{"id":3949,"url":"https://patchwork.libcamera.org/api/patches/3949/?format=json","web_url":"https://patchwork.libcamera.org/patch/3949/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20200605141002.49119-6-jacopo@jmondi.org>","date":"2020-06-05T14:09:59","name":"[libcamera-devel,v3,5/8] libcamera: properties: Add FrameDurationLimits","commit_ref":null,"pull_url":null,"state":"superseded","archived":true,"hash":"4dc94547fcc1497d04c2fe287cbe9baccc75dd7a","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/?format=json","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"delegate":{"id":15,"url":"https://patchwork.libcamera.org/api/users/15/?format=json","username":"jmondi","first_name":"Jacopo","last_name":"Mondi","email":"jacopo@jmondi.org"},"mbox":"https://patchwork.libcamera.org/patch/3949/mbox/","series":[{"id":958,"url":"https://patchwork.libcamera.org/api/series/958/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=958","date":"2020-06-05T14:09:54","name":"android: Build stream configuration map","version":3,"mbox":"https://patchwork.libcamera.org/series/958/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/3949/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/3949/checks/","tags":{},"headers":{"Return-Path":"","Received":["from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net\n\t[217.70.183.200])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6E7CB61645\n\tfor ;\n\tFri, 5 Jun 2020 16:07:11 +0200 (CEST)","from localhost.localdomain (93-34-118-233.ip49.fastwebnet.it\n\t[93.34.118.233]) (Authenticated sender: jacopo@jmondi.org)\n\tby relay7-d.mail.gandi.net (Postfix) with ESMTPSA id A143120003;\n\tFri, 5 Jun 2020 14:07:10 +0000 (UTC)"],"X-Originating-IP":"93.34.118.233","From":"Jacopo Mondi ","To":"libcamera-devel@lists.libcamera.org","Date":"Fri, 5 Jun 2020 16:09:59 +0200","Message-Id":"<20200605141002.49119-6-jacopo@jmondi.org>","X-Mailer":"git-send-email 2.27.0","In-Reply-To":"<20200605141002.49119-1-jacopo@jmondi.org>","References":"<20200605141002.49119-1-jacopo@jmondi.org>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v3 5/8] libcamera: properties: Add\n\tFrameDurationLimits","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","X-List-Received-Date":"Fri, 05 Jun 2020 14:07:11 -0000"},"content":"Add a camera property to express the minimum and maximum frame durations.\n\nSigned-off-by: Jacopo Mondi \n---\n\nCc Naush and Dave as this could potentially conflict with their on-going FPS\nhandling series. Sending it out for discussion.\n\n---\n src/libcamera/property_ids.yaml | 47 +++++++++++++++++++++++++++++++++\n 1 file changed, 47 insertions(+)\n\n--\n2.27.0","diff":"diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml\nindex ce627fa042ba..d703ab31eaac 100644\n--- a/src/libcamera/property_ids.yaml\n+++ b/src/libcamera/property_ids.yaml\n@@ -386,4 +386,51 @@ controls:\n | |\n | |\n +--------------------+\n+\n+ - FrameDurationLimits:\n+ type: int32_t\n+ size: [2]\n+ description: |\n+ The camera supported frame durations interval.\n+\n+ This property reports the camera minimum and maximum frame durations (in\n+ this order) expressed in nanoseconds to report the limits of the\n+ achievable frame rate.\n+\n+ Camera devices should here report durations calculated by inspecting the\n+ camera sensor supported frame rate interval, and adding to it any\n+ known additional delay caused by the image acquisition process that\n+ incurs in the time between a frame is captured and delivered to\n+ applications.\n+\n+ The here reported durations represent the time interval that occurs\n+ between the delivery of two consecutive frames for the fastest and\n+ slower streams, without considering additional delays introduced by the\n+ sharing of system resources when multiple streams are captured at the\n+ same time.\n+\n+ This implies that the minimum reported frame duration, which corresponds\n+ to the highest possible camera frame rate, is calculated without taking\n+ into consideration how multiple streams capture requests sent to\n+ the camera as part of the same capture session might influence the frame\n+ delivery rate by, in example, introducing delays due to the requirement\n+ of time-sharing components part of the image acquisition pipeline. In\n+ example, request containing two scaled-down streams might require\n+ time-sharing the single scaler available in the system, introducing an\n+ additional delay that prevents the camera to deliver frames at the\n+ here reported rate.\n+\n+ In the same way, the maximum frame duration, which corresponds to the\n+ lowest possible frame rate, does not take into consideration additional\n+ processing delays introduced by image encoding and processing that\n+ happens sporadically, in example, to produce still images in JPEG\n+ format.\n+\n+ As a consequence, application should inspect this property to know the\n+ camera capability limits, but should not assume the here reported values\n+ are achievable under all circumstances.\n+\n+ # \\todo Expand to better describe how stalling streams (ie JPEG) impacts\n+ # the frame rate calculation.\n+\n ...\n","prefixes":["libcamera-devel","v3","5/8"]}