{"id":14310,"url":"https://patchwork.libcamera.org/api/patches/14310/?format=json","web_url":"https://patchwork.libcamera.org/patch/14310/","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":"<20211026082142.69023-1-jeanmichel.hautbois@ideasonboard.com>","date":"2021-10-26T08:21:42","name":"[libcamera-devel] ipa: ipu3: agc: Clamp shutter speed","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"316c23166d870f07eb95098ceff71f68ca90a4f4","submitter":{"id":75,"url":"https://patchwork.libcamera.org/api/people/75/?format=json","name":"Jean-Michel Hautbois","email":"jeanmichel.hautbois@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/14310/mbox/","series":[{"id":2655,"url":"https://patchwork.libcamera.org/api/series/2655/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=2655","date":"2021-10-26T08:21:42","name":"[libcamera-devel] ipa: ipu3: agc: Clamp shutter speed","version":1,"mbox":"https://patchwork.libcamera.org/series/2655/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/14310/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/14310/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 70C97BF415\n\tfor ;\n\tTue, 26 Oct 2021 08:21:47 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id CDCFD64878;\n\tTue, 26 Oct 2021 10:21:46 +0200 (CEST)","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 36E3760123\n\tfor ;\n\tTue, 26 Oct 2021 10:21:46 +0200 (CEST)","from tatooine.ideasonboard.com (unknown\n\t[IPv6:2a01:e0a:169:7140:dce3:eb54:18d7:6f3d])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id C20103F0;\n\tTue, 26 Oct 2021 10:21:45 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"pSANcc6D\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1635236505;\n\tbh=PtVlSlsFtLGpF6G6mzj99vEfbLejpButPp1RBv8o44Q=;\n\th=From:To:Cc:Subject:Date:From;\n\tb=pSANcc6DApN71ZMkj8x+ujT7lLsI0rVtDIqOcl2Qt0gtyXql8MhwbA3i1NGiiwCZv\n\tE0+1da7lJci49fe3W2WX3R0pvDz18RtsOKVXTZSJNrXwhGX3lkMwUmOh2ze9inuNSD\n\tnaT8LsVtFfpOq2j9WYMaAYMhV+jvkxYeHDV9c4og=","From":"Jean-Michel Hautbois ","To":"libcamera-devel@lists.libcamera.org","Date":"Tue, 26 Oct 2021 10:21:42 +0200","Message-Id":"<20211026082142.69023-1-jeanmichel.hautbois@ideasonboard.com>","X-Mailer":"git-send-email 2.32.0","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH] ipa: ipu3: agc: Clamp shutter speed","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":"In case the maximum exposure received from the sensor is very high, we\ncan have a very high shutter speed with a small analogue gain, and it\nmay result in very slow framerate. We are not really supporting it for\nthe moment, so clamp the shutter speed to an arbitrary value of 60ms.\n\nSigned-off-by: Jean-Michel Hautbois \n---\n src/ipa/ipu3/algorithms/agc.cpp | 6 +++++-\n 1 file changed, 5 insertions(+), 1 deletion(-)","diff":"diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp\nindex 6c151232..5927b5d3 100644\n--- a/src/ipa/ipu3/algorithms/agc.cpp\n+++ b/src/ipa/ipu3/algorithms/agc.cpp\n@@ -34,6 +34,9 @@ static constexpr uint32_t kFrameSkipCount = 6;\n static constexpr double kMinAnalogueGain = 1.0;\n static constexpr double kMaxAnalogueGain = 8.0;\n \n+/* Maximum shutter speed allowed */\n+static constexpr utils::Duration kMaxShutterSpeed = 60ms;\n+\n /* Histogram constants */\n static constexpr uint32_t knumHistogramBins = 256;\n static constexpr double kEvGainTarget = 0.5;\n@@ -54,7 +57,8 @@ int Agc::configure(IPAContext &context, const IPAConfigInfo &configInfo)\n \n \t/* \\todo replace the exposure in lines storage with time based ones. */\n \tminExposureLines_ = context.configuration.agc.minShutterSpeed / lineDuration_;\n-\tmaxExposureLines_ = context.configuration.agc.maxShutterSpeed / lineDuration_;\n+\tmaxExposureLines_ = std::min(context.configuration.agc.maxShutterSpeed / lineDuration_,\n+\t\t\t\t kMaxShutterSpeed / lineDuration_);\n \n \tminAnalogueGain_ = std::max(context.configuration.agc.minAnalogueGain, kMinAnalogueGain);\n \tmaxAnalogueGain_ = std::min(context.configuration.agc.maxAnalogueGain, kMaxAnalogueGain);\n","prefixes":["libcamera-devel"]}