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{ "id": 11174, "url": "https://patchwork.libcamera.org/api/1.1/covers/11174/?format=api", "web_url": "https://patchwork.libcamera.org/cover/11174/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20210205131044.512128-1-helen.koike@collabora.com>", "date": "2021-02-05T13:10:41", "name": "[libcamera-devel,RFC,0/3] libcamera: Use extended fmt and buffer ioctls API", "submitter": { "id": 20, "url": "https://patchwork.libcamera.org/api/1.1/people/20/?format=api", "name": "Helen Koike", "email": "helen.koike@collabora.com" }, "mbox": "https://patchwork.libcamera.org/cover/11174/mbox/", "series": [ { "id": 1657, "url": "https://patchwork.libcamera.org/api/1.1/series/1657/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=1657", "date": "2021-02-05T13:10:41", "name": "libcamera: Use extended fmt and buffer ioctls API", "version": 1, "mbox": "https://patchwork.libcamera.org/series/1657/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/covers/11174/comments/", "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "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 32A7EBD162\n\tfor <parsemail@patchwork.libcamera.org>;\n\tFri, 5 Feb 2021 13:10:59 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id CE73760306;\n\tFri, 5 Feb 2021 14:10:58 +0100 (CET)", "from bhuna.collabora.co.uk (bhuna.collabora.co.uk\n\t[IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 5D6F560306\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tFri, 5 Feb 2021 14:10:57 +0100 (CET)", "from [127.0.0.1] (localhost [127.0.0.1])\n\t(Authenticated sender: koike) with ESMTPSA id 7D1FB1F466AB" ], "From": "Helen Koike <helen.koike@collabora.com>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Fri, 5 Feb 2021 10:10:41 -0300", "Message-Id": "<20210205131044.512128-1-helen.koike@collabora.com>", "X-Mailer": "git-send-email 2.30.0", "MIME-Version": "1.0", "Subject": "[libcamera-devel] [RFC PATCH 0/3] libcamera: Use extended fmt and\n\tbuffer ioctls API", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Cc": "kieran.bingham+renesas@ideasonboard.com, frkoenig@chromium.org,\n\tkernel@collabora.com", "Content-Type": "text/plain; charset=\"us-ascii\"", "Content-Transfer-Encoding": "7bit", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "Hi,\n\nThis RFC migrate libcamera to use the kernel V4L2 Ext API.\nPlease see kernel patchset cover letter on [1] for more details on the\nAPI and the features it would bring for userspace.\n\nThe purpose of this RFC is:\n* To use as a proof-of-concept of the proposed Ext API on [1].\n* To promote discussions/reviews on the proposed uapi, to make sure we get it right.\n* To discuss how this would be integrated with libcamera.\n\nThis RFC replaces the traditional ioctls:\n* VIDIOC_{S,G,TRY}_FMT\n* VIDIOC_(D)QBUF\nBy:\n* VIDIOC_{S,G,TRY}_EXT_PIX_FMT\n* VIDIOC_EXT_(D)QBUF\n\nWhich is far from the final solution, since libcamera would need a\nfallback mechanism for older kernels.\n\nSo I would like to get some ideas and pointers regarding how this would\nbe implemented, and also if you see issues on the uapi.\n\nAnother point is regarding memory planes and color planes.\nQUERYBUF and EXPBUF deals with memory planes, but QBUF requires\ninformation per color planes, which requires some special handling in\nthe code.\n\nI'd like to hear your thoughts.\n\nThis RFC was tested with qcam on vimc. It works with my wip-v7\nbranch [2] (which is v6 with some fixes that I'm going to post to\nlinux-media soon), and it is also available at my tree [3].\n\n[1] https://patchwork.linuxtv.org/project/linux-media/cover/20210114180738.1758707-1-helen.koike@collabora.com/\n[2] https://gitlab.collabora.com/koike/linux/-/tree/v4l2/ext-api/wip-v7\n[3] https://gitlab.collabora.com/koike/libcamera/-/tree/ext_api\n\nThanks!\n\nHelen Koike (3):\n include: uapi: Add header definitions for V4L2 Ext API\n libcamera: Use VIDIOC_{S,G,TRY}_EXT_PIX_FMT API\n libcamera: Use VIDIOC_EXT_(D)QBUF for buffer handling\n\n include/libcamera/internal/v4l2_videodevice.h | 8 +-\n include/linux/videodev2.h | 96 +++++++\n src/libcamera/pipeline/ipu3/cio2.cpp | 1 -\n src/libcamera/pipeline/ipu3/imgu.cpp | 1 -\n .../pipeline/raspberrypi/raspberrypi.cpp | 4 +\n src/libcamera/pipeline/rkisp1/rkisp1_path.cpp | 4 +-\n src/libcamera/pipeline/simple/converter.cpp | 6 +-\n src/libcamera/pipeline/simple/simple.cpp | 8 +-\n src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 2 +\n src/libcamera/pipeline/vimc/vimc.cpp | 2 +\n src/libcamera/v4l2_videodevice.cpp | 258 ++++++------------\n src/v4l2/v4l2_camera_proxy.cpp | 20 +-\n 12 files changed, 212 insertions(+), 198 deletions(-)" }