7 files changed, 102 insertions, 16 deletions
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index af516f1c..f73e77f3 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -253,7 +253,7 @@ int CamApp::prepareConfig()
 
 			/* TODO: Translate 4CC string to ID. */
 			if (opt.isSet("pixelformat"))
-				cfg.pixelFormat = opt["pixelformat"];
+				cfg.pixelFormat = PixelFormat(opt["pixelformat"]);
 		}
 	}
 
@@ -304,8 +304,8 @@ int CamApp::infoConfiguration()
 
 		const StreamFormats &formats = cfg.formats();
 		for (PixelFormat pixelformat : formats.pixelformats()) {
-			std::cout << " * Pixelformat: 0x" << std::hex
-				  << std::setw(8) << pixelformat << " "
+			std::cout << " * Pixelformat: "
+				  << pixelformat.toString() << " "
 				  << formats.range(pixelformat).toString()
 				  << std::endl;
 
diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 5ff29240..9876d8c9 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -115,8 +115,9 @@ CameraConfiguration::Status UVCCameraConfiguration::validate()
 	if (iter == pixelFormats.end()) {
 		cfg.pixelFormat = pixelFormats.front();
 		LOG(UVC, Debug)
-			<< "Adjusting pixel format from " << pixelFormat
-			<< " to " << cfg.pixelFormat;
+			<< "Adjusting pixel format from "
+			<< pixelFormat.toString() << " to "
+			<< cfg.pixelFormat.toString();
 		status = Adjusted;
 	}
 
diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
index 82649952..00cb7389 100644
--- a/src/libcamera/pipeline/vimc.cpp
+++ b/src/libcamera/pipeline/vimc.cpp
@@ -105,7 +105,7 @@ private:
 
 namespace {
 
-constexpr std::array<PixelFormat, 3> pixelformats{
+static const std::array<PixelFormat, 3> pixelformats{
 	DRM_FORMAT_RGB888,
 	DRM_FORMAT_BGR888,
 	DRM_FORMAT_BGRA8888,
diff --git a/src/libcamera/pixelformats.cpp b/src/libcamera/pixelformats.cpp
index c0333540..87557d98 100644
--- a/src/libcamera/pixelformats.cpp
+++ b/src/libcamera/pixelformats.cpp
@@ -15,14 +15,102 @@
 namespace libcamera {
 
 /**
- * \typedef PixelFormat
+ * \class PixelFormat
  * \brief libcamera image pixel format
  *
  * The PixelFormat type describes the format of images in the public libcamera
- * API. It stores a FourCC value as a 32-bit unsigned integer. The values are
- * defined in the Linux kernel DRM/KMS API (see linux/drm_fourcc.h).
+ * API. It stores a FourCC value as a 32-bit unsigned integer and a set of
+ * modifiers. The FourCC and modifiers values are defined in the Linux kernel
+ * DRM/KMS API (see linux/drm_fourcc.h).
+ */
+
+/**
+ * \brief Construct a PixelFormat with an invalid format
+ *
+ * PixelFormat instances constructed with the default constructor are
+ * invalid, calling the isValid() function returns false.
+ */
+PixelFormat::PixelFormat()
+	: fourcc_(0)
+{
+}
+
+/**
+ * \brief Construct a PixelFormat from a DRM FourCC and a set of modifiers
+ * \param[in] fourcc A DRM FourCC
+ * \param[in] modifiers A set of DRM FourCC modifiers
+ */
+PixelFormat::PixelFormat(uint32_t fourcc, const std::set<uint64_t> &modifiers)
+	: fourcc_(fourcc), modifiers_(modifiers)
+{
+}
+
+/**
+ * \brief Compare pixel formats for equality
+ * \return True if the two pixel formats are equal, false otherwise
+ */
+bool PixelFormat::operator==(const PixelFormat &other) const
+{
+	return fourcc_ == other.fourcc() && modifiers_ == other.modifiers_;
+}
+
+/**
+ * \fn bool PixelFormat::operator!=(const PixelFormat &other) const
+ * \brief Compare pixel formats for inequality
+ * \return True if the two pixel formats are not equal, false otherwise
+ */
+
+/**
+ * \brief Compare pixel formats for smaller than order
+ * \return True if \a this is smaller than \a other, false otherwise
+ */
+bool PixelFormat::operator<(const PixelFormat &other) const
+{
+	if (fourcc_ < other.fourcc_)
+		return true;
+	if (fourcc_ > other.fourcc_)
+		return false;
+	return modifiers_ < modifiers_;
+}
+
+/**
+ * \fn bool PixelFormat::isValid() const
+ * \brief Check if the pixel format is valid
+ *
+ * PixelFormat instances constructed with the default constructor are
+ * invalid. Instances constructed with a FourCC defined in the DRM API
+ * are valid. The behaviour is undefined otherwise.
  *
- * \todo Add support for format modifiers
+ * \return True if the pixel format is valid, false otherwise
+ */
+
+/**
+ * \fn PixelFormat::operator uint32_t() const
+ * \brief Convert the the pixel format numerical value
+ * \return The pixel format numerical value
+ */
+
+/**
+ * \fn PixelFormat::fourcc() const
+ * \brief Retrieve the pixel format FourCC
+ * \return DRM FourCC
+ */
+
+/**
+ * \fn PixelFormat::modifiers() const
+ * \brief Retrieve the pixel format modifiers
+ * \return Set of DRM modifiers
+ */
+
+/**
+ * \brief Assemble and return a string describing the pixel format
+ * \return A string describing the pixel format
  */
+std::string PixelFormat::toString() const
+{
+	char str[11];
+	snprintf(str, 11, "0x%08x", fourcc_);
+	return str;
+}
 
 } /* namespace libcamera */
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
index 13789e9e..0716de38 100644
--- a/src/libcamera/stream.cpp
+++ b/src/libcamera/stream.cpp
@@ -347,9 +347,7 @@ StreamConfiguration::StreamConfiguration(const StreamFormats &formats)
  */
 std::string StreamConfiguration::toString() const
 {
-	std::stringstream ss;
-	ss << size.toString() << "-" << utils::hex(pixelFormat);
-	return ss.str();
+	return size.toString() + "-" + pixelFormat.toString();
 }
 
 /**
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index ca0d147f..ce67e04c 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -1551,8 +1551,7 @@ uint32_t V4L2VideoDevice::toV4L2Fourcc(PixelFormat pixelFormat, bool multiplanar
 	 * class. Until we fix the logger, work around it.
 	 */
 	libcamera::_log(__FILE__, __LINE__, _LOG_CATEGORY(V4L2)(), LogError).stream()
-		<< "Unsupported V4L2 pixel format "
-		<< utils::hex(pixelFormat);
+		<< "Unsupported V4L2 pixel format " << pixelFormat.toString();
 	return 0;
 }
 
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index e349fbdd..3bc1c1aa 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -533,7 +533,7 @@ struct PixelFormatInfo {
 
 namespace {
 
-constexpr std::array<PixelFormatInfo, 13> pixelFormatInfo = {{
+static const std::array<PixelFormatInfo, 13> pixelFormatInfo = {{
 	/* RGB formats. */
 	{ DRM_FORMAT_RGB888,	V4L2_PIX_FMT_BGR24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },
 	{ DRM_FORMAT_BGR888,	V4L2_PIX_FMT_RGB24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },