@@ -12,6 +12,8 @@
namespace libcamera {
+class PixelFormat;
+
class ColorSpace
{
public:
@@ -61,6 +63,8 @@ public:
static std::string toString(const std::optional<ColorSpace> &colorSpace);
static std::optional<ColorSpace> fromString(const std::string &str);
+
+ bool adjust(PixelFormat format);
};
bool operator==(const ColorSpace &lhs, const ColorSpace &rhs);
@@ -317,17 +317,6 @@ std::size_t CameraConfiguration::size() const
return config_.size();
}
-namespace {
-
-bool isRaw(const PixelFormat &pixFmt)
-{
- const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
- return info.isValid() &&
- info.colourEncoding == PixelFormatInfo::ColourEncodingRAW;
-}
-
-} /* namespace */
-
/**
* \enum CameraConfiguration::ColorSpaceFlag
* \brief Specify the behaviour of validateColorSpaces
@@ -368,29 +357,31 @@ CameraConfiguration::Status CameraConfiguration::validateColorSpaces(ColorSpaceF
Status status = Valid;
/*
- * Set all raw streams to the Raw color space, and make a note of the largest
- * non-raw stream with a defined color space (if there is one).
+ * Set all raw streams to the Raw color space, and make a note of the
+ * largest non-raw stream with a defined color space (if there is one).
*/
- int index = -1;
+ std::optional<ColorSpace> colorSpace;
+
for (auto [i, cfg] : utils::enumerate(config_)) {
- if (isRaw(cfg.pixelFormat)) {
- if (cfg.colorSpace != ColorSpace::Raw) {
- cfg.colorSpace = ColorSpace::Raw;
- status = Adjusted;
- }
- } else if (cfg.colorSpace && (index == -1 || cfg.size > config_[i].size)) {
- index = i;
- }
+ if (!cfg.colorSpace)
+ continue;
+
+ if (cfg.colorSpace->adjust(cfg.pixelFormat))
+ status = Adjusted;
+
+ if (cfg.colorSpace != ColorSpace::Raw &&
+ (!colorSpace || cfg.size > config_[i].size))
+ colorSpace = cfg.colorSpace;
}
- if (index < 0 || !(flags & ColorSpaceFlag::StreamsShareColorSpace))
+ if (!colorSpace || !(flags & ColorSpaceFlag::StreamsShareColorSpace))
return status;
/* Make all output color spaces the same, if requested. */
for (auto &cfg : config_) {
- if (!isRaw(cfg.pixelFormat) &&
- cfg.colorSpace != config_[index].colorSpace) {
- cfg.colorSpace = config_[index].colorSpace;
+ if (cfg.colorSpace != ColorSpace::Raw &&
+ cfg.colorSpace != colorSpace) {
+ cfg.colorSpace = colorSpace;
status = Adjusted;
}
}
@@ -16,6 +16,8 @@
#include <libcamera/base/utils.h>
+#include "libcamera/internal/formats.h"
+
/**
* \file color_space.h
* \brief Class and enums to represent color spaces
@@ -398,6 +400,105 @@ std::optional<ColorSpace> ColorSpace::fromString(const std::string &str)
return colorSpace;
}
+/**
+ * \brief Adjust the color space to match a pixel format
+ * \param[in] format The pixel format
+ *
+ * Not all combinations of pixel formats and color spaces make sense. For
+ * instance, nobody uses a limited quantization range with raw Bayer formats,
+ * and the YcbcrEncoding::None encoding isn't valid for YUV formats. This
+ * function adjusts the ColorSpace to make it compatible with the given \a
+ * format, by applying the following rules:
+ *
+ * - The color space for RAW formats must be Raw.
+ * - The Y'CbCr encoding and quantization range for RGB formats must be
+ * YcbcrEncoding::None and Range::Full respectively.
+ * - The Y'CbCr encoding for YUV formats must not be YcbcrEncoding::None. The
+ * best encoding is in that case guessed based on the primaries and transfer
+ * function.
+ *
+ * \return True if the color space has been adjusted, or false if it was
+ * already compatible with the format and hasn't been changed
+ */
+bool ColorSpace::adjust(PixelFormat format)
+{
+ const PixelFormatInfo &info = PixelFormatInfo::info(format);
+ bool adjusted = false;
+
+ switch (info.colourEncoding) {
+ case PixelFormatInfo::ColourEncodingRAW:
+ /* Raw formats must use the raw color space. */
+ if (*this != ColorSpace::Raw) {
+ *this = ColorSpace::Raw;
+ adjusted = true;
+ }
+ break;
+
+ case PixelFormatInfo::ColourEncodingRGB:
+ /*
+ * RGB formats can't have a Y'CbCr encoding, and must use full
+ * range quantization.
+ */
+ if (ycbcrEncoding != YcbcrEncoding::None) {
+ ycbcrEncoding = YcbcrEncoding::None;
+ adjusted = true;
+ }
+
+ if (range != Range::Full) {
+ range = Range::Full;
+ adjusted = true;
+ }
+ break;
+
+ case PixelFormatInfo::ColourEncodingYUV:
+ if (ycbcrEncoding != YcbcrEncoding::None)
+ break;
+
+ /*
+ * YUV formats must have a Y'CbCr encoding. Infer the most
+ * probable option from the transfer function and primaries.
+ */
+ switch (transferFunction) {
+ case TransferFunction::Linear:
+ /*
+ * Linear YUV is not used in any standard color space,
+ * pick the widely supported and used Rec601 as default.
+ */
+ ycbcrEncoding = YcbcrEncoding::Rec601;
+ break;
+
+ case TransferFunction::Rec709:
+ switch (primaries) {
+ /* Raw should never happen. */
+ case Primaries::Raw:
+ case Primaries::Smpte170m:
+ ycbcrEncoding = YcbcrEncoding::Rec601;
+ break;
+ case Primaries::Rec709:
+ ycbcrEncoding = YcbcrEncoding::Rec709;
+ break;
+ case Primaries::Rec2020:
+ ycbcrEncoding = YcbcrEncoding::Rec2020;
+ break;
+ }
+ break;
+
+ case TransferFunction::Srgb:
+ /*
+ * Only the sYCC color space uses the sRGB transfer
+ * function, the corresponding encoding is Rec601.
+ */
+ ycbcrEncoding = YcbcrEncoding::Rec601;
+ break;
+ }
+
+ adjusted = true;
+ break;
+ }
+
+ return adjusted;
+}
+
/**
* \brief Compare color spaces for equality
* \return True if the two color spaces are identical, false otherwise