{"id":3478,"url":"https://patchwork.libcamera.org/api/1.1/patches/3478/?format=json","web_url":"https://patchwork.libcamera.org/patch/3478/","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":"<20200417124110.72313-5-jacopo@jmondi.org>","date":"2020-04-17T12:41:03","name":"[libcamera-devel,v9,04/11] media: v4l2-ctrl: Document V4L2_CID_CAMERA_SENSOR_ROTATION","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"1c8b844812eb6754ba3aecaf618174d4cc55fb71","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/1.1/people/3/?format=json","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"delegate":{"id":15,"url":"https://patchwork.libcamera.org/api/1.1/users/15/?format=json","username":"jmondi","first_name":"Jacopo","last_name":"Mondi","email":"jacopo@jmondi.org"},"mbox":"https://patchwork.libcamera.org/patch/3478/mbox/","series":[{"id":815,"url":"https://patchwork.libcamera.org/api/1.1/series/815/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=815","date":"2020-04-17T12:40:59","name":"media: report camera sensor properties","version":9,"mbox":"https://patchwork.libcamera.org/series/815/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/3478/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/3478/checks/","tags":{},"headers":{"Return-Path":"","Received":["from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net\n\t[217.70.183.195])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 38D9160402\n\tfor ;\n\tFri, 17 Apr 2020 14:38:31 +0200 (CEST)","from uno.homenet.telecomitalia.it (unknown [87.13.136.104])\n\t(Authenticated sender: jacopo@jmondi.org)\n\tby relay3-d.mail.gandi.net (Postfix) with ESMTPSA id E4E5E60017;\n\tFri, 17 Apr 2020 12:38:26 +0000 (UTC)"],"X-Originating-IP":"87.13.136.104","From":"Jacopo Mondi ","To":"Mauro Carvalho Chehab ,\n\tHans Verkuil ,\n\tSakari Ailus ,\n\tLaurent Pinchart , tfiga@google.com,\n\tpavel@ucw.cz","Cc":"Jacopo Mondi ,\n\tlinux-media@vger.kernel.org (open list:MEDIA INPUT INFRASTRUCTURE\n\t(V4L/DVB)), libcamera-devel@lists.libcamera.org","Date":"Fri, 17 Apr 2020 14:41:03 +0200","Message-Id":"<20200417124110.72313-5-jacopo@jmondi.org>","X-Mailer":"git-send-email 2.26.1","In-Reply-To":"<20200417124110.72313-1-jacopo@jmondi.org>","References":"<20200417124110.72313-1-jacopo@jmondi.org>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH v9 04/11] media: v4l2-ctrl: Document\n\tV4L2_CID_CAMERA_SENSOR_ROTATION","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, 17 Apr 2020 12:38:31 -0000"},"content":"Add documentation for the V4L2_CID_CAMERA_SENSOR_ROTATION camera\ncontrol. The newly added read-only control reports the rotation\ncorrection to be applied to images before displaying them to the user.\n\nSigned-off-by: Jacopo Mondi \n---\n .../media/v4l/ext-ctrls-camera.rst | 121 ++++++++++++++++++\n 1 file changed, 121 insertions(+)","diff":"diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst\nindex 01a9042d53a6..140f985c7f06 100644\n--- a/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst\n+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst\n@@ -542,6 +542,127 @@ enum v4l2_scene_mode -\n \n \n \n+``V4L2_CID_CAMERA_SENSOR_ROTATION (integer)``\n+ This read-only control describes the rotation correction in degrees in the\n+ counter-clockwise direction to be applied to the captured images once\n+ captured to memory to compensate for the camera sensor mounting rotation.\n+\n+ For a precise definition of the sensor mounting rotation refer to the\n+ extensive description of the 'rotation' properties in the device tree\n+ bindings file 'video-interfaces.txt'.\n+\n+ A few examples are below reported, using a shark swimming from left to\n+ right in front of the user as the example scene to capture. ::\n+\n+ 0 X-axis\n+ 0 +------------------------------------->\n+ !\n+ !\n+ !\n+ ! |\\____)\\___\n+ ! ) _____ __`<\n+ ! |/ )/\n+ !\n+ !\n+ !\n+ V\n+ Y-axis\n+\n+ Example one - Webcam\n+\n+ Assuming you can bring your laptop with you while swimming with sharks,\n+ the camera module of the laptop is installed on the user facing part of a\n+ laptop screen casing, and is typically used for video calls. The captured\n+ images are meant to be displayed in landscape mode (width > height) on the\n+ laptop screen.\n+\n+ The camera is typically mounted upside-down to compensate the lens optical\n+ inversion effect. In this case the value of the\n+ V4L2_CID_CAMERA_SENSOR_ROTATION control is 0, no rotation is required to\n+ display images correctly to the user.\n+\n+ If the camera sensor is not mounted upside-down it is required to compensate\n+ the lens optical inversion effect and the value of the\n+ V4L2_CID_CAMERA_SENSOR_ROTATION control is 180 degrees, as images will\n+ result rotated when captured to memory. ::\n+\n+ +--------------------------------------+\n+ ! !\n+ ! !\n+ ! !\n+ ! __/(_____/| !\n+ ! >.___ ____ ( !\n+ ! \\( \\| !\n+ ! !\n+ ! !\n+ ! !\n+ +--------------------------------------+\n+\n+ A software rotation correction of 180 degrees has to be applied to correctly\n+ display the image on the user screen. ::\n+\n+ +--------------------------------------+\n+ ! !\n+ ! !\n+ ! !\n+ ! |\\____)\\___ !\n+ ! ) _____ __`< !\n+ ! |/ )/ !\n+ ! !\n+ ! !\n+ ! !\n+ +--------------------------------------+\n+\n+ Example two - Phone camera\n+\n+ It is more handy to go and swim with sharks with only your mobile phone\n+ with you and take pictures with the camera that is installed on the back\n+ side of the device, facing away from the user. The captured images are meant\n+ to be displayed in portrait mode (height > width) to match the device screen\n+ orientation and the device usage orientation used when taking the picture.\n+\n+ The camera sensor is typically mounted with its pixel array longer side\n+ aligned to the device longer side, upside-down mounted to compensate for\n+ the lens optical inversion effect.\n+\n+ The images once captured to memory will be rotated and the value of the\n+ V4L2_CID_CAMERA_SENSOR_ROTATION will report a 90 degree rotation. ::\n+\n+\n+ +-------------------------------------+\n+ | _ _ |\n+ | \\ / |\n+ | | | |\n+ | | | |\n+ | | > |\n+ | < | |\n+ | | | |\n+ | . |\n+ | V |\n+ +-------------------------------------+\n+\n+ A correction of 90 degrees in counter-clockwise direction has to be\n+ applied to correctly display the image in portrait mode on the device\n+ screen. ::\n+\n+ +--------------------+\n+ | |\n+ | |\n+ | |\n+ | |\n+ | |\n+ | |\n+ | |\\____)\\___ |\n+ | ) _____ __`< |\n+ | |/ )/ |\n+ | |\n+ | |\n+ | |\n+ | |\n+ | |\n+ +--------------------+\n+\n+\n .. [#f1]\n This control may be changed to a menu control in the future, if more\n options are required.\n","prefixes":["libcamera-devel","v9","04/11"]}