[libcamera-devel] [PATCH v2 2/3] libcamera: Support passing ColorSpaces to V4L2 drivers
David Plowman
david.plowman at raspberrypi.com
Mon Sep 27 14:33:26 CEST 2021
The ColorSpace class is added to the StreamConfiguration, and is now
passed to V4L2 devices where it is handled appropriately. Note how
this means that the colour space is configured per-stream (though
platforms may restrict this).
Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
include/libcamera/internal/v4l2_videodevice.h | 2 +
include/libcamera/stream.h | 3 +
src/libcamera/v4l2_videodevice.cpp | 119 ++++++++++++++++++
3 files changed, 124 insertions(+)
diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h
index efe34d47..34cc9cdd 100644
--- a/include/libcamera/internal/v4l2_videodevice.h
+++ b/include/libcamera/internal/v4l2_videodevice.h
@@ -20,6 +20,7 @@
#include <libcamera/base/log.h>
#include <libcamera/base/signal.h>
+#include <libcamera/color_space.h>
#include <libcamera/framebuffer.h>
#include <libcamera/geometry.h>
#include <libcamera/pixel_format.h>
@@ -163,6 +164,7 @@ public:
V4L2PixelFormat fourcc;
Size size;
+ ColorSpace colorSpace;
std::array<Plane, 3> planes;
unsigned int planesCount = 0;
diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index 0c55e716..131f7733 100644
--- a/include/libcamera/stream.h
+++ b/include/libcamera/stream.h
@@ -12,6 +12,7 @@
#include <string>
#include <vector>
+#include <libcamera/color_space.h>
#include <libcamera/framebuffer.h>
#include <libcamera/geometry.h>
#include <libcamera/pixel_format.h>
@@ -47,6 +48,8 @@ struct StreamConfiguration {
unsigned int bufferCount;
+ ColorSpace colorSpace;
+
Stream *stream() const { return stream_; }
void setStream(Stream *stream) { stream_ = stream; }
const StreamFormats &formats() const { return formats_; }
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index ba5f88cd..3e6c8b87 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -369,6 +369,11 @@ bool V4L2BufferCache::Entry::operator==(const FrameBuffer &buffer) const
* \brief The image size in pixels
*/
+/**
+ * \var V4L2DeviceFormat::colorSpace
+ * \brief The color space of the pixels
+ */
+
/**
* \var V4L2DeviceFormat::fourcc
* \brief The fourcc code describing the pixel encoding scheme
@@ -752,6 +757,114 @@ int V4L2VideoDevice::getFormat(V4L2DeviceFormat *format)
return getFormatSingleplane(format);
}
+static const std::vector<std::pair<ColorSpace, v4l2_colorspace>> colorSpaceToV4l2 = {
+ { ColorSpace::RAW, V4L2_COLORSPACE_RAW },
+ { ColorSpace::JFIF, V4L2_COLORSPACE_JPEG },
+ { ColorSpace::SMPTE170M, V4L2_COLORSPACE_SMPTE170M },
+ { ColorSpace::REC709, V4L2_COLORSPACE_REC709 },
+ { ColorSpace::REC2020, V4L2_COLORSPACE_BT2020 },
+};
+
+static const std::map<ColorSpace::Encoding, v4l2_ycbcr_encoding> encodingToV4l2 = {
+ { ColorSpace::Encoding::REC601, V4L2_YCBCR_ENC_601 },
+ { ColorSpace::Encoding::REC709, V4L2_YCBCR_ENC_709 },
+ { ColorSpace::Encoding::REC2020, V4L2_YCBCR_ENC_BT2020 },
+};
+
+static const std::map<ColorSpace::TransferFunction, v4l2_xfer_func> transferFunctionToV4l2 = {
+ { ColorSpace::TransferFunction::IDENTITY, V4L2_XFER_FUNC_NONE },
+ { ColorSpace::TransferFunction::SRGB, V4L2_XFER_FUNC_SRGB },
+ { ColorSpace::TransferFunction::REC709, V4L2_XFER_FUNC_709 },
+};
+
+static const std::map<ColorSpace::Range, v4l2_quantization> rangeToV4l2 = {
+ { ColorSpace::Range::FULL, V4L2_QUANTIZATION_FULL_RANGE },
+ { ColorSpace::Range::LIMITED, V4L2_QUANTIZATION_LIM_RANGE },
+};
+
+static const std::map<uint32_t, ColorSpace> v4l2ToColorSpace = {
+ { V4L2_COLORSPACE_RAW, ColorSpace::RAW },
+ { V4L2_COLORSPACE_JPEG, ColorSpace::JFIF },
+ { V4L2_COLORSPACE_SRGB, ColorSpace::JFIF },
+ { V4L2_COLORSPACE_SMPTE170M, ColorSpace::SMPTE170M },
+ { V4L2_COLORSPACE_REC709, ColorSpace::REC709 },
+ { V4L2_COLORSPACE_BT2020, ColorSpace::REC2020 },
+};
+
+static const std::map<uint32_t, ColorSpace::Encoding> v4l2ToEncoding = {
+ { V4L2_YCBCR_ENC_601, ColorSpace::Encoding::REC601 },
+ { V4L2_YCBCR_ENC_709, ColorSpace::Encoding::REC709 },
+ { V4L2_YCBCR_ENC_BT2020, ColorSpace::Encoding::REC2020 },
+};
+
+static const std::map<uint32_t, ColorSpace::TransferFunction> v4l2ToTransferFunction = {
+ { V4L2_XFER_FUNC_NONE, ColorSpace::TransferFunction::IDENTITY },
+ { V4L2_XFER_FUNC_SRGB, ColorSpace::TransferFunction::SRGB },
+ { V4L2_XFER_FUNC_709, ColorSpace::TransferFunction::REC709 },
+};
+
+static const std::map<uint32_t, ColorSpace::Range> v4l2ToRange = {
+ { V4L2_QUANTIZATION_FULL_RANGE, ColorSpace::Range::FULL },
+ { V4L2_QUANTIZATION_LIM_RANGE, ColorSpace::Range::LIMITED },
+};
+
+template<typename T>
+static void setColorSpace(const ColorSpace &colorSpace, T &v4l2PixFormat)
+{
+ if (!colorSpace.isFullyDefined())
+ LOG(V4L2, Warning) << "Setting non-fully defined colour space"
+ << colorSpace.toString();
+
+ v4l2PixFormat.colorspace = V4L2_COLORSPACE_DEFAULT;
+ v4l2PixFormat.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+ v4l2PixFormat.xfer_func = V4L2_XFER_FUNC_DEFAULT;
+ v4l2PixFormat.quantization = V4L2_QUANTIZATION_DEFAULT;
+
+ auto itColor = std::find_if(colorSpaceToV4l2.begin(), colorSpaceToV4l2.end(),
+ [&colorSpace](const std::pair<ColorSpace, v4l2_colorspace> &item) { return colorSpace == item.first; });
+ if (itColor != colorSpaceToV4l2.end())
+ v4l2PixFormat.colorspace = itColor->second;
+
+ auto itEncoding = encodingToV4l2.find(colorSpace.encoding);
+ if (itEncoding != encodingToV4l2.end())
+ v4l2PixFormat.ycbcr_enc = itEncoding->second;
+
+ auto itTransfer = transferFunctionToV4l2.find(colorSpace.transferFunction);
+ if (itTransfer != transferFunctionToV4l2.end())
+ v4l2PixFormat.xfer_func = itTransfer->second;
+
+ auto itRange = rangeToV4l2.find(colorSpace.range);
+ if (itRange != rangeToV4l2.end())
+ v4l2PixFormat.quantization = itRange->second;
+}
+
+template<typename T>
+static ColorSpace getColorSpace(const T &v4l2PixFormat)
+{
+ ColorSpace colorSpace;
+
+ auto itColor = v4l2ToColorSpace.find(v4l2PixFormat.colorspace);
+ if (itColor != v4l2ToColorSpace.end())
+ colorSpace = itColor->second;
+
+ auto itEncoding = v4l2ToEncoding.find(v4l2PixFormat.ycbcr_enc);
+ if (itEncoding != v4l2ToEncoding.end())
+ colorSpace.encoding = itEncoding->second;
+
+ auto itTransfer = v4l2ToTransferFunction.find(v4l2PixFormat.xfer_func);
+ if (itTransfer != v4l2ToTransferFunction.end())
+ colorSpace.transferFunction = itTransfer->second;
+
+ auto itRange = v4l2ToRange.find(v4l2PixFormat.quantization);
+ if (itRange != v4l2ToRange.end())
+ colorSpace.range = itRange->second;
+
+ if (!colorSpace.isFullyDefined())
+ LOG(V4L2, Warning) << "Returning non-fully defined colour space"
+ << colorSpace.toString();
+ return colorSpace;
+}
+
/**
* \brief Try an image format on the V4L2 video device
* \param[inout] format The image format to test applicability to the video device
@@ -871,6 +984,7 @@ int V4L2VideoDevice::getFormatMultiplane(V4L2DeviceFormat *format)
format->size.width = pix->width;
format->size.height = pix->height;
format->fourcc = V4L2PixelFormat(pix->pixelformat);
+ format->colorSpace = getColorSpace(*pix);
format->planesCount = pix->num_planes;
for (unsigned int i = 0; i < format->planesCount; ++i) {
@@ -893,6 +1007,7 @@ int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set)
pix->pixelformat = format->fourcc;
pix->num_planes = format->planesCount;
pix->field = V4L2_FIELD_NONE;
+ setColorSpace(format->colorSpace, *pix);
ASSERT(pix->num_planes <= std::size(pix->plane_fmt));
@@ -921,6 +1036,7 @@ int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set)
format->planes[i].bpl = pix->plane_fmt[i].bytesperline;
format->planes[i].size = pix->plane_fmt[i].sizeimage;
}
+ format->colorSpace = getColorSpace(*pix);
return 0;
}
@@ -941,6 +1057,7 @@ int V4L2VideoDevice::getFormatSingleplane(V4L2DeviceFormat *format)
format->size.width = pix->width;
format->size.height = pix->height;
format->fourcc = V4L2PixelFormat(pix->pixelformat);
+ format->colorSpace = getColorSpace(*pix);
format->planesCount = 1;
format->planes[0].bpl = pix->bytesperline;
format->planes[0].size = pix->sizeimage;
@@ -960,6 +1077,7 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set)
pix->pixelformat = format->fourcc;
pix->bytesperline = format->planes[0].bpl;
pix->field = V4L2_FIELD_NONE;
+ setColorSpace(format->colorSpace, *pix);
ret = ioctl(set ? VIDIOC_S_FMT : VIDIOC_TRY_FMT, &v4l2Format);
if (ret) {
LOG(V4L2, Error)
@@ -978,6 +1096,7 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set)
format->planesCount = 1;
format->planes[0].bpl = pix->bytesperline;
format->planes[0].size = pix->sizeimage;
+ format->colorSpace = getColorSpace(*pix);
return 0;
}
--
2.20.1
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