[libcamera-devel] [PATCH v6 6/7] libcamera: Add validateColorSpaces to CameraConfiguration class

[David Plowman]

This method forces raw streams to have the "raw" color space, and also
optionally makes all output streams to share the same color space as
some platforms may require this.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 include/libcamera/camera.h |  2 ++
 src/libcamera/camera.cpp   | 51 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index 601ee46e..fdab4410 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -69,6 +69,8 @@ public:
 protected:
 	CameraConfiguration();
 
+	Status validateColorSpaces(bool sharedColorSpace);
+
 	std::vector<StreamConfiguration> config_;
 };
 
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 400a7cf0..c1541685 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -20,6 +20,7 @@
 
 #include "libcamera/internal/camera.h"
 #include "libcamera/internal/camera_controls.h"
+#include "libcamera/internal/formats.h"
 #include "libcamera/internal/pipeline_handler.h"
 
 /**
@@ -314,6 +315,56 @@ std::size_t CameraConfiguration::size() const
 	return config_.size();
 }
 
+static bool isRaw(const PixelFormat &pixFmt)
+{
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
+	return info.isValid() &&
+	       info.colourEncoding == PixelFormatInfo::ColourEncodingRAW;
+}
+
+CameraConfiguration::Status CameraConfiguration::validateColorSpaces(bool sharedColorSpace)
+{
+	Status status = Valid;
+
+	/* Find the largest non-raw stream (if any). */
+	int index = -1;
+	for (unsigned int i = 0; i < config_.size(); i++) {
+		const StreamConfiguration &cfg = config_[i];
+		if (!isRaw(cfg.pixelFormat) && (index < 0 || cfg.size > config_[i].size))
+			index = i;
+	}
+
+	/*
+	 * Here we force raw streams to the correct color space. We handle
+	 * the case where all output streams are to share a color space,
+	 * which will match the color space of the largest (non-raw) stream.
+	 */
+	for (auto &cfg : config_) {
+		std::optional<ColorSpace> initialColorSpace = cfg.colorSpace;
+
+		if (isRaw(cfg.pixelFormat))
+			cfg.colorSpace = ColorSpace::Raw;
+		else if (sharedColorSpace) {
+			/*
+			 * When all outputs share a color space, use the biggest
+			 * output if that was set. If that was blank, but this
+			 * stream's is not, then use this stream's color space for
+			 * largest stream.
+			 * (index must be != -1 if there are any non-raw streams.)
+			 */
+			if (config_[index].colorSpace)
+				cfg.colorSpace = config_[index].colorSpace;
+			else if (cfg.colorSpace)
+				config_[index].colorSpace = cfg.colorSpace;
+		}
+
+		if (cfg.colorSpace != initialColorSpace)
+			status = Adjusted;
+	}
+
+	return status;
+}
+
 /**
  * \var CameraConfiguration::transform
  * \brief User-specified transform to be applied to the image
-- 
2.20.1