[{"id":18927,"web_url":"https://patchwork.libcamera.org/comment/18927/","msgid":"","date":"2021-08-18T20:29:53","subject":"Re: [libcamera-devel] [PATCH v3 2/9] ipa: ipu3: Introduce a Context\n\tstructure","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Jean-Michel,\n\nThank you for the patch.\n\nOn Wed, Aug 18, 2021 at 05:53:56PM +0200, Jean-Michel Hautbois wrote:\n> An increasing amount of data and information needs to be shared between\n> the components that build up to implement image processing algorithms.\n> \n> Create a context structure which will allow us to work towards calling\n> algorithms in a modular way, and sharing information between the modules.\n> \n> The IPA context is a global context set at configure time (IPAConfiguration)\n> and a per-frame context (IPAFrameContext) used while streaming.\n> \n> Signed-off-by: Kieran Bingham \n> Signed-off-by: Jean-Michel Hautbois \n> ---\n> src/ipa/ipu3/ipa_context.h | 53 ++++++++++++++++++++++++++++++++++++++\n> 1 file changed, 53 insertions(+)\n> create mode 100644 src/ipa/ipu3/ipa_context.h\n> \n> diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h\n> new file mode 100644\n> index 00000000..76534f7f\n> --- /dev/null\n> +++ b/src/ipa/ipu3/ipa_context.h\n> @@ -0,0 +1,53 @@\n> +/* SPDX-License-Identifier: LGPL-2.1-or-later */\n> +/*\n> + * Copyright (C) 2021, Google Inc.\n> + *\n> + * ipu3_ipa_context.h - IPU3 IPA Context\n> + *\n> + */\n> +#ifndef __LIBCAMERA_IPU3_IPA_CONTEXT_H__\n> +#define __LIBCAMERA_IPU3_IPA_CONTEXT_H__\n> +\n> +#include \n> +\n> +namespace libcamera {\n> +\n> +namespace ipa::ipu3 {\n> +\n\nNormally documentation would go to .cpp files, but as this is private to\nthe IPU3, I'm OK relaxing the rule.\n\n> +/**\n> + * Fixed configuration of the IPA\n\nDoxygen style, so this should be a \\brief.\n\n> + *\n> + * This structure contains data set at the configure state of the IPA.\n> + * It can't be modified while streaming.\n\n\"Fixed configuration\" sounds like it's fixed, while I suspect this is a\nsession configuration that is set when from configure(), and can be\nmodified for the next session. If that's correct, How about naming the\nstructure IPASessionConfiguration to make this clear ? I may be biased\non the terminology, \"session\" probably comes from Android, and I'm open\nto alternative terms.\n\nAs for the documentation, I'd then write it as follows\n\n/**\n * \\brief Session configuration for the IPA module\n *\n * The session configuration contains all IPA configuration parameters that\n * remain constant during the capture session, from IPA module start to stop.\n * It is typically set during the configure() operation of the IPA module, but\n * may also be updated in the start() operation.\n */\n\n> + */\n> +struct IPAConfiguration {\n> +};\n> +\n> +/**\n> + * Context of a frame for each algorithms\n> + *\n> + * This may be stored in a way that is associated with a given request\n> + * lifetime, though for now a single instance is used.\n> + * It contains informations updated while streaming by the algorithms.\n\nLet's expand that, with how I understand the structure is meant to be\nused today.\n\n/**\n * \\brief Per-frame context for algorithms\n *\n * The frame context stores data specific to a single frame processed by the\n * IPA. Each frame processed by the IPA has a context associated with it,\n * accessible through the IPAContext structure.\n *\n * \\todo Detail how to access contexts for a particular frame\n *\n * Each of the fields in the frame context belongs to either a specific\n * algorithm, or to the top-level IPA module. A field may be read by any\n * algorithm, but only be written by its owner.\n */\n\n> + */\n> +struct IPAFrameContext {\n> +};\n> +\n> +/**\n> + * Context information shared between the algorithms\n> + *\n> + * The global context structure contains:\n> + * - a configuration structure set while the IPA is configured, and not\n> + * modified when streaming\n> + * - a frameContext structure updated by the algorithms while streaming\n\nThis should use doxygen documentation for the fields.\n\n> + */\n\n/**\n * \\brief Global IPA context data shared between all algorithms\n *\n * \\var IPAContext::configuration\n * \\brief The IPA session configuration, immutable during the session\n *\n * \\var IPAContext::frameContext\n * \\brief The frame context for the frame being processed\n * \\todo While the frame context is supposed to be per-frame, this\n * single frame context stores data related to both the current frame\n * and the previous frames, with fields being updated as the algorithms\n * are run. This needs to be turned into real per-frame data storage.\n */\n\n> +struct IPAContext {\n> +\tIPAConfiguration configuration;\n> +\tIPAFrameContext frameContext;\n> +};\n> +\n> +} /* namespace ipa::ipu3 */\n> +\n> +} /* namespace libcamera*/\n> +\n> +#endif /* __LIBCAMERA_IPU3_IPA_CONTEXT_H__ */","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 57EFFBD87D\n\tfor ;\n\tWed, 18 Aug 2021 20:30:04 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id B01CB68895;\n\tWed, 18 Aug 2021 22:30:03 +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 0A3DE6888A\n\tfor ;\n\tWed, 18 Aug 2021 22:30:02 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 72F00EE;\n\tWed, 18 Aug 2021 22:30:01 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"DdVv7v49\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1629318601;\n\tbh=kSpjm1R0G5giDcbFNHrxYSWv/G6RKI/qBRomWXnWLnA=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=DdVv7v49oCkcLjjA8a+WLY3hZeqtzrNCLrV4ziyDdi1Z8J/nLA27w2l+BCW84tRM0\n\tHLmsWyZgGmxLCJoRvoDdzpQfxgX8aG0iFHDL6BmecnTkTUB/GyWYd+K9mMPR5Evs24\n\t7IQcwvt7ZYcZdGLt9dXzflEo/G+MsnGE+rf0M4Rk=","Date":"Wed, 18 Aug 2021 23:29:53 +0300","From":"Laurent Pinchart ","To":"Jean-Michel Hautbois ","Message-ID":"","References":"<20210818155403.268694-1-jeanmichel.hautbois@ideasonboard.com>\n\t<20210818155403.268694-3-jeanmichel.hautbois@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20210818155403.268694-3-jeanmichel.hautbois@ideasonboard.com>","Subject":"Re: [libcamera-devel] [PATCH v3 2/9] ipa: ipu3: Introduce a Context\n\tstructure","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","Cc":"libcamera-devel@lists.libcamera.org","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]