[{"id":20345,"web_url":"https://patchwork.libcamera.org/comment/20345/","msgid":"","date":"2021-10-21T02:23:22","subject":"Re: [libcamera-devel] [PATCH v2 06/13] ipa: ipu3: agc: Change\n\texposure limits","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Jean-Michel,\n\nThank you for the patch.\n\nOn Wed, Oct 20, 2021 at 05:46:00PM +0200, Jean-Michel Hautbois wrote:\n> The exposure limits are set for one sensor until now, in a number of\n> lines. We should not use those, but exposure limits in a time unit.\n> \n> Introduce default limits which with a default minimum of 20ms. This\n> value should be given by the IPAIPU3. Use cached values expressed as a\n> number of lines in the configure() call.\n\nThe commit message doesn't match the patch anymore.\n\n> Adapt the process() call accordingly.\n> \n> Signed-off-by: Jean-Michel Hautbois \n> Reviewed-by: Kieran Bingham \n> ---\n> src/ipa/ipu3/algorithms/agc.cpp | 34 ++++++++++++++++++---------------\n> src/ipa/ipu3/algorithms/agc.h | 3 ++-\n> 2 files changed, 21 insertions(+), 16 deletions(-)\n> \n> diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp\n> index b1757b91..8e1b6d8c 100644\n> --- a/src/ipa/ipu3/algorithms/agc.cpp\n> +++ b/src/ipa/ipu3/algorithms/agc.cpp\n> @@ -39,18 +39,14 @@ static constexpr uint32_t kMaxISO = 1500;\n> static constexpr uint32_t kMinGain = kMinISO / 100;\n> static constexpr uint32_t kMaxGain = kMaxISO / 100;\n> \n> -/* \\todo use calculated value based on sensor */\n> -static constexpr uint32_t kMinExposure = 1;\n> -static constexpr uint32_t kMaxExposure = 1976;\n> -\n> /* Histogram constants */\n> static constexpr uint32_t knumHistogramBins = 256;\n> static constexpr double kEvGainTarget = 0.5;\n> \n> Agc::Agc()\n> \t: frameCount_(0), lastFrame_(0), iqMean_(0.0), lineDuration_(0s),\n> -\t maxExposureTime_(0s), filteredExposure_(0s), filteredExposureNoDg_(0s),\n> -\t currentExposure_(0s), currentExposureNoDg_(0s)\n> +\t minExposureLines_(0), maxExposureLines_(0), filteredExposure_(0s),\n> +\t filteredExposureNoDg_(0s), currentExposure_(0s), currentExposureNoDg_(0s)\n> {\n> }\n> \n> @@ -60,13 +56,14 @@ int Agc::configure(IPAContext &context, const IPAConfigInfo &configInfo)\n> \n> \tlineDuration_ = configInfo.sensorInfo.lineLength * 1.0s\n> \t\t / configInfo.sensorInfo.pixelRate;\n> -\tmaxExposureTime_ = context.configuration.agc.maxShutterSpeed;\n> \n> \t/* Configure the default exposure and gain */\n> \tcontext.frameContext.agc.gain =\n> \t\tcontext.configuration.agc.minAnalogueGain;\n> -\tcontext.frameContext.agc.exposure =\n> -\t\tcontext.configuration.agc.minShutterSpeed / lineDuration_;\n> +\tcontext.frameContext.agc.exposure = minExposureLines_;\n\nYou use minExposureLines_ before calculating it below.\n\n> +\n> +\tminExposureLines_ = context.configuration.agc.minShutterSpeed / lineDuration_;\n> +\tmaxExposureLines_ = context.configuration.agc.maxShutterSpeed / lineDuration_;\n> \n> \treturn 0;\n> }\n> @@ -151,23 +148,30 @@ void Agc::lockExposureGain(uint32_t &exposure, double &gain)\n> \t\tLOG(IPU3Agc, Debug) << \"Actual total exposure \" << currentExposureNoDg_\n> \t\t\t\t << \" Shutter speed \" << currentShutter\n> \t\t\t\t << \" Gain \" << gain;\n> +\n> \t\tcurrentExposure_ = currentExposureNoDg_ * newGain;\n> -\t\tutils::Duration maxTotalExposure = maxExposureTime_ * kMaxGain;\n> +\t\tutils::Duration maxShutterSpeed = maxExposureLines_ * lineDuration_;\n> +\t\tutils::Duration maxTotalExposure = maxShutterSpeed * kMaxGain;\n> \t\tcurrentExposure_ = std::min(currentExposure_, maxTotalExposure);\n> -\t\tLOG(IPU3Agc, Debug) << \"Target total exposure \" << currentExposure_;\n> +\t\tLOG(IPU3Agc, Debug) << \"Target total exposure \" << currentExposure_\n> +\t\t\t\t << \", maximum is \" << maxTotalExposure;\n> \n> \t\t/* \\todo: estimate if we need to desaturate */\n> \t\tfilterExposure();\n> \n> \t\tutils::Duration newExposure = 0.0s;\n> -\t\tif (currentShutter < maxExposureTime_) {\n> -\t\t\texposure = std::clamp(static_cast(exposure * currentExposure_ / currentExposureNoDg_), kMinExposure, kMaxExposure);\n> +\t\tif (currentShutter < maxShutterSpeed) {\n> +\t\t\texposure = std::clamp(exposure * currentExposure_ / currentExposureNoDg_,\n> +\t\t\t\t\t\t\tminExposureLines_,\n> +\t\t\t\t\t\t\tmaxExposureLines_);\n> \t\t\tnewExposure = currentExposure_ / exposure;\n> \t\t\tgain = std::clamp(static_cast(gain * currentExposure_ / newExposure), kMinGain, kMaxGain);\n> -\t\t} else if (currentShutter >= maxExposureTime_) {\n> +\t\t} else if (currentShutter >= maxShutterSpeed) {\n\nYou could simply write this as\n\n\t\t} else {\n\nWith these issues fixed,\n\nReviewed-by: Laurent Pinchart \n\n> \t\t\tgain = std::clamp(static_cast(gain * currentExposure_ / currentExposureNoDg_), kMinGain, kMaxGain);\n> \t\t\tnewExposure = currentExposure_ / gain;\n> -\t\t\texposure = std::clamp(static_cast(exposure * currentExposure_ / newExposure), kMinExposure, kMaxExposure);\n> +\t\t\texposure = std::clamp(exposure * currentExposure_ / newExposure,\n> +\t\t\t\t\t\t\tminExposureLines_,\n> +\t\t\t\t\t\t\tmaxExposureLines_);\n> \t\t}\n> \t\tLOG(IPU3Agc, Debug) << \"Adjust exposure \" << exposure * lineDuration_ << \" and gain \" << gain;\n> \t}\n> diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h\n> index 16b9fa0a..cd26d08c 100644\n> --- a/src/ipa/ipu3/algorithms/agc.h\n> +++ b/src/ipa/ipu3/algorithms/agc.h\n> @@ -42,7 +42,8 @@ private:\n> \tdouble iqMean_;\n> \n> \tutils::Duration lineDuration_;\n> -\tutils::Duration maxExposureTime_;\n> +\tuint32_t minExposureLines_;\n> +\tuint32_t maxExposureLines_;\n> \n> \tutils::Duration filteredExposure_;\n> \tutils::Duration filteredExposureNoDg_;","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 44893BDB1C\n\tfor ;\n\tThu, 21 Oct 2021 02:23:43 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A44DD68F58;\n\tThu, 21 Oct 2021 04:23:42 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0076F60124\n\tfor ;\n\tThu, 21 Oct 2021 04:23:41 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 6C0182BA;\n\tThu, 21 Oct 2021 04:23:41 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"iYUqvqHj\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1634783021;\n\tbh=hPsFRbxsuqVkR0/z3TxB6rjRXvM0hlm1BW0es48Y154=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=iYUqvqHjLBsrxasBVUKLbDnrWf3D2V2ZMK3vFYA4YrAO1SZYz2d214P4ZFN1bV/Gn\n\tPNYOAdwfF4RLRGU0vuxfSakaAhc4n+5TfAM/ms/yBS4GyHpI6knrQ4gIAbi0o6BtDZ\n\tdMhLgu6sK+qNodMeUFwWDJ64O/r3H9orXKlVZBic=","Date":"Thu, 21 Oct 2021 05:23:22 +0300","From":"Laurent Pinchart ","To":"Jean-Michel Hautbois ","Message-ID":"","References":"<20211020154607.180161-1-jeanmichel.hautbois@ideasonboard.com>\n\t<20211020154607.180161-7-jeanmichel.hautbois@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20211020154607.180161-7-jeanmichel.hautbois@ideasonboard.com>","Subject":"Re: [libcamera-devel] [PATCH v2 06/13] ipa: ipu3: agc: Change\n\texposure limits","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","Cc":"libcamera-devel@lists.libcamera.org","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]