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{
    "id": 21848,
    "url": "https://patchwork.libcamera.org/api/patches/21848/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/21848/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20241107114819.57599-2-dan.scally@ideasonboard.com>",
    "date": "2024-11-07T11:48:09",
    "name": "[v3,01/11] ipa: helpers: Add Unsigned Q(m, n) helpers",
    "commit_ref": null,
    "pull_url": null,
    "state": "superseded",
    "archived": false,
    "hash": "155d3a6a3e6a659b5b5f9241bcb544c346d25e7a",
    "submitter": {
        "id": 156,
        "url": "https://patchwork.libcamera.org/api/people/156/?format=api",
        "name": "Dan Scally",
        "email": "dan.scally@ideasonboard.com"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/21848/mbox/",
    "series": [
        {
            "id": 4777,
            "url": "https://patchwork.libcamera.org/api/series/4777/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=4777",
            "date": "2024-11-07T11:48:08",
            "name": "Add Mali-C55 IPA Module and Algorithms",
            "version": 3,
            "mbox": "https://patchwork.libcamera.org/series/4777/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/21848/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/21848/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>",
        "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 71098C323E\n\tfor <parsemail@patchwork.libcamera.org>;\n\tThu,  7 Nov 2024 11:48:32 +0000 (UTC)",
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        ],
        "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"sTMxNPfj\"; dkim-atps=neutral",
        "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1730980098;\n\tbh=1/zdVU+wNFShOtkldi4YY/AGhOETMeIlUIgRx67CmL8=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=sTMxNPfjKrwlyKT19R+8vd7saPPC4EueKpqjkwGinNsHJXT10yfqJsm3aWJyWPA6p\n\tLWzZxJADe+ePYWiuTK53oVil6atvfeW6W75kDJ6DATPhrJ8ZoleD6/wawSjS3xgHaw\n\tNMnIpYkCk4JUcEYr6INi8lecmGfq3WABcDAdGJ/U=",
        "From": "Daniel Scally <dan.scally@ideasonboard.com>",
        "To": "libcamera-devel@lists.libcamera.org",
        "Cc": "Anthony.McGivern@arm.com,\n\tDaniel Scally <dan.scally@ideasonboard.com>",
        "Subject": "[PATCH v3 01/11] ipa: helpers: Add Unsigned Q(m, n) helpers",
        "Date": "Thu,  7 Nov 2024 11:48:09 +0000",
        "Message-Id": "<20241107114819.57599-2-dan.scally@ideasonboard.com>",
        "X-Mailer": "git-send-email 2.34.1",
        "In-Reply-To": "<20241107114819.57599-1-dan.scally@ideasonboard.com>",
        "References": "<20241107114819.57599-1-dan.scally@ideasonboard.com>",
        "MIME-Version": "1.0",
        "Content-Transfer-Encoding": "8bit",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "Errors-To": "libcamera-devel-bounces@lists.libcamera.org",
        "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"
    },
    "content": "Add functions to convert a double to or from an unsigned Q(m,n)\nformat. As the format is unsigned this most resembles the UQ variant\nof the TI implementation detailed on Wikipedia:\n\nhttps://en.wikipedia.org/wiki/Q_(number_format)\n\nSigned-off-by: Daniel Scally <dan.scally@ideasonboard.com>\n---\nChanges in v3:\n\n\t- New patch\n\n src/ipa/libipa/helpers.cpp | 29 +++++++++++++++++++++++++++++\n src/ipa/libipa/helpers.h   |  2 ++\n 2 files changed, 31 insertions(+)",
    "diff": "diff --git a/src/ipa/libipa/helpers.cpp b/src/ipa/libipa/helpers.cpp\nindex 6c038895..908c6e93 100644\n--- a/src/ipa/libipa/helpers.cpp\n+++ b/src/ipa/libipa/helpers.cpp\n@@ -72,6 +72,35 @@ uint32_t estimateCCT(double red, double green, double blue)\n \treturn 449 * n * n * n + 3525 * n * n + 6823.3 * n + 5520.33;\n }\n \n+/**\n+ * \\brief Convert double to Q(m.n) format\n+ * \\param[in] value The value to convert\n+ * \\param[in] m The number of bits used to represent the integer part\n+ * \\param[in] n The number of bits used to represent the fraction part\n+ *\n+ * This function converts a double into an unsigned fractional Q format,\n+ * clamping at the largest possible value given m and n. As these formats are\n+ * unsigned the m figure does not include a sign bit.\n+ */\n+unsigned int toUnsignedQFormat(double value, unsigned int m, unsigned int n)\n+{\n+\tdouble maxVal = (std::pow(2, m + n) - 1) / std::pow(2, n);\n+\n+\treturn std::clamp(value, 0.0, maxVal) * std::pow(2, n);\n+}\n+\n+/**\n+ * \\brief Convert Q(m.n) formatted number to double\n+ * \\param[in] value The value to convert\n+ * \\param[in] n The number of bits used to represent the fraction part\n+ *\n+ * This function converts an unsigned Q formatted value into a double.\n+ */\n+double fromUnsignedQFormat(unsigned int value, unsigned int n)\n+{\n+\treturn value / std::pow(2, n);\n+}\n+\n } /* namespace ipa */\n \n } /* namespace libcamera */\ndiff --git a/src/ipa/libipa/helpers.h b/src/ipa/libipa/helpers.h\nindex 51c74a36..1f26e768 100644\n--- a/src/ipa/libipa/helpers.h\n+++ b/src/ipa/libipa/helpers.h\n@@ -15,6 +15,8 @@ namespace ipa {\n \n double rec601LuminanceFromRGB(unsigned int r, unsigned int g, unsigned int b);\n uint32_t estimateCCT(double red, double green, double blue);\n+unsigned int toUnsignedQFormat(double value, unsigned int m, unsigned int n);\n+double fromUnsignedQFormat(unsigned int value, unsigned int n);\n \n } /* namespace ipa */\n \n",
    "prefixes": [
        "v3",
        "01/11"
    ]
}