From patchwork Mon Jan 20 20:45:00 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 22596 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 25D73C327C for ; Mon, 20 Jan 2025 20:45:46 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 65BAE6855D; Mon, 20 Jan 2025 21:45:45 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="f8hFHY8O"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id F27C068557 for ; Mon, 20 Jan 2025 21:45:34 +0100 (CET) Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 4607422A; Mon, 20 Jan 2025 21:44:33 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1737405873; bh=+lCqw42hmVojvuF3K5LzCeAFVYpuMkSmbs2mDiv7s+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f8hFHY8OG5NuMSVUvzq9M+Wn3MLH0hhR1rtZHgRi4kaiEDNGAXp5xvnibjIBLZoSe 6FtVziXDYLNHdBGXDGEtbC6PKwFgGrTdTr8620SfAx4cAErSC0NVpdBXb2qAolcW5p OLFCdpZfkzy3SDhfPgPogKshEDF2DAzFJsWsRijQ= From: Laurent Pinchart To: libcamera-devel@lists.libcamera.org Cc: Naushir Patuck , David Plowman , Paul Elder Subject: [PATCH v9 09/12] controls: Redefine AeEnable Date: Mon, 20 Jan 2025 22:45:00 +0200 Message-ID: <20250120204515.24096-10-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250120204515.24096-1-laurent.pinchart@ideasonboard.com> References: <20250120204515.24096-1-laurent.pinchart@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" From: Paul Elder In the redesign of the AE-related controls, the AeEnable control was intended to be removed in favor of more specific sub-controls for analogue gain and exposure time. However this will cause problems if aperture sub-controls are introduced, and an application from a pre-aperture era uses a camera that supports aperture. If there is no AeEnable control, then a pre-aperture era application might set analogue gain and exposure time to manual, while aperture silently stays auto since that's the default mode. Thus aperture would be uncontrollable by the application. With an AeEnable control, then a pre-aperture era application can set AeEnable to manual, and under the hood all three of analogue gain and exposure time and aperture will be set to manual. The application won't be able to set the manual aperture, however. Although the above scenario is expected to be rare, the scenario with an AeEnable control seems less detrimental. With an AeEnable control at least the aperture would be static at a reasonably usable value, whereas without an AeEnable the aperture would be more-or-less uncontrolable and could go to extreme values as the AEGC algorithm tries to compensate for the manual analogue gain and exposure time values. Thus we redefine the AeEnable control, available only as a control and not in metadata. It will be preprocessed by the Camera class so that the relevant sub-controls are set. No pipline handler nor IPA shall act on the AeEnable control. The IPA still has to report the control as available, however. Signed-off-by: Paul Elder Reviewed-by: Laurent Pinchart Reviewed-by: Stefan Klug Signed-off-by: Laurent Pinchart --- Documentation/design/ae.rst | 23 +++++++++++++++++------ src/libcamera/control_ids_core.yaml | 12 +++++++++--- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/Documentation/design/ae.rst b/Documentation/design/ae.rst index 9d5bb507858d..df9b1fa7660e 100644 --- a/Documentation/design/ae.rst +++ b/Documentation/design/ae.rst @@ -185,6 +185,10 @@ A diagram of our solution: 0: Auto 1: Manual + AeEnable + - True -> ExposureTimeMode:Auto + AnalogueGainMode:Auto + - False -> ExposureTimeMode:Manual + AnalogueGainMode:Manual + The diagram is divided in four sections horizontally: @@ -225,10 +229,14 @@ This simulates an auto -> locked -> manual or auto -> manual state transition, and makes it impossible to do the nonsensical manual -> locked state transition. -We specifically do not have a "master AE control" like the old AeEnable. This -is because we have the individual mode controls, and if we had a master AE -control it would be a "control that sets other controls", which could easily -get out of control. +AeEnable still exists to allow applications to set the mode of all the +sub-controls at once. Besides being for convenience, this will also be useful +when we eventually implement an aperture control. This is because applications +that will be made before aperture will have been available would still be able +to set aperture mode to auto or manual, as opposed to having the aperture stuck +at auto while the application really wanted manual. Although the aperture would +still be stuck at an uncontrollable value, at least it would be at a static +usable value as opposed to varying via the AEGC algorithm. With this solution, the earlier example would become: @@ -277,9 +285,12 @@ and gain: - AeState +- AeEnable + Auto-exposure and auto-gain can be enabled and disabled separately using the -ExposureTimeMode and AnalogueGainMode controls respectively. There is no -overarching AeEnable control. +ExposureTimeMode and AnalogueGainMode controls respectively. The AeEnable +control can also be used, as it sets both of the modes simultaneously. The +AeEnable control is not returned in metadata. When the respective mode is set to auto, the respective value that is computed by the AEGC algorithm is applied to the image sensor. Any value that is diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml index d88c1852ec44..aa7448645880 100644 --- a/src/libcamera/control_ids_core.yaml +++ b/src/libcamera/control_ids_core.yaml @@ -10,11 +10,17 @@ vendor: libcamera controls: - AeEnable: type: bool - direction: inout + direction: in description: | - Enable or disable the AE. + Enable or disable the AEGC algorithm. When this control is set to true, + both ExposureTimeMode and AnalogueGainMode are set to auto, and if this + control is set to false then both are set to manual. - \sa ExposureTime AnalogueGain + If ExposureTimeMode or AnalogueGainMode are also set in the same + request as AeEnable, then the modes supplied by ExposureTimeMode or + AnalogueGainMode will take precedence. + + \sa ExposureTimeMode AnalogueGainMode - AeState: type: int32_t