From patchwork Fri Aug 8 14:12:42 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 24075 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 5A110BDCC1 for ; Fri, 8 Aug 2025 14:13:56 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 081EE69227; Fri, 8 Aug 2025 16:13:56 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="DDsUnPmx"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id E11C66921A for ; Fri, 8 Aug 2025 16:13:54 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:3ea1:35ac:90da:a221]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id F281F42D0; Fri, 8 Aug 2025 16:13:04 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1754662385; bh=rcAPl7FLQ/9uSo2Qf9fn+WlLmij6pbv6z6EzGHNyjCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DDsUnPmx678zQNaBPJqPmZ59B01US8Br+ssY+m4vyhgxk2d5zoG0O1vFQZw8GJvQv nkJ0XtdJWtt+OZVpoJI4R8qqsJwsA6yqvJF4qslb9Gr2B8IGXoyFX84AmRm3Lr5o+2 lGgEi9yisad4MMYU3Gep3ANhlCU0ctazj+0k6zW4= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug Subject: [PATCH v2 04/16] libipa: exposure_mode_helper: Take exposure/gain quantization into account Date: Fri, 8 Aug 2025 16:12:42 +0200 Message-ID: <20250808141315.413839-5-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250808141315.413839-1-stefan.klug@ideasonboard.com> References: <20250808141315.413839-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" In ExposureModeHelper::splitExposure() the quantization of exposure time and gain is not taken into account. This can lead to visible flicker when the quantization steps are too big. As a preparation to fixing that, add a function to set the sensor line length and the current sensor mode helper and extend the clampXXX functions to return the quantization error. By default the exposure time quantization is assumed to be 1us and gain is assumed to not be quantized at all. This patch doesn't introduce any functional changes. Signed-off-by: Stefan Klug Reviewed-by: Kieran Bingham Reviewed-by: Daniel Scally --- src/ipa/libipa/exposure_mode_helper.cpp | 49 ++++++++++++++++++++----- src/ipa/libipa/exposure_mode_helper.h | 10 ++++- 2 files changed, 48 insertions(+), 11 deletions(-) diff --git a/src/ipa/libipa/exposure_mode_helper.cpp b/src/ipa/libipa/exposure_mode_helper.cpp index 0c1e99e31a47..d0a61908c966 100644 --- a/src/ipa/libipa/exposure_mode_helper.cpp +++ b/src/ipa/libipa/exposure_mode_helper.cpp @@ -70,18 +70,37 @@ namespace ipa { * the runtime limits set through setLimits() instead. */ ExposureModeHelper::ExposureModeHelper(const Span> stages) + : lineLength_(1us), minExposureTime_(0us), maxExposureTime_(0us), + minGain_(0), maxGain_(0), sensorHelper_(nullptr) { - minExposureTime_ = 0us; - maxExposureTime_ = 0us; - minGain_ = 0; - maxGain_ = 0; - for (const auto &[s, g] : stages) { exposureTimes_.push_back(s); gains_.push_back(g); } } +/** + * \brief Configure sensor details + * \param[in] lineLength The current line length of the sensor + * \param[in] sensorHelper The sensor helper + * + * This function sets the line length and sensor helper. These are used in + * splitExposure() to take the quantization of the exposure and gain into + * account. + * + * When this is not called, is is assumed that exposure is in micro second + * granularity and gain has no quantization at all. + * + * The caller has to ensure that sensorHelper is valid for the lifetime of + * ExposureModeHelper or the next call to configure. + */ +void ExposureModeHelper::configure(utils::Duration lineLength, + const CameraSensorHelper *sensorHelper) +{ + lineLength_ = lineLength; + sensorHelper_ = sensorHelper; +} + /** * \brief Set the exposure time and gain limits * \param[in] minExposureTime The minimum exposure time supported @@ -108,14 +127,26 @@ void ExposureModeHelper::setLimits(utils::Duration minExposureTime, maxGain_ = maxGain; } -utils::Duration ExposureModeHelper::clampExposureTime(utils::Duration exposureTime) const +utils::Duration ExposureModeHelper::clampExposureTime(utils::Duration exposureTime, + double *quantizationGain) const { - return std::clamp(exposureTime, minExposureTime_, maxExposureTime_); + utils::Duration clamped; + utils::Duration exp; + + clamped = std::clamp(exposureTime, minExposureTime_, maxExposureTime_); + exp = static_cast(clamped / lineLength_) * lineLength_; + if (quantizationGain) + *quantizationGain = clamped / exp; + + return exp; } -double ExposureModeHelper::clampGain(double gain) const +double ExposureModeHelper::clampGain(double gain, double *quantizationGain) const { - return std::clamp(gain, minGain_, maxGain_); + double clamped = std::clamp(gain, minGain_, maxGain_); + if (!sensorHelper_) + return clamped; + return sensorHelper_->quantizeGain(clamped, quantizationGain); } /** diff --git a/src/ipa/libipa/exposure_mode_helper.h b/src/ipa/libipa/exposure_mode_helper.h index c5be1b6703a8..8701fae9a26e 100644 --- a/src/ipa/libipa/exposure_mode_helper.h +++ b/src/ipa/libipa/exposure_mode_helper.h @@ -14,6 +14,8 @@ #include #include +#include "camera_sensor_helper.h" + namespace libcamera { namespace ipa { @@ -24,6 +26,7 @@ public: ExposureModeHelper(const Span> stages); ~ExposureModeHelper() = default; + void configure(utils::Duration lineLength, const CameraSensorHelper *sensorHelper); void setLimits(utils::Duration minExposureTime, utils::Duration maxExposureTime, double minGain, double maxGain); @@ -36,16 +39,19 @@ public: double maxGain() const { return maxGain_; } private: - utils::Duration clampExposureTime(utils::Duration exposureTime) const; - double clampGain(double gain) const; + utils::Duration clampExposureTime(utils::Duration exposureTime, + double *quantizationGain = nullptr) const; + double clampGain(double gain, double *quantizationGain = nullptr) const; std::vector exposureTimes_; std::vector gains_; + utils::Duration lineLength_; utils::Duration minExposureTime_; utils::Duration maxExposureTime_; double minGain_; double maxGain_; + const CameraSensorHelper *sensorHelper_; }; } /* namespace ipa */