[{"id":21465,"web_url":"https://patchwork.libcamera.org/comment/21465/","msgid":"<20211130211105.v6yx2crkwea5us6u@uno.localdomain>","date":"2021-11-30T21:11:05","subject":"Re: [libcamera-devel] [PATCH v7 3/7] libcamera: Convert between\n\tColorSpace class and V4L2 formats","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"content":"Hi David\n\nOn Fri, Nov 26, 2021 at 10:40:41AM +0000, David Plowman wrote:\n> Add functions to the V4L2Device class to convert to and from\n> libcamera ColorSpace.\n>\n> These methods are added to the base V4L2Device class so that they can\n> be shared both by the video device class and subdevices.\n>\n> With the ColorSpace class, the color space and related other fields\n> are stored together, corresponding to a number of fields in the\n> various different V4L2 format structures. Template methods are\n> therefore a convenient implementation, and we must explicitly\n> instantiate the templates that will be needed.\n>\n> Note that unset color spaces are converted to requests for the\n> device's \"default\" color space.\n>\n> Signed-off-by: David Plowman \n> ---\n> include/libcamera/internal/v4l2_device.h | 7 +\n> src/libcamera/v4l2_device.cpp | 192 +++++++++++++++++++++++\n> 2 files changed, 199 insertions(+)\n>\n> diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h\n> index 7816a290..7f9b0f42 100644\n> --- a/include/libcamera/internal/v4l2_device.h\n> +++ b/include/libcamera/internal/v4l2_device.h\n> @@ -17,6 +17,7 @@\n> #include \n> #include \n>\n> +#include \n> #include \n>\n> namespace libcamera {\n> @@ -44,6 +45,12 @@ public:\n>\n> \tvoid updateControlInfo();\n>\n> +\ttemplate\n> +\tstatic std::optional toColorSpace(const T &v4l2Format);\n> +\n> +\ttemplate\n> +\tstatic int fromColorSpace(const std::optional &colorSpace, T &v4l2Format);\n> +\n\nThese can be protected\n\nReviewed-by: Jacopo Mondi \n\nThanks\n j\n\n> protected:\n> \tV4L2Device(const std::string &deviceNode);\n> \t~V4L2Device();\n> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\n> index 9c783c9c..df92fa9e 100644\n> --- a/src/libcamera/v4l2_device.cpp\n> +++ b/src/libcamera/v4l2_device.cpp\n> @@ -16,6 +16,8 @@\n> #include \n> #include \n>\n> +#include \n> +\n> #include \n> #include \n> #include \n> @@ -731,4 +733,194 @@ void V4L2Device::eventAvailable()\n> \tframeStart.emit(event.u.frame_sync.frame_sequence);\n> }\n>\n> +static const std::map v4l2ToColorSpace = {\n> +\t{ V4L2_COLORSPACE_RAW, ColorSpace::Raw },\n> +\t{ V4L2_COLORSPACE_JPEG, ColorSpace::Jpeg },\n> +\t{ V4L2_COLORSPACE_SRGB, ColorSpace::Srgb },\n> +\t{ V4L2_COLORSPACE_SMPTE170M, ColorSpace::Smpte170m },\n> +\t{ V4L2_COLORSPACE_REC709, ColorSpace::Rec709 },\n> +\t{ V4L2_COLORSPACE_BT2020, ColorSpace::Rec2020 },\n> +};\n> +\n> +static const std::map v4l2ToYcbcrEncoding = {\n> +\t{ V4L2_YCBCR_ENC_601, ColorSpace::YcbcrEncoding::Rec601 },\n> +\t{ V4L2_YCBCR_ENC_709, ColorSpace::YcbcrEncoding::Rec709 },\n> +\t{ V4L2_YCBCR_ENC_BT2020, ColorSpace::YcbcrEncoding::Rec2020 },\n> +};\n> +\n> +static const std::map v4l2ToTransferFunction = {\n> +\t{ V4L2_XFER_FUNC_NONE, ColorSpace::TransferFunction::Linear },\n> +\t{ V4L2_XFER_FUNC_SRGB, ColorSpace::TransferFunction::Srgb },\n> +\t{ V4L2_XFER_FUNC_709, ColorSpace::TransferFunction::Rec709 },\n> +};\n> +\n> +static const std::map v4l2ToRange = {\n> +\t{ V4L2_QUANTIZATION_FULL_RANGE, ColorSpace::Range::Full },\n> +\t{ V4L2_QUANTIZATION_LIM_RANGE, ColorSpace::Range::Limited },\n> +};\n> +\n> +static const std::vector> colorSpaceToV4l2 = {\n> +\t{ ColorSpace::Raw, V4L2_COLORSPACE_RAW },\n> +\t{ ColorSpace::Jpeg, V4L2_COLORSPACE_JPEG },\n> +\t{ ColorSpace::Srgb, V4L2_COLORSPACE_SRGB },\n> +\t{ ColorSpace::Smpte170m, V4L2_COLORSPACE_SMPTE170M },\n> +\t{ ColorSpace::Rec709, V4L2_COLORSPACE_REC709 },\n> +\t{ ColorSpace::Rec2020, V4L2_COLORSPACE_BT2020 },\n> +};\n> +\n> +static const std::map primariesToV4l2 = {\n> +\t{ ColorSpace::Primaries::Raw, V4L2_COLORSPACE_RAW },\n> +\t{ ColorSpace::Primaries::Smpte170m, V4L2_COLORSPACE_SMPTE170M },\n> +\t{ ColorSpace::Primaries::Rec709, V4L2_COLORSPACE_REC709 },\n> +\t{ ColorSpace::Primaries::Rec2020, V4L2_COLORSPACE_BT2020 },\n> +};\n> +\n> +static const std::map ycbcrEncodingToV4l2 = {\n> +\t{ ColorSpace::YcbcrEncoding::Rec601, V4L2_YCBCR_ENC_601 },\n> +\t{ ColorSpace::YcbcrEncoding::Rec709, V4L2_YCBCR_ENC_709 },\n> +\t{ ColorSpace::YcbcrEncoding::Rec2020, V4L2_YCBCR_ENC_BT2020 },\n> +};\n> +\n> +static const std::map transferFunctionToV4l2 = {\n> +\t{ ColorSpace::TransferFunction::Linear, V4L2_XFER_FUNC_NONE },\n> +\t{ ColorSpace::TransferFunction::Srgb, V4L2_XFER_FUNC_SRGB },\n> +\t{ ColorSpace::TransferFunction::Rec709, V4L2_XFER_FUNC_709 },\n> +};\n> +\n> +static const std::map rangeToV4l2 = {\n> +\t{ ColorSpace::Range::Full, V4L2_QUANTIZATION_FULL_RANGE },\n> +\t{ ColorSpace::Range::Limited, V4L2_QUANTIZATION_LIM_RANGE },\n> +};\n> +\n> +/**\n> + * \\brief Convert the color space fields in a V4L2 format to a ColorSpace\n> + * \\param[in] v4l2Format A V4L2 format containing color space information\n> + *\n> + * The colorspace, ycbcr_enc, xfer_func and quantization fields within a\n> + * V4L2 format structure are converted to a corresponding ColorSpace.\n> + *\n> + * If any V4L2 fields are not recognised then we return an \"unset\"\n> + * color space.\n> + *\n> + * \\return The ColorSpace corresponding to the input V4L2 format\n> + * \\retval std::nullopt One or more V4L2 color space fields were not recognised\n> + */\n> +template\n> +std::optional V4L2Device::toColorSpace(const T &v4l2Format)\n> +{\n> +\tauto itColor = v4l2ToColorSpace.find(v4l2Format.colorspace);\n> +\tif (itColor == v4l2ToColorSpace.end())\n> +\t\treturn std::nullopt;\n> +\n> +\t/* This sets all the color space fields to the correct \"default\" values. */\n> +\tColorSpace colorSpace = itColor->second;\n> +\n> +\tif (v4l2Format.ycbcr_enc != V4L2_YCBCR_ENC_DEFAULT) {\n> +\t\tauto itYcbcrEncoding = v4l2ToYcbcrEncoding.find(v4l2Format.ycbcr_enc);\n> +\t\tif (itYcbcrEncoding == v4l2ToYcbcrEncoding.end())\n> +\t\t\treturn std::nullopt;\n> +\n> +\t\tcolorSpace.ycbcrEncoding = itYcbcrEncoding->second;\n> +\t}\n> +\n> +\tif (v4l2Format.xfer_func != V4L2_XFER_FUNC_DEFAULT) {\n> +\t\tauto itTransfer = v4l2ToTransferFunction.find(v4l2Format.xfer_func);\n> +\t\tif (itTransfer == v4l2ToTransferFunction.end())\n> +\t\t\treturn std::nullopt;\n> +\n> +\t\tcolorSpace.transferFunction = itTransfer->second;\n> +\t}\n> +\n> +\tif (v4l2Format.quantization != V4L2_QUANTIZATION_DEFAULT) {\n> +\t\tauto itRange = v4l2ToRange.find(v4l2Format.quantization);\n> +\t\tif (itRange == v4l2ToRange.end())\n> +\t\t\treturn std::nullopt;\n> +\n> +\t\tcolorSpace.range = itRange->second;\n> +\t}\n> +\n> +\treturn colorSpace;\n> +}\n> +\n> +template std::optional V4L2Device::toColorSpace(const struct v4l2_pix_format &);\n> +template std::optional V4L2Device::toColorSpace(const struct v4l2_pix_format_mplane &);\n> +template std::optional V4L2Device::toColorSpace(const struct v4l2_mbus_framefmt &);\n> +\n> +/**\n> + * \\brief Fill in the color space fields of a V4L2 format from a ColorSpace\n> + * \\param[in] colorSpace The ColorSpace to be converted\n> + * \\param[out] v4l2Format A V4L2 format containing color space information\n> + *\n> + * The colorspace, ycbcr_enc, xfer_func and quantization fields within a\n> + * V4L2 format structure are filled in from a corresponding ColorSpace.\n> + *\n> + * An error is returned if any of the V4L2 fields do not support the\n> + * value given in the ColorSpace. Such fields are set to the V4L2\n> + * \"default\" values, but all other fields are still filled in where\n> + * possible.\n> + *\n> + * If the color space is completely unset, \"default\" V4L2 values are used\n> + * everywhere, so a driver would then choose its preferred color space.\n> + *\n> + * \\return 0 on success or a negative error code otherwise\n> + * \\retval -EINVAL The ColorSpace does not have a representation using V4L2 enums\n> + */\n> +template\n> +int V4L2Device::fromColorSpace(const std::optional &colorSpace, T &v4l2Format)\n> +{\n> +\tv4l2Format.colorspace = V4L2_COLORSPACE_DEFAULT;\n> +\tv4l2Format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;\n> +\tv4l2Format.xfer_func = V4L2_XFER_FUNC_DEFAULT;\n> +\tv4l2Format.quantization = V4L2_QUANTIZATION_DEFAULT;\n> +\n> +\tif (!colorSpace)\n> +\t\treturn 0;\n> +\n> +\tauto itColor = std::find_if(colorSpaceToV4l2.begin(), colorSpaceToV4l2.end(),\n> +\t\t\t\t [&colorSpace](const auto &item) {\n> +\t\t\t\t\t return colorSpace == item.first;\n> +\t\t\t\t });\n> +\tif (itColor != colorSpaceToV4l2.end()) {\n> +\t\tv4l2Format.colorspace = itColor->second;\n> +\t\t/* Leaving all the other fields as \"default\" should be fine. */\n> +\t\treturn 0;\n> +\t}\n> +\n> +\t/*\n> +\t * If the colorSpace doesn't precisely match a standard color space,\n> +\t * then we must choose a V4L2 colorspace with matching primaries.\n> +\t */\n> +\tint ret = 0;\n> +\n> +\tauto itPrimaries = primariesToV4l2.find(colorSpace->primaries);\n> +\tif (itPrimaries != primariesToV4l2.end())\n> +\t\tv4l2Format.colorspace = itPrimaries->second;\n> +\telse\n> +\t\tret = -EINVAL;\n> +\n> +\tauto itYcbcrEncoding = ycbcrEncodingToV4l2.find(colorSpace->ycbcrEncoding);\n> +\tif (itYcbcrEncoding != ycbcrEncodingToV4l2.end())\n> +\t\tv4l2Format.ycbcr_enc = itYcbcrEncoding->second;\n> +\telse\n> +\t\tret = -EINVAL;\n> +\n> +\tauto itTransfer = transferFunctionToV4l2.find(colorSpace->transferFunction);\n> +\tif (itTransfer != transferFunctionToV4l2.end())\n> +\t\tv4l2Format.xfer_func = itTransfer->second;\n> +\telse\n> +\t\tret = -EINVAL;\n> +\n> +\tauto itRange = rangeToV4l2.find(colorSpace->range);\n> +\tif (itRange != rangeToV4l2.end())\n> +\t\tv4l2Format.quantization = itRange->second;\n> +\telse\n> +\t\tret = -EINVAL;\n> +\n> +\treturn ret;\n> +}\n> +\n> +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_pix_format &);\n> +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_pix_format_mplane &);\n> +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_mbus_framefmt &);\n> +\n> } /* namespace libcamera */\n> --\n> 2.30.2\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id AD7C9BDB13\n\tfor ;\n\tTue, 30 Nov 2021 21:10:18 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id B85A060723;\n\tTue, 30 Nov 2021 22:10:17 +0100 (CET)","from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net\n\t[217.70.183.193])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DCE45605C4\n\tfor ;\n\tTue, 30 Nov 2021 22:10:15 +0100 (CET)","(Authenticated sender: jacopo@jmondi.org)\n\tby relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 78A9E240002;\n\tTue, 30 Nov 2021 21:10:13 +0000 (UTC)"],"Date":"Tue, 30 Nov 2021 22:11:05 +0100","From":"Jacopo Mondi ","To":"David Plowman ","Message-ID":"<20211130211105.v6yx2crkwea5us6u@uno.localdomain>","References":"<20211126104045.4756-1-david.plowman@raspberrypi.com>\n\t<20211126104045.4756-4-david.plowman@raspberrypi.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20211126104045.4756-4-david.plowman@raspberrypi.com>","Subject":"Re: [libcamera-devel] [PATCH v7 3/7] libcamera: Convert between\n\tColorSpace class and V4L2 formats","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"Tomasz Figa , libcamera-devel@lists.libcamera.org,\n\tHans Verkuil ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":21515,"web_url":"https://patchwork.libcamera.org/comment/21515/","msgid":"","date":"2021-12-01T11:50:50","subject":"Re: [libcamera-devel] [PATCH v7 3/7] libcamera: Convert between\n\tColorSpace class and V4L2 formats","submitter":{"id":42,"url":"https://patchwork.libcamera.org/api/people/42/","name":"David Plowman","email":"david.plowman@raspberrypi.com"},"content":"Hi Jacopo\n\nThanks for the review!\n\nOn Tue, 30 Nov 2021 at 21:10, Jacopo Mondi wrote:\n>\n> Hi David\n>\n> On Fri, Nov 26, 2021 at 10:40:41AM +0000, David Plowman wrote:\n> > Add functions to the V4L2Device class to convert to and from\n> > libcamera ColorSpace.\n> >\n> > These methods are added to the base V4L2Device class so that they can\n> > be shared both by the video device class and subdevices.\n> >\n> > With the ColorSpace class, the color space and related other fields\n> > are stored together, corresponding to a number of fields in the\n> > various different V4L2 format structures. Template methods are\n> > therefore a convenient implementation, and we must explicitly\n> > instantiate the templates that will be needed.\n> >\n> > Note that unset color spaces are converted to requests for the\n> > device's \"default\" color space.\n> >\n> > Signed-off-by: David Plowman \n> > ---\n> > include/libcamera/internal/v4l2_device.h | 7 +\n> > src/libcamera/v4l2_device.cpp | 192 +++++++++++++++++++++++\n> > 2 files changed, 199 insertions(+)\n> >\n> > diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h\n> > index 7816a290..7f9b0f42 100644\n> > --- a/include/libcamera/internal/v4l2_device.h\n> > +++ b/include/libcamera/internal/v4l2_device.h\n> > @@ -17,6 +17,7 @@\n> > #include \n> > #include \n> >\n> > +#include \n> > #include \n> >\n> > namespace libcamera {\n> > @@ -44,6 +45,12 @@ public:\n> >\n> > void updateControlInfo();\n> >\n> > + template\n> > + static std::optional toColorSpace(const T &v4l2Format);\n> > +\n> > + template\n> > + static int fromColorSpace(const std::optional &colorSpace, T &v4l2Format);\n> > +\n>\n> These can be protected\n\nSo the only reason I didn't do this was that I could envisage pipeline\nhandlers wanting to check if their chosen colour space is known to\nV4L2. I know that can't happen at the moment, but there is a possible\nfuture with new or custom colour spaces... But that's all a bit\nhypothetical, so maybe it's better to make them protected now and\nchange it back later if we ever want to?\n\nBut I don't feel strongly - happy to change this if folks prefer it that way!\n\nThanks\nDavid\n\n>\n> Reviewed-by: Jacopo Mondi \n>\n> Thanks\n> j\n>\n> > protected:\n> > V4L2Device(const std::string &deviceNode);\n> > ~V4L2Device();\n> > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\n> > index 9c783c9c..df92fa9e 100644\n> > --- a/src/libcamera/v4l2_device.cpp\n> > +++ b/src/libcamera/v4l2_device.cpp\n> > @@ -16,6 +16,8 @@\n> > #include \n> > #include \n> >\n> > +#include \n> > +\n> > #include \n> > #include \n> > #include \n> > @@ -731,4 +733,194 @@ void V4L2Device::eventAvailable()\n> > frameStart.emit(event.u.frame_sync.frame_sequence);\n> > }\n> >\n> > +static const std::map v4l2ToColorSpace = {\n> > + { V4L2_COLORSPACE_RAW, ColorSpace::Raw },\n> > + { V4L2_COLORSPACE_JPEG, ColorSpace::Jpeg },\n> > + { V4L2_COLORSPACE_SRGB, ColorSpace::Srgb },\n> > + { V4L2_COLORSPACE_SMPTE170M, ColorSpace::Smpte170m },\n> > + { V4L2_COLORSPACE_REC709, ColorSpace::Rec709 },\n> > + { V4L2_COLORSPACE_BT2020, ColorSpace::Rec2020 },\n> > +};\n> > +\n> > +static const std::map v4l2ToYcbcrEncoding = {\n> > + { V4L2_YCBCR_ENC_601, ColorSpace::YcbcrEncoding::Rec601 },\n> > + { V4L2_YCBCR_ENC_709, ColorSpace::YcbcrEncoding::Rec709 },\n> > + { V4L2_YCBCR_ENC_BT2020, ColorSpace::YcbcrEncoding::Rec2020 },\n> > +};\n> > +\n> > +static const std::map v4l2ToTransferFunction = {\n> > + { V4L2_XFER_FUNC_NONE, ColorSpace::TransferFunction::Linear },\n> > + { V4L2_XFER_FUNC_SRGB, ColorSpace::TransferFunction::Srgb },\n> > + { V4L2_XFER_FUNC_709, ColorSpace::TransferFunction::Rec709 },\n> > +};\n> > +\n> > +static const std::map v4l2ToRange = {\n> > + { V4L2_QUANTIZATION_FULL_RANGE, ColorSpace::Range::Full },\n> > + { V4L2_QUANTIZATION_LIM_RANGE, ColorSpace::Range::Limited },\n> > +};\n> > +\n> > +static const std::vector> colorSpaceToV4l2 = {\n> > + { ColorSpace::Raw, V4L2_COLORSPACE_RAW },\n> > + { ColorSpace::Jpeg, V4L2_COLORSPACE_JPEG },\n> > + { ColorSpace::Srgb, V4L2_COLORSPACE_SRGB },\n> > + { ColorSpace::Smpte170m, V4L2_COLORSPACE_SMPTE170M },\n> > + { ColorSpace::Rec709, V4L2_COLORSPACE_REC709 },\n> > + { ColorSpace::Rec2020, V4L2_COLORSPACE_BT2020 },\n> > +};\n> > +\n> > +static const std::map primariesToV4l2 = {\n> > + { ColorSpace::Primaries::Raw, V4L2_COLORSPACE_RAW },\n> > + { ColorSpace::Primaries::Smpte170m, V4L2_COLORSPACE_SMPTE170M },\n> > + { ColorSpace::Primaries::Rec709, V4L2_COLORSPACE_REC709 },\n> > + { ColorSpace::Primaries::Rec2020, V4L2_COLORSPACE_BT2020 },\n> > +};\n> > +\n> > +static const std::map ycbcrEncodingToV4l2 = {\n> > + { ColorSpace::YcbcrEncoding::Rec601, V4L2_YCBCR_ENC_601 },\n> > + { ColorSpace::YcbcrEncoding::Rec709, V4L2_YCBCR_ENC_709 },\n> > + { ColorSpace::YcbcrEncoding::Rec2020, V4L2_YCBCR_ENC_BT2020 },\n> > +};\n> > +\n> > +static const std::map transferFunctionToV4l2 = {\n> > + { ColorSpace::TransferFunction::Linear, V4L2_XFER_FUNC_NONE },\n> > + { ColorSpace::TransferFunction::Srgb, V4L2_XFER_FUNC_SRGB },\n> > + { ColorSpace::TransferFunction::Rec709, V4L2_XFER_FUNC_709 },\n> > +};\n> > +\n> > +static const std::map rangeToV4l2 = {\n> > + { ColorSpace::Range::Full, V4L2_QUANTIZATION_FULL_RANGE },\n> > + { ColorSpace::Range::Limited, V4L2_QUANTIZATION_LIM_RANGE },\n> > +};\n> > +\n> > +/**\n> > + * \\brief Convert the color space fields in a V4L2 format to a ColorSpace\n> > + * \\param[in] v4l2Format A V4L2 format containing color space information\n> > + *\n> > + * The colorspace, ycbcr_enc, xfer_func and quantization fields within a\n> > + * V4L2 format structure are converted to a corresponding ColorSpace.\n> > + *\n> > + * If any V4L2 fields are not recognised then we return an \"unset\"\n> > + * color space.\n> > + *\n> > + * \\return The ColorSpace corresponding to the input V4L2 format\n> > + * \\retval std::nullopt One or more V4L2 color space fields were not recognised\n> > + */\n> > +template\n> > +std::optional V4L2Device::toColorSpace(const T &v4l2Format)\n> > +{\n> > + auto itColor = v4l2ToColorSpace.find(v4l2Format.colorspace);\n> > + if (itColor == v4l2ToColorSpace.end())\n> > + return std::nullopt;\n> > +\n> > + /* This sets all the color space fields to the correct \"default\" values. */\n> > + ColorSpace colorSpace = itColor->second;\n> > +\n> > + if (v4l2Format.ycbcr_enc != V4L2_YCBCR_ENC_DEFAULT) {\n> > + auto itYcbcrEncoding = v4l2ToYcbcrEncoding.find(v4l2Format.ycbcr_enc);\n> > + if (itYcbcrEncoding == v4l2ToYcbcrEncoding.end())\n> > + return std::nullopt;\n> > +\n> > + colorSpace.ycbcrEncoding = itYcbcrEncoding->second;\n> > + }\n> > +\n> > + if (v4l2Format.xfer_func != V4L2_XFER_FUNC_DEFAULT) {\n> > + auto itTransfer = v4l2ToTransferFunction.find(v4l2Format.xfer_func);\n> > + if (itTransfer == v4l2ToTransferFunction.end())\n> > + return std::nullopt;\n> > +\n> > + colorSpace.transferFunction = itTransfer->second;\n> > + }\n> > +\n> > + if (v4l2Format.quantization != V4L2_QUANTIZATION_DEFAULT) {\n> > + auto itRange = v4l2ToRange.find(v4l2Format.quantization);\n> > + if (itRange == v4l2ToRange.end())\n> > + return std::nullopt;\n> > +\n> > + colorSpace.range = itRange->second;\n> > + }\n> > +\n> > + return colorSpace;\n> > +}\n> > +\n> > +template std::optional V4L2Device::toColorSpace(const struct v4l2_pix_format &);\n> > +template std::optional V4L2Device::toColorSpace(const struct v4l2_pix_format_mplane &);\n> > +template std::optional V4L2Device::toColorSpace(const struct v4l2_mbus_framefmt &);\n> > +\n> > +/**\n> > + * \\brief Fill in the color space fields of a V4L2 format from a ColorSpace\n> > + * \\param[in] colorSpace The ColorSpace to be converted\n> > + * \\param[out] v4l2Format A V4L2 format containing color space information\n> > + *\n> > + * The colorspace, ycbcr_enc, xfer_func and quantization fields within a\n> > + * V4L2 format structure are filled in from a corresponding ColorSpace.\n> > + *\n> > + * An error is returned if any of the V4L2 fields do not support the\n> > + * value given in the ColorSpace. Such fields are set to the V4L2\n> > + * \"default\" values, but all other fields are still filled in where\n> > + * possible.\n> > + *\n> > + * If the color space is completely unset, \"default\" V4L2 values are used\n> > + * everywhere, so a driver would then choose its preferred color space.\n> > + *\n> > + * \\return 0 on success or a negative error code otherwise\n> > + * \\retval -EINVAL The ColorSpace does not have a representation using V4L2 enums\n> > + */\n> > +template\n> > +int V4L2Device::fromColorSpace(const std::optional &colorSpace, T &v4l2Format)\n> > +{\n> > + v4l2Format.colorspace = V4L2_COLORSPACE_DEFAULT;\n> > + v4l2Format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;\n> > + v4l2Format.xfer_func = V4L2_XFER_FUNC_DEFAULT;\n> > + v4l2Format.quantization = V4L2_QUANTIZATION_DEFAULT;\n> > +\n> > + if (!colorSpace)\n> > + return 0;\n> > +\n> > + auto itColor = std::find_if(colorSpaceToV4l2.begin(), colorSpaceToV4l2.end(),\n> > + [&colorSpace](const auto &item) {\n> > + return colorSpace == item.first;\n> > + });\n> > + if (itColor != colorSpaceToV4l2.end()) {\n> > + v4l2Format.colorspace = itColor->second;\n> > + /* Leaving all the other fields as \"default\" should be fine. */\n> > + return 0;\n> > + }\n> > +\n> > + /*\n> > + * If the colorSpace doesn't precisely match a standard color space,\n> > + * then we must choose a V4L2 colorspace with matching primaries.\n> > + */\n> > + int ret = 0;\n> > +\n> > + auto itPrimaries = primariesToV4l2.find(colorSpace->primaries);\n> > + if (itPrimaries != primariesToV4l2.end())\n> > + v4l2Format.colorspace = itPrimaries->second;\n> > + else\n> > + ret = -EINVAL;\n> > +\n> > + auto itYcbcrEncoding = ycbcrEncodingToV4l2.find(colorSpace->ycbcrEncoding);\n> > + if (itYcbcrEncoding != ycbcrEncodingToV4l2.end())\n> > + v4l2Format.ycbcr_enc = itYcbcrEncoding->second;\n> > + else\n> > + ret = -EINVAL;\n> > +\n> > + auto itTransfer = transferFunctionToV4l2.find(colorSpace->transferFunction);\n> > + if (itTransfer != transferFunctionToV4l2.end())\n> > + v4l2Format.xfer_func = itTransfer->second;\n> > + else\n> > + ret = -EINVAL;\n> > +\n> > + auto itRange = rangeToV4l2.find(colorSpace->range);\n> > + if (itRange != rangeToV4l2.end())\n> > + v4l2Format.quantization = itRange->second;\n> > + else\n> > + ret = -EINVAL;\n> > +\n> > + return ret;\n> > +}\n> > +\n> > +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_pix_format &);\n> > +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_pix_format_mplane &);\n> > +template int V4L2Device::fromColorSpace(const std::optional &, struct v4l2_mbus_framefmt &);\n> > +\n> > } /* namespace libcamera */\n> > --\n> > 2.30.2\n> >","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 48052BDB13\n\tfor ;\n\tWed, 1 Dec 2021 11:51:04 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A48E26071A;\n\tWed, 1 Dec 2021 12:51:03 +0100 (CET)","from mail-wr1-x433.google.com (mail-wr1-x433.google.com\n\t[IPv6:2a00:1450:4864:20::433])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id AF2466011A\n\tfor ;\n\tWed, 1 Dec 2021 12:51:01 +0100 (CET)","by mail-wr1-x433.google.com with SMTP id o13so51485255wrs.12\n\tfor ;\n\tWed, 01 Dec 2021 03:51:01 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=raspberrypi.com header.i=@raspberrypi.com\n\theader.b=\"h/oggjTt\"; 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charset=\"UTF-8\"","Subject":"Re: [libcamera-devel] [PATCH v7 3/7] libcamera: Convert between\n\tColorSpace class and V4L2 formats","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"Tomasz Figa ,\n\tlibcamera devel ,\n\tHans Verkuil ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]