[{"id":37913,"web_url":"https://patchwork.libcamera.org/comment/37913/","msgid":"<176917829300.302817.15331273037194731250@localhost>","date":"2026-01-23T14:24:53","subject":"Re: [PATCH v6 12/16] ipa: mali-c55: Convert AWB to UQ<4, 8> usage","submitter":{"id":184,"url":"https://patchwork.libcamera.org/api/people/184/","name":"Stefan Klug","email":"stefan.klug@ideasonboard.com"},"content":"Hi Kieran,\n\nQuoting Kieran Bingham (2026-01-21 18:37:31)\n> Utilise the new FixedPoint type to explicitly calculate gains for AWB in Q4.8\n> format. This ensures that reporting of gains in metadata reflect the true\n> AWB gains applied.\n> \n> Reviewed-by: Isaac Scott \n> Reviewed-by: Barnabás Pőcze \n> Signed-off-by: Kieran Bingham \n> \n> ---\n> v5:\n> - Use UQ<4, 8> directly\n> - Change debug prints to use operator<<\n> - Now based on top of float types instead of doubles\n> \n> Signed-off-by: Kieran Bingham \n> ---\n> src/ipa/mali-c55/algorithms/awb.cpp | 36 ++++++++++++++---------------\n> src/ipa/mali-c55/ipa_context.h | 10 ++++----\n> 2 files changed, 24 insertions(+), 22 deletions(-)\n> \n> diff --git a/src/ipa/mali-c55/algorithms/awb.cpp b/src/ipa/mali-c55/algorithms/awb.cpp\n> index b179dd7f0c1c..a5150bbf3d97 100644\n> --- a/src/ipa/mali-c55/algorithms/awb.cpp\n> +++ b/src/ipa/mali-c55/algorithms/awb.cpp\n> @@ -37,8 +37,8 @@ int Awb::configure([[maybe_unused]] IPAContext &context,\n> * for the first frame we will make no assumptions and leave the R/B\n> * channels unmodified.\n> */\n> - context.activeState.awb.rGain = 1.0;\n> - context.activeState.awb.bGain = 1.0;\n> + context.activeState.awb.rGain = 1.0f;\n> + context.activeState.awb.bGain = 1.0f;\n> \n> return 0;\n> }\n> @@ -46,8 +46,8 @@ int Awb::configure([[maybe_unused]] IPAContext &context,\n> void Awb::fillGainsParamBlock(MaliC55Params *params, IPAContext &context,\n> IPAFrameContext &frameContext)\n> {\n> - double rGain = context.activeState.awb.rGain;\n> - double bGain = context.activeState.awb.bGain;\n> + UQ<4, 8> rGain = context.activeState.awb.rGain;\n> + UQ<4, 8> bGain = context.activeState.awb.bGain;\n> \n> /*\n> * The gains here map as follows:\n> @@ -61,10 +61,10 @@ void Awb::fillGainsParamBlock(MaliC55Params *params, IPAContext &context,\n> */\n> auto block = params->block();\n> \n> - block->gain00 = floatingToFixedPoint<4, 8, uint16_t, double>(rGain);\n> - block->gain01 = floatingToFixedPoint<4, 8, uint16_t, double>(1.0);\n> - block->gain10 = floatingToFixedPoint<4, 8, uint16_t, double>(1.0);\n> - block->gain11 = floatingToFixedPoint<4, 8, uint16_t, double>(bGain);\n> + block->gain00 = rGain.quantized();\n> + block->gain01 = UQ<4, 8>(1.0f).quantized();\n> + block->gain10 = UQ<4, 8>(1.0f).quantized();\n> + block->gain11 = bGain.quantized();\n> \n> frameContext.awb.rGain = rGain;\n> frameContext.awb.bGain = bGain;\n> @@ -140,18 +140,18 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> * gain figures that we can apply to approximate a grey world.\n> */\n> unsigned int counted_zones = 0;\n> - double rgSum = 0, bgSum = 0;\n> + float rgSum = 0, bgSum = 0;\n> \n> for (unsigned int i = 0; i < 225; i++) {\n> if (!awb_ratios[i].num_pixels)\n> continue;\n> \n> /*\n> - * The statistics are in Q4.8 format, so we convert to double\n> + * The statistics are in Q4.8 format, so we convert to float\n> * here.\n> */\n> - rgSum += fixedToFloatingPoint<4, 8, double, uint16_t>(awb_ratios[i].avg_rg_gr);\n> - bgSum += fixedToFloatingPoint<4, 8, double, uint16_t>(awb_ratios[i].avg_bg_br);\n> + rgSum += UQ<4, 8>(awb_ratios[i].avg_rg_gr).value();\n> + bgSum += UQ<4, 8>(awb_ratios[i].avg_bg_br).value();\n> counted_zones++;\n> }\n> \n> @@ -174,8 +174,8 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> * figure by the gains that were applied when the statistics for this\n> * frame were generated.\n> */\n> - float rRatio = rgAvg / frameContext.awb.rGain;\n> - float bRatio = bgAvg / frameContext.awb.bGain;\n> + float rRatio = rgAvg / frameContext.awb.rGain.value();\n> + float bRatio = bgAvg / frameContext.awb.bGain.value();\n> \n> /*\n> * And then we can simply invert the ratio to find the gain we should\n> @@ -191,15 +191,15 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> * want to fix the miscolouring as quickly as possible.\n> */\n> float speed = frame < kNumStartupFrames ? 1.0 : 0.2;\n> - rGain = speed * rGain + context.activeState.awb.rGain * (1.0 - speed);\n> - bGain = speed * bGain + context.activeState.awb.bGain * (1.0 - speed);\n> + rGain = speed * rGain + context.activeState.awb.rGain.value() * (1.0 - speed);\n> + bGain = speed * bGain + context.activeState.awb.bGain.value() * (1.0 - speed);\n> \n> context.activeState.awb.rGain = rGain;\n> context.activeState.awb.bGain = bGain;\n> \n> metadata.set(controls::ColourGains, {\n> - static_cast(frameContext.awb.rGain),\n> - static_cast(frameContext.awb.bGain),\n> + frameContext.awb.rGain.value(),\n> + frameContext.awb.bGain.value(),\n> });\n> \n> LOG(MaliC55Awb, Debug) << \"For frame number \" << frame << \": \"\n> diff --git a/src/ipa/mali-c55/ipa_context.h b/src/ipa/mali-c55/ipa_context.h\n> index 13885eb83b5c..08f78e4f74ce 100644\n> --- a/src/ipa/mali-c55/ipa_context.h\n> +++ b/src/ipa/mali-c55/ipa_context.h\n> @@ -14,6 +14,8 @@\n> \n> #include \n> \n> +#include \"libipa/fixedpoint.h\"\n> +\n> namespace libcamera {\n> \n> namespace ipa::mali_c55 {\n> @@ -53,8 +55,8 @@ struct IPAActiveState {\n> } agc;\n> \n> struct {\n> - double rGain;\n> - double bGain;\n> + UQ<4, 8> rGain;\n> + UQ<4, 8> bGain;\n> } awb;\n> };\n> \n> @@ -66,8 +68,8 @@ struct IPAFrameContext : public FrameContext {\n> } agc;\n> \n> struct {\n> - double rGain;\n> - double bGain;\n> + UQ<4, 8> rGain;\n> + UQ<4, 8> bGain;\n\nThis is the only part I don't really like. We encode hardware specific\nsizes in the context structure which I think are better kept in the\nalgorithm (this is the same in the RkISP1). But as you already planned\nto pull in the context types from the corresponding algorithms I guess\nthis is temporary.\n\nReviewed-by: Stefan Klug \n\nCheers,\nStefan\n\n> } awb;\n> };\n> \n> -- \n> 2.52.0\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 828C6BDCBF\n\tfor ;\n\tFri, 23 Jan 2026 14:24:59 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 73B6661FC9;\n\tFri, 23 Jan 2026 15:24:58 +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 5282F615B2\n\tfor ;\n\tFri, 23 Jan 2026 15:24:56 +0100 (CET)","from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:1d92:9f27:5dd1:dc89])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id AD915103D; \n\tFri, 23 Jan 2026 15:24:22 +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=\"ZIi2JGMA\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1769178262;\n\tbh=x9uBcWnHAD27CdbUsNZSVzwjWnwwlSZd2Rb4wOFYInQ=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=ZIi2JGMAHGdOcdqIsDotGBzRIhczK2qc5xTds4XH3a59AGW3vqjuo2QR7d1JqUxzS\n\t0P94nnfbXlHa3uJXIEE+tFyHiCYa84OpoEic5cHyzHMq0G8XNgTUZ/ZGSlscK6wEu+\n\tYUcmneAYcZOD+ZG8LGZmUHtysSx8FZOvm1CdCiVs=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20260121173737.376113-13-kieran.bingham@ideasonboard.com>","References":"<20260121173737.376113-1-kieran.bingham@ideasonboard.com>\n\t<20260121173737.376113-13-kieran.bingham@ideasonboard.com>","Subject":"Re: [PATCH v6 12/16] ipa: mali-c55: Convert AWB to UQ<4, 8> usage","From":"Stefan Klug ","Cc":"Kieran Bingham , Isaac Scott\n\t, =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?=\n\t","To":"Kieran Bingham ,\n\tlibcamera devel ","Date":"Fri, 23 Jan 2026 15:24:53 +0100","Message-ID":"<176917829300.302817.15331273037194731250@localhost>","User-Agent":"alot/0.12.dev8+g2c003385c862.d20250602","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\" "}}]