{"id":21512,"url":"https://patchwork.libcamera.org/api/1.1/patches/21512/?format=json","web_url":"https://patchwork.libcamera.org/patch/21512/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/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":"<20241004115558.9166-2-david.plowman@raspberrypi.com>","date":"2024-10-04T11:55:53","name":"[1/6] controls: rpi: Add controls for the camera sync algorithm","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"ba808df79a0db6dcd2e48353bafc9e6bed0dbb63","submitter":{"id":42,"url":"https://patchwork.libcamera.org/api/1.1/people/42/?format=json","name":"David Plowman","email":"david.plowman@raspberrypi.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/21512/mbox/","series":[{"id":4658,"url":"https://patchwork.libcamera.org/api/1.1/series/4658/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=4658","date":"2024-10-04T11:55:52","name":"Raspberry Pi software camera sync algorithm","version":1,"mbox":"https://patchwork.libcamera.org/series/4658/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/21512/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/21512/checks/","tags":{},"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 DEAB0BD80A\n\tfor ;\n\tFri, 4 Oct 2024 11:56:11 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id B58B76352C;\n\tFri, 4 Oct 2024 13:56:06 +0200 (CEST)","from mail-wr1-x435.google.com (mail-wr1-x435.google.com\n\t[IPv6:2a00:1450:4864:20::435])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 898FB62C8F\n\tfor ;\n\tFri, 4 Oct 2024 13:56:03 +0200 (CEST)","by mail-wr1-x435.google.com with SMTP id\n\tffacd0b85a97d-37cca239886so1274633f8f.2\n\tfor ;\n\tFri, 04 Oct 2024 04:56:03 -0700 (PDT)","from raspberrypi.pitowers.org\n\t([2a00:1098:3142:1f:daa2:371b:a97:3e3e])\n\tby smtp.gmail.com with ESMTPSA id\n\tffacd0b85a97d-37d081f743esm3107147f8f.21.2024.10.04.04.56.02\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tFri, 04 Oct 2024 04:56:02 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; 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\n\tFri, 04 Oct 2024 04:56:02 -0700 (PDT)","From":"David Plowman ","To":"libcamera-devel@lists.libcamera.org","Cc":"David Plowman ,\n\tArsen Mikovic ,\n\tNaushir Patuck ","Subject":"[PATCH 1/6] controls: rpi: Add controls for the camera sync\n\talgorithm","Date":"Fri, 4 Oct 2024 12:55:53 +0100","Message-Id":"<20241004115558.9166-2-david.plowman@raspberrypi.com>","X-Mailer":"git-send-email 2.39.5","In-Reply-To":"<20241004115558.9166-1-david.plowman@raspberrypi.com>","References":"<20241004115558.9166-1-david.plowman@raspberrypi.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","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","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"The camera sync algorithm uses the following new controls:\n\nSyncMode - a camera can be a server or client\nSyncWait - whether the sync point has been reached\nSyncLag - how far away from synchronisation a camera was\nSyncFrameWallClock - for passing wall clock time to the IPA.\n\nSigned-off-by: David Plowman \nSigned-off-by: Arsen Mikovic \nReviewed-by: Naushir Patuck \n---\n src/libcamera/control_ids_rpi.yaml | 76 ++++++++++++++++++++++++++++++\n 1 file changed, 76 insertions(+)","diff":"diff --git a/src/libcamera/control_ids_rpi.yaml b/src/libcamera/control_ids_rpi.yaml\nindex 42c4bf5d..b5605dfa 100644\n--- a/src/libcamera/control_ids_rpi.yaml\n+++ b/src/libcamera/control_ids_rpi.yaml\n@@ -30,4 +30,80 @@ controls:\n \n \\sa StatsOutputEnable\n \n+ - FrameWallClock:\n+ type: int64_t\n+ description: |\n+ Control that returns the wall clock timestamp of a frame. This\n+ is the \"time since epoch\" value obtained from the system, in\n+ microseconds. This value is likely to be subject to\n+ significantly more jitter than the recorded SensorTimestamp.\n+\n+ - SyncMode:\n+ type: int32_t\n+ description: |\n+ Puts the camera system into sync mode, so that frames can be\n+ temporally synchronised with another camera, either on the same\n+ device, or on a different one.\n+ enum:\n+ - name: SyncModeOff\n+ value: 0\n+ description: Sync not in use.\n+ - name: SyncModeServer\n+ value: 1\n+ description: |\n+ Sync on, act as server. The server broadcasts timing\n+ messages to any clients that are listening, so that the\n+ clients can synchronise their camera frames with the\n+ server's.\n+ - name: SyncModeClient\n+ value: 2\n+ description: |\n+ Sync on, act as client. A client listens for any server\n+ messages, and arranges for its camera frames to synchronise\n+ as closely as possible with the server's. Many clients\n+ can listen out for the same server.\n+\n+ - SyncWait:\n+ type: bool\n+ description: |\n+ When using the camera syncrhonisation algorithm, the server\n+ broadcasts timing information to the client. This also includes\n+ the time (some number of frames in the future) at which it will\n+ tell the application running on the server when to start using\n+ the image frames (the \"ready time\").\n+\n+ The client receives the \"ready time\" from the server, and will\n+ tell the application on its end to start using the frames at\n+ this same moment.\n+\n+ While this control value is true, applications (on both client\n+ and server) should continue to wait.\n+\n+ Once this value is false, it means that this is the frame where\n+ client and server have agreed that it is the first synchronised\n+ frame that should be used by the application.\n+\n+ - SyncLag:\n+ type: int64_t\n+ description: |\n+ The lag is the amount of time since the \"ready time\", at which\n+ the server and client will signal their controlling applications\n+ that the frames are now synchronised and should be used.\n+\n+ Normally, therefore, the value will start negative (the \"ready\n+ time\" is in the future), and increase towards zero, before\n+ becoming positive (the \"ready time\" has elapsed).\n+\n+ Servers always report this value; clients will omit this control\n+ until they have received a message from the server that enables\n+ them to calculate it.\n+\n+ Normally there will be just one frame where the lag value is, or\n+ is very close to, zero - the one for which SyncWait becomes\n+ false. But note that if frames are being dropped, then the \"near\n+ zero\" value, or indeed any other, could be skipped. In these\n+ cases the lag value allows an application to work out exactly\n+ what has happened.\n+\n+ \\sa SyncWait\n ...\n","prefixes":["1/6"]}