1 files changed, 115 insertions, 1 deletions

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index c912fd16..4323c98a 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -312,6 +312,7 @@ class RPiCameraConfiguration : public CameraConfiguration
 public:
 	RPiCameraConfiguration(const RPiCameraData *data);
 
+	CameraConfiguration::Status validateColorSpaces(ColorSpaceFlags flags);
 	Status validate() override;
 
 	/* Cache the combinedTransform_ that will be applied to the sensor */
@@ -319,6 +320,14 @@ public:
 
 private:
 	const RPiCameraData *data_;
+
+	/*
+	 * Store the colour spaces that all our streams will have. RGB format streams
+	 * will have the same colorspace as YUV streams, with YCbCr field cleared and
+	 * range set to full.
+         */
+	std::optional<ColorSpace> yuvColorSpace_;
+	std::optional<ColorSpace> rgbColorSpace_;
 };
 
 class PipelineHandlerRPi : public PipelineHandler
@@ -359,6 +368,105 @@ RPiCameraConfiguration::RPiCameraConfiguration(const RPiCameraData *data)
 {
 }
 
+static const std::vector<ColorSpace> validColorSpaces = {
+	ColorSpace::Sycc,
+	ColorSpace::Smpte170m,
+	ColorSpace::Rec709
+};
+
+static std::optional<ColorSpace> findValidColorSpace(const ColorSpace &colourSpace)
+{
+	for (auto cs : validColorSpaces) {
+		if (colourSpace.primaries == cs.primaries &&
+		    colourSpace.transferFunction == cs.transferFunction)
+			return cs;
+	}
+
+	return std::nullopt;
+}
+
+static bool isRgb(const PixelFormat &pixFmt)
+{
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
+	return info.colourEncoding == PixelFormatInfo::ColourEncodingRGB;
+}
+
+static bool isYuv(const PixelFormat &pixFmt)
+{
+	/* The code below would return true for raw mono streams, so weed those out first. */
+	if (isRaw(pixFmt))
+		return false;
+
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
+	return info.colourEncoding == PixelFormatInfo::ColourEncodingYUV;
+}
+
+/*
+ * Raspberry Pi drivers expect the following colour spaces:
+ * - V4L2_COLORSPACE_RAW for raw streams.
+ * - One of V4L2_COLORSPACE_JPEG, V4L2_COLORSPACE_SMPTE170M, V4L2_COLORSPACE_REC709 for
+ *   non-raw streams. Other fields such as transfer function, YCbCr encoding and
+ *   quantisation are not used.
+ *
+ * The libcamera colour spaces that we wish to use corresponding to these are therefore:
+ * - ColorSpace::Raw for V4L2_COLORSPACE_RAW
+ * - ColorSpace::Sycc for V4L2_COLORSPACE_JPEG
+ * - ColorSpace::Smpte170m for V4L2_COLORSPACE_SMPTE170M
+ * - ColorSpace::Rec709 for V4L2_COLORSPACE_REC709
+ */
+
+CameraConfiguration::Status RPiCameraConfiguration::validateColorSpaces([[maybe_unused]] ColorSpaceFlags flags)
+{
+	Status status = Valid;
+	yuvColorSpace_.reset();
+
+	for (auto cfg : config_) {
+		/* First fix up raw streams to have the "raw" colour space. */
+		if (isRaw(cfg.pixelFormat)) {
+			/* If there was no value here, that doesn't count as "adjusted". */
+			if (cfg.colorSpace && cfg.colorSpace != ColorSpace::Raw) {
+				status = Adjusted;
+				cfg.colorSpace = ColorSpace::Raw;
+			}
+			continue;
+		}
+
+		/* Next we need to find our shared colour space. The first valid one will do. */
+		if (cfg.colorSpace && !yuvColorSpace_)
+			yuvColorSpace_ = findValidColorSpace(cfg.colorSpace.value());
+	}
+
+	/* If no colour space was given anywhere, choose sYCC. */
+	if (!yuvColorSpace_)
+		yuvColorSpace_ = ColorSpace::Sycc;
+
+	/* Note the version of this that any RGB streams will have to use. */
+	rgbColorSpace_ = yuvColorSpace_;
+	rgbColorSpace_->ycbcrEncoding = ColorSpace::YcbcrEncoding::None;
+	rgbColorSpace_->range = ColorSpace::Range::Full;
+
+	/* Go through the streams again and force everyone to the same colour space. */
+	for (auto cfg : config_) {
+		if (cfg.colorSpace == ColorSpace::Raw)
+			continue;
+
+		if (isYuv(cfg.pixelFormat) && cfg.colorSpace != yuvColorSpace_) {
+			/* Again, no value means "not adjusted". */
+			if (cfg.colorSpace)
+				status = Adjusted;
+			cfg.colorSpace = yuvColorSpace_;
+		}
+		if (isRgb(cfg.pixelFormat) && cfg.colorSpace != rgbColorSpace_) {
+			/* Be nice, and let the YUV version count as non-adjusted too. */
+			if (cfg.colorSpace && cfg.colorSpace != yuvColorSpace_)
+				status = Adjusted;
+			cfg.colorSpace = rgbColorSpace_;
+		}
+	}
+
+	return status;
+}
+
 CameraConfiguration::Status RPiCameraConfiguration::validate()
 {
 	Status status = Valid;
@@ -490,7 +598,8 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
 		V4L2DeviceFormat format;
 		format.fourcc = dev->toV4L2PixelFormat(cfg.pixelFormat);
 		format.size = cfg.size;
-		format.colorSpace = cfg.colorSpace;
+		/* We want to send the associated YCbCr info through to the driver. */
+		format.colorSpace = yuvColorSpace_;
 
 		LOG(RPI, Debug)
 			<< "Try color space " << ColorSpace::toString(cfg.colorSpace);
@@ -499,6 +608,11 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
 		if (ret)
 			return Invalid;
 
+		/*
+		 * But for RGB streams, the YCbCr info gets overwritten on the way back
+		 * so we must check against what the stream cfg says, not what we actually
+		 * requested (which carefully included the YCbCr info)!
+		 */
 		if (cfg.colorSpace != format.colorSpace) {
 			status = Adjusted;
 			LOG(RPI, Debug)