From patchwork Tue Jan 6 16:57:47 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= X-Patchwork-Id: 25645 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 2BA07C32AF for ; Tue, 6 Jan 2026 16:58:19 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 4798461FD3; Tue, 6 Jan 2026 17:58:14 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="c0VD5JTJ"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id B9C1D61FC9 for ; Tue, 6 Jan 2026 17:58:01 +0100 (CET) Received: from pb-laptop.local (185.221.143.114.nat.pool.zt.hu [185.221.143.114]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id AB5A91AAE; Tue, 6 Jan 2026 17:57:40 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1767718660; bh=feYXSQdNRDE377ftRoz1dXJzRqiPbSFTQ4/oH38D3f0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c0VD5JTJokRnF5zVKg++0Kd1hREZPR4bM2EKWWkv98/Di5xJ0OXCRiqI/O1lpQVU+ kRL66SVJy9XCqeeXwY2dsQB1DdMWdwjzshthALdS0LvOGArHdFF0baixgYaggNezuj 1LbEBKvgO+wgM0lanwZe0Vtgi9zugvez0TZksqbs= From: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= To: libcamera-devel@lists.libcamera.org Cc: Jacopo Mondi , Kieran Bingham Subject: [PATCH v4 15/22] guides: application: Document Camera::metadataAvailable Date: Tue, 6 Jan 2026 17:57:47 +0100 Message-ID: <20260106165754.1759831-16-barnabas.pocze@ideasonboard.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260106165754.1759831-1-barnabas.pocze@ideasonboard.com> References: <20260106165754.1759831-1-barnabas.pocze@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: Jacopo Mondi Document the Camera::metadataAvailable signal in the application developer guide as an opt-in feature to receive early metadata notifications. Signed-off-by: Jacopo Mondi Signed-off-by: Barnabás Pőcze Reviewed-by: Kieran Bingham --- Original: https://patchwork.libcamera.org/patch/22228/ changes in v3: * adjust previous paragraph about signals --- Documentation/guides/application-developer.rst | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/Documentation/guides/application-developer.rst b/Documentation/guides/application-developer.rst index 06c07d1e9..344c2a6df 100644 --- a/Documentation/guides/application-developer.rst +++ b/Documentation/guides/application-developer.rst @@ -350,8 +350,17 @@ them. .. _Qt Signals and Slots: https://doc.qt.io/qt-6/signalsandslots.html -The ``Camera`` device emits two signals that applications can connect to in -order to execute callbacks on frame completion events. +During request processing, the ``Camera`` device emits certain signals +to notify the application about events regarding each and every request. +These signals are described below. + +The ``Camera::metadataAvailable`` signal notifies applications of the +availability of metadata results before a request completes. Receiving +notification about metadata availability enables applications to fast-track +handling of metadata results before all the image buffers in a request are +ready. The full list of metadata results associated with a Request is also +available at request complete time, and receiving notifications for early +metadata availability is an optional feature for applications. The ``Camera::bufferCompleted`` signal notifies applications that a buffer with image data is available. Receiving notifications about the single buffer