[{"id":32890,"web_url":"https://patchwork.libcamera.org/comment/32890/","msgid":"<20241220093410.GA6745@pendragon.ideasonboard.com>","date":"2024-12-20T09:34:10","subject":"Re: [PATCH v6 1/9] libcamera: controls: Update the ColourTemperature\n\tcontrol to be writable","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Stefan,\n\nThank you for the patch.\n\nOn Thu, Dec 19, 2024 at 06:57:18PM +0100, Stefan Klug wrote:\n> For manual control it is helpful to be able to specify a fixed colour\n> temperature. It also provides an easy way to apply the temperature\n> specific CCMs and colour gains that are contained in the tuning files.\n> \n> Document this and update the control dependencies.\n> \n> Signed-off-by: Stefan Klug \n> Reviewed-by: Paul Elder \n> Reviewed-by: Kieran Bingham \n\nReviewed-by: Laurent Pinchart \n\n> ---\n> Changes in v6:\n> - Clarify interdependencies between ColourTemperature, ColourGains and\n> ColourCorrectionMatrix\n> \n> Changes in v5:\n> - Improve documentation\n> ---\n> src/libcamera/control_ids_core.yaml | 38 +++++++++++++++++++++++++++--\n> 1 file changed, 36 insertions(+), 2 deletions(-)\n> \n> diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml\n> index 073e0611d47c..1dfaee0c6327 100644\n> --- a/src/libcamera/control_ids_core.yaml\n> +++ b/src/libcamera/control_ids_core.yaml\n> @@ -298,7 +298,19 @@ controls:\n> description: |\n> Enable or disable the AWB.\n> \n> + When AWB is enabled, the algorithm estimates the colour temperature of\n> + the scene and computes colour gains and the colour correction matrix\n> + automatically. The computed colour temperature, gains and correction\n> + matrix are reported in metadata. The corresponding controls are ignored\n> + if set in a request.\n> +\n> + When AWB is disabled, the colour temperature, gains and correction\n> + matrix are not updated automatically and can be set manually in\n> + requests.\n> +\n> + \\sa ColourCorrectionMatrix\n> \\sa ColourGains\n> + \\sa ColourTemperature\n> \n> # AwbMode needs further attention:\n> # - Auto-generate max enum value.\n> @@ -357,17 +369,34 @@ controls:\n> order.\n> \n> ColourGains can only be applied in a Request when the AWB is disabled.\n> + If ColourGains is set in a request but ColourTemperature is not, the\n> + implementation shall calculate and set the ColourTemperature based on\n> + the ColourGains.\n> \n> \\sa AwbEnable\n> + \\sa ColourTemperature\n> size: [2]\n> \n> - ColourTemperature:\n> type: int32_t\n> direction: out\n> description: |\n> - Report the estimate of the colour temperature for the frame, in kelvin.\n> + ColourTemperature of the frame, in kelvin.\n> +\n> + ColourTemperature can only be applied in a Request when the AWB is\n> + disabled.\n> \n> - The ColourTemperature control can only be returned in metadata.\n> + If ColourTemperature is set in a request but ColourGains is not, the\n> + implementation shall calculate and set the ColourGains based on the\n> + given ColourTemperature. If ColourTemperature is set (either directly,\n> + or indirectly by setting ColourGains) but ColourCorrectionMatrix is not,\n> + the ColourCorrectionMatrix is updated based on the ColourTemperature.\n> +\n> + The ColourTemperature used to process the frame is reported in metadata.\n> +\n> + \\sa AwbEnable\n> + \\sa ColourCorrectionMatrix\n> + \\sa ColourGains\n> \n> - Saturation:\n> type: float\n> @@ -429,6 +458,11 @@ controls:\n> stored in conventional reading order in an array of 9 floating point\n> values.\n> \n> + ColourCorrectionMatrix can only be applied in a Request when the AWB is \n> + disabled.\n> +\n> + \\sa AwbEnable\n> + \\sa ColourTemperature\n> size: [3,3]\n> \n> - ScalerCrop:","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 195ACC3272\n\tfor ;\n\tFri, 20 Dec 2024 09:34:29 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 8C5DA68488;\n\tFri, 20 Dec 2024 10:34:27 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6B2D262C8A\n\tfor ;\n\tFri, 20 Dec 2024 10:34:17 +0100 (CET)","from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi\n\t[81.175.209.231])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id AC48CABE;\n\tFri, 20 Dec 2024 10:33:37 +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=\"Pvd8RuhG\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1734687217;\n\tbh=9XAIMCwM4CtAxGTffoObp6ddCIqjZthVdLUCYzUs5FM=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=Pvd8RuhGiuEZbc5qOSPDD+cArRGJXj7ghLh6ksW07IXfSHfzAXTePXEPpY1CvN+97\n\tSJZtznFxO64P8ySmFQkhI/UapaQnsXHeY7OLfTSzVpNZT9afC8IC1LOBEYm90g2HVy\n\tLIlFLOcxyBYpGdpA1lOXgVA4Nsj493j/RykWDubE=","Date":"Fri, 20 Dec 2024 11:34:10 +0200","From":"Laurent Pinchart ","To":"Stefan Klug ","Cc":"libcamera-devel@lists.libcamera.org,\n\tPaul Elder ,\n\tKieran Bingham ","Subject":"Re: [PATCH v6 1/9] libcamera: controls: Update the ColourTemperature\n\tcontrol to be writable","Message-ID":"<20241220093410.GA6745@pendragon.ideasonboard.com>","References":"<20241219175729.293782-1-stefan.klug@ideasonboard.com>\n\t<20241219175729.293782-2-stefan.klug@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20241219175729.293782-2-stefan.klug@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\" "}}]