{"id":24896,"url":"https://patchwork.libcamera.org/api/patches/24896/?format=json","web_url":"https://patchwork.libcamera.org/patch/24896/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20251029172439.1513907-8-kieran.bingham@ideasonboard.com>","date":"2025-10-29T17:24:32","name":"[v2,07/13] ipa: libipa: fixedpoint: Provide a ScaledFixedPoint type","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"83f55c8a70c97197829650214a7ffed4baee7667","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/?format=json","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24896/mbox/","series":[{"id":5544,"url":"https://patchwork.libcamera.org/api/series/5544/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5544","date":"2025-10-29T17:24:25","name":"libipa: Introduce a Quantized type","version":2,"mbox":"https://patchwork.libcamera.org/series/5544/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24896/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24896/checks/","tags":{},"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 5CED9C32DB\n\tfor ;\n\tWed, 29 Oct 2025 17:25:05 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id C71C760896;\n\tWed, 29 Oct 2025 18:25:04 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 16F956085D\n\tfor ;\n\tWed, 29 Oct 2025 18:24:48 +0100 (CET)","from Monstersaurus.hippo-penny.ts.net\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id B38034E56;\n\tWed, 29 Oct 2025 18:22:58 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"C+1xsz0v\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1761758578;\n\tbh=qtciVlkHQP17kVgBOI2psXZNZNVKNA4SMUPtzt+80GI=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=C+1xsz0vGUxziHmKgxb0jCDgtg/iWA6Dlyi8G6ec8scNGYdTGkZ2fAQcCKSlOk4N6\n\t1Z5gS3svaVw8OccYPrs/Gi6InqaM7s8w4I7IqURlNrLPHzjNqSf4elLd3YdWqdcfi+\n\t69zaYGQE5FJIMEfMpQCK1EFRj6r5MaOKXr2qyaDA=","From":"Kieran Bingham ","To":"libcamera devel ","Cc":"Kieran Bingham ","Subject":"[PATCH v2 07/13] ipa: libipa: fixedpoint: Provide a ScaledFixedPoint\n\ttype","Date":"Wed, 29 Oct 2025 17:24:32 +0000","Message-ID":"<20251029172439.1513907-8-kieran.bingham@ideasonboard.com>","X-Mailer":"git-send-email 2.50.1","In-Reply-To":"<20251029172439.1513907-1-kieran.bingham@ideasonboard.com>","References":"<20251029172439.1513907-1-kieran.bingham@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":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Extend the new Quantized FixedPoint capabilities with a ScaledFixedPointQTraits\nwhich takes an existing Quantized type and scales the conversion by the\ngiven Scale template parameter.\n\nThis can be useful to represent fixed point values which represent\na linear range with a different scale to the underlying float\nor integral type.\n\nSigned-off-by: Kieran Bingham \n---\n src/ipa/libipa/fixedpoint.cpp | 59 +++++++++++++++++++++++++++++++++++\n src/ipa/libipa/fixedpoint.h | 24 ++++++++++++++\n 2 files changed, 83 insertions(+)","diff":"diff --git a/src/ipa/libipa/fixedpoint.cpp b/src/ipa/libipa/fixedpoint.cpp\nindex 2568c7921348..e6e1408ccff6 100644\n--- a/src/ipa/libipa/fixedpoint.cpp\n+++ b/src/ipa/libipa/fixedpoint.cpp\n@@ -151,6 +151,65 @@ namespace ipa {\n * Represents values in the range [0.0, 4095.9375] with a resolution of 1/16.\n */\n \n+/**\n+ * \\struct ScaledFixedPointQTraits\n+ * \\brief Wrap a FixedPointQTraits with a linear scaling factor\n+ *\n+ * This trait extends an existing fixed-point quantisation policy\n+ * by applying an additional multiplicative scale between the\n+ * floating-point and quantised domains.\n+ *\n+ * \\tparam Q The base fixed-point traits type\n+ * \\tparam Scale The scale factor applied to the floating-point domain\n+ */\n+\n+/**\n+ * \\typedef ScaledFixedPointQTraits::quantized_type\n+ * \\copydoc FixedPointQTraits::quantized_type\n+ */\n+\n+/**\n+ * \\var ScaledFixedPointQTraits::scale\n+ * \\brief The constant scaling factor applied to the floating-point domain.\n+ *\n+ * Floating-point inputs are divided by this factor before quantisation,\n+ * and multiplied by it after dequantisation.\n+ */\n+\n+/**\n+ * \\var ScaledFixedPointQTraits::qmin\n+ * \\copydoc FixedPointQTraits::qmin\n+ */\n+\n+/**\n+ * \\var ScaledFixedPointQTraits::qmax\n+ * \\copydoc FixedPointQTraits::qmax\n+ */\n+\n+/**\n+ * \\var ScaledFixedPointQTraits::min\n+ * \\copydoc FixedPointQTraits::min\n+ */\n+\n+/**\n+ * \\var ScaledFixedPointQTraits::max\n+ * \\copydoc FixedPointQTraits::max\n+ */\n+\n+/**\n+ * \\fn ScaledFixedPointQTraits::fromFloat(float v)\n+ * \\copydoc FixedPointQTraits::fromFloat(float v)\n+ *\n+ * The input value \\a v is divided by the scaling factor before conversion.\n+ */\n+\n+/**\n+ * \\fn ScaledFixedPointQTraits::toFloat(quantized_type q)\n+ * \\copydoc FixedPointQTraits::toFloat(quantized_type q)\n+ *\n+ * The output value is multiplied by the scaling factor after conversion.\n+ */\n+\n } /* namespace ipa */\n \n } /* namespace libcamera */\ndiff --git a/src/ipa/libipa/fixedpoint.h b/src/ipa/libipa/fixedpoint.h\nindex 557f7f5b3382..7a9103ed3a77 100644\n--- a/src/ipa/libipa/fixedpoint.h\n+++ b/src/ipa/libipa/fixedpoint.h\n@@ -106,6 +106,30 @@ using UQ1_7 = Quantized>;\n using Q12_4 = Quantized>;\n using UQ12_4 = Quantized>;\n \n+template\n+struct ScaledFixedPointQTraits {\n+\tusing quantized_type = typename Q::quantized_type;\n+\n+\tstatic constexpr float scale = static_cast(Scale);\n+\n+\t/* Re-expose base limits, adjusted by the scaling factor */\n+\tstatic constexpr quantized_type qmin = Q::qmin;\n+\tstatic constexpr quantized_type qmax = Q::qmax;\n+\tstatic constexpr float min = Q::min * scale;\n+\tstatic constexpr float max = Q::max * scale;\n+\n+\tstatic quantized_type fromFloat(float v)\n+\t{\n+\t\tv = std::clamp(v, min, max);\n+\t\treturn Q::fromFloat(v / scale);\n+\t}\n+\n+\tstatic float toFloat(quantized_type q)\n+\t{\n+\t\treturn Q::toFloat(q) * scale;\n+\t}\n+};\n+\n } /* namespace ipa */\n \n } /* namespace libcamera */\n","prefixes":["v2","07/13"]}