{"id":25040,"url":"https://patchwork.libcamera.org/api/1.1/patches/25040/?format=json","web_url":"https://patchwork.libcamera.org/patch/25040/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/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":"<20251114005428.90024-11-kieran.bingham@ideasonboard.com>","date":"2025-11-14T00:54:14","name":"[v4,10/21] ipa: libipa: fixedpoint: Provide a ScaledFixedPoint type","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"992fd5b731929d64595478750d96b9cded713187","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/1.1/people/4/?format=json","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/25040/mbox/","series":[{"id":5589,"url":"https://patchwork.libcamera.org/api/1.1/series/5589/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5589","date":"2025-11-14T00:54:04","name":"libipa: Introduce a Quantized type","version":4,"mbox":"https://patchwork.libcamera.org/series/5589/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/25040/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/25040/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 A7318C3331\n\tfor ;\n\tFri, 14 Nov 2025 00:55:05 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 45C9A60B33;\n\tFri, 14 Nov 2025 01:55:01 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 61AA860AAF\n\tfor ;\n\tFri, 14 Nov 2025 01:54:51 +0100 (CET)","from charm.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 D22031D1C;\n\tFri, 14 Nov 2025 01:52:50 +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=\"tRemIF5s\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1763081571;\n\tbh=DUlrlB6Trv3GWQH/Kyuo8tA9uj00B6YqWBYvIM2LaE4=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=tRemIF5sfHlhePWHVJr41J0kZYUZJCU3z+D5+udrkvfWet325JjmE/ZxwS4kDkDw5\n\two6OjrFCd6oWqbsl8Hk6ojWcYWLsaNHv3AbnGmVVIKQuji5cDWKKor6BmWJ4Izt4p+\n\tclBQmS+g5YANd4ProMUZGMlnf9fdC+jsacoV1NrY=","From":"Kieran Bingham ","To":"libcamera devel ","Cc":"Kieran Bingham ","Subject":"[PATCH v4 10/21] ipa: libipa: fixedpoint: Provide a ScaledFixedPoint\n\ttype","Date":"Fri, 14 Nov 2025 00:54:14 +0000","Message-ID":"<20251114005428.90024-11-kieran.bingham@ideasonboard.com>","X-Mailer":"git-send-email 2.51.1","In-Reply-To":"<20251114005428.90024-1-kieran.bingham@ideasonboard.com>","References":"<20251114005428.90024-1-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---\n\nv3:\n- Rename quantized_type to QuantizedType\n\nv4:\n- Fix copydoc for ScaledFixedPointQTraits::toFloat\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 03053668ed79..97cdd9b3f7aa 100644\n--- a/src/ipa/libipa/fixedpoint.cpp\n+++ b/src/ipa/libipa/fixedpoint.cpp\n@@ -185,6 +185,65 @@ 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::QuantizedType\n+ * \\copydoc FixedPointQTraits::QuantizedType\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(QuantizedType q)\n+ * \\copydoc FixedPointQTraits::toFloat()\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 05dd97e64f40..1e984350111c 100644\n--- a/src/ipa/libipa/fixedpoint.h\n+++ b/src/ipa/libipa/fixedpoint.h\n@@ -113,6 +113,30 @@ using UQ5_8 = Quantized>;\n using Q12_4 = Quantized>;\n using UQ12_4 = Quantized>;\n \n+template\n+struct ScaledFixedPointQTraits {\n+\tusing QuantizedType = typename Q::QuantizedType;\n+\n+\tstatic constexpr float scale = static_cast(Scale);\n+\n+\t/* Re-expose base limits, adjusted by the scaling factor */\n+\tstatic constexpr QuantizedType qmin = Q::qmin;\n+\tstatic constexpr QuantizedType qmax = Q::qmax;\n+\tstatic constexpr float min = Q::min * scale;\n+\tstatic constexpr float max = Q::max * scale;\n+\n+\tstatic QuantizedType 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(QuantizedType q)\n+\t{\n+\t\treturn Q::toFloat(q) * scale;\n+\t}\n+};\n+\n } /* namespace ipa */\n \n } /* namespace libcamera */\n","prefixes":["v4","10/21"]}