From patchwork Thu Oct 30 16:58:09 2025 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: 24919 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 12F02C3334 for ; Thu, 30 Oct 2025 16:58:47 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id AD38F609DC; Thu, 30 Oct 2025 17:58:46 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="XBSLleRO"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 3A0E5608F5 for ; Thu, 30 Oct 2025 17:58:25 +0100 (CET) Received: from pb-laptop.local (185.221.140.239.nat.pool.zt.hu [185.221.140.239]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 2174D6F3; Thu, 30 Oct 2025 17:56:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1761843395; bh=uyiGdGvWow9KOc5Sy+G/2EdD5abElQRSJ2vENI1m0c0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XBSLleROLStdi2cxbNMrZl/KSAekbEb672nWKAc4Dvpf2I4NipIi7Mx1VCb6couXT SV0XADL2tZj//BA4zpeg9/dRuS32Y++MA0JJA5JvFxm8SVPdFXnPPkdG2m+8p9yKyJ k9a1+14hiFwk4x5hx0AwdhjXgeSO9snzHsjmOCUo= From: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= To: libcamera-devel@lists.libcamera.org Cc: Jacopo Mondi Subject: [RFC PATCH v3 15/22] guides: application: Document Camera::metadataAvailable Date: Thu, 30 Oct 2025 17:58:09 +0100 Message-ID: <20251030165816.1095180-16-barnabas.pocze@ideasonboard.com> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251030165816.1095180-1-barnabas.pocze@ideasonboard.com> References: <20251030165816.1095180-1-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 06c07d1e94..166919cf62 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 allows application 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