count = 0;
+
+	for (const PixelFormatPlaneInfo &p : planes) {
+		if (p.bytesPerGroup == 0)
+			break;
+
+		count++;
+	}
+
+	return count;
+}
+
 } /* namespace libcamera */