libcamera: PixelFormat: Turn into a class

Create a class to represent a pixel format. This is done to add support
for modifiers for the formats. So far no modifiers are added by any
pipeline handler, all plumbing to deal with them is however in place.

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

include/libcamera/pixelformats.h

@@ -7,13 +7,36 @@
 #ifndef __LIBCAMERA_PIXEL_FORMATS_H__
 #define __LIBCAMERA_PIXEL_FORMATS_H__
 
+#include <set>
 #include <stdint.h>
+#include <string>
 
 #include <linux/drm_fourcc.h>
 
 namespace libcamera {
 
-using PixelFormat = uint32_t;
+class PixelFormat
+{
+public:
+	PixelFormat();
+	PixelFormat(uint32_t fourcc, const std::set<uint64_t> &modifiers = {});
+
+	bool operator==(const PixelFormat &other) const;
+	bool operator!=(const PixelFormat &other) const { return !(*this == other); }
+	bool operator<(const PixelFormat &other) const;
+
+	bool isValid() const { return fourcc_ != 0; }
+
+	operator uint32_t() const { return fourcc_; }
+	uint32_t fourcc() const { return fourcc_; }
+	const std::set<uint64_t> &modifiers() const { return modifiers_; }
+
+	std::string toString() const;
+
+private:
+	uint32_t fourcc_;
+	std::set<uint64_t> modifiers_;
+};
 
 } /* namespace libcamera */