[libcamera-devel] [PATCH v5 4/7] libcamera: Support passing ColorSpaces to V4L2 video devices
Jacopo Mondi
jacopo at jmondi.org
Sat Nov 6 17:32:20 CET 2021
Hi David,
On Thu, Nov 04, 2021 at 01:58:02PM +0000, David Plowman wrote:
> The ColorSpace from the StreamConfiguration is now handled
> appropriately in the V4L2VideoDevice.
>
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
> include/libcamera/internal/v4l2_videodevice.h | 2 +
> src/libcamera/v4l2_videodevice.cpp | 67 +++++++++++++++++--
> 2 files changed, 65 insertions(+), 4 deletions(-)
>
> diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h
> index a1c458e4..6ca749c1 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>
> @@ -167,6 +168,7 @@ public:
>
> V4L2PixelFormat fourcc;
> Size size;
> + ColorSpace colorSpace;
>
> std::array<Plane, 3> planes;
> unsigned int planesCount = 0;
> diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
> index 4f04212d..ccf3d28c 100644
> --- a/src/libcamera/v4l2_videodevice.cpp
> +++ b/src/libcamera/v4l2_videodevice.cpp
> @@ -370,17 +370,29 @@ bool V4L2BufferCache::Entry::operator==(const FrameBuffer &buffer) const
> * \brief The plane line stride (in bytes)
> */
>
> +/**
> + * \var V4L2DeviceFormat::fourcc
> + * \brief The fourcc code describing the pixel encoding scheme
> + *
> + * The fourcc code, as defined by the V4L2 API with the V4L2_PIX_FMT_* macros,
> + * that identifies the image format pixel encoding scheme.
> + */
> +
> /**
> * \var V4L2DeviceFormat::size
> * \brief The image size in pixels
> */
>
> /**
> - * \var V4L2DeviceFormat::fourcc
> - * \brief The fourcc code describing the pixel encoding scheme
> + * \var V4L2DeviceFormat::colorSpace
> + * \brief The color space of the pixels
> *
> - * The fourcc code, as defined by the V4L2 API with the V4L2_PIX_FMT_* macros,
> - * that identifies the image format pixel encoding scheme.
> + * When setting or trying a format, passing in "Undefined" fields in the
> + * ColorSpace is not permitted because the driver will then make an
> + * arbitrary choice of its own. Choices made by the driver will be
> + * passed back in the normal way, though note that "Undefined" values can
> + * be returned if the device has chosen something that the ColorSpace
> + * class cannot represent.
> */
>
> /**
> @@ -879,6 +891,12 @@ int V4L2VideoDevice::getFormatMultiplane(V4L2DeviceFormat *format)
> format->fourcc = V4L2PixelFormat(pix->pixelformat);
> format->planesCount = pix->num_planes;
>
> + format->colorSpace = toColorSpace(*pix);
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Warning)
> + << "Retrieved undefined color space: "
> + << format->colorSpace.toString();
> +
If this gets in in the current form, all other platforms will have
their log polluted by these messages. For most pipeline handlers I
assume with the appropriate knowledge if applications are not
instrumented to pass in a valid color space, it can be adjusted to
something meaningul. But what about the simple pipeline handler which
works with devices that simply transfer to application streams in
YUV/RGB formats produced by the sensor ? What colorspace should
pipeline handler adjust to ?
> for (unsigned int i = 0; i < format->planesCount; ++i) {
> format->planes[i].bpl = pix->plane_fmt[i].bytesperline;
> format->planes[i].size = pix->plane_fmt[i].sizeimage;
> @@ -893,6 +911,11 @@ int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set)
> struct v4l2_pix_format_mplane *pix = &v4l2Format.fmt.pix_mp;
> int ret;
>
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Error)
> + << "Trying to set undefined color space: "
> + << format->colorSpace.toString();
> +
> v4l2Format.type = bufferType_;
> pix->width = format->size.width;
> pix->height = format->size.height;
> @@ -900,6 +923,12 @@ int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set)
> pix->num_planes = format->planesCount;
> pix->field = V4L2_FIELD_NONE;
>
> + ret = fromColorSpace(format->colorSpace, *pix);
> + if (ret < 0)
> + LOG(V4L2, Warning)
> + << "Setting color space unrecognised by V4L2: "
> + << format->colorSpace.toString();
> +
> ASSERT(pix->num_planes <= std::size(pix->plane_fmt));
>
> for (unsigned int i = 0; i < pix->num_planes; ++i) {
> @@ -928,6 +957,12 @@ int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set)
> format->planes[i].size = pix->plane_fmt[i].sizeimage;
> }
>
> + format->colorSpace = toColorSpace(*pix);
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Warning)
> + << "Undefined color space has been set: "
> + << format->colorSpace.toString();
> +
> return 0;
> }
>
> @@ -951,6 +986,12 @@ int V4L2VideoDevice::getFormatSingleplane(V4L2DeviceFormat *format)
> format->planes[0].bpl = pix->bytesperline;
> format->planes[0].size = pix->sizeimage;
>
> + format->colorSpace = toColorSpace(*pix);
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Warning)
> + << "Retrieved undefined color space: "
> + << format->colorSpace.toString();
> +
> return 0;
> }
>
> @@ -960,12 +1001,24 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set)
> struct v4l2_pix_format *pix = &v4l2Format.fmt.pix;
> int ret;
>
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Error)
> + << "Trying to set undefined color space: "
> + << format->colorSpace.toString();
> +
> v4l2Format.type = bufferType_;
> pix->width = format->size.width;
> pix->height = format->size.height;
> pix->pixelformat = format->fourcc;
> pix->bytesperline = format->planes[0].bpl;
> pix->field = V4L2_FIELD_NONE;
> +
> + ret = fromColorSpace(format->colorSpace, *pix);
> + if (ret < 0)
> + LOG(V4L2, Warning)
> + << "Set color space unrecognised by V4L2: "
> + << format->colorSpace.toString();
> +
> ret = ioctl(set ? VIDIOC_S_FMT : VIDIOC_TRY_FMT, &v4l2Format);
> if (ret) {
> LOG(V4L2, Error)
> @@ -985,6 +1038,12 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set)
> format->planes[0].bpl = pix->bytesperline;
> format->planes[0].size = pix->sizeimage;
>
> + format->colorSpace = toColorSpace(*pix);
> + if (!format->colorSpace.isFullyDefined())
> + LOG(V4L2, Warning)
> + << "Undefined color space has been set: "
> + << format->colorSpace.toString();
> +
> return 0;
> }
>
> --
> 2.20.1
>
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