[{"id":23408,"web_url":"https://patchwork.libcamera.org/comment/23408/","msgid":"<165533399870.2586493.16234670743517695560@Monstersaurus>","date":"2022-06-15T22:59:58","subject":"Re: [libcamera-devel] [PATCH v2 2/5] libcamera: pipeline: simple:\n\tDocument the pipeline traversal algorithm","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Laurent Pinchart via libcamera-devel (2022-06-12 16:23:08)\n> Add a section to the documentation at the top of the file to describe in\n> a bit more details how the media graph is traversed.\n> \n> Signed-off-by: Laurent Pinchart \n> ---\n> src/libcamera/pipeline/simple/simple.cpp | 15 +++++++++++++++\n> 1 file changed, 15 insertions(+)\n> \n> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp\n> index efb28ccd97e8..b09368aee20b 100644\n> --- a/src/libcamera/pipeline/simple/simple.cpp\n> +++ b/src/libcamera/pipeline/simple/simple.cpp\n> @@ -95,6 +95,21 @@ LOG_DEFINE_CATEGORY(SimplePipeline)\n> * valid pipeline configurations are found, a Camera is registered for the\n> * SimpleCameraData instance.\n> *\n> + * Pipeline Traversal\n> + * ------------------\n> + *\n> + * During the breadth-first search, the pipeline is traversed from entity to\n> + * entity, by following media graph links from source to sink, starting at the\n> + * camera sensor. When reaching an entity (on its sink side), all its source\n> + * pads are considered to continue the graph traversal.\n> + *\n> + * The shortest path between the camera sensor and a video node is stored in\n> + * SimpleCameraData::entities_ as a list of SimpleCameraData::Entity structures,\n> + * ordered along the data path from the camera sensor to the video node. The\n> + * Entity structure stores a pointer to the MediaEntity, as well as information\n> + * about how it is connected in that particular path for later usage when\n> + * configuring the pipeline.\n> + *\n\nI still think a generalised pipeline traversal like proposed by Naush\nmight be helpful sometime.\n\nBut ... that's a separate topic, this documents the current behaviour,\nsounds reasonable so it's good to add.\n\n\nReviewed-by: Kieran Bingham \n\n> * Pipeline Configuration\n> * ----------------------\n> *\n> -- \n> Regards,\n> \n> Laurent Pinchart\n>","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 95531BD161\n\tfor ;\n\tWed, 15 Jun 2022 23:00:04 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id EB69965635;\n\tThu, 16 Jun 2022 01:00:03 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 3A3D4601EF\n\tfor ;\n\tThu, 16 Jun 2022 01:00:02 +0200 (CEST)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 745D5415;\n\tThu, 16 Jun 2022 01:00:01 +0200 (CEST)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1655334003;\n\tbh=Zx3Y+1EO89CS55jwjKY4ftgOKjpLZ2kINsn7mahQjgg=;\n\th=In-Reply-To:References:To:Date:Subject:List-Id:List-Unsubscribe:\n\tList-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:\n\tFrom;\n\tb=nklTqwx4F1EXAYZdMb/6SSLC1d6Qj5wEZ96AAOPnVIan99T33JrO+uKvHofktWTEL\n\tmJGMFIT50vc9cnGSOnbEWEJwZeN2TbiHGhYimMNcN3i0AH69wvFPyFDFAXH4Qylr+H\n\tWqjJisJmIwfcH/awzla9GaWEMSPRdc7ASfrD7HbOlInDtHjNBlkiIoAgvEA8603cJo\n\tCIxED40uPT02s18DxpgjoswHXf8Zhr4BIgtgonIZrsUK6hzN+TbwKBupHHbN2zyxBb\n\tdFHAleYEAnuRSIbdSHFYEXjuZ1Eq15VHWdThYe/OLNcvaTQwG31IgIr0VRrivE6UZ1\n\tb3jp8cbppsgCg==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1655334001;\n\tbh=Zx3Y+1EO89CS55jwjKY4ftgOKjpLZ2kINsn7mahQjgg=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=X+HkrRufe/YRZch8vNyDTZV1Ew3NBWBiGB937x9mQ/y25cFz0Vr0fR8z2ZqGJbuXG\n\tDPaMXGQ8JxckXSp3Av5mfEx/2D8e0aXQhOOklQSGat4ki1WIE8VGy1R3A+C1LAO0Ye\n\tvWLL21WbNdDA9JDCGI89AW5mK5wU4yr31u53is8E="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"X+HkrRuf\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20220612152311.8408-3-laurent.pinchart@ideasonboard.com>","References":"<20220612152311.8408-1-laurent.pinchart@ideasonboard.com>\n\t<20220612152311.8408-3-laurent.pinchart@ideasonboard.com>","To":"Laurent Pinchart ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Wed, 15 Jun 2022 23:59:58 +0100","Message-ID":"<165533399870.2586493.16234670743517695560@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v2 2/5] libcamera: pipeline: simple:\n\tDocument the pipeline traversal algorithm","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","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Cc":"Dorota Czaplejewicz ,\n\tBenjamin Schaaf ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]