[{"id":38205,"web_url":"https://patchwork.libcamera.org/comment/38205/","msgid":"<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","date":"2026-02-16T16:40:50","subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"content":"2026. 02. 13. 17:57 keltezéssel, Kieran Bingham írta:\n> The AWB calculations are determined using double precision, and then\n> will be soon stored in a quantized float.\n> \n> Use float types for the intermediate types after the sums have been\n> converted to an average to remove static cast assignments.\n> \n> Signed-off-by: Kieran Bingham \n> \n> ---\n> v5:\n> - New in v5\n> ---\n> src/ipa/mali-c55/algorithms/awb.cpp | 12 ++++++------\n> 1 file changed, 6 insertions(+), 6 deletions(-)\n> \n> diff --git a/src/ipa/mali-c55/algorithms/awb.cpp b/src/ipa/mali-c55/algorithms/awb.cpp\n> index 964e810882a9..b179dd7f0c1c 100644\n> --- a/src/ipa/mali-c55/algorithms/awb.cpp\n> +++ b/src/ipa/mali-c55/algorithms/awb.cpp\n> @@ -159,7 +159,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> \t * Sometimes the first frame's statistics have no valid pixels, in which\n> \t * case we'll just assume a grey world until they say otherwise.\n> \t */\n> -\tdouble rgAvg, bgAvg;\n> +\tfloat rgAvg, bgAvg;\n> \tif (!counted_zones) {\n> \t\trgAvg = 1.0;\n> \t\tbgAvg = 1.0;\n> @@ -174,15 +174,15 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> \t * figure by the gains that were applied when the statistics for this\n> \t * frame were generated.\n> \t */\n> -\tdouble rRatio = rgAvg / frameContext.awb.rGain;\n> -\tdouble bRatio = bgAvg / frameContext.awb.bGain;\n> +\tfloat rRatio = rgAvg / frameContext.awb.rGain;\n> +\tfloat bRatio = bgAvg / frameContext.awb.bGain;\n> \n> \t/*\n> \t * And then we can simply invert the ratio to find the gain we should\n> \t * apply.\n> \t */\n> -\tdouble rGain = 1 / rRatio;\n> -\tdouble bGain = 1 / bRatio;\n> +\tfloat rGain = 1 / rRatio;\n> +\tfloat bGain = 1 / bRatio;\n> \n> \t/*\n> \t * Running at full speed, this algorithm results in oscillations in the\n> @@ -190,7 +190,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> \t * changes in gain, unless we're in the startup phase in which case we\n> \t * want to fix the miscolouring as quickly as possible.\n> \t */\n> -\tdouble speed = frame < kNumStartupFrames ? 1.0 : 0.2;\n> +\tfloat speed = frame < kNumStartupFrames ? 1.0 : 0.2;\n> \trGain = speed * rGain + context.activeState.awb.rGain * (1.0 - speed);\n> \tbGain = speed * bGain + context.activeState.awb.bGain * (1.0 - speed);\n\nThat `1.0 - speed` is `double`. There is `-Wfloat-conversion` to diagnose such cases.\n(There are quite few places where that warning fires in the current code base.)\n\nThe precision of `float` looks sufficient to me, in any case.\n\nReviewed-by: Barnabás Pőcze \n\nAnd I think a review was missed: https://patchwork.libcamera.org/patch/25918/#37912\n\n\n\n\n> \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 33500C31E9\n\tfor ;\n\tMon, 16 Feb 2026 16:40:57 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 11927621F6;\n\tMon, 16 Feb 2026 17:40:56 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 5703662084\n\tfor ;\n\tMon, 16 Feb 2026 17:40:54 +0100 (CET)","from [192.168.33.73] (185.221.141.206.nat.pool.zt.hu\n\t[185.221.141.206])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id EF225DA8;\n\tMon, 16 Feb 2026 17:40:02 +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=\"TKLXWEi0\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1771260003;\n\tbh=hW2vYOZ4duqp7oMkxNpCEZ6l9XzPxGhuGNW7tSMqNAc=;\n\th=Date:Subject:To:References:From:In-Reply-To:From;\n\tb=TKLXWEi0E93tal5PIwqLEV9g4pxoW4MDzA9TZ3SVaX+Idp8aPay6sE2r8/e0MEx3A\n\txeaKXyXPA4NuBr4SeMBPAv+CWGO39pJhVta0eCnx89ydRyhCafYIjog13k+dMP01IJ\n\tMPD9MBLxG0DLWWU8k6dLMovXTUr4e4OxIPN9Yid4=","Message-ID":"<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","Date":"Mon, 16 Feb 2026 17:40:50 +0100","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","To":"Kieran Bingham ,\n\tlibcamera-devel@lists.libcamera.org","References":"<20260213-kbingham-quantizers-v7-0-1626b9aaabf1@ideasonboard.com>\n\t<20260213-kbingham-quantizers-v7-11-1626b9aaabf1@ideasonboard.com>","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Content-Language":"en-US, hu-HU","In-Reply-To":"<20260213-kbingham-quantizers-v7-11-1626b9aaabf1@ideasonboard.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","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\" "}},{"id":38206,"web_url":"https://patchwork.libcamera.org/comment/38206/","msgid":"<177126912210.2938025.2921049311047885086@ping.linuxembedded.co.uk>","date":"2026-02-16T19:12:02","subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Barnabás Pőcze (2026-02-16 16:40:50)\n> 2026. 02. 13. 17:57 keltezéssel, Kieran Bingham írta:\n> > The AWB calculations are determined using double precision, and then\n> > will be soon stored in a quantized float.\n> > \n> > Use float types for the intermediate types after the sums have been\n> > converted to an average to remove static cast assignments.\n> > \n> > Signed-off-by: Kieran Bingham \n> > \n> > ---\n> > v5:\n> > - New in v5\n> > ---\n> > src/ipa/mali-c55/algorithms/awb.cpp | 12 ++++++------\n> > 1 file changed, 6 insertions(+), 6 deletions(-)\n> > \n> > diff --git a/src/ipa/mali-c55/algorithms/awb.cpp b/src/ipa/mali-c55/algorithms/awb.cpp\n> > index 964e810882a9..b179dd7f0c1c 100644\n> > --- a/src/ipa/mali-c55/algorithms/awb.cpp\n> > +++ b/src/ipa/mali-c55/algorithms/awb.cpp\n> > @@ -159,7 +159,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> > * Sometimes the first frame's statistics have no valid pixels, in which\n> > * case we'll just assume a grey world until they say otherwise.\n> > */\n> > - double rgAvg, bgAvg;\n> > + float rgAvg, bgAvg;\n> > if (!counted_zones) {\n> > rgAvg = 1.0;\n> > bgAvg = 1.0;\n> > @@ -174,15 +174,15 @@ 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> > - double rRatio = rgAvg / frameContext.awb.rGain;\n> > - double bRatio = bgAvg / frameContext.awb.bGain;\n> > + float rRatio = rgAvg / frameContext.awb.rGain;\n> > + float bRatio = bgAvg / frameContext.awb.bGain;\n> > \n> > /*\n> > * And then we can simply invert the ratio to find the gain we should\n> > * apply.\n> > */\n> > - double rGain = 1 / rRatio;\n> > - double bGain = 1 / bRatio;\n> > + float rGain = 1 / rRatio;\n> > + float bGain = 1 / bRatio;\n> > \n> > /*\n> > * Running at full speed, this algorithm results in oscillations in the\n> > @@ -190,7 +190,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> > * changes in gain, unless we're in the startup phase in which case we\n> > * want to fix the miscolouring as quickly as possible.\n> > */\n> > - double speed = frame < kNumStartupFrames ? 1.0 : 0.2;\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> \n> That `1.0 - speed` is `double`. There is `-Wfloat-conversion` to diagnose such cases.\n> (There are quite few places where that warning fires in the current code base.)\n> \n> The precision of `float` looks sufficient to me, in any case.\n> \n> Reviewed-by: Barnabás Pőcze \n> \n> And I think a review was missed: https://patchwork.libcamera.org/patch/25918/#37912\n\nAha, thanks, - I'll collect that here for patchwork:\n\nReviewed-by: Stefan Klug \n\n> \n> \n> \n> \n> > \n> > \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 242C6C0DA4\n\tfor ;\n\tMon, 16 Feb 2026 19:12:08 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 6EB9D621F6;\n\tMon, 16 Feb 2026 20:12:07 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0085C62084\n\tfor ;\n\tMon, 16 Feb 2026 20:12:04 +0100 (CET)","from monstersaurus.ideasonboard.com\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 DD789250;\n\tMon, 16 Feb 2026 20:11:13 +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=\"Q6L1LwLq\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1771269073;\n\tbh=AIdrXPr4RrWMo6FEQSVgSg/Xs4FWT9VvAs+AAL64mYI=;\n\th=In-Reply-To:References:Subject:From:To:Date:From;\n\tb=Q6L1LwLqll/4UMYIGszZF08H3/EQMKJmxxFJ8igUkTa7cljsL6NQ7LGcxknjJ5Ifn\n\taX/f1PwVsfL7MyoXrmogmXwJicMvcEn8B4sYaXNuGpQJmTmlJaF6aIFW691wUlFAdU\n\t6kL0c+OsGd6mSTvz66B7FPvTQcerhkqapqNnWcsI=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","References":"<20260213-kbingham-quantizers-v7-0-1626b9aaabf1@ideasonboard.com>\n\t<20260213-kbingham-quantizers-v7-11-1626b9aaabf1@ideasonboard.com>\n\t<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","Subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","From":"Kieran Bingham ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 16 Feb 2026 19:12:02 +0000","Message-ID":"<177126912210.2938025.2921049311047885086@ping.linuxembedded.co.uk>","User-Agent":"alot/0.9.1","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\" "}},{"id":38241,"web_url":"https://patchwork.libcamera.org/comment/38241/","msgid":"<20260219115603.GB688396@killaraus.ideasonboard.com>","date":"2026-02-19T11:56:03","subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"On Mon, Feb 16, 2026 at 05:40:50PM +0100, Barnabás Pőcze wrote:\n> 2026. 02. 13. 17:57 keltezéssel, Kieran Bingham írta:\n> > The AWB calculations are determined using double precision, and then\n> > will be soon stored in a quantized float.\n> > \n> > Use float types for the intermediate types after the sums have been\n> > converted to an average to remove static cast assignments.\n> > \n> > Signed-off-by: Kieran Bingham \n> > \n> > ---\n> > v5:\n> > - New in v5\n> > ---\n> > src/ipa/mali-c55/algorithms/awb.cpp | 12 ++++++------\n> > 1 file changed, 6 insertions(+), 6 deletions(-)\n> > \n> > diff --git a/src/ipa/mali-c55/algorithms/awb.cpp b/src/ipa/mali-c55/algorithms/awb.cpp\n> > index 964e810882a9..b179dd7f0c1c 100644\n> > --- a/src/ipa/mali-c55/algorithms/awb.cpp\n> > +++ b/src/ipa/mali-c55/algorithms/awb.cpp\n> > @@ -159,7 +159,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> > \t * Sometimes the first frame's statistics have no valid pixels, in which\n> > \t * case we'll just assume a grey world until they say otherwise.\n> > \t */\n> > -\tdouble rgAvg, bgAvg;\n> > +\tfloat rgAvg, bgAvg;\n> > \tif (!counted_zones) {\n> > \t\trgAvg = 1.0;\n> > \t\tbgAvg = 1.0;\n> > @@ -174,15 +174,15 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> > \t * figure by the gains that were applied when the statistics for this\n> > \t * frame were generated.\n> > \t */\n> > -\tdouble rRatio = rgAvg / frameContext.awb.rGain;\n> > -\tdouble bRatio = bgAvg / frameContext.awb.bGain;\n> > +\tfloat rRatio = rgAvg / frameContext.awb.rGain;\n> > +\tfloat bRatio = bgAvg / frameContext.awb.bGain;\n> > \n> > \t/*\n> > \t * And then we can simply invert the ratio to find the gain we should\n> > \t * apply.\n> > \t */\n> > -\tdouble rGain = 1 / rRatio;\n> > -\tdouble bGain = 1 / bRatio;\n> > +\tfloat rGain = 1 / rRatio;\n> > +\tfloat bGain = 1 / bRatio;\n> > \n> > \t/*\n> > \t * Running at full speed, this algorithm results in oscillations in the\n> > @@ -190,7 +190,7 @@ void Awb::process(IPAContext &context, const uint32_t frame,\n> > \t * changes in gain, unless we're in the startup phase in which case we\n> > \t * want to fix the miscolouring as quickly as possible.\n> > \t */\n> > -\tdouble speed = frame < kNumStartupFrames ? 1.0 : 0.2;\n> > +\tfloat speed = frame < kNumStartupFrames ? 1.0 : 0.2;\n> > \trGain = speed * rGain + context.activeState.awb.rGain * (1.0 - speed);\n> > \tbGain = speed * bGain + context.activeState.awb.bGain * (1.0 - speed);\n> \n> That `1.0 - speed` is `double`. There is `-Wfloat-conversion` to diagnose such cases.\n> (There are quite few places where that warning fires in the current code base.)\n\nIt could be a good idea to enable the warning and fix the existing code.\n\nWith 1.0f and 0.2f above,\n\nReviewed-by: Laurent Pinchart \n\n> The precision of `float` looks sufficient to me, in any case.\n> \n> Reviewed-by: Barnabás Pőcze \n> \n> And I think a review was missed: https://patchwork.libcamera.org/patch/25918/#37912","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 A65CEC0DA4\n\tfor ;\n\tThu, 19 Feb 2026 11:56:11 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id C73FB6223E;\n\tThu, 19 Feb 2026 12:56:10 +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 57FC8620C9\n\tfor ;\n\tThu, 19 Feb 2026 12:56:09 +0100 (CET)","from killaraus.ideasonboard.com (unknown [83.245.237.175])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id B2B39673;\n\tThu, 19 Feb 2026 12:55:15 +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=\"d4JUzrn6\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1771502116;\n\tbh=80e7f7f+LRa20EF9uCBaDonIOSrg7GisK4OcA5q+JUc=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=d4JUzrn6U6uby2MO2Mu+L+jo73MaDxagrSRs4sNIrzFm1s+amTH7c0C7SGfMvUuDu\n\tX7IObEYvHzTeMBrtcH+iaUfBcak1nlCpfBzXt/iA5eRm0SV3MkXGRSDbUub+fqsI6Q\n\t/bBX3y5H1QvfoNoeKkodMcwJCoNC2cB6kVc5pAog=","Date":"Thu, 19 Feb 2026 12:56:03 +0100","From":"Laurent Pinchart ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Cc":"Kieran Bingham ,\n\tlibcamera-devel@lists.libcamera.org","Subject":"Re: [PATCH v7 11/15] ipa: mali-c55: Reduce AWB calculations to float\n\tprecision","Message-ID":"<20260219115603.GB688396@killaraus.ideasonboard.com>","References":"<20260213-kbingham-quantizers-v7-0-1626b9aaabf1@ideasonboard.com>\n\t<20260213-kbingham-quantizers-v7-11-1626b9aaabf1@ideasonboard.com>\n\t<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","Content-Transfer-Encoding":"8bit","In-Reply-To":"<4d366a1c-bc05-4107-9c96-c4554e16cf25@ideasonboard.com>","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\" "}}]